staging: zcache: delete it

zcache is obsolete and not used anymore, Bob Liu has rewritten it and is
submitting it for inclusion through the main -mm tree, as it should have
been done in the first place...

Cc: Bob Liu <lliubbo@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/Kconfig

@@ -130,8 +130,6 @@ source "drivers/staging/sb105x/Kconfig"
 
 source "drivers/staging/fwserial/Kconfig"
 
-source "drivers/staging/zcache/Kconfig"
-
 source "drivers/staging/goldfish/Kconfig"
 
 source "drivers/staging/netlogic/Kconfig"

drivers/staging/Makefile

@@ -58,7 +58,6 @@ obj-$(CONFIG_DRM_IMX)		+= imx-drm/
 obj-$(CONFIG_DGRP)		+= dgrp/
 obj-$(CONFIG_SB105X)		+= sb105x/
 obj-$(CONFIG_FIREWIRE_SERIAL)	+= fwserial/
-obj-$(CONFIG_ZCACHE)		+= zcache/
 obj-$(CONFIG_GOLDFISH)		+= goldfish/
 obj-$(CONFIG_USB_DWC2)		+= dwc2/
 obj-$(CONFIG_LUSTRE_FS)		+= lustre/

drivers/staging/zcache/Kconfig

@@ -1,59 +0,0 @@
-config ZCACHE
-	tristate "Dynamic compression of swap pages and clean pagecache pages"
-	depends on CRYPTO=y && SWAP=y && CLEANCACHE && FRONTSWAP
-	select CRYPTO_LZO
-	default n
-	help
-	  Zcache doubles RAM efficiency while providing a significant
-	  performance boosts on many workloads.  Zcache uses
-	  compression and an in-kernel implementation of transcendent
-	  memory to store clean page cache pages and swap in RAM,
-	  providing a noticeable reduction in disk I/O.
-
-config ZCACHE_DEBUG
-	bool "Enable debug statistics"
-	depends on DEBUG_FS && ZCACHE
-	default n
-	help
-	  This is used to provide an debugfs directory with counters of
-	  how zcache is doing. You probably want to set this to 'N'.
-
-config RAMSTER
-	tristate "Cross-machine RAM capacity sharing, aka peer-to-peer tmem"
-	depends on CONFIGFS_FS=y && SYSFS=y && !HIGHMEM && ZCACHE
-	depends on NET
-	# must ensure struct page is 8-byte aligned
-	select HAVE_ALIGNED_STRUCT_PAGE if !64BIT
-	default n
-	help
-	  RAMster allows RAM on other machines in a cluster to be utilized
-	  dynamically and symmetrically instead of swapping to a local swap
-	  disk, thus improving performance on memory-constrained workloads
-	  while minimizing total RAM across the cluster.  RAMster, like
-	  zcache2, compresses swap pages into local RAM, but then remotifies
-	  the compressed pages to another node in the RAMster cluster.
-
-config RAMSTER_DEBUG
-        bool "Enable ramster debug statistics"
-        depends on DEBUG_FS && RAMSTER
-        default n
-        help
-          This is used to provide an debugfs directory with counters of
-          how ramster is doing. You probably want to set this to 'N'.
-
-# Depends on not-yet-upstreamed mm patches to export end_swap_bio_write and
-# __add_to_swap_cache, and implement __swap_writepage (which is swap_writepage
-# without the frontswap call. When these are in-tree, the dependency on
-# BROKEN can be removed
-config ZCACHE_WRITEBACK
-	bool "Allow compressed swap pages to be writtenback to swap disk"
-	depends on ZCACHE=y && BROKEN
-	default n
-	help
-	  Zcache caches compressed swap pages (and other data) in RAM which
-	  often improves performance by avoiding I/O's due to swapping.
-	  In some workloads with very long-lived large processes, it can
-	  instead reduce performance.  Writeback decompresses zcache-compressed
-	  pages (in LRU order) when under memory pressure and writes them to
-	  the backing swap disk to ameliorate this problem.  Policy driving
-	  writeback is still under development.

drivers/staging/zcache/Makefile

@@ -1,8 +0,0 @@
-zcache-y	:=		zcache-main.o tmem.o zbud.o
-zcache-$(CONFIG_ZCACHE_DEBUG) += debug.o
-zcache-$(CONFIG_RAMSTER_DEBUG) += ramster/debug.o
-zcache-$(CONFIG_RAMSTER)	+=	ramster/ramster.o ramster/r2net.o
-zcache-$(CONFIG_RAMSTER)	+=	ramster/nodemanager.o ramster/tcp.o
-zcache-$(CONFIG_RAMSTER)	+=	ramster/heartbeat.o ramster/masklog.o
-
-obj-$(CONFIG_ZCACHE)	+=	zcache.o

drivers/staging/zcache/TODO

@@ -1,64 +0,0 @@
-
-** ZCACHE PLAN FOR PROMOTION FROM STAGING **
-
-Last updated: Feb 13, 2013
-
-PLAN STEPS
-
-1. merge zcache and ramster to eliminate horrible code duplication
-2. converge on a predictable, writeback-capable allocator
-3. use debugfs instead of sysfs (per akpm feedback in 2011)
-4. zcache side of cleancache/mm WasActive patch
-5. zcache side of frontswap exclusive gets
-6. zcache must be able to writeback to physical swap disk
-    (per Andrea Arcangeli feedback in 2011)
-7. implement adequate policy for writeback
-8. frontswap/cleancache work to allow zcache to be loaded
-    as a module
-9. get core mm developer to review
-10. incorporate feedback from review
-11. get review/acks from 1-2 additional mm developers
-12. incorporate any feedback from additional mm reviews
-13. propose location/file-naming in mm tree
-14. repeat 9-13 as necessary until akpm is happy and merges
-
-STATUS/OWNERSHIP
-
-1. DONE as part of "new" zcache; in staging/zcache for 3.9
-2. DONE as part of "new" zcache (cf zbud.[ch]); in staging/zcache for 3.9
-    (this was the core of the zcache1 vs zcache2 flail)
-3. DONE as part of "new" zcache; in staging/zcache for 3.9
-4. DONE (w/caveats) as part of "new" zcache; per cleancache performance
-    feedback see https://lkml.org/lkml/2011/8/17/351, in
-    staging/zcache for 3.9; dependent on proposed mm patch, see
-    https://lkml.org/lkml/2012/1/25/300 
-5. DONE as part of "new" zcache; performance tuning only,
-    in staging/zcache for 3.9; dependent on frontswap patch
-    merged in 3.7 (33c2a174)
-6. DONE (w/caveats), prototyped as part of "new" zcache, had
-    bad memory leak; reimplemented to use sjennings clever tricks
-    and proposed mm patches with new version in staging/zcache
-    for 3.9, see https://lkml.org/lkml/2013/2/6/437;
-7. PROTOTYPED as part of "new" zcache; in staging/zcache for 3.9;
-    needs more review (plan to discuss at LSF/MM 2013)
-9. IN PROGRESS; owned by Konrad Wilk; Mel Gorman provided
-   great feedback in August 2012 (unfortunately of "old"
-   zcache)
-11. NOT DONE; owned by Konrad Wilk and Bob Liu
-12. TBD (depends on quantity of feedback)
-13. PROPOSED; one suggestion proposed by Dan; needs more ideas/feedback
-14. TBD (depends on feedback)
-
-WHO NEEDS TO AGREE
-
-Not sure.  Seth Jennings is now pursuing a separate but semi-parallel
-track.  Akpm clearly has to approve for any mm merge to happen.  Minchan
-Kim has interest but may be happy if/when zram is merged into mm.  Konrad
-Wilk may be maintainer if akpm decides compression is maintainable
-separately from the rest of mm.  (More LSF/MM 2013 discussion.)
-
-ZCACHE FUTURE NEW FUNCTIONALITY
-
-A. Support zsmalloc as an alternative high-density allocator
-    (See https://lkml.org/lkml/2013/1/23/511)
-B. Possibly support three zbuds per pageframe when space allows

drivers/staging/zcache/debug.c

@@ -1,107 +0,0 @@
-#include <linux/atomic.h>
-#include "debug.h"
-
-#ifdef CONFIG_ZCACHE_DEBUG
-#include <linux/debugfs.h>
-
-ssize_t zcache_obj_count;
-ssize_t zcache_obj_count_max;
-ssize_t zcache_objnode_count;
-ssize_t zcache_objnode_count_max;
-u64 zcache_eph_zbytes;
-u64 zcache_eph_zbytes_max;
-u64 zcache_pers_zbytes_max;
-ssize_t zcache_eph_pageframes_max;
-ssize_t zcache_pers_pageframes_max;
-ssize_t zcache_pageframes_alloced;
-ssize_t zcache_pageframes_freed;
-ssize_t zcache_eph_zpages;
-ssize_t zcache_eph_zpages_max;
-ssize_t zcache_pers_zpages_max;
-ssize_t zcache_flush_total;
-ssize_t zcache_flush_found;
-ssize_t zcache_flobj_total;
-ssize_t zcache_flobj_found;
-ssize_t zcache_failed_eph_puts;
-ssize_t zcache_failed_pers_puts;
-ssize_t zcache_failed_getfreepages;
-ssize_t zcache_failed_alloc;
-ssize_t zcache_put_to_flush;
-ssize_t zcache_compress_poor;
-ssize_t zcache_mean_compress_poor;
-ssize_t zcache_eph_ate_tail;
-ssize_t zcache_eph_ate_tail_failed;
-ssize_t zcache_pers_ate_eph;
-ssize_t zcache_pers_ate_eph_failed;
-ssize_t zcache_evicted_eph_zpages;
-ssize_t zcache_evicted_eph_pageframes;
-ssize_t zcache_zero_filled_pages;
-ssize_t zcache_zero_filled_pages_max;
-
-#define ATTR(x)  { .name = #x, .val = &zcache_##x, }
-static struct debug_entry {
-	const char *name;
-	ssize_t *val;
-} attrs[] = {
-	ATTR(obj_count), ATTR(obj_count_max),
-	ATTR(objnode_count), ATTR(objnode_count_max),
-	ATTR(flush_total), ATTR(flush_found),
-	ATTR(flobj_total), ATTR(flobj_found),
-	ATTR(failed_eph_puts), ATTR(failed_pers_puts),
-	ATTR(failed_getfreepages), ATTR(failed_alloc),
-	ATTR(put_to_flush),
-	ATTR(compress_poor), ATTR(mean_compress_poor),
-	ATTR(eph_ate_tail), ATTR(eph_ate_tail_failed),
-	ATTR(pers_ate_eph), ATTR(pers_ate_eph_failed),
-	ATTR(evicted_eph_zpages), ATTR(evicted_eph_pageframes),
-	ATTR(eph_pageframes), ATTR(eph_pageframes_max),
-	ATTR(pers_pageframes), ATTR(pers_pageframes_max),
-	ATTR(eph_zpages), ATTR(eph_zpages_max),
-	ATTR(pers_zpages), ATTR(pers_zpages_max),
-	ATTR(last_active_file_pageframes),
-	ATTR(last_inactive_file_pageframes),
-	ATTR(last_active_anon_pageframes),
-	ATTR(last_inactive_anon_pageframes),
-	ATTR(eph_nonactive_puts_ignored),
-	ATTR(pers_nonactive_puts_ignored),
-	ATTR(zero_filled_pages),
-#ifdef CONFIG_ZCACHE_WRITEBACK
-	ATTR(outstanding_writeback_pages),
-	ATTR(writtenback_pages),
-#endif
-};
-#undef ATTR
-int zcache_debugfs_init(void)
-{
-	unsigned int i;
-	struct dentry *root = debugfs_create_dir("zcache", NULL);
-	if (root == NULL)
-		return -ENXIO;
-
-	for (i = 0; i < ARRAY_SIZE(attrs); i++)
-		if (!debugfs_create_size_t(attrs[i].name, S_IRUGO, root, attrs[i].val))
-			goto out;
-
-	debugfs_create_u64("eph_zbytes", S_IRUGO, root, &zcache_eph_zbytes);
-	debugfs_create_u64("eph_zbytes_max", S_IRUGO, root, &zcache_eph_zbytes_max);
-	debugfs_create_u64("pers_zbytes", S_IRUGO, root, &zcache_pers_zbytes);
-	debugfs_create_u64("pers_zbytes_max", S_IRUGO, root, &zcache_pers_zbytes_max);
-
-	return 0;
-out:
-	return -ENODEV;
-}
-
-/* developers can call this in case of ooms, e.g. to find memory leaks */
-void zcache_dump(void)
-{
-	unsigned int i;
-	for (i = 0; i < ARRAY_SIZE(attrs); i++)
-		pr_debug("zcache: %s=%zu\n", attrs[i].name, *attrs[i].val);
-
-	pr_debug("zcache: eph_zbytes=%llu\n", (unsigned long long)zcache_eph_zbytes);
-	pr_debug("zcache: eph_zbytes_max=%llu\n", (unsigned long long)zcache_eph_zbytes_max);
-	pr_debug("zcache: pers_zbytes=%llu\n", (unsigned long long)zcache_pers_zbytes);
-	pr_debug("zcache: pers_zbytes_max=%llu\n", (unsigned long long)zcache_pers_zbytes_max);
-}
-#endif

drivers/staging/zcache/debug.h

@@ -1,305 +0,0 @@
-#include <linux/bug.h>
-
-#ifdef CONFIG_ZCACHE_DEBUG
-
-/* we try to keep these statistics SMP-consistent */
-extern ssize_t zcache_obj_count;
-static atomic_t zcache_obj_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_obj_count_max;
-static inline void inc_zcache_obj_count(void)
-{
-	zcache_obj_count = atomic_inc_return(&zcache_obj_atomic);
-	if (zcache_obj_count > zcache_obj_count_max)
-		zcache_obj_count_max = zcache_obj_count;
-}
-static inline void dec_zcache_obj_count(void)
-{
-	zcache_obj_count = atomic_dec_return(&zcache_obj_atomic);
-	BUG_ON(zcache_obj_count < 0);
-};
-extern ssize_t zcache_objnode_count;
-static atomic_t zcache_objnode_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_objnode_count_max;
-static inline void inc_zcache_objnode_count(void)
-{
-	zcache_objnode_count = atomic_inc_return(&zcache_objnode_atomic);
-	if (zcache_objnode_count > zcache_objnode_count_max)
-		zcache_objnode_count_max = zcache_objnode_count;
-};
-static inline void dec_zcache_objnode_count(void)
-{
-	zcache_objnode_count = atomic_dec_return(&zcache_objnode_atomic);
-	BUG_ON(zcache_objnode_count < 0);
-};
-extern u64 zcache_eph_zbytes;
-static atomic_long_t zcache_eph_zbytes_atomic = ATOMIC_INIT(0);
-extern u64 zcache_eph_zbytes_max;
-static inline void inc_zcache_eph_zbytes(unsigned clen)
-{
-	zcache_eph_zbytes = atomic_long_add_return(clen, &zcache_eph_zbytes_atomic);
-	if (zcache_eph_zbytes > zcache_eph_zbytes_max)
-		zcache_eph_zbytes_max = zcache_eph_zbytes;
-};
-static inline void dec_zcache_eph_zbytes(unsigned zsize)
-{
-	zcache_eph_zbytes = atomic_long_sub_return(zsize, &zcache_eph_zbytes_atomic);
-};
-extern  u64 zcache_pers_zbytes;
-static atomic_long_t zcache_pers_zbytes_atomic = ATOMIC_INIT(0);
-extern u64 zcache_pers_zbytes_max;
-static inline void inc_zcache_pers_zbytes(unsigned clen)
-{
-	zcache_pers_zbytes = atomic_long_add_return(clen, &zcache_pers_zbytes_atomic);
-	if (zcache_pers_zbytes > zcache_pers_zbytes_max)
-		zcache_pers_zbytes_max = zcache_pers_zbytes;
-}
-static inline void dec_zcache_pers_zbytes(unsigned zsize)
-{
-	zcache_pers_zbytes = atomic_long_sub_return(zsize, &zcache_pers_zbytes_atomic);
-}
-extern ssize_t zcache_eph_pageframes;
-static atomic_t zcache_eph_pageframes_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_eph_pageframes_max;
-static inline void inc_zcache_eph_pageframes(void)
-{
-	zcache_eph_pageframes = atomic_inc_return(&zcache_eph_pageframes_atomic);
-	if (zcache_eph_pageframes > zcache_eph_pageframes_max)
-		zcache_eph_pageframes_max = zcache_eph_pageframes;
-};
-static inline void dec_zcache_eph_pageframes(void)
-{
-	zcache_eph_pageframes = atomic_dec_return(&zcache_eph_pageframes_atomic);
-};
-extern ssize_t zcache_pers_pageframes;
-static atomic_t zcache_pers_pageframes_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_pers_pageframes_max;
-static inline void inc_zcache_pers_pageframes(void)
-{
-	zcache_pers_pageframes = atomic_inc_return(&zcache_pers_pageframes_atomic);
-	if (zcache_pers_pageframes > zcache_pers_pageframes_max)
-		zcache_pers_pageframes_max = zcache_pers_pageframes;
-}
-static inline void dec_zcache_pers_pageframes(void)
-{
-	zcache_pers_pageframes = atomic_dec_return(&zcache_pers_pageframes_atomic);
-}
-extern ssize_t zcache_pageframes_alloced;
-static atomic_t zcache_pageframes_alloced_atomic = ATOMIC_INIT(0);
-static inline void inc_zcache_pageframes_alloced(void)
-{
-	zcache_pageframes_alloced = atomic_inc_return(&zcache_pageframes_alloced_atomic);
-};
-extern ssize_t zcache_pageframes_freed;
-static atomic_t zcache_pageframes_freed_atomic = ATOMIC_INIT(0);
-static inline void inc_zcache_pageframes_freed(void)
-{
-	zcache_pageframes_freed = atomic_inc_return(&zcache_pageframes_freed_atomic);
-}
-extern ssize_t zcache_eph_zpages;
-static atomic_t zcache_eph_zpages_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_eph_zpages_max;
-static inline void inc_zcache_eph_zpages(void)
-{
-	zcache_eph_zpages = atomic_inc_return(&zcache_eph_zpages_atomic);
-	if (zcache_eph_zpages > zcache_eph_zpages_max)
-		zcache_eph_zpages_max = zcache_eph_zpages;
-}
-static inline void dec_zcache_eph_zpages(unsigned zpages)
-{
-	zcache_eph_zpages = atomic_sub_return(zpages, &zcache_eph_zpages_atomic);
-}
-extern ssize_t zcache_pers_zpages;
-static atomic_t zcache_pers_zpages_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_pers_zpages_max;
-static inline void inc_zcache_pers_zpages(void)
-{
-	zcache_pers_zpages = atomic_inc_return(&zcache_pers_zpages_atomic);
-	if (zcache_pers_zpages > zcache_pers_zpages_max)
-		zcache_pers_zpages_max = zcache_pers_zpages;
-}
-static inline void dec_zcache_pers_zpages(unsigned zpages)
-{
-	zcache_pers_zpages = atomic_sub_return(zpages, &zcache_pers_zpages_atomic);
-}
-
-extern ssize_t zcache_zero_filled_pages;
-static atomic_t zcache_zero_filled_pages_atomic = ATOMIC_INIT(0);
-extern ssize_t zcache_zero_filled_pages_max;
-static inline void inc_zcache_zero_filled_pages(void)
-{
-	zcache_zero_filled_pages = atomic_inc_return(
-					&zcache_zero_filled_pages_atomic);
-	if (zcache_zero_filled_pages > zcache_zero_filled_pages_max)
-		zcache_zero_filled_pages_max = zcache_zero_filled_pages;
-}
-static inline void dec_zcache_zero_filled_pages(void)
-{
-	zcache_zero_filled_pages = atomic_dec_return(
-					&zcache_zero_filled_pages_atomic);
-}
-static inline unsigned long curr_pageframes_count(void)
-{
-	return zcache_pageframes_alloced -
-		atomic_read(&zcache_pageframes_freed_atomic) -
-		atomic_read(&zcache_eph_pageframes_atomic) -
-		atomic_read(&zcache_pers_pageframes_atomic);
-};
-/* but for the rest of these, counting races are ok */
-extern ssize_t zcache_flush_total;
-extern ssize_t zcache_flush_found;
-extern ssize_t zcache_flobj_total;
-extern ssize_t zcache_flobj_found;
-extern ssize_t zcache_failed_eph_puts;
-extern ssize_t zcache_failed_pers_puts;
-extern ssize_t zcache_failed_getfreepages;
-extern ssize_t zcache_failed_alloc;
-extern ssize_t zcache_put_to_flush;
-extern ssize_t zcache_compress_poor;
-extern ssize_t zcache_mean_compress_poor;
-extern ssize_t zcache_eph_ate_tail;
-extern ssize_t zcache_eph_ate_tail_failed;
-extern ssize_t zcache_pers_ate_eph;
-extern ssize_t zcache_pers_ate_eph_failed;
-extern ssize_t zcache_evicted_eph_zpages;
-extern ssize_t zcache_evicted_eph_pageframes;
-
-extern ssize_t zcache_last_active_file_pageframes;
-extern ssize_t zcache_last_inactive_file_pageframes;
-extern ssize_t zcache_last_active_anon_pageframes;
-extern ssize_t zcache_last_inactive_anon_pageframes;
-static ssize_t zcache_eph_nonactive_puts_ignored;
-static ssize_t zcache_pers_nonactive_puts_ignored;
-#ifdef CONFIG_ZCACHE_WRITEBACK
-extern ssize_t zcache_writtenback_pages;
-extern ssize_t zcache_outstanding_writeback_pages;
-#endif
-
-static inline void inc_zcache_flush_total(void)
-{
-	zcache_flush_total++;
-};
-static inline void inc_zcache_flush_found(void)
-{
-	zcache_flush_found++;
-};
-static inline void inc_zcache_flobj_total(void)
-{
-	zcache_flobj_total++;
-};
-static inline void inc_zcache_flobj_found(void)
-{
-	zcache_flobj_found++;
-};
-static inline void inc_zcache_failed_eph_puts(void)
-{
-	zcache_failed_eph_puts++;
-};
-static inline void inc_zcache_failed_pers_puts(void)
-{
-	zcache_failed_pers_puts++;
-};
-static inline void inc_zcache_failed_getfreepages(void)
-{
-	zcache_failed_getfreepages++;
-};
-static inline void inc_zcache_failed_alloc(void)
-{
-	zcache_failed_alloc++;
-};
-static inline void inc_zcache_put_to_flush(void)
-{
-	zcache_put_to_flush++;
-};
-static inline void inc_zcache_compress_poor(void)
-{
-	zcache_compress_poor++;
-};
-static inline void inc_zcache_mean_compress_poor(void)
-{
-	zcache_mean_compress_poor++;
-};
-static inline void inc_zcache_eph_ate_tail(void)
-{
-	zcache_eph_ate_tail++;
-};
-static inline void inc_zcache_eph_ate_tail_failed(void)
-{
-	zcache_eph_ate_tail_failed++;
-};
-static inline void inc_zcache_pers_ate_eph(void)
-{
-	zcache_pers_ate_eph++;
-};
-static inline void inc_zcache_pers_ate_eph_failed(void)
-{
-	zcache_pers_ate_eph_failed++;
-};
-static inline void inc_zcache_evicted_eph_zpages(unsigned zpages)
-{
-	zcache_evicted_eph_zpages += zpages;
-};
-static inline void inc_zcache_evicted_eph_pageframes(void)
-{
-	zcache_evicted_eph_pageframes++;
-};
-
-static inline void inc_zcache_eph_nonactive_puts_ignored(void)
-{
-	zcache_eph_nonactive_puts_ignored++;
-};
-static inline void inc_zcache_pers_nonactive_puts_ignored(void)
-{
-	zcache_pers_nonactive_puts_ignored++;
-};
-
-int zcache_debugfs_init(void);
-#else
-static inline void inc_zcache_obj_count(void) { };
-static inline void dec_zcache_obj_count(void) { };
-static inline void inc_zcache_objnode_count(void) { };
-static inline void dec_zcache_objnode_count(void) { };
-static inline void inc_zcache_eph_zbytes(unsigned clen) { };
-static inline void dec_zcache_eph_zbytes(unsigned zsize) { };
-static inline void inc_zcache_pers_zbytes(unsigned clen) { };
-static inline void dec_zcache_pers_zbytes(unsigned zsize) { };
-static inline void inc_zcache_eph_pageframes(void) { };
-static inline void dec_zcache_eph_pageframes(void) { };
-static inline void inc_zcache_pers_pageframes(void) { };
-static inline void dec_zcache_pers_pageframes(void) { };
-static inline void inc_zcache_pageframes_alloced(void) { };
-static inline void inc_zcache_pageframes_freed(void) { };
-static inline void inc_zcache_eph_zpages(void) { };
-static inline void dec_zcache_eph_zpages(unsigned zpages) { };
-static inline void inc_zcache_pers_zpages(void) { };
-static inline void dec_zcache_pers_zpages(unsigned zpages) { };
-static inline void inc_zcache_zero_filled_pages(void) { };
-static inline void dec_zcache_zero_filled_pages(void) { };
-static inline unsigned long curr_pageframes_count(void)
-{
-	return 0;
-};
-static inline int zcache_debugfs_init(void)
-{
-	return 0;
-};
-static inline void inc_zcache_flush_total(void) { };
-static inline void inc_zcache_flush_found(void) { };
-static inline void inc_zcache_flobj_total(void) { };
-static inline void inc_zcache_flobj_found(void) { };
-static inline void inc_zcache_failed_eph_puts(void) { };
-static inline void inc_zcache_failed_pers_puts(void) { };
-static inline void inc_zcache_failed_getfreepages(void) { };
-static inline void inc_zcache_failed_alloc(void) { };
-static inline void inc_zcache_put_to_flush(void) { };
-static inline void inc_zcache_compress_poor(void) { };
-static inline void inc_zcache_mean_compress_poor(void) { };
-static inline void inc_zcache_eph_ate_tail(void) { };
-static inline void inc_zcache_eph_ate_tail_failed(void) { };
-static inline void inc_zcache_pers_ate_eph(void) { };
-static inline void inc_zcache_pers_ate_eph_failed(void) { };
-static inline void inc_zcache_evicted_eph_zpages(unsigned zpages) { };
-static inline void inc_zcache_evicted_eph_pageframes(void) { };
-
-static inline void inc_zcache_eph_nonactive_puts_ignored(void) { };
-static inline void inc_zcache_pers_nonactive_puts_ignored(void) { };
-#endif

drivers/staging/zcache/ramster.h

@@ -1,59 +0,0 @@
-
-/*
- * zcache/ramster.h
- *
- * Placeholder to resolve ramster references when !CONFIG_RAMSTER
- * Real ramster.h lives in ramster subdirectory.
- *
- * Copyright (c) 2009-2012, Dan Magenheimer, Oracle Corp.
- */
-
-#ifndef _ZCACHE_RAMSTER_H_
-#define _ZCACHE_RAMSTER_H_
-
-#ifdef CONFIG_RAMSTER
-#include "ramster/ramster.h"
-#else
-static inline void ramster_init(bool x, bool y, bool z, bool w)
-{
-}
-
-static inline void ramster_register_pamops(struct tmem_pamops *p)
-{
-}
-
-static inline int ramster_remotify_pageframe(bool b)
-{
-	return 0;
-}
-
-static inline void *ramster_pampd_free(void *v, struct tmem_pool *p,
-			struct tmem_oid *o, uint32_t u, bool b)
-{
-	return NULL;
-}
-
-static inline int ramster_do_preload_flnode(struct tmem_pool *p)
-{
-	return -1;
-}
-
-static inline bool pampd_is_remote(void *v)
-{
-	return false;
-}
-
-static inline void ramster_count_foreign_pages(bool b, int i)
-{
-}
-
-static inline void ramster_cpu_up(int cpu)
-{
-}
-
-static inline void ramster_cpu_down(int cpu)
-{
-}
-#endif
-
-#endif /* _ZCACHE_RAMSTER_H */

drivers/staging/zcache/ramster/debug.c

@@ -1,68 +0,0 @@
-#include <linux/atomic.h>
-#include "debug.h"
-
-ssize_t ramster_foreign_eph_pages;
-ssize_t ramster_foreign_pers_pages;
-#ifdef CONFIG_DEBUG_FS
-#include <linux/debugfs.h>
-
-ssize_t ramster_eph_pages_remoted;
-ssize_t ramster_pers_pages_remoted;
-ssize_t ramster_eph_pages_remote_failed;
-ssize_t ramster_pers_pages_remote_failed;
-ssize_t ramster_remote_eph_pages_succ_get;
-ssize_t ramster_remote_pers_pages_succ_get;
-ssize_t ramster_remote_eph_pages_unsucc_get;
-ssize_t ramster_remote_pers_pages_unsucc_get;
-ssize_t ramster_pers_pages_remote_nomem;
-ssize_t ramster_remote_objects_flushed;
-ssize_t ramster_remote_object_flushes_failed;
-ssize_t ramster_remote_pages_flushed;
-ssize_t ramster_remote_page_flushes_failed;
-
-#define ATTR(x)  { .name = #x, .val = &ramster_##x, }
-static struct debug_entry {
-	const char *name;
-	ssize_t *val;
-} attrs[] = {
-	ATTR(eph_pages_remoted),
-	ATTR(pers_pages_remoted),
-	ATTR(eph_pages_remote_failed),
-	ATTR(pers_pages_remote_failed),
-	ATTR(remote_eph_pages_succ_get),
-	ATTR(remote_pers_pages_succ_get),
-	ATTR(remote_eph_pages_unsucc_get),
-	ATTR(remote_pers_pages_unsucc_get),
-	ATTR(pers_pages_remote_nomem),
-	ATTR(remote_objects_flushed),
-	ATTR(remote_pages_flushed),
-	ATTR(remote_object_flushes_failed),
-	ATTR(remote_page_flushes_failed),
-	ATTR(foreign_eph_pages),
-	ATTR(foreign_eph_pages_max),
-	ATTR(foreign_pers_pages),
-	ATTR(foreign_pers_pages_max),
-};
-#undef ATTR
-
-int ramster_debugfs_init(void)
-{
-	int i;
-	struct dentry *root = debugfs_create_dir("ramster", NULL);
-	if (root == NULL)
-		return -ENXIO;
-
-	for (i = 0; i < ARRAY_SIZE(attrs); i++)
-		if (!debugfs_create_size_t(attrs[i].name,
-				S_IRUGO, root, attrs[i].val))
-			goto out;
-	return 0;
-out:
-	return -ENODEV;
-}
-#else
-static inline int ramster_debugfs_init(void)
-{
-	return 0;
-}
-#endif

drivers/staging/zcache/ramster/debug.h

@@ -1,145 +0,0 @@
-#include <linux/bug.h>
-
-#ifdef CONFIG_RAMSTER_DEBUG
-
-extern long ramster_flnodes;
-static atomic_t ramster_flnodes_atomic = ATOMIC_INIT(0);
-static unsigned long ramster_flnodes_max;
-static inline void inc_ramster_flnodes(void)
-{
-	ramster_flnodes = atomic_inc_return(&ramster_flnodes_atomic);
-	if (ramster_flnodes > ramster_flnodes_max)
-		ramster_flnodes_max = ramster_flnodes;
-}
-static inline void dec_ramster_flnodes(void)
-{
-	ramster_flnodes = atomic_dec_return(&ramster_flnodes_atomic);
-}
-extern ssize_t ramster_foreign_eph_pages;
-static atomic_t ramster_foreign_eph_pages_atomic = ATOMIC_INIT(0);
-static ssize_t ramster_foreign_eph_pages_max;
-static inline void inc_ramster_foreign_eph_pages(void)
-{
-	ramster_foreign_eph_pages = atomic_inc_return(
-		&ramster_foreign_eph_pages_atomic);
-	if (ramster_foreign_eph_pages > ramster_foreign_eph_pages_max)
-		ramster_foreign_eph_pages_max = ramster_foreign_eph_pages;
-}
-static inline void dec_ramster_foreign_eph_pages(void)
-{
-	ramster_foreign_eph_pages = atomic_dec_return(
-		&ramster_foreign_eph_pages_atomic);
-}
-extern ssize_t ramster_foreign_pers_pages;
-static atomic_t ramster_foreign_pers_pages_atomic = ATOMIC_INIT(0);
-static ssize_t ramster_foreign_pers_pages_max;
-static inline void inc_ramster_foreign_pers_pages(void)
-{
-	ramster_foreign_pers_pages = atomic_inc_return(
-		&ramster_foreign_pers_pages_atomic);
-	if (ramster_foreign_pers_pages > ramster_foreign_pers_pages_max)
-		ramster_foreign_pers_pages_max = ramster_foreign_pers_pages;
-}
-static inline void dec_ramster_foreign_pers_pages(void)
-{
-	ramster_foreign_pers_pages = atomic_dec_return(
-		&ramster_foreign_pers_pages_atomic);
-}
-
-extern ssize_t ramster_eph_pages_remoted;
-extern ssize_t ramster_pers_pages_remoted;
-extern ssize_t ramster_eph_pages_remote_failed;
-extern ssize_t ramster_pers_pages_remote_failed;
-extern ssize_t ramster_remote_eph_pages_succ_get;
-extern ssize_t ramster_remote_pers_pages_succ_get;
-extern ssize_t ramster_remote_eph_pages_unsucc_get;
-extern ssize_t ramster_remote_pers_pages_unsucc_get;
-extern ssize_t ramster_pers_pages_remote_nomem;
-extern ssize_t ramster_remote_objects_flushed;
-extern ssize_t ramster_remote_object_flushes_failed;
-extern ssize_t ramster_remote_pages_flushed;
-extern ssize_t ramster_remote_page_flushes_failed;
-
-int ramster_debugfs_init(void);
-
-static inline void inc_ramster_eph_pages_remoted(void)
-{
-	ramster_eph_pages_remoted++;
-};
-static inline void inc_ramster_pers_pages_remoted(void)
-{
-	ramster_pers_pages_remoted++;
-};
-static inline void inc_ramster_eph_pages_remote_failed(void)
-{
-	ramster_eph_pages_remote_failed++;
-};
-static inline void inc_ramster_pers_pages_remote_failed(void)
-{
-	ramster_pers_pages_remote_failed++;
-};
-static inline void inc_ramster_remote_eph_pages_succ_get(void)
-{
-	ramster_remote_eph_pages_succ_get++;
-};
-static inline void inc_ramster_remote_pers_pages_succ_get(void)
-{
-	ramster_remote_pers_pages_succ_get++;
-};
-static inline void inc_ramster_remote_eph_pages_unsucc_get(void)
-{
-	ramster_remote_eph_pages_unsucc_get++;
-};
-static inline void inc_ramster_remote_pers_pages_unsucc_get(void)
-{
-	ramster_remote_pers_pages_unsucc_get++;
-};
-static inline void inc_ramster_pers_pages_remote_nomem(void)
-{
-	ramster_pers_pages_remote_nomem++;
-};
-static inline void inc_ramster_remote_objects_flushed(void)
-{
-	ramster_remote_objects_flushed++;
-};
-static inline void inc_ramster_remote_object_flushes_failed(void)
-{
-	ramster_remote_object_flushes_failed++;
-};
-static inline void inc_ramster_remote_pages_flushed(void)
-{
-	ramster_remote_pages_flushed++;
-};
-static inline void inc_ramster_remote_page_flushes_failed(void)
-{
-	ramster_remote_page_flushes_failed++;
-};
-
-#else
-
-static inline void inc_ramster_flnodes(void) { };
-static inline void dec_ramster_flnodes(void) { };
-static inline void inc_ramster_foreign_eph_pages(void) { };
-static inline void dec_ramster_foreign_eph_pages(void) { };
-static inline void inc_ramster_foreign_pers_pages(void) { };
-static inline void dec_ramster_foreign_pers_pages(void) { };
-
-static inline void inc_ramster_eph_pages_remoted(void) { };
-static inline void inc_ramster_pers_pages_remoted(void) { };
-static inline void inc_ramster_eph_pages_remote_failed(void) { };
-static inline void inc_ramster_pers_pages_remote_failed(void) { };
-static inline void inc_ramster_remote_eph_pages_succ_get(void) { };
-static inline void inc_ramster_remote_pers_pages_succ_get(void) { };
-static inline void inc_ramster_remote_eph_pages_unsucc_get(void) { };
-static inline void inc_ramster_remote_pers_pages_unsucc_get(void) { };
-static inline void inc_ramster_pers_pages_remote_nomem(void) { };
-static inline void inc_ramster_remote_objects_flushed(void) { };
-static inline void inc_ramster_remote_object_flushes_failed(void) { };
-static inline void inc_ramster_remote_pages_flushed(void) { };
-static inline void inc_ramster_remote_page_flushes_failed(void) { };
-
-static inline int ramster_debugfs_init(void)
-{
-	return 0;
-}
-#endif

drivers/staging/zcache/ramster/heartbeat.c

@@ -1,462 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2004, 2005, 2012 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/configfs.h>
-
-#include "heartbeat.h"
-#include "tcp.h"
-#include "nodemanager.h"
-
-#include "masklog.h"
-
-/*
- * The first heartbeat pass had one global thread that would serialize all hb
- * callback calls.  This global serializing sem should only be removed once
- * we've made sure that all callees can deal with being called concurrently
- * from multiple hb region threads.
- */
-static DECLARE_RWSEM(r2hb_callback_sem);
-
-/*
- * multiple hb threads are watching multiple regions.  A node is live
- * whenever any of the threads sees activity from the node in its region.
- */
-static DEFINE_SPINLOCK(r2hb_live_lock);
-static unsigned long r2hb_live_node_bitmap[BITS_TO_LONGS(R2NM_MAX_NODES)];
-
-static struct r2hb_callback {
-	struct list_head list;
-} r2hb_callbacks[R2HB_NUM_CB];
-
-enum r2hb_heartbeat_modes {
-	R2HB_HEARTBEAT_LOCAL		= 0,
-	R2HB_HEARTBEAT_GLOBAL,
-	R2HB_HEARTBEAT_NUM_MODES,
-};
-
-char *r2hb_heartbeat_mode_desc[R2HB_HEARTBEAT_NUM_MODES] = {
-		"local",	/* R2HB_HEARTBEAT_LOCAL */
-		"global",	/* R2HB_HEARTBEAT_GLOBAL */
-};
-
-unsigned int r2hb_dead_threshold = R2HB_DEFAULT_DEAD_THRESHOLD;
-unsigned int r2hb_heartbeat_mode = R2HB_HEARTBEAT_LOCAL;
-
-/* Only sets a new threshold if there are no active regions.
- *
- * No locking or otherwise interesting code is required for reading
- * r2hb_dead_threshold as it can't change once regions are active and
- * it's not interesting to anyone until then anyway. */
-static void r2hb_dead_threshold_set(unsigned int threshold)
-{
-	if (threshold > R2HB_MIN_DEAD_THRESHOLD) {
-		spin_lock(&r2hb_live_lock);
-		r2hb_dead_threshold = threshold;
-		spin_unlock(&r2hb_live_lock);
-	}
-}
-
-static int r2hb_global_hearbeat_mode_set(unsigned int hb_mode)
-{
-	int ret = -1;
-
-	if (hb_mode < R2HB_HEARTBEAT_NUM_MODES) {
-		spin_lock(&r2hb_live_lock);
-		r2hb_heartbeat_mode = hb_mode;
-		ret = 0;
-		spin_unlock(&r2hb_live_lock);
-	}
-
-	return ret;
-}
-
-void r2hb_exit(void)
-{
-}
-
-int r2hb_init(void)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(r2hb_callbacks); i++)
-		INIT_LIST_HEAD(&r2hb_callbacks[i].list);
-
-	memset(r2hb_live_node_bitmap, 0, sizeof(r2hb_live_node_bitmap));
-
-	return 0;
-}
-
-/* if we're already in a callback then we're already serialized by the sem */
-static void r2hb_fill_node_map_from_callback(unsigned long *map,
-					     unsigned bytes)
-{
-	BUG_ON(bytes < (BITS_TO_LONGS(R2NM_MAX_NODES) * sizeof(unsigned long)));
-
-	memcpy(map, &r2hb_live_node_bitmap, bytes);
-}
-
-/*
- * get a map of all nodes that are heartbeating in any regions
- */
-void r2hb_fill_node_map(unsigned long *map, unsigned bytes)
-{
-	/* callers want to serialize this map and callbacks so that they
-	 * can trust that they don't miss nodes coming to the party */
-	down_read(&r2hb_callback_sem);
-	spin_lock(&r2hb_live_lock);
-	r2hb_fill_node_map_from_callback(map, bytes);
-	spin_unlock(&r2hb_live_lock);
-	up_read(&r2hb_callback_sem);
-}
-EXPORT_SYMBOL_GPL(r2hb_fill_node_map);
-
-/*
- * heartbeat configfs bits.  The heartbeat set is a default set under
- * the cluster set in nodemanager.c.
- */
-
-/* heartbeat set */
-
-struct r2hb_hb_group {
-	struct config_group hs_group;
-	/* some stuff? */
-};
-
-static struct r2hb_hb_group *to_r2hb_hb_group(struct config_group *group)
-{
-	return group ?
-		container_of(group, struct r2hb_hb_group, hs_group)
-		: NULL;
-}
-
-static struct config_item r2hb_config_item;
-
-static struct config_item *r2hb_hb_group_make_item(struct config_group *group,
-							  const char *name)
-{
-	int ret;
-
-	if (strlen(name) > R2HB_MAX_REGION_NAME_LEN) {
-		ret = -ENAMETOOLONG;
-		goto free;
-	}
-
-	config_item_put(&r2hb_config_item);
-
-	return &r2hb_config_item;
-free:
-	return ERR_PTR(ret);
-}
-
-static void r2hb_hb_group_drop_item(struct config_group *group,
-					   struct config_item *item)
-{
-	if (r2hb_global_heartbeat_active()) {
-		pr_notice("ramster: Heartbeat %s on region %s (%s)\n",
-			"stopped/aborted", config_item_name(item),
-			"no region");
-	}
-
-	config_item_put(item);
-}
-
-struct r2hb_hb_group_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct r2hb_hb_group *, char *);
-	ssize_t (*store)(struct r2hb_hb_group *, const char *, size_t);
-};
-
-static ssize_t r2hb_hb_group_show(struct config_item *item,
-					 struct configfs_attribute *attr,
-					 char *page)
-{
-	struct r2hb_hb_group *reg = to_r2hb_hb_group(to_config_group(item));
-	struct r2hb_hb_group_attribute *r2hb_hb_group_attr =
-		container_of(attr, struct r2hb_hb_group_attribute, attr);
-	ssize_t ret = 0;
-
-	if (r2hb_hb_group_attr->show)
-		ret = r2hb_hb_group_attr->show(reg, page);
-	return ret;
-}
-
-static ssize_t r2hb_hb_group_store(struct config_item *item,
-					  struct configfs_attribute *attr,
-					  const char *page, size_t count)
-{
-	struct r2hb_hb_group *reg = to_r2hb_hb_group(to_config_group(item));
-	struct r2hb_hb_group_attribute *r2hb_hb_group_attr =
-		container_of(attr, struct r2hb_hb_group_attribute, attr);
-	ssize_t ret = -EINVAL;
-
-	if (r2hb_hb_group_attr->store)
-		ret = r2hb_hb_group_attr->store(reg, page, count);
-	return ret;
-}
-
-static ssize_t r2hb_hb_group_threshold_show(struct r2hb_hb_group *group,
-						     char *page)
-{
-	return sprintf(page, "%u\n", r2hb_dead_threshold);
-}
-
-static ssize_t r2hb_hb_group_threshold_store(struct r2hb_hb_group *group,
-						    const char *page,
-						    size_t count)
-{
-	unsigned long tmp;
-	char *p = (char *)page;
-	int err;
-
-	err = kstrtoul(p, 10, &tmp);
-	if (err)
-		return err;
-
-	/* this will validate ranges for us. */
-	r2hb_dead_threshold_set((unsigned int) tmp);
-
-	return count;
-}
-
-static
-ssize_t r2hb_hb_group_mode_show(struct r2hb_hb_group *group,
-				       char *page)
-{
-	return sprintf(page, "%s\n",
-		       r2hb_heartbeat_mode_desc[r2hb_heartbeat_mode]);
-}
-
-static
-ssize_t r2hb_hb_group_mode_store(struct r2hb_hb_group *group,
-					const char *page, size_t count)
-{
-	unsigned int i;
-	int ret;
-	size_t len;
-
-	len = (page[count - 1] == '\n') ? count - 1 : count;
-	if (!len)
-		return -EINVAL;
-
-	for (i = 0; i < R2HB_HEARTBEAT_NUM_MODES; ++i) {
-		if (strnicmp(page, r2hb_heartbeat_mode_desc[i], len))
-			continue;
-
-		ret = r2hb_global_hearbeat_mode_set(i);
-		if (!ret)
-			pr_notice("ramster: Heartbeat mode set to %s\n",
-			       r2hb_heartbeat_mode_desc[i]);
-		return count;
-	}
-
-	return -EINVAL;
-
-}
-
-static struct r2hb_hb_group_attribute r2hb_hb_group_attr_threshold = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "dead_threshold",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2hb_hb_group_threshold_show,
-	.store	= r2hb_hb_group_threshold_store,
-};
-
-static struct r2hb_hb_group_attribute r2hb_hb_group_attr_mode = {
-	.attr   = { .ca_owner = THIS_MODULE,
-		.ca_name = "mode",
-		.ca_mode = S_IRUGO | S_IWUSR },
-	.show   = r2hb_hb_group_mode_show,
-	.store  = r2hb_hb_group_mode_store,
-};
-
-static struct configfs_attribute *r2hb_hb_group_attrs[] = {
-	&r2hb_hb_group_attr_threshold.attr,
-	&r2hb_hb_group_attr_mode.attr,
-	NULL,
-};
-
-static struct configfs_item_operations r2hb_hearbeat_group_item_ops = {
-	.show_attribute		= r2hb_hb_group_show,
-	.store_attribute	= r2hb_hb_group_store,
-};
-
-static struct configfs_group_operations r2hb_hb_group_group_ops = {
-	.make_item	= r2hb_hb_group_make_item,
-	.drop_item	= r2hb_hb_group_drop_item,
-};
-
-static struct config_item_type r2hb_hb_group_type = {
-	.ct_group_ops	= &r2hb_hb_group_group_ops,
-	.ct_item_ops	= &r2hb_hearbeat_group_item_ops,
-	.ct_attrs	= r2hb_hb_group_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-/* this is just here to avoid touching group in heartbeat.h which the
- * entire damn world #includes */
-struct config_group *r2hb_alloc_hb_set(void)
-{
-	struct r2hb_hb_group *hs = NULL;
-	struct config_group *ret = NULL;
-
-	hs = kzalloc(sizeof(struct r2hb_hb_group), GFP_KERNEL);
-	if (hs == NULL)
-		goto out;
-
-	config_group_init_type_name(&hs->hs_group, "heartbeat",
-				    &r2hb_hb_group_type);
-
-	ret = &hs->hs_group;
-out:
-	if (ret == NULL)
-		kfree(hs);
-	return ret;
-}
-
-void r2hb_free_hb_set(struct config_group *group)
-{
-	struct r2hb_hb_group *hs = to_r2hb_hb_group(group);
-	kfree(hs);
-}
-
-/* hb callback registration and issuing */
-
-static struct r2hb_callback *hbcall_from_type(enum r2hb_callback_type type)
-{
-	if (type == R2HB_NUM_CB)
-		return ERR_PTR(-EINVAL);
-
-	return &r2hb_callbacks[type];
-}
-
-void r2hb_setup_callback(struct r2hb_callback_func *hc,
-			 enum r2hb_callback_type type,
-			 r2hb_cb_func *func,
-			 void *data,
-			 int priority)
-{
-	INIT_LIST_HEAD(&hc->hc_item);
-	hc->hc_func = func;
-	hc->hc_data = data;
-	hc->hc_priority = priority;
-	hc->hc_type = type;
-	hc->hc_magic = R2HB_CB_MAGIC;
-}
-EXPORT_SYMBOL_GPL(r2hb_setup_callback);
-
-int r2hb_register_callback(const char *region_uuid,
-			   struct r2hb_callback_func *hc)
-{
-	struct r2hb_callback_func *tmp;
-	struct list_head *iter;
-	struct r2hb_callback *hbcall;
-	int ret;
-
-	BUG_ON(hc->hc_magic != R2HB_CB_MAGIC);
-	BUG_ON(!list_empty(&hc->hc_item));
-
-	hbcall = hbcall_from_type(hc->hc_type);
-	if (IS_ERR(hbcall)) {
-		ret = PTR_ERR(hbcall);
-		goto out;
-	}
-
-	down_write(&r2hb_callback_sem);
-
-	list_for_each(iter, &hbcall->list) {
-		tmp = list_entry(iter, struct r2hb_callback_func, hc_item);
-		if (hc->hc_priority < tmp->hc_priority) {
-			list_add_tail(&hc->hc_item, iter);
-			break;
-		}
-	}
-	if (list_empty(&hc->hc_item))
-		list_add_tail(&hc->hc_item, &hbcall->list);
-
-	up_write(&r2hb_callback_sem);
-	ret = 0;
-out:
-	mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
-	     ret, __builtin_return_address(0), hc);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(r2hb_register_callback);
-
-void r2hb_unregister_callback(const char *region_uuid,
-			      struct r2hb_callback_func *hc)
-{
-	BUG_ON(hc->hc_magic != R2HB_CB_MAGIC);
-
-	mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
-	     __builtin_return_address(0), hc);
-
-	/* XXX Can this happen _with_ a region reference? */
-	if (list_empty(&hc->hc_item))
-		return;
-
-	down_write(&r2hb_callback_sem);
-
-	list_del_init(&hc->hc_item);
-
-	up_write(&r2hb_callback_sem);
-}
-EXPORT_SYMBOL_GPL(r2hb_unregister_callback);
-
-int r2hb_check_node_heartbeating_from_callback(u8 node_num)
-{
-	unsigned long testing_map[BITS_TO_LONGS(R2NM_MAX_NODES)];
-
-	r2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
-	if (!test_bit(node_num, testing_map)) {
-		mlog(ML_HEARTBEAT,
-		     "node (%u) does not have heartbeating enabled.\n",
-		     node_num);
-		return 0;
-	}
-
-	return 1;
-}
-EXPORT_SYMBOL_GPL(r2hb_check_node_heartbeating_from_callback);
-
-void r2hb_stop_all_regions(void)
-{
-}
-EXPORT_SYMBOL_GPL(r2hb_stop_all_regions);
-
-/*
- * this is just a hack until we get the plumbing which flips file systems
- * read only and drops the hb ref instead of killing the node dead.
- */
-int r2hb_global_heartbeat_active(void)
-{
-	return (r2hb_heartbeat_mode == R2HB_HEARTBEAT_GLOBAL);
-}
-EXPORT_SYMBOL(r2hb_global_heartbeat_active);
-
-/* added for RAMster */
-void r2hb_manual_set_node_heartbeating(int node_num)
-{
-	if (node_num < R2NM_MAX_NODES)
-		set_bit(node_num, r2hb_live_node_bitmap);
-}
-EXPORT_SYMBOL(r2hb_manual_set_node_heartbeating);

drivers/staging/zcache/ramster/heartbeat.h

@@ -1,87 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * heartbeat.h
- *
- * Function prototypes
- *
- * Copyright (C) 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- */
-
-#ifndef R2CLUSTER_HEARTBEAT_H
-#define R2CLUSTER_HEARTBEAT_H
-
-#define R2HB_REGION_TIMEOUT_MS		2000
-
-#define R2HB_MAX_REGION_NAME_LEN	32
-
-/* number of changes to be seen as live */
-#define R2HB_LIVE_THRESHOLD	   2
-/* number of equal samples to be seen as dead */
-extern unsigned int r2hb_dead_threshold;
-#define R2HB_DEFAULT_DEAD_THRESHOLD	   31
-/* Otherwise MAX_WRITE_TIMEOUT will be zero... */
-#define R2HB_MIN_DEAD_THRESHOLD	  2
-#define R2HB_MAX_WRITE_TIMEOUT_MS \
-	(R2HB_REGION_TIMEOUT_MS * (r2hb_dead_threshold - 1))
-
-#define R2HB_CB_MAGIC		0x51d1e4ec
-
-/* callback stuff */
-enum r2hb_callback_type {
-	R2HB_NODE_DOWN_CB = 0,
-	R2HB_NODE_UP_CB,
-	R2HB_NUM_CB
-};
-
-struct r2nm_node;
-typedef void (r2hb_cb_func)(struct r2nm_node *, int, void *);
-
-struct r2hb_callback_func {
-	u32			hc_magic;
-	struct list_head	hc_item;
-	r2hb_cb_func		*hc_func;
-	void			*hc_data;
-	int			hc_priority;
-	enum r2hb_callback_type hc_type;
-};
-
-struct config_group *r2hb_alloc_hb_set(void);
-void r2hb_free_hb_set(struct config_group *group);
-
-void r2hb_setup_callback(struct r2hb_callback_func *hc,
-			 enum r2hb_callback_type type,
-			 r2hb_cb_func *func,
-			 void *data,
-			 int priority);
-int r2hb_register_callback(const char *region_uuid,
-			   struct r2hb_callback_func *hc);
-void r2hb_unregister_callback(const char *region_uuid,
-			      struct r2hb_callback_func *hc);
-void r2hb_fill_node_map(unsigned long *map,
-			unsigned bytes);
-void r2hb_exit(void);
-int r2hb_init(void);
-int r2hb_check_node_heartbeating_from_callback(u8 node_num);
-void r2hb_stop_all_regions(void);
-int r2hb_get_all_regions(char *region_uuids, u8 numregions);
-int r2hb_global_heartbeat_active(void);
-void r2hb_manual_set_node_heartbeating(int);
-
-#endif /* R2CLUSTER_HEARTBEAT_H */

drivers/staging/zcache/ramster/masklog.c

@@ -1,155 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2004, 2005, 2012 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include <linux/string.h>
-#include <linux/uaccess.h>
-
-#include "masklog.h"
-
-struct mlog_bits r2_mlog_and_bits = MLOG_BITS_RHS(MLOG_INITIAL_AND_MASK);
-EXPORT_SYMBOL_GPL(r2_mlog_and_bits);
-struct mlog_bits r2_mlog_not_bits = MLOG_BITS_RHS(0);
-EXPORT_SYMBOL_GPL(r2_mlog_not_bits);
-
-static ssize_t mlog_mask_show(u64 mask, char *buf)
-{
-	char *state;
-
-	if (__mlog_test_u64(mask, r2_mlog_and_bits))
-		state = "allow";
-	else if (__mlog_test_u64(mask, r2_mlog_not_bits))
-		state = "deny";
-	else
-		state = "off";
-
-	return snprintf(buf, PAGE_SIZE, "%s\n", state);
-}
-
-static ssize_t mlog_mask_store(u64 mask, const char *buf, size_t count)
-{
-	if (!strnicmp(buf, "allow", 5)) {
-		__mlog_set_u64(mask, r2_mlog_and_bits);
-		__mlog_clear_u64(mask, r2_mlog_not_bits);
-	} else if (!strnicmp(buf, "deny", 4)) {
-		__mlog_set_u64(mask, r2_mlog_not_bits);
-		__mlog_clear_u64(mask, r2_mlog_and_bits);
-	} else if (!strnicmp(buf, "off", 3)) {
-		__mlog_clear_u64(mask, r2_mlog_not_bits);
-		__mlog_clear_u64(mask, r2_mlog_and_bits);
-	} else
-		return -EINVAL;
-
-	return count;
-}
-
-struct mlog_attribute {
-	struct attribute attr;
-	u64 mask;
-};
-
-#define to_mlog_attr(_attr) container_of(_attr, struct mlog_attribute, attr)
-
-#define define_mask(_name) {			\
-	.attr = {				\
-		.name = #_name,			\
-		.mode = S_IRUGO | S_IWUSR,	\
-	},					\
-	.mask = ML_##_name,			\
-}
-
-static struct mlog_attribute mlog_attrs[MLOG_MAX_BITS] = {
-	define_mask(TCP),
-	define_mask(MSG),
-	define_mask(SOCKET),
-	define_mask(HEARTBEAT),
-	define_mask(HB_BIO),
-	define_mask(DLMFS),
-	define_mask(DLM),
-	define_mask(DLM_DOMAIN),
-	define_mask(DLM_THREAD),
-	define_mask(DLM_MASTER),
-	define_mask(DLM_RECOVERY),
-	define_mask(DLM_GLUE),
-	define_mask(VOTE),
-	define_mask(CONN),
-	define_mask(QUORUM),
-	define_mask(BASTS),
-	define_mask(CLUSTER),
-	define_mask(ERROR),
-	define_mask(NOTICE),
-	define_mask(KTHREAD),
-};
-
-static struct attribute *mlog_attr_ptrs[MLOG_MAX_BITS] = {NULL, };
-
-static ssize_t mlog_show(struct kobject *obj, struct attribute *attr,
-			 char *buf)
-{
-	struct mlog_attribute *mlog_attr = to_mlog_attr(attr);
-
-	return mlog_mask_show(mlog_attr->mask, buf);
-}
-
-static ssize_t mlog_store(struct kobject *obj, struct attribute *attr,
-			  const char *buf, size_t count)
-{
-	struct mlog_attribute *mlog_attr = to_mlog_attr(attr);
-
-	return mlog_mask_store(mlog_attr->mask, buf, count);
-}
-
-static const struct sysfs_ops mlog_attr_ops = {
-	.show  = mlog_show,
-	.store = mlog_store,
-};
-
-static struct kobj_type mlog_ktype = {
-	.default_attrs = mlog_attr_ptrs,
-	.sysfs_ops     = &mlog_attr_ops,
-};
-
-static struct kset mlog_kset = {
-	.kobj   = {.ktype = &mlog_ktype},
-};
-
-int r2_mlog_sys_init(struct kset *r2cb_kset)
-{
-	int i = 0;
-
-	while (mlog_attrs[i].attr.mode) {
-		mlog_attr_ptrs[i] = &mlog_attrs[i].attr;
-		i++;
-	}
-	mlog_attr_ptrs[i] = NULL;
-
-	kobject_set_name(&mlog_kset.kobj, "logmask");
-	mlog_kset.kobj.kset = r2cb_kset;
-	return kset_register(&mlog_kset);
-}
-
-void r2_mlog_sys_shutdown(void)
-{
-	kset_unregister(&mlog_kset);
-}

drivers/staging/zcache/ramster/masklog.h

@@ -1,220 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2005, 2012 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#ifndef R2CLUSTER_MASKLOG_H
-#define R2CLUSTER_MASKLOG_H
-
-/*
- * For now this is a trivial wrapper around printk() that gives the critical
- * ability to enable sets of debugging output at run-time.  In the future this
- * will almost certainly be redirected to relayfs so that it can pay a
- * substantially lower heisenberg tax.
- *
- * Callers associate the message with a bitmask and a global bitmask is
- * maintained with help from /proc.  If any of the bits match the message is
- * output.
- *
- * We must have efficient bit tests on i386 and it seems gcc still emits crazy
- * code for the 64bit compare.  It emits very good code for the dual unsigned
- * long tests, though, completely avoiding tests that can never pass if the
- * caller gives a constant bitmask that fills one of the longs with all 0s.  So
- * the desire is to have almost all of the calls decided on by comparing just
- * one of the longs.  This leads to having infrequently given bits that are
- * frequently matched in the high bits.
- *
- * _ERROR and _NOTICE are used for messages that always go to the console and
- * have appropriate KERN_ prefixes.  We wrap these in our function instead of
- * just calling printk() so that this can eventually make its way through
- * relayfs along with the debugging messages.  Everything else gets KERN_DEBUG.
- * The inline tests and macro dance give GCC the opportunity to quite cleverly
- * only emit the appropriage printk() when the caller passes in a constant
- * mask, as is almost always the case.
- *
- * All this bitmask nonsense is managed from the files under
- * /sys/fs/r2cb/logmask/.  Reading the files gives a straightforward
- * indication of which bits are allowed (allow) or denied (off/deny).
- *	ENTRY deny
- *	EXIT deny
- *	TCP off
- *	MSG off
- *	SOCKET off
- *	ERROR allow
- *	NOTICE allow
- *
- * Writing changes the state of a given bit and requires a strictly formatted
- * single write() call:
- *
- *	write(fd, "allow", 5);
- *
- * Echoing allow/deny/off string into the logmask files can flip the bits
- * on or off as expected; here is the bash script for example:
- *
- * log_mask="/sys/fs/r2cb/log_mask"
- * for node in ENTRY EXIT TCP MSG SOCKET ERROR NOTICE; do
- *	echo allow >"$log_mask"/"$node"
- * done
- *
- * The debugfs.ramster tool can also flip the bits with the -l option:
- *
- * debugfs.ramster -l TCP allow
- */
-
-/* for task_struct */
-#include <linux/sched.h>
-
-/* bits that are frequently given and infrequently matched in the low word */
-/* NOTE: If you add a flag, you need to also update masklog.c! */
-#define ML_TCP		0x0000000000000001ULL /* net cluster/tcp.c */
-#define ML_MSG		0x0000000000000002ULL /* net network messages */
-#define ML_SOCKET	0x0000000000000004ULL /* net socket lifetime */
-#define ML_HEARTBEAT	0x0000000000000008ULL /* hb all heartbeat tracking */
-#define ML_HB_BIO	0x0000000000000010ULL /* hb io tracing */
-#define ML_DLMFS	0x0000000000000020ULL /* dlm user dlmfs */
-#define ML_DLM		0x0000000000000040ULL /* dlm general debugging */
-#define ML_DLM_DOMAIN	0x0000000000000080ULL /* dlm domain debugging */
-#define ML_DLM_THREAD	0x0000000000000100ULL /* dlm domain thread */
-#define ML_DLM_MASTER	0x0000000000000200ULL /* dlm master functions */
-#define ML_DLM_RECOVERY	0x0000000000000400ULL /* dlm master functions */
-#define ML_DLM_GLUE	0x0000000000000800ULL /* ramster dlm glue layer */
-#define ML_VOTE		0x0000000000001000ULL /* ramster node messaging  */
-#define ML_CONN		0x0000000000002000ULL /* net connection management */
-#define ML_QUORUM	0x0000000000004000ULL /* net connection quorum */
-#define ML_BASTS	0x0000000000008000ULL /* dlmglue asts and basts */
-#define ML_CLUSTER	0x0000000000010000ULL /* cluster stack */
-
-/* bits that are infrequently given and frequently matched in the high word */
-#define ML_ERROR	0x1000000000000000ULL /* sent to KERN_ERR */
-#define ML_NOTICE	0x2000000000000000ULL /* setn to KERN_NOTICE */
-#define ML_KTHREAD	0x4000000000000000ULL /* kernel thread activity */
-
-#define MLOG_INITIAL_AND_MASK (ML_ERROR|ML_NOTICE)
-#ifndef MLOG_MASK_PREFIX
-#define MLOG_MASK_PREFIX 0
-#endif
-
-/*
- * When logging is disabled, force the bit test to 0 for anything other
- * than errors and notices, allowing gcc to remove the code completely.
- * When enabled, allow all masks.
- */
-#if defined(CONFIG_RAMSTER_DEBUG_MASKLOG)
-#define ML_ALLOWED_BITS (~0)
-#else
-#define ML_ALLOWED_BITS (ML_ERROR|ML_NOTICE)
-#endif
-
-#define MLOG_MAX_BITS 64
-
-struct mlog_bits {
-	unsigned long words[MLOG_MAX_BITS / BITS_PER_LONG];
-};
-
-extern struct mlog_bits r2_mlog_and_bits, r2_mlog_not_bits;
-
-#if BITS_PER_LONG == 32
-
-#define __mlog_test_u64(mask, bits)			\
-	((u32)(mask & 0xffffffff) & bits.words[0] ||	\
-	  ((u64)(mask) >> 32) & bits.words[1])
-#define __mlog_set_u64(mask, bits) do {			\
-	bits.words[0] |= (u32)(mask & 0xffffffff);	\
-	bits.words[1] |= (u64)(mask) >> 32;		\
-} while (0)
-#define __mlog_clear_u64(mask, bits) do {		\
-	bits.words[0] &= ~((u32)(mask & 0xffffffff));	\
-	bits.words[1] &= ~((u64)(mask) >> 32);		\
-} while (0)
-#define MLOG_BITS_RHS(mask) {				\
-	{						\
-		[0] = (u32)(mask & 0xffffffff),		\
-		[1] = (u64)(mask) >> 32,		\
-	}						\
-}
-
-#else /* 32bit long above, 64bit long below */
-
-#define __mlog_test_u64(mask, bits)	((mask) & bits.words[0])
-#define __mlog_set_u64(mask, bits) do {		\
-	bits.words[0] |= (mask);		\
-} while (0)
-#define __mlog_clear_u64(mask, bits) do {	\
-	bits.words[0] &= ~(mask);		\
-} while (0)
-#define MLOG_BITS_RHS(mask) { { (mask) } }
-
-#endif
-
-/*
- * smp_processor_id() "helpfully" screams when called outside preemptible
- * regions in current kernels.  sles doesn't have the variants that don't
- * scream.  just do this instead of trying to guess which we're building
- * against.. *sigh*.
- */
-#define __mlog_cpu_guess ({		\
-	unsigned long _cpu = get_cpu();	\
-	put_cpu();			\
-	_cpu;				\
-})
-
-/* In the following two macros, the whitespace after the ',' just
- * before ##args is intentional. Otherwise, gcc 2.95 will eat the
- * previous token if args expands to nothing.
- */
-#define __mlog_printk(level, fmt, args...)				\
-	printk(level "(%s,%u,%lu):%s:%d " fmt, current->comm,		\
-	       task_pid_nr(current), __mlog_cpu_guess,			\
-	       __PRETTY_FUNCTION__, __LINE__ , ##args)
-
-#define mlog(mask, fmt, args...) do {					\
-	u64 __m = MLOG_MASK_PREFIX | (mask);				\
-	if ((__m & ML_ALLOWED_BITS) &&					\
-	    __mlog_test_u64(__m, r2_mlog_and_bits) &&			\
-	    !__mlog_test_u64(__m, r2_mlog_not_bits)) {			\
-		if (__m & ML_ERROR)					\
-			__mlog_printk(KERN_ERR, "ERROR: "fmt , ##args);	\
-		else if (__m & ML_NOTICE)				\
-			__mlog_printk(KERN_NOTICE, fmt , ##args);	\
-		else							\
-			__mlog_printk(KERN_INFO, fmt , ##args);		\
-	}								\
-} while (0)
-
-#define mlog_errno(st) do {						\
-	int _st = (st);							\
-	if (_st != -ERESTARTSYS && _st != -EINTR &&			\
-	    _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC)		\
-		mlog(ML_ERROR, "status = %lld\n", (long long)_st);	\
-} while (0)
-
-#define mlog_bug_on_msg(cond, fmt, args...) do {			\
-	if (cond) {							\
-		mlog(ML_ERROR, "bug expression: " #cond "\n");		\
-		mlog(ML_ERROR, fmt, ##args);				\
-		BUG();							\
-	}								\
-} while (0)
-
-#include <linux/kobject.h>
-#include <linux/sysfs.h>
-int r2_mlog_sys_init(struct kset *r2cb_subsys);
-void r2_mlog_sys_shutdown(void);
-
-#endif /* R2CLUSTER_MASKLOG_H */

drivers/staging/zcache/ramster/nodemanager.c

@@ -1,996 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2004, 2005, 2012 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#include <linux/slab.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/configfs.h>
-
-#include "tcp.h"
-#include "nodemanager.h"
-#include "heartbeat.h"
-#include "masklog.h"
-
-/* for now we operate under the assertion that there can be only one
- * cluster active at a time.  Changing this will require trickling
- * cluster references throughout where nodes are looked up */
-struct r2nm_cluster *r2nm_single_cluster;
-
-char *r2nm_fence_method_desc[R2NM_FENCE_METHODS] = {
-		"reset",	/* R2NM_FENCE_RESET */
-		"panic",	/* R2NM_FENCE_PANIC */
-};
-
-struct r2nm_node *r2nm_get_node_by_num(u8 node_num)
-{
-	struct r2nm_node *node = NULL;
-
-	if (node_num >= R2NM_MAX_NODES || r2nm_single_cluster == NULL)
-		goto out;
-
-	read_lock(&r2nm_single_cluster->cl_nodes_lock);
-	node = r2nm_single_cluster->cl_nodes[node_num];
-	if (node)
-		config_item_get(&node->nd_item);
-	read_unlock(&r2nm_single_cluster->cl_nodes_lock);
-out:
-	return node;
-}
-EXPORT_SYMBOL_GPL(r2nm_get_node_by_num);
-
-int r2nm_configured_node_map(unsigned long *map, unsigned bytes)
-{
-	struct r2nm_cluster *cluster = r2nm_single_cluster;
-
-	BUG_ON(bytes < (sizeof(cluster->cl_nodes_bitmap)));
-
-	if (cluster == NULL)
-		return -EINVAL;
-
-	read_lock(&cluster->cl_nodes_lock);
-	memcpy(map, cluster->cl_nodes_bitmap, sizeof(cluster->cl_nodes_bitmap));
-	read_unlock(&cluster->cl_nodes_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(r2nm_configured_node_map);
-
-static struct r2nm_node *r2nm_node_ip_tree_lookup(struct r2nm_cluster *cluster,
-						  __be32 ip_needle,
-						  struct rb_node ***ret_p,
-						  struct rb_node **ret_parent)
-{
-	struct rb_node **p = &cluster->cl_node_ip_tree.rb_node;
-	struct rb_node *parent = NULL;
-	struct r2nm_node *node, *ret = NULL;
-
-	while (*p) {
-		int cmp;
-
-		parent = *p;
-		node = rb_entry(parent, struct r2nm_node, nd_ip_node);
-
-		cmp = memcmp(&ip_needle, &node->nd_ipv4_address,
-				sizeof(ip_needle));
-		if (cmp < 0)
-			p = &(*p)->rb_left;
-		else if (cmp > 0)
-			p = &(*p)->rb_right;
-		else {
-			ret = node;
-			break;
-		}
-	}
-
-	if (ret_p != NULL)
-		*ret_p = p;
-	if (ret_parent != NULL)
-		*ret_parent = parent;
-
-	return ret;
-}
-
-struct r2nm_node *r2nm_get_node_by_ip(__be32 addr)
-{
-	struct r2nm_node *node = NULL;
-	struct r2nm_cluster *cluster = r2nm_single_cluster;
-
-	if (cluster == NULL)
-		goto out;
-
-	read_lock(&cluster->cl_nodes_lock);
-	node = r2nm_node_ip_tree_lookup(cluster, addr, NULL, NULL);
-	if (node)
-		config_item_get(&node->nd_item);
-	read_unlock(&cluster->cl_nodes_lock);
-
-out:
-	return node;
-}
-EXPORT_SYMBOL_GPL(r2nm_get_node_by_ip);
-
-void r2nm_node_put(struct r2nm_node *node)
-{
-	config_item_put(&node->nd_item);
-}
-EXPORT_SYMBOL_GPL(r2nm_node_put);
-
-void r2nm_node_get(struct r2nm_node *node)
-{
-	config_item_get(&node->nd_item);
-}
-EXPORT_SYMBOL_GPL(r2nm_node_get);
-
-u8 r2nm_this_node(void)
-{
-	u8 node_num = R2NM_MAX_NODES;
-
-	if (r2nm_single_cluster && r2nm_single_cluster->cl_has_local)
-		node_num = r2nm_single_cluster->cl_local_node;
-
-	return node_num;
-}
-EXPORT_SYMBOL_GPL(r2nm_this_node);
-
-/* node configfs bits */
-
-static struct r2nm_cluster *to_r2nm_cluster(struct config_item *item)
-{
-	return item ?
-		container_of(to_config_group(item), struct r2nm_cluster,
-			     cl_group)
-		: NULL;
-}
-
-static struct r2nm_node *to_r2nm_node(struct config_item *item)
-{
-	return item ? container_of(item, struct r2nm_node, nd_item) : NULL;
-}
-
-static void r2nm_node_release(struct config_item *item)
-{
-	struct r2nm_node *node = to_r2nm_node(item);
-	kfree(node);
-}
-
-static ssize_t r2nm_node_num_read(struct r2nm_node *node, char *page)
-{
-	return sprintf(page, "%d\n", node->nd_num);
-}
-
-static struct r2nm_cluster *to_r2nm_cluster_from_node(struct r2nm_node *node)
-{
-	/* through the first node_set .parent
-	 * mycluster/nodes/mynode == r2nm_cluster->r2nm_node_group->r2nm_node */
-	return to_r2nm_cluster(node->nd_item.ci_parent->ci_parent);
-}
-
-enum {
-	R2NM_NODE_ATTR_NUM = 0,
-	R2NM_NODE_ATTR_PORT,
-	R2NM_NODE_ATTR_ADDRESS,
-	R2NM_NODE_ATTR_LOCAL,
-};
-
-static ssize_t r2nm_node_num_write(struct r2nm_node *node, const char *page,
-				   size_t count)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster_from_node(node);
-	unsigned long tmp;
-	char *p = (char *)page;
-	int err;
-
-	err = kstrtoul(p, 10, &tmp);
-	if (err)
-		return err;
-
-	if (tmp >= R2NM_MAX_NODES)
-		return -ERANGE;
-
-	/* once we're in the cl_nodes tree networking can look us up by
-	 * node number and try to use our address and port attributes
-	 * to connect to this node.. make sure that they've been set
-	 * before writing the node attribute? */
-	if (!test_bit(R2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
-	    !test_bit(R2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
-		return -EINVAL; /* XXX */
-
-	write_lock(&cluster->cl_nodes_lock);
-	if (cluster->cl_nodes[tmp])
-		p = NULL;
-	else  {
-		cluster->cl_nodes[tmp] = node;
-		node->nd_num = tmp;
-		set_bit(tmp, cluster->cl_nodes_bitmap);
-	}
-	write_unlock(&cluster->cl_nodes_lock);
-	if (p == NULL)
-		return -EEXIST;
-
-	return count;
-}
-static ssize_t r2nm_node_ipv4_port_read(struct r2nm_node *node, char *page)
-{
-	return sprintf(page, "%u\n", ntohs(node->nd_ipv4_port));
-}
-
-static ssize_t r2nm_node_ipv4_port_write(struct r2nm_node *node,
-					 const char *page, size_t count)
-{
-	unsigned long tmp;
-	char *p = (char *)page;
-	int err;
-
-	err = kstrtoul(p, 10, &tmp);
-	if (err)
-		return err;
-
-	if (tmp == 0)
-		return -EINVAL;
-	if (tmp >= (u16)-1)
-		return -ERANGE;
-
-	node->nd_ipv4_port = htons(tmp);
-
-	return count;
-}
-
-static ssize_t r2nm_node_ipv4_address_read(struct r2nm_node *node, char *page)
-{
-	return sprintf(page, "%pI4\n", &node->nd_ipv4_address);
-}
-
-static ssize_t r2nm_node_ipv4_address_write(struct r2nm_node *node,
-					    const char *page,
-					    size_t count)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster_from_node(node);
-	int ret, i;
-	struct rb_node **p, *parent;
-	unsigned int octets[4];
-	__be32 ipv4_addr = 0;
-
-	ret = sscanf(page, "%3u.%3u.%3u.%3u", &octets[3], &octets[2],
-		     &octets[1], &octets[0]);
-	if (ret != 4)
-		return -EINVAL;
-
-	for (i = 0; i < ARRAY_SIZE(octets); i++) {
-		if (octets[i] > 255)
-			return -ERANGE;
-		be32_add_cpu(&ipv4_addr, octets[i] << (i * 8));
-	}
-
-	ret = 0;
-	write_lock(&cluster->cl_nodes_lock);
-	if (r2nm_node_ip_tree_lookup(cluster, ipv4_addr, &p, &parent))
-		ret = -EEXIST;
-	else {
-		rb_link_node(&node->nd_ip_node, parent, p);
-		rb_insert_color(&node->nd_ip_node, &cluster->cl_node_ip_tree);
-	}
-	write_unlock(&cluster->cl_nodes_lock);
-	if (ret)
-		return ret;
-
-	memcpy(&node->nd_ipv4_address, &ipv4_addr, sizeof(ipv4_addr));
-
-	return count;
-}
-
-static ssize_t r2nm_node_local_read(struct r2nm_node *node, char *page)
-{
-	return sprintf(page, "%d\n", node->nd_local);
-}
-
-static ssize_t r2nm_node_local_write(struct r2nm_node *node, const char *page,
-				     size_t count)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster_from_node(node);
-	unsigned long tmp;
-	char *p = (char *)page;
-	ssize_t ret;
-	int err;
-
-	err = kstrtoul(p, 10, &tmp);
-	if (err)
-		return err;
-
-	tmp = !!tmp; /* boolean of whether this node wants to be local */
-
-	/* setting local turns on networking rx for now so we require having
-	 * set everything else first */
-	if (!test_bit(R2NM_NODE_ATTR_ADDRESS, &node->nd_set_attributes) ||
-	    !test_bit(R2NM_NODE_ATTR_NUM, &node->nd_set_attributes) ||
-	    !test_bit(R2NM_NODE_ATTR_PORT, &node->nd_set_attributes))
-		return -EINVAL; /* XXX */
-
-	/* the only failure case is trying to set a new local node
-	 * when a different one is already set */
-	if (tmp && tmp == cluster->cl_has_local &&
-	    cluster->cl_local_node != node->nd_num)
-		return -EBUSY;
-
-	/* bring up the rx thread if we're setting the new local node. */
-	if (tmp && !cluster->cl_has_local) {
-		ret = r2net_start_listening(node);
-		if (ret)
-			return ret;
-	}
-
-	if (!tmp && cluster->cl_has_local &&
-	    cluster->cl_local_node == node->nd_num) {
-		r2net_stop_listening(node);
-		cluster->cl_local_node = R2NM_INVALID_NODE_NUM;
-	}
-
-	node->nd_local = tmp;
-	if (node->nd_local) {
-		cluster->cl_has_local = tmp;
-		cluster->cl_local_node = node->nd_num;
-	}
-
-	return count;
-}
-
-struct r2nm_node_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct r2nm_node *, char *);
-	ssize_t (*store)(struct r2nm_node *, const char *, size_t);
-};
-
-static struct r2nm_node_attribute r2nm_node_attr_num = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "num",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_node_num_read,
-	.store	= r2nm_node_num_write,
-};
-
-static struct r2nm_node_attribute r2nm_node_attr_ipv4_port = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "ipv4_port",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_node_ipv4_port_read,
-	.store	= r2nm_node_ipv4_port_write,
-};
-
-static struct r2nm_node_attribute r2nm_node_attr_ipv4_address = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "ipv4_address",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_node_ipv4_address_read,
-	.store	= r2nm_node_ipv4_address_write,
-};
-
-static struct r2nm_node_attribute r2nm_node_attr_local = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "local",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_node_local_read,
-	.store	= r2nm_node_local_write,
-};
-
-static struct configfs_attribute *r2nm_node_attrs[] = {
-	[R2NM_NODE_ATTR_NUM] = &r2nm_node_attr_num.attr,
-	[R2NM_NODE_ATTR_PORT] = &r2nm_node_attr_ipv4_port.attr,
-	[R2NM_NODE_ATTR_ADDRESS] = &r2nm_node_attr_ipv4_address.attr,
-	[R2NM_NODE_ATTR_LOCAL] = &r2nm_node_attr_local.attr,
-	NULL,
-};
-
-static int r2nm_attr_index(struct configfs_attribute *attr)
-{
-	int i;
-	for (i = 0; i < ARRAY_SIZE(r2nm_node_attrs); i++) {
-		if (attr == r2nm_node_attrs[i])
-			return i;
-	}
-	BUG();
-	return 0;
-}
-
-static ssize_t r2nm_node_show(struct config_item *item,
-			      struct configfs_attribute *attr,
-			      char *page)
-{
-	struct r2nm_node *node = to_r2nm_node(item);
-	struct r2nm_node_attribute *r2nm_node_attr =
-		container_of(attr, struct r2nm_node_attribute, attr);
-	ssize_t ret = 0;
-
-	if (r2nm_node_attr->show)
-		ret = r2nm_node_attr->show(node, page);
-	return ret;
-}
-
-static ssize_t r2nm_node_store(struct config_item *item,
-			       struct configfs_attribute *attr,
-			       const char *page, size_t count)
-{
-	struct r2nm_node *node = to_r2nm_node(item);
-	struct r2nm_node_attribute *r2nm_node_attr =
-		container_of(attr, struct r2nm_node_attribute, attr);
-	ssize_t ret;
-	int attr_index = r2nm_attr_index(attr);
-
-	if (r2nm_node_attr->store == NULL) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (test_bit(attr_index, &node->nd_set_attributes))
-		return -EBUSY;
-
-	ret = r2nm_node_attr->store(node, page, count);
-	if (ret < count)
-		goto out;
-
-	set_bit(attr_index, &node->nd_set_attributes);
-out:
-	return ret;
-}
-
-static struct configfs_item_operations r2nm_node_item_ops = {
-	.release		= r2nm_node_release,
-	.show_attribute		= r2nm_node_show,
-	.store_attribute	= r2nm_node_store,
-};
-
-static struct config_item_type r2nm_node_type = {
-	.ct_item_ops	= &r2nm_node_item_ops,
-	.ct_attrs	= r2nm_node_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-/* node set */
-
-struct r2nm_node_group {
-	struct config_group ns_group;
-	/* some stuff? */
-};
-
-#if 0
-static struct r2nm_node_group *to_r2nm_node_group(struct config_group *group)
-{
-	return group ?
-		container_of(group, struct r2nm_node_group, ns_group)
-		: NULL;
-}
-#endif
-
-struct r2nm_cluster_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct r2nm_cluster *, char *);
-	ssize_t (*store)(struct r2nm_cluster *, const char *, size_t);
-};
-
-static ssize_t r2nm_cluster_attr_write(const char *page, ssize_t count,
-					unsigned int *val)
-{
-	unsigned long tmp;
-	char *p = (char *)page;
-	int err;
-
-	err = kstrtoul(p, 10, &tmp);
-	if (err)
-		return err;
-
-	if (tmp == 0)
-		return -EINVAL;
-	if (tmp >= (u32)-1)
-		return -ERANGE;
-
-	*val = tmp;
-
-	return count;
-}
-
-static ssize_t r2nm_cluster_attr_idle_timeout_ms_read(
-	struct r2nm_cluster *cluster, char *page)
-{
-	return sprintf(page, "%u\n", cluster->cl_idle_timeout_ms);
-}
-
-static ssize_t r2nm_cluster_attr_idle_timeout_ms_write(
-	struct r2nm_cluster *cluster, const char *page, size_t count)
-{
-	ssize_t ret;
-	unsigned int val = 0;
-
-	ret =  r2nm_cluster_attr_write(page, count, &val);
-
-	if (ret > 0) {
-		if (cluster->cl_idle_timeout_ms != val
-			&& r2net_num_connected_peers()) {
-			mlog(ML_NOTICE,
-			     "r2net: cannot change idle timeout after "
-			     "the first peer has agreed to it."
-			     "  %d connected peers\n",
-			     r2net_num_connected_peers());
-			ret = -EINVAL;
-		} else if (val <= cluster->cl_keepalive_delay_ms) {
-			mlog(ML_NOTICE,
-			     "r2net: idle timeout must be larger "
-			     "than keepalive delay\n");
-			ret = -EINVAL;
-		} else {
-			cluster->cl_idle_timeout_ms = val;
-		}
-	}
-
-	return ret;
-}
-
-static ssize_t r2nm_cluster_attr_keepalive_delay_ms_read(
-	struct r2nm_cluster *cluster, char *page)
-{
-	return sprintf(page, "%u\n", cluster->cl_keepalive_delay_ms);
-}
-
-static ssize_t r2nm_cluster_attr_keepalive_delay_ms_write(
-	struct r2nm_cluster *cluster, const char *page, size_t count)
-{
-	ssize_t ret;
-	unsigned int val = 0;
-
-	ret =  r2nm_cluster_attr_write(page, count, &val);
-
-	if (ret > 0) {
-		if (cluster->cl_keepalive_delay_ms != val
-		    && r2net_num_connected_peers()) {
-			mlog(ML_NOTICE,
-			     "r2net: cannot change keepalive delay after"
-			     " the first peer has agreed to it."
-			     "  %d connected peers\n",
-			     r2net_num_connected_peers());
-			ret = -EINVAL;
-		} else if (val >= cluster->cl_idle_timeout_ms) {
-			mlog(ML_NOTICE,
-			     "r2net: keepalive delay must be "
-			     "smaller than idle timeout\n");
-			ret = -EINVAL;
-		} else {
-			cluster->cl_keepalive_delay_ms = val;
-		}
-	}
-
-	return ret;
-}
-
-static ssize_t r2nm_cluster_attr_reconnect_delay_ms_read(
-	struct r2nm_cluster *cluster, char *page)
-{
-	return sprintf(page, "%u\n", cluster->cl_reconnect_delay_ms);
-}
-
-static ssize_t r2nm_cluster_attr_reconnect_delay_ms_write(
-	struct r2nm_cluster *cluster, const char *page, size_t count)
-{
-	return r2nm_cluster_attr_write(page, count,
-					&cluster->cl_reconnect_delay_ms);
-}
-
-static ssize_t r2nm_cluster_attr_fence_method_read(
-	struct r2nm_cluster *cluster, char *page)
-{
-	ssize_t ret = 0;
-
-	if (cluster)
-		ret = sprintf(page, "%s\n",
-			      r2nm_fence_method_desc[cluster->cl_fence_method]);
-	return ret;
-}
-
-static ssize_t r2nm_cluster_attr_fence_method_write(
-	struct r2nm_cluster *cluster, const char *page, size_t count)
-{
-	unsigned int i;
-
-	if (page[count - 1] != '\n')
-		goto bail;
-
-	for (i = 0; i < R2NM_FENCE_METHODS; ++i) {
-		if (count != strlen(r2nm_fence_method_desc[i]) + 1)
-			continue;
-		if (strncasecmp(page, r2nm_fence_method_desc[i], count - 1))
-			continue;
-		if (cluster->cl_fence_method != i) {
-			pr_info("ramster: Changing fence method to %s\n",
-			       r2nm_fence_method_desc[i]);
-			cluster->cl_fence_method = i;
-		}
-		return count;
-	}
-
-bail:
-	return -EINVAL;
-}
-
-static struct r2nm_cluster_attribute r2nm_cluster_attr_idle_timeout_ms = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "idle_timeout_ms",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_cluster_attr_idle_timeout_ms_read,
-	.store	= r2nm_cluster_attr_idle_timeout_ms_write,
-};
-
-static struct r2nm_cluster_attribute r2nm_cluster_attr_keepalive_delay_ms = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "keepalive_delay_ms",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_cluster_attr_keepalive_delay_ms_read,
-	.store	= r2nm_cluster_attr_keepalive_delay_ms_write,
-};
-
-static struct r2nm_cluster_attribute r2nm_cluster_attr_reconnect_delay_ms = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "reconnect_delay_ms",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_cluster_attr_reconnect_delay_ms_read,
-	.store	= r2nm_cluster_attr_reconnect_delay_ms_write,
-};
-
-static struct r2nm_cluster_attribute r2nm_cluster_attr_fence_method = {
-	.attr	= { .ca_owner = THIS_MODULE,
-		    .ca_name = "fence_method",
-		    .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= r2nm_cluster_attr_fence_method_read,
-	.store	= r2nm_cluster_attr_fence_method_write,
-};
-
-static struct configfs_attribute *r2nm_cluster_attrs[] = {
-	&r2nm_cluster_attr_idle_timeout_ms.attr,
-	&r2nm_cluster_attr_keepalive_delay_ms.attr,
-	&r2nm_cluster_attr_reconnect_delay_ms.attr,
-	&r2nm_cluster_attr_fence_method.attr,
-	NULL,
-};
-static ssize_t r2nm_cluster_show(struct config_item *item,
-					struct configfs_attribute *attr,
-					char *page)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster(item);
-	struct r2nm_cluster_attribute *r2nm_cluster_attr =
-		container_of(attr, struct r2nm_cluster_attribute, attr);
-	ssize_t ret = 0;
-
-	if (r2nm_cluster_attr->show)
-		ret = r2nm_cluster_attr->show(cluster, page);
-	return ret;
-}
-
-static ssize_t r2nm_cluster_store(struct config_item *item,
-					struct configfs_attribute *attr,
-					const char *page, size_t count)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster(item);
-	struct r2nm_cluster_attribute *r2nm_cluster_attr =
-		container_of(attr, struct r2nm_cluster_attribute, attr);
-	ssize_t ret;
-
-	if (r2nm_cluster_attr->store == NULL) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = r2nm_cluster_attr->store(cluster, page, count);
-	if (ret < count)
-		goto out;
-out:
-	return ret;
-}
-
-static struct config_item *r2nm_node_group_make_item(struct config_group *group,
-						     const char *name)
-{
-	struct r2nm_node *node = NULL;
-
-	if (strlen(name) > R2NM_MAX_NAME_LEN)
-		return ERR_PTR(-ENAMETOOLONG);
-
-	node = kzalloc(sizeof(struct r2nm_node), GFP_KERNEL);
-	if (node == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	strcpy(node->nd_name, name); /* use item.ci_namebuf instead? */
-	config_item_init_type_name(&node->nd_item, name, &r2nm_node_type);
-	spin_lock_init(&node->nd_lock);
-
-	mlog(ML_CLUSTER, "r2nm: Registering node %s\n", name);
-
-	return &node->nd_item;
-}
-
-static void r2nm_node_group_drop_item(struct config_group *group,
-				      struct config_item *item)
-{
-	struct r2nm_node *node = to_r2nm_node(item);
-	struct r2nm_cluster *cluster =
-				to_r2nm_cluster(group->cg_item.ci_parent);
-
-	r2net_disconnect_node(node);
-
-	if (cluster->cl_has_local &&
-	    (cluster->cl_local_node == node->nd_num)) {
-		cluster->cl_has_local = 0;
-		cluster->cl_local_node = R2NM_INVALID_NODE_NUM;
-		r2net_stop_listening(node);
-	}
-
-	/* XXX call into net to stop this node from trading messages */
-
-	write_lock(&cluster->cl_nodes_lock);
-
-	/* XXX sloppy */
-	if (node->nd_ipv4_address)
-		rb_erase(&node->nd_ip_node, &cluster->cl_node_ip_tree);
-
-	/* nd_num might be 0 if the node number hasn't been set.. */
-	if (cluster->cl_nodes[node->nd_num] == node) {
-		cluster->cl_nodes[node->nd_num] = NULL;
-		clear_bit(node->nd_num, cluster->cl_nodes_bitmap);
-	}
-	write_unlock(&cluster->cl_nodes_lock);
-
-	mlog(ML_CLUSTER, "r2nm: Unregistered node %s\n",
-	     config_item_name(&node->nd_item));
-
-	config_item_put(item);
-}
-
-static struct configfs_group_operations r2nm_node_group_group_ops = {
-	.make_item	= r2nm_node_group_make_item,
-	.drop_item	= r2nm_node_group_drop_item,
-};
-
-static struct config_item_type r2nm_node_group_type = {
-	.ct_group_ops	= &r2nm_node_group_group_ops,
-	.ct_owner	= THIS_MODULE,
-};
-
-/* cluster */
-
-static void r2nm_cluster_release(struct config_item *item)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster(item);
-
-	kfree(cluster->cl_group.default_groups);
-	kfree(cluster);
-}
-
-static struct configfs_item_operations r2nm_cluster_item_ops = {
-	.release	= r2nm_cluster_release,
-	.show_attribute		= r2nm_cluster_show,
-	.store_attribute	= r2nm_cluster_store,
-};
-
-static struct config_item_type r2nm_cluster_type = {
-	.ct_item_ops	= &r2nm_cluster_item_ops,
-	.ct_attrs	= r2nm_cluster_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-/* cluster set */
-
-struct r2nm_cluster_group {
-	struct configfs_subsystem cs_subsys;
-	/* some stuff? */
-};
-
-#if 0
-static struct r2nm_cluster_group *
-to_r2nm_cluster_group(struct config_group *group)
-{
-	return group ?
-		container_of(to_configfs_subsystem(group),
-				struct r2nm_cluster_group, cs_subsys)
-	       : NULL;
-}
-#endif
-
-static struct config_group *
-r2nm_cluster_group_make_group(struct config_group *group,
-							  const char *name)
-{
-	struct r2nm_cluster *cluster = NULL;
-	struct r2nm_node_group *ns = NULL;
-	struct config_group *r2hb_group = NULL, *ret = NULL;
-	void *defs = NULL;
-
-	/* this runs under the parent dir's i_mutex; there can be only
-	 * one caller in here at a time */
-	if (r2nm_single_cluster)
-		return ERR_PTR(-ENOSPC);
-
-	cluster = kzalloc(sizeof(struct r2nm_cluster), GFP_KERNEL);
-	ns = kzalloc(sizeof(struct r2nm_node_group), GFP_KERNEL);
-	defs = kcalloc(3, sizeof(struct config_group *), GFP_KERNEL);
-	r2hb_group = r2hb_alloc_hb_set();
-	if (cluster == NULL || ns == NULL || r2hb_group == NULL || defs == NULL)
-		goto out;
-
-	config_group_init_type_name(&cluster->cl_group, name,
-				    &r2nm_cluster_type);
-	config_group_init_type_name(&ns->ns_group, "node",
-				    &r2nm_node_group_type);
-
-	cluster->cl_group.default_groups = defs;
-	cluster->cl_group.default_groups[0] = &ns->ns_group;
-	cluster->cl_group.default_groups[1] = r2hb_group;
-	cluster->cl_group.default_groups[2] = NULL;
-	rwlock_init(&cluster->cl_nodes_lock);
-	cluster->cl_node_ip_tree = RB_ROOT;
-	cluster->cl_reconnect_delay_ms = R2NET_RECONNECT_DELAY_MS_DEFAULT;
-	cluster->cl_idle_timeout_ms    = R2NET_IDLE_TIMEOUT_MS_DEFAULT;
-	cluster->cl_keepalive_delay_ms = R2NET_KEEPALIVE_DELAY_MS_DEFAULT;
-	cluster->cl_fence_method       = R2NM_FENCE_RESET;
-
-	ret = &cluster->cl_group;
-	r2nm_single_cluster = cluster;
-
-out:
-	if (ret == NULL) {
-		kfree(cluster);
-		kfree(ns);
-		r2hb_free_hb_set(r2hb_group);
-		kfree(defs);
-		ret = ERR_PTR(-ENOMEM);
-	}
-
-	return ret;
-}
-
-static void r2nm_cluster_group_drop_item(struct config_group *group,
-						struct config_item *item)
-{
-	struct r2nm_cluster *cluster = to_r2nm_cluster(item);
-	int i;
-	struct config_item *killme;
-
-	BUG_ON(r2nm_single_cluster != cluster);
-	r2nm_single_cluster = NULL;
-
-	for (i = 0; cluster->cl_group.default_groups[i]; i++) {
-		killme = &cluster->cl_group.default_groups[i]->cg_item;
-		cluster->cl_group.default_groups[i] = NULL;
-		config_item_put(killme);
-	}
-
-	config_item_put(item);
-}
-
-static struct configfs_group_operations r2nm_cluster_group_group_ops = {
-	.make_group	= r2nm_cluster_group_make_group,
-	.drop_item	= r2nm_cluster_group_drop_item,
-};
-
-static struct config_item_type r2nm_cluster_group_type = {
-	.ct_group_ops	= &r2nm_cluster_group_group_ops,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct r2nm_cluster_group r2nm_cluster_group = {
-	.cs_subsys = {
-		.su_group = {
-			.cg_item = {
-				.ci_namebuf = "cluster",
-				.ci_type = &r2nm_cluster_group_type,
-			},
-		},
-	},
-};
-
-int r2nm_depend_item(struct config_item *item)
-{
-	return configfs_depend_item(&r2nm_cluster_group.cs_subsys, item);
-}
-
-void r2nm_undepend_item(struct config_item *item)
-{
-	configfs_undepend_item(&r2nm_cluster_group.cs_subsys, item);
-}
-
-int r2nm_depend_this_node(void)
-{
-	int ret = 0;
-	struct r2nm_node *local_node;
-
-	local_node = r2nm_get_node_by_num(r2nm_this_node());
-	if (!local_node) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = r2nm_depend_item(&local_node->nd_item);
-	r2nm_node_put(local_node);
-
-out:
-	return ret;
-}
-
-void r2nm_undepend_this_node(void)
-{
-	struct r2nm_node *local_node;
-
-	local_node = r2nm_get_node_by_num(r2nm_this_node());
-	BUG_ON(!local_node);
-
-	r2nm_undepend_item(&local_node->nd_item);
-	r2nm_node_put(local_node);
-}
-
-
-static void __exit exit_r2nm(void)
-{
-	/* XXX sync with hb callbacks and shut down hb? */
-	r2net_unregister_hb_callbacks();
-	configfs_unregister_subsystem(&r2nm_cluster_group.cs_subsys);
-
-	r2net_exit();
-	r2hb_exit();
-}
-
-int r2nm_init(void)
-{
-	int ret = -1;
-
-	ret = r2hb_init();
-	if (ret)
-		goto out;
-
-	ret = r2net_init();
-	if (ret)
-		goto out_r2hb;
-
-	ret = r2net_register_hb_callbacks();
-	if (ret)
-		goto out_r2net;
-
-	config_group_init(&r2nm_cluster_group.cs_subsys.su_group);
-	mutex_init(&r2nm_cluster_group.cs_subsys.su_mutex);
-	ret = configfs_register_subsystem(&r2nm_cluster_group.cs_subsys);
-	if (ret) {
-		pr_err("nodemanager: Registration returned %d\n", ret);
-		goto out_callbacks;
-	}
-
-	if (!ret)
-		goto out;
-
-	configfs_unregister_subsystem(&r2nm_cluster_group.cs_subsys);
-out_callbacks:
-	r2net_unregister_hb_callbacks();
-out_r2net:
-	r2net_exit();
-out_r2hb:
-	r2hb_exit();
-out:
-	return ret;
-}
-EXPORT_SYMBOL_GPL(r2nm_init);
-
-MODULE_AUTHOR("Oracle");
-MODULE_LICENSE("GPL");
-
-#ifndef CONFIG_RAMSTER_MODULE
-late_initcall(r2nm_init);
-#endif

drivers/staging/zcache/ramster/nodemanager.h

@@ -1,88 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * nodemanager.h
- *
- * Function prototypes
- *
- * Copyright (C) 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- */
-
-#ifndef R2CLUSTER_NODEMANAGER_H
-#define R2CLUSTER_NODEMANAGER_H
-
-#include "ramster_nodemanager.h"
-
-/* This totally doesn't belong here. */
-#include <linux/configfs.h>
-#include <linux/rbtree.h>
-
-enum r2nm_fence_method {
-	R2NM_FENCE_RESET	= 0,
-	R2NM_FENCE_PANIC,
-	R2NM_FENCE_METHODS,	/* Number of fence methods */
-};
-
-struct r2nm_node {
-	spinlock_t		nd_lock;
-	struct config_item	nd_item;
-	char			nd_name[R2NM_MAX_NAME_LEN+1]; /* replace? */
-	__u8			nd_num;
-	/* only one address per node, as attributes, for now. */
-	__be32			nd_ipv4_address;
-	__be16			nd_ipv4_port;
-	struct rb_node		nd_ip_node;
-	/* there can be only one local node for now */
-	int			nd_local;
-
-	unsigned long		nd_set_attributes;
-};
-
-struct r2nm_cluster {
-	struct config_group	cl_group;
-	unsigned		cl_has_local:1;
-	u8			cl_local_node;
-	rwlock_t		cl_nodes_lock;
-	struct r2nm_node	*cl_nodes[R2NM_MAX_NODES];
-	struct rb_root		cl_node_ip_tree;
-	unsigned int		cl_idle_timeout_ms;
-	unsigned int		cl_keepalive_delay_ms;
-	unsigned int		cl_reconnect_delay_ms;
-	enum r2nm_fence_method	cl_fence_method;
-
-	/* part of a hack for disk bitmap.. will go eventually. - zab */
-	unsigned long	cl_nodes_bitmap[BITS_TO_LONGS(R2NM_MAX_NODES)];
-};
-
-extern struct r2nm_cluster *r2nm_single_cluster;
-
-u8 r2nm_this_node(void);
-
-int r2nm_configured_node_map(unsigned long *map, unsigned bytes);
-struct r2nm_node *r2nm_get_node_by_num(u8 node_num);
-struct r2nm_node *r2nm_get_node_by_ip(__be32 addr);
-void r2nm_node_get(struct r2nm_node *node);
-void r2nm_node_put(struct r2nm_node *node);
-
-int r2nm_depend_item(struct config_item *item);
-void r2nm_undepend_item(struct config_item *item);
-int r2nm_depend_this_node(void);
-void r2nm_undepend_this_node(void);
-
-#endif /* R2CLUSTER_NODEMANAGER_H */

drivers/staging/zcache/ramster/r2net.c

@@ -1,414 +0,0 @@
-/*
- * r2net.c
- *
- * Copyright (c) 2011-2012, Dan Magenheimer, Oracle Corp.
- *
- * Ramster_r2net provides an interface between zcache and r2net.
- *
- * FIXME: support more than two nodes
- */
-
-#include <linux/list.h>
-#include "tcp.h"
-#include "nodemanager.h"
-#include "../tmem.h"
-#include "../zcache.h"
-#include "ramster.h"
-
-#define RAMSTER_TESTING
-
-#define RMSTR_KEY	0x77347734
-
-enum {
-	RMSTR_TMEM_PUT_EPH = 100,
-	RMSTR_TMEM_PUT_PERS,
-	RMSTR_TMEM_ASYNC_GET_REQUEST,
-	RMSTR_TMEM_ASYNC_GET_AND_FREE_REQUEST,
-	RMSTR_TMEM_ASYNC_GET_REPLY,
-	RMSTR_TMEM_FLUSH,
-	RMSTR_TMEM_FLOBJ,
-	RMSTR_TMEM_DESTROY_POOL,
-};
-
-#define RMSTR_R2NET_MAX_LEN \
-		(R2NET_MAX_PAYLOAD_BYTES - sizeof(struct tmem_xhandle))
-
-#include "tcp_internal.h"
-
-static struct r2nm_node *r2net_target_node;
-static int r2net_target_nodenum;
-
-int r2net_remote_target_node_set(int node_num)
-{
-	int ret = -1;
-
-	r2net_target_node = r2nm_get_node_by_num(node_num);
-	if (r2net_target_node != NULL) {
-		r2net_target_nodenum = node_num;
-		r2nm_node_put(r2net_target_node);
-		ret = 0;
-	}
-	return ret;
-}
-
-/* FIXME following buffer should be per-cpu, protected by preempt_disable */
-static char ramster_async_get_buf[R2NET_MAX_PAYLOAD_BYTES];
-
-static int ramster_remote_async_get_request_handler(struct r2net_msg *msg,
-				u32 len, void *data, void **ret_data)
-{
-	char *pdata;
-	struct tmem_xhandle xh;
-	int found;
-	size_t size = RMSTR_R2NET_MAX_LEN;
-	u16 msgtype = be16_to_cpu(msg->msg_type);
-	bool get_and_free = (msgtype == RMSTR_TMEM_ASYNC_GET_AND_FREE_REQUEST);
-	unsigned long flags;
-
-	xh = *(struct tmem_xhandle *)msg->buf;
-	if (xh.xh_data_size > RMSTR_R2NET_MAX_LEN)
-		BUG();
-	pdata = ramster_async_get_buf;
-	*(struct tmem_xhandle *)pdata = xh;
-	pdata += sizeof(struct tmem_xhandle);
-	local_irq_save(flags);
-	found = zcache_get_page(xh.client_id, xh.pool_id, &xh.oid, xh.index,
-				pdata, &size, true, get_and_free ? 1 : -1);
-	local_irq_restore(flags);
-	if (found < 0) {
-		/* a zero size indicates the get failed */
-		size = 0;
-	}
-	if (size > RMSTR_R2NET_MAX_LEN)
-		BUG();
-	*ret_data = pdata - sizeof(struct tmem_xhandle);
-	/* now make caller (r2net_process_message) handle specially */
-	r2net_force_data_magic(msg, RMSTR_TMEM_ASYNC_GET_REPLY, RMSTR_KEY);
-	return size + sizeof(struct tmem_xhandle);
-}
-
-static int ramster_remote_async_get_reply_handler(struct r2net_msg *msg,
-				u32 len, void *data, void **ret_data)
-{
-	char *in = (char *)msg->buf;
-	int datalen = len - sizeof(struct r2net_msg);
-	int ret = -1;
-	struct tmem_xhandle *xh = (struct tmem_xhandle *)in;
-
-	in += sizeof(struct tmem_xhandle);
-	datalen -= sizeof(struct tmem_xhandle);
-	BUG_ON(datalen < 0 || datalen > PAGE_SIZE);
-	ret = ramster_localify(xh->pool_id, &xh->oid, xh->index,
-				in, datalen, xh->extra);
-#ifdef RAMSTER_TESTING
-	if (ret == -EEXIST)
-		pr_err("TESTING ArrgREP, aborted overwrite on racy put\n");
-#endif
-	return ret;
-}
-
-int ramster_remote_put_handler(struct r2net_msg *msg,
-				u32 len, void *data, void **ret_data)
-{
-	struct tmem_xhandle *xh;
-	char *p = (char *)msg->buf;
-	int datalen = len - sizeof(struct r2net_msg) -
-				sizeof(struct tmem_xhandle);
-	u16 msgtype = be16_to_cpu(msg->msg_type);
-	bool ephemeral = (msgtype == RMSTR_TMEM_PUT_EPH);
-	unsigned long flags;
-	int ret;
-
-	xh = (struct tmem_xhandle *)p;
-	p += sizeof(struct tmem_xhandle);
-	zcache_autocreate_pool(xh->client_id, xh->pool_id, ephemeral);
-	local_irq_save(flags);
-	ret = zcache_put_page(xh->client_id, xh->pool_id, &xh->oid, xh->index,
-				p, datalen, true, ephemeral);
-	local_irq_restore(flags);
-	return ret;
-}
-
-int ramster_remote_flush_handler(struct r2net_msg *msg,
-				u32 len, void *data, void **ret_data)
-{
-	struct tmem_xhandle *xh;
-	char *p = (char *)msg->buf;
-
-	xh = (struct tmem_xhandle *)p;
-	p += sizeof(struct tmem_xhandle);
-	(void)zcache_flush_page(xh->client_id, xh->pool_id,
-					&xh->oid, xh->index);
-	return 0;
-}
-
-int ramster_remote_flobj_handler(struct r2net_msg *msg,
-				u32 len, void *data, void **ret_data)
-{
-	struct tmem_xhandle *xh;
-	char *p = (char *)msg->buf;
-
-	xh = (struct tmem_xhandle *)p;
-	p += sizeof(struct tmem_xhandle);
-	(void)zcache_flush_object(xh->client_id, xh->pool_id, &xh->oid);
-	return 0;
-}
-
-int r2net_remote_async_get(struct tmem_xhandle *xh, bool free, int remotenode,
-				size_t expect_size, uint8_t expect_cksum,
-				void *extra)
-{
-	int nodenum, ret = -1, status;
-	struct r2nm_node *node = NULL;
-	struct kvec vec[1];
-	size_t veclen = 1;
-	u32 msg_type;
-	struct r2net_node *nn;
-
-	node = r2nm_get_node_by_num(remotenode);
-	if (node == NULL)
-		goto out;
-	xh->client_id = r2nm_this_node(); /* which node is getting */
-	xh->xh_data_cksum = expect_cksum;
-	xh->xh_data_size = expect_size;
-	xh->extra = extra;
-	vec[0].iov_len = sizeof(*xh);
-	vec[0].iov_base = xh;
-
-	node = r2net_target_node;
-	if (!node)
-		goto out;
-
-	nodenum = r2net_target_nodenum;
-
-	r2nm_node_get(node);
-	nn = r2net_nn_from_num(nodenum);
-	if (nn->nn_persistent_error || !nn->nn_sc_valid) {
-		ret = -ENOTCONN;
-		r2nm_node_put(node);
-		goto out;
-	}
-
-	if (free)
-		msg_type = RMSTR_TMEM_ASYNC_GET_AND_FREE_REQUEST;
-	else
-		msg_type = RMSTR_TMEM_ASYNC_GET_REQUEST;
-	ret = r2net_send_message_vec(msg_type, RMSTR_KEY,
-					vec, veclen, remotenode, &status);
-	r2nm_node_put(node);
-	if (ret < 0) {
-		if (ret == -ENOTCONN || ret == -EHOSTDOWN)
-			goto out;
-		if (ret == -EAGAIN)
-			goto out;
-		/* FIXME handle bad message possibilities here? */
-		pr_err("UNTESTED ret<0 in ramster_remote_async_get: ret=%d\n",
-				ret);
-	}
-	ret = status;
-out:
-	return ret;
-}
-
-#ifdef RAMSTER_TESTING
-/* leave me here to see if it catches a weird crash */
-static void ramster_check_irq_counts(void)
-{
-	static int last_hardirq_cnt, last_softirq_cnt, last_preempt_cnt;
-	int cur_hardirq_cnt, cur_softirq_cnt, cur_preempt_cnt;
-
-	cur_hardirq_cnt = hardirq_count() >> HARDIRQ_SHIFT;
-	if (cur_hardirq_cnt > last_hardirq_cnt) {
-		last_hardirq_cnt = cur_hardirq_cnt;
-		if (!(last_hardirq_cnt&(last_hardirq_cnt-1)))
-			pr_err("RAMSTER TESTING RRP hardirq_count=%d\n",
-				last_hardirq_cnt);
-	}
-	cur_softirq_cnt = softirq_count() >> SOFTIRQ_SHIFT;
-	if (cur_softirq_cnt > last_softirq_cnt) {
-		last_softirq_cnt = cur_softirq_cnt;
-		if (!(last_softirq_cnt&(last_softirq_cnt-1)))
-			pr_err("RAMSTER TESTING RRP softirq_count=%d\n",
-				last_softirq_cnt);
-	}
-	cur_preempt_cnt = preempt_count() & PREEMPT_MASK;
-	if (cur_preempt_cnt > last_preempt_cnt) {
-		last_preempt_cnt = cur_preempt_cnt;
-		if (!(last_preempt_cnt&(last_preempt_cnt-1)))
-			pr_err("RAMSTER TESTING RRP preempt_count=%d\n",
-				last_preempt_cnt);
-	}
-}
-#endif
-
-int r2net_remote_put(struct tmem_xhandle *xh, char *data, size_t size,
-				bool ephemeral, int *remotenode)
-{
-	int nodenum, ret = -1, status;
-	struct r2nm_node *node = NULL;
-	struct kvec vec[2];
-	size_t veclen = 2;
-	u32 msg_type;
-	struct r2net_node *nn;
-
-	BUG_ON(size > RMSTR_R2NET_MAX_LEN);
-	xh->client_id = r2nm_this_node(); /* which node is putting */
-	vec[0].iov_len = sizeof(*xh);
-	vec[0].iov_base = xh;
-	vec[1].iov_len = size;
-	vec[1].iov_base = data;
-
-	node = r2net_target_node;
-	if (!node)
-		goto out;
-
-	nodenum = r2net_target_nodenum;
-
-	r2nm_node_get(node);
-
-	nn = r2net_nn_from_num(nodenum);
-	if (nn->nn_persistent_error || !nn->nn_sc_valid) {
-		ret = -ENOTCONN;
-		r2nm_node_put(node);
-		goto out;
-	}
-
-	if (ephemeral)
-		msg_type = RMSTR_TMEM_PUT_EPH;
-	else
-		msg_type = RMSTR_TMEM_PUT_PERS;
-#ifdef RAMSTER_TESTING
-	/* leave me here to see if it catches a weird crash */
-	ramster_check_irq_counts();
-#endif
-
-	ret = r2net_send_message_vec(msg_type, RMSTR_KEY, vec, veclen,
-						nodenum, &status);
-	if (ret < 0)
-		ret = -1;
-	else {
-		ret = status;
-		*remotenode = nodenum;
-	}
-
-	r2nm_node_put(node);
-out:
-	return ret;
-}
-
-int r2net_remote_flush(struct tmem_xhandle *xh, int remotenode)
-{
-	int ret = -1, status;
-	struct r2nm_node *node = NULL;
-	struct kvec vec[1];
-	size_t veclen = 1;
-
-	node = r2nm_get_node_by_num(remotenode);
-	BUG_ON(node == NULL);
-	xh->client_id = r2nm_this_node(); /* which node is flushing */
-	vec[0].iov_len = sizeof(*xh);
-	vec[0].iov_base = xh;
-	BUG_ON(irqs_disabled());
-	BUG_ON(in_softirq());
-	ret = r2net_send_message_vec(RMSTR_TMEM_FLUSH, RMSTR_KEY,
-					vec, veclen, remotenode, &status);
-	r2nm_node_put(node);
-	return ret;
-}
-
-int r2net_remote_flush_object(struct tmem_xhandle *xh, int remotenode)
-{
-	int ret = -1, status;
-	struct r2nm_node *node = NULL;
-	struct kvec vec[1];
-	size_t veclen = 1;
-
-	node = r2nm_get_node_by_num(remotenode);
-	BUG_ON(node == NULL);
-	xh->client_id = r2nm_this_node(); /* which node is flobjing */
-	vec[0].iov_len = sizeof(*xh);
-	vec[0].iov_base = xh;
-	ret = r2net_send_message_vec(RMSTR_TMEM_FLOBJ, RMSTR_KEY,
-					vec, veclen, remotenode, &status);
-	r2nm_node_put(node);
-	return ret;
-}
-
-/*
- * Handler registration
- */
-
-static LIST_HEAD(r2net_unreg_list);
-
-static void r2net_unregister_handlers(void)
-{
-	r2net_unregister_handler_list(&r2net_unreg_list);
-}
-
-int r2net_register_handlers(void)
-{
-	int status;
-
-	status = r2net_register_handler(RMSTR_TMEM_PUT_EPH, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_put_handler,
-				NULL, NULL, &r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_PUT_PERS, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_put_handler,
-				NULL, NULL, &r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_ASYNC_GET_REQUEST, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_async_get_request_handler,
-				NULL, NULL,
-				&r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_ASYNC_GET_AND_FREE_REQUEST,
-				RMSTR_KEY, RMSTR_R2NET_MAX_LEN,
-				ramster_remote_async_get_request_handler,
-				NULL, NULL,
-				&r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_ASYNC_GET_REPLY, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_async_get_reply_handler,
-				NULL, NULL,
-				&r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_FLUSH, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_flush_handler,
-				NULL, NULL,
-				&r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	status = r2net_register_handler(RMSTR_TMEM_FLOBJ, RMSTR_KEY,
-				RMSTR_R2NET_MAX_LEN,
-				ramster_remote_flobj_handler,
-				NULL, NULL,
-				&r2net_unreg_list);
-	if (status)
-		goto bail;
-
-	pr_info("ramster: r2net handlers registered\n");
-
-bail:
-	if (status) {
-		r2net_unregister_handlers();
-		pr_err("ramster: couldn't register r2net handlers\n");
-	}
-	return status;
-}

drivers/staging/zcache/ramster/ramster-howto.txt

@@ -1,366 +0,0 @@
-			RAMSTER HOW-TO
-
-Author: Dan Magenheimer
-Ramster maintainer: Konrad Wilk <konrad.wilk@oracle.com>
-
-This is a HOWTO document for ramster which, as of this writing, is in
-the kernel as a subdirectory of zcache in drivers/staging, called ramster.
-(Zcache can be built with or without ramster functionality.)  If enabled
-and properly configured, ramster allows memory capacity load balancing
-across multiple machines in a cluster.  Further, the ramster code serves
-as an example of asynchronous access for zcache (as well as cleancache and
-frontswap) that may prove useful for future transcendent memory
-implementations, such as KVM and NVRAM.  While ramster works today on
-any network connection that supports kernel sockets, its features may
-become more interesting on future high-speed fabrics/interconnects.
-
-Ramster requires both kernel and userland support.  The userland support,
-called ramster-tools, is known to work with EL6-based distros, but is a
-set of poorly-hacked slightly-modified cluster tools based on ocfs2, which
-includes an init file, a config file, and a userland binary that interfaces
-to the kernel.  This state of userland support reflects the abysmal userland
-skills of this suitably-embarrassed author; any help/patches to turn
-ramster-tools into more distributable rpms/debs useful for a wider range
-of distros would be appreciated.  The source RPM that can be used as a
-starting point is available at:
-    http://oss.oracle.com/projects/tmem/files/RAMster/ 
-
-As a result of this author's ignorance, userland setup described in this
-HOWTO assumes an EL6 distro and is described in EL6 syntax.  Apologies
-if this offends anyone!
-
-Kernel support has only been tested on x86_64.  Systems with an active
-ocfs2 filesystem should work, but since ramster leverages a lot of
-code from ocfs2, there may be latent issues.  A kernel configuration that
-includes CONFIG_OCFS2_FS should build OK, and should certainly run OK
-if no ocfs2 filesystem is mounted.
-
-This HOWTO demonstrates memory capacity load balancing for a two-node
-cluster, where one node called the "local" node becomes overcommitted
-and the other node called the "remote" node provides additional RAM
-capacity for use by the local node.  Ramster is capable of more complex
-topologies; see the last section titled "ADVANCED RAMSTER TOPOLOGIES".
-
-If you find any terms in this HOWTO unfamiliar or don't understand the
-motivation for ramster, the following LWN reading is recommended:
--- Transcendent Memory in a Nutshell (lwn.net/Articles/454795)
--- The future calculus of memory management (lwn.net/Articles/475681)
-And since ramster is built on top of zcache, this article may be helpful:
--- In-kernel memory compression (lwn.net/Articles/545244)
-
-Now that you've memorized the contents of those articles, let's get started!
-
-A. PRELIMINARY
-
-1) Install two x86_64 Linux systems that are known to work when
-   upgraded to a recent upstream Linux kernel version.
-
-On each system:
-
-2) Configure, build and install, then boot Linux, just to ensure it
-   can be done with an unmodified upstream kernel.  Confirm you booted
-   the upstream kernel with "uname -a".
-
-3) If you plan to do any performance testing or unless you plan to
-   test only swapping, the "WasActive" patch is also highly recommended.
-   (Search lkml.org for WasActive, apply the patch, rebuild your kernel.)
-   For a demo or simple testing, the patch can be ignored.
-
-4) Install ramster-tools as root.  An x86_64 rpm for EL6-based systems
-   can be found at:
-    http://oss.oracle.com/projects/tmem/files/RAMster/ 
-   (Sorry but for now, non-EL6 users must recreate ramster-tools on
-   their own from source.  See above.)
-
-5) Ensure that debugfs is mounted at each boot.  Examples below assume it
-   is mounted at /sys/kernel/debug.
-
-B. BUILDING RAMSTER INTO THE KERNEL
-
-Do the following on each system:
-
-1) Using the kernel configuration mechanism of your choice, change
-   your config to include:
-
-	CONFIG_CLEANCACHE=y
-	CONFIG_FRONTSWAP=y
-	CONFIG_STAGING=y
-	CONFIG_CONFIGFS_FS=y # NOTE: MUST BE y, not m
-	CONFIG_ZCACHE=y
-	CONFIG_RAMSTER=y
-
-   For a linux-3.10 or later kernel, you should also set:
-
-	CONFIG_ZCACHE_DEBUG=y
-	CONFIG_RAMSTER_DEBUG=y
-
-   Before building the kernel please doublecheck your kernel config
-   file to ensure all of the settings are correct.
-
-2) Build this kernel and change your boot file (e.g. /etc/grub.conf)
-   so that the new kernel will boot.
-
-3) Add "zcache" and "ramster" as kernel boot parameters for the new kernel.
-
-4) Reboot each system approximately simultaneously.
-
-5) Check dmesg to ensure there are some messages from ramster, prefixed
-   by "ramster:"
-
-	# dmesg | grep ramster
-
-   You should also see a lot of files in:
-
-	# ls /sys/kernel/debug/zcache
-	# ls /sys/kernel/debug/ramster
-
-   These are mostly counters for various zcache and ramster activities.
-   You should also see files in:
-
-	# ls /sys/kernel/mm/ramster
-
-   These are sysfs files that control ramster as we shall see.
-
-   Ramster now will act as a single-system zcache on each system
-   but doesn't yet know anything about the cluster so can't yet do
-   anything remotely.
-
-C. CONFIGURING THE RAMSTER CLUSTER
-
-This part can be error prone unless you are familiar with clustering
-filesystems.  We need to describe the cluster in a /etc/ramster.conf
-file and the init scripts that parse it are extremely picky about
-the syntax.
-
-1) Create a /etc/ramster.conf file and ensure it is identical on both
-   systems.  This file mimics the ocfs2 format and there is a good amount
-   of documentation that can be searched for ocfs2.conf, but you can use:
-
-	cluster:
-		name = ramster
-		node_count = 2
-	node:
-		name = system1
-		cluster = ramster
-		number = 0
-		ip_address = my.ip.ad.r1
-		ip_port = 7777
-	node:
-		name = system2
-		cluster = ramster
-		number = 1
-		ip_address = my.ip.ad.r2
-		ip_port = 7777
-
-   You must ensure that the "name" field in the file exactly matches
-   the output of "hostname" on each system; if "hostname" shows a
-   fully-qualified hostname, ensure the name is fully qualified in
-   /etc/ramster.conf.  Obviously, substitute my.ip.ad.rx with proper
-   ip addresses.
-
-2) Enable the ramster service and configure it.  If you used the
-   EL6 ramster-tools, this would be:
-
-	# chkconfig --add ramster
-	# service ramster configure
-
-   Set "load on boot" to "y", cluster to start is "ramster" (or whatever
-   name you chose in ramster.conf), heartbeat dead threshold as "500",
-   network idle timeout as "1000000".  Leave the others as default.
-
-3) Reboot both systems.  After reboot, try (assuming EL6 ramster-tools):
-
-	# service ramster status
-
-   You should see "Checking RAMSTER cluster "ramster": Online".  If you do
-   not, something is wrong and ramster will not work.  Note that you
-   should also see that the driver for "configfs" is loaded and mounted,
-   the driver for ocfs2_dlmfs is not loaded, and some numbers for network
-   parameters.  You will also see "Checking RAMSTER heartbeat: Not active".
-   That's all OK.
-
-4) Now you need to start the cluster heartbeat; the cluster is not "up"
-   until all nodes detect a heartbeat.  In a real cluster, heartbeat detection
-   is done via a cluster filesystem, but ramster doesn't require one.  Some
-   hack-y kernel code in ramster can start the heartbeat for you though if
-   you tell it what nodes are "up".  To enable the heartbeat, do:
-
-	# echo 0 > /sys/kernel/mm/ramster/manual_node_up
-	# echo 1 > /sys/kernel/mm/ramster/manual_node_up
-
-   This must be done on BOTH nodes and, to avoid timeouts, must be done
-   approximately concurrently on both nodes.  On an EL6 system, it is
-   convenient to put these lines in /etc/rc.local.  To confirm that the
-   cluster is now up, on both systems do:
-
-	# dmesg | grep ramster
-
-   You should see ramster "Accepted connection" messages in dmesg on both
-   nodes after this.  Note that if you check userland status again with
-
-	# service ramster status
-
-   you will still see "Checking RAMSTER heartbeat: Not active".  That's
-   still OK... the ramster kernel heartbeat hack doesn't communicate to
-   userland.
-
-5) You now must tell each node the node to which it should "remotify" pages.
-   On this two node cluster, we will assume the "local" node, node 0, has
-   memory overcommitted and will use ramster to utilize RAM capacity on
-   the "remote node", node 1.  To configure this, on node 0, you do:
-
-	# echo 1 > /sys/kernel/mm/ramster/remote_target_nodenum
-
-   You should see "ramster: node 1 set as remotification target" in dmesg
-   on node 0.  Again, on EL6, /etc/rc.local is a good place to put this
-   on node 0 so you don't forget to do it at each boot.
-
-6) One more step:  By default, the ramster code does not "remotify" any
-   pages; this is primarily for testing purposes, but sometimes it is
-   useful.  This may change in the future, but for now, on node 0, you do:
-
-	# echo 1 > /sys/kernel/mm/ramster/pers_remotify_enable
-	# echo 1 > /sys/kernel/mm/ramster/eph_remotify_enable
-
-   The first enables remotifying swap (persistent, aka frontswap) pages,
-   the second enables remotifying of page cache (ephemeral, cleancache)
-   pages.
-
-   On EL6, these lines can also be put in /etc/rc.local (AFTER the
-   node_up lines), or at the beginning of a script that runs a workload.
-
-7) Note that most testing has been done with both/all machines booted
-   roughly simultaneously to avoid cluster timeouts.  Ideally, you should
-   do this too unless you are trying to break ramster rather than just
-   use it. ;-)
-
-D. TESTING RAMSTER
-
-1) Note that ramster has no value unless pages get "remotified".  For
-   swap/frontswap/persistent pages, this doesn't happen unless/until
-   the workload would cause swapping to occur, at which point pages
-   are put into frontswap/zcache, and the remotification thread starts
-   working.  To get to the point where the system swaps, you either
-   need a workload for which the working set exceeds the RAM in the
-   system; or you need to somehow reduce the amount of RAM one of
-   the system sees.  This latter is easy when testing in a VM, but
-   harder on physical systems.  In some cases, "mem=xxxM" on the
-   kernel command line restricts memory, but for some values of xxx
-   the kernel may fail to boot.  One may also try creating a fixed
-   RAMdisk, doing nothing with it, but ensuring that it eats up a fixed
-   amount of RAM.
-
-2) To see if ramster is working, on the "remote node", node 1, try:
-
-	# grep . /sys/kernel/debug/ramster/foreign_*
-        # # note, that is space-dot-space between grep and the pathname
-
-   to monitor the number (and max) ephemeral and persistent pages
-   that ramster has sent.  If these stay at zero, ramster is not working
-   either because the workload on the local node (node 0) isn't creating
-   enough memory pressure or because "remotifying" isn't working.  On the
-   local system, node 0, you can watch lots of useful information also.
-   Try:
-
-	grep . /sys/kernel/debug/zcache/*pageframes* \
-		/sys/kernel/debug/zcache/*zbytes* \
-		/sys/kernel/debug/zcache/*zpages* \
-		/sys/kernel/debug/ramster/*remote*
-
-   Of particular note are the remote_*_pages_succ_get counters.  These
-   show how many disk reads and/or disk writes have been avoided on the
-   overcommitted local system by storing pages remotely using ramster.
-
-   At the risk of information overload, you can also grep:
-
-        /sys/kernel/debug/cleancache/* and /sys/kernel/debug/frontswap/*
-
-   These show, for example, how many disk reads and/or disk writes have
-   been avoided by using zcache to optimize RAM on the local system.
-
-
-AUTOMATIC SWAP REPATRIATION
-
-You may notice that while the systems are idle, the foreign persistent
-page count on the remote machine slowly decreases.  This is because
-ramster implements "frontswap selfshrinking":  When possible, swap
-pages that have been remotified are slowly repatriated to the local
-machine.  This is so that local RAM can be used when possible and
-so that, in case of remote machine crash, the probability of loss
-of data is reduced.
-
-REBOOTING / POWEROFF
-
-If a system is shut down while some of its swap pages still reside
-on a remote system, the system may lock up during the shutdown
-sequence.  This will occur if the network is shut down before the
-swap mechansim is shut down, which is the default ordering on many
-distros.  To avoid this annoying problem, simply shut off the swap
-subsystem before starting the shutdown sequence, e.g.:
-
-	# swapoff -a
-	# reboot
-
-Ideally, this swapoff-before-ifdown ordering should be enforced permanently
-using shutdown scripts.
-
-KNOWN PROBLEMS
-
-1) You may periodically see messages such as:
-
-    ramster_r2net, message length problem
-
-   This is harmless but indicates that a node is sending messages
-   containing compressed pages that exceed the maximum for zcache
-   (PAGE_SIZE*15/16).  The sender side needs to be fixed.
-
-2) If you see a "No longer connected to node..." message or a "No connection
-   established with node X after N seconds", it is possible you may
-   be in an unrecoverable state.  If you are certain all of the
-   appropriate cluster configuration steps described above have been
-   performed, try rebooting the two servers concurrently to see if
-   the cluster starts.
-
-   Note that "Connection to node... shutdown, state 7" is an intermediate
-   connection state.  As long as you later see "Accepted connection", the
-   intermediate states are harmless.
-
-3) There are known issues in counting certain values.  As a result
-   you may see periodic warnings from the kernel.  Almost always you
-   will see "ramster: bad accounting for XXX".  There are also "WARN_ONCE"
-   messages.  If you see kernel warnings with a tombstone, please report
-   them.  They are harmless but reflect bugs that need to be eventually fixed.
-
-ADVANCED RAMSTER TOPOLOGIES
-
-The kernel code for ramster can support up to eight nodes in a cluster,
-but no testing has been done with more than three nodes.
-
-In the example described above, the "remote" node serves as a RAM
-overflow for the "local" node.  This can be made symmetric by appropriate
-settings of the sysfs remote_target_nodenum file.  For example, by setting:
-
-	# echo 1 > /sys/kernel/mm/ramster/remote_target_nodenum
-
-on node 0, and
-
-	# echo 0 > /sys/kernel/mm/ramster/remote_target_nodenum
-
-on node 1, each node can serve as a RAM overflow for the other.
-
-For more than two nodes, a "RAM server" can be configured.  For a
-three node system, set:
-
-	# echo 0 > /sys/kernel/mm/ramster/remote_target_nodenum
-
-on node 1, and
-
-	# echo 0 > /sys/kernel/mm/ramster/remote_target_nodenum
-
-on node 2.  Then node 0 is a RAM server for node 1 and node 2.
-
-In this implementation of ramster, any remote node is potentially a single
-point of failure (SPOF).  Though the probability of failure is reduced
-by automatic swap repatriation (see above), a proposed future enhancement
-to ramster improves high-availability for the cluster by sending a copy
-of each page of date to two other nodes.  Patches welcome!

drivers/staging/zcache/ramster/ramster.c

@@ -1,925 +0,0 @@
-/*
- * ramster.c
- *
- * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
- *
- * RAMster implements peer-to-peer transcendent memory, allowing a "cluster" of
- * kernels to dynamically pool their RAM so that a RAM-hungry workload on one
- * machine can temporarily and transparently utilize RAM on another machine
- * which is presumably idle or running a non-RAM-hungry workload.
- *
- * RAMster combines a clustering and messaging foundation based on the ocfs2
- * cluster layer with the in-kernel compression implementation of zcache, and
- * adds code to glue them together.  When a page is "put" to RAMster, it is
- * compressed and stored locally.  Periodically, a thread will "remotify" these
- * pages by sending them via messages to a remote machine.  When the page is
- * later needed as indicated by a page fault, a "get" is issued.  If the data
- * is local, it is uncompressed and the fault is resolved.  If the data is
- * remote, a message is sent to fetch the data and the faulting thread sleeps;
- * when the data arrives, the thread awakens, the data is decompressed and
- * the fault is resolved.
-
- * As of V5, clusters up to eight nodes are supported; each node can remotify
- * pages to one specified node, so clusters can be configured as clients to
- * a "memory server".  Some simple policy is in place that will need to be
- * refined over time.  Larger clusters and fault-resistant protocols can also
- * be added over time.
- */
-
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/highmem.h>
-#include <linux/list.h>
-#include <linux/lzo.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/types.h>
-#include <linux/atomic.h>
-#include <linux/frontswap.h>
-#include "../tmem.h"
-#include "../zcache.h"
-#include "../zbud.h"
-#include "ramster.h"
-#include "ramster_nodemanager.h"
-#include "tcp.h"
-#include "debug.h"
-
-#define RAMSTER_TESTING
-
-#ifndef CONFIG_SYSFS
-#error "ramster needs sysfs to define cluster nodes to use"
-#endif
-
-static bool use_cleancache __read_mostly;
-static bool use_frontswap __read_mostly;
-static bool use_frontswap_exclusive_gets __read_mostly;
-
-/* These must be sysfs not debugfs as they are checked/used by userland!! */
-static unsigned long ramster_interface_revision __read_mostly =
-	R2NM_API_VERSION; /* interface revision must match userspace! */
-static unsigned long ramster_pers_remotify_enable __read_mostly;
-static unsigned long ramster_eph_remotify_enable __read_mostly;
-static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0);
-#define MANUAL_NODES 8
-static bool ramster_nodes_manual_up[MANUAL_NODES] __read_mostly;
-static int ramster_remote_target_nodenum __read_mostly = -1;
-
-/* Used by this code. */
-long ramster_flnodes;
-/* FIXME frontswap selfshrinking knobs in debugfs? */
-
-static LIST_HEAD(ramster_rem_op_list);
-static DEFINE_SPINLOCK(ramster_rem_op_list_lock);
-static DEFINE_PER_CPU(struct ramster_preload, ramster_preloads);
-
-static DEFINE_PER_CPU(unsigned char *, ramster_remoteputmem1);
-static DEFINE_PER_CPU(unsigned char *, ramster_remoteputmem2);
-
-static struct kmem_cache *ramster_flnode_cache __read_mostly;
-
-static struct flushlist_node *ramster_flnode_alloc(struct tmem_pool *pool)
-{
-	struct flushlist_node *flnode = NULL;
-	struct ramster_preload *kp;
-
-	kp = &__get_cpu_var(ramster_preloads);
-	flnode = kp->flnode;
-	BUG_ON(flnode == NULL);
-	kp->flnode = NULL;
-	inc_ramster_flnodes();
-	return flnode;
-}
-
-/* the "flush list" asynchronously collects pages to remotely flush */
-#define FLUSH_ENTIRE_OBJECT ((uint32_t)-1)
-static void ramster_flnode_free(struct flushlist_node *flnode,
-				struct tmem_pool *pool)
-{
-	dec_ramster_flnodes();
-	BUG_ON(ramster_flnodes < 0);
-	kmem_cache_free(ramster_flnode_cache, flnode);
-}
-
-int ramster_do_preload_flnode(struct tmem_pool *pool)
-{
-	struct ramster_preload *kp;
-	struct flushlist_node *flnode;
-	int ret = -ENOMEM;
-
-	BUG_ON(!irqs_disabled());
-	if (unlikely(ramster_flnode_cache == NULL))
-		BUG();
-	kp = &__get_cpu_var(ramster_preloads);
-	flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC);
-	if (unlikely(flnode == NULL) && kp->flnode == NULL)
-		BUG();  /* FIXME handle more gracefully, but how??? */
-	else if (kp->flnode == NULL)
-		kp->flnode = flnode;
-	else
-		kmem_cache_free(ramster_flnode_cache, flnode);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(ramster_do_preload_flnode);
-
-/*
- * Called by the message handler after a (still compressed) page has been
- * fetched from the remote machine in response to an "is_remote" tmem_get
- * or persistent tmem_localify.  For a tmem_get, "extra" is the address of
- * the page that is to be filled to successfully resolve the tmem_get; for
- * a (persistent) tmem_localify, "extra" is NULL (as the data is placed only
- * in the local zcache).  "data" points to "size" bytes of (compressed) data
- * passed in the message.  In the case of a persistent remote get, if
- * pre-allocation was successful (see ramster_repatriate_preload), the page
- * is placed into both local zcache and at "extra".
- */
-int ramster_localify(int pool_id, struct tmem_oid *oidp, uint32_t index,
-			char *data, unsigned int size, void *extra)
-{
-	int ret = -ENOENT;
-	unsigned long flags;
-	struct tmem_pool *pool;
-	bool eph, delete = false;
-	void *pampd, *saved_hb;
-	struct tmem_obj *obj;
-
-	pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id);
-	if (unlikely(pool == NULL))
-		/* pool doesn't exist anymore */
-		goto out;
-	eph = is_ephemeral(pool);
-	local_irq_save(flags);  /* FIXME: maybe only disable softirqs? */
-	pampd = tmem_localify_get_pampd(pool, oidp, index, &obj, &saved_hb);
-	if (pampd == NULL) {
-		/* hmmm... must have been a flush while waiting */
-#ifdef RAMSTER_TESTING
-		pr_err("UNTESTED pampd==NULL in ramster_localify\n");
-#endif
-		if (eph)
-			inc_ramster_remote_eph_pages_unsucc_get();
-		else
-			inc_ramster_remote_pers_pages_unsucc_get();
-		obj = NULL;
-		goto finish;
-	} else if (unlikely(!pampd_is_remote(pampd))) {
-		/* hmmm... must have been a dup put while waiting */
-#ifdef RAMSTER_TESTING
-		pr_err("UNTESTED dup while waiting in ramster_localify\n");
-#endif
-		if (eph)
-			inc_ramster_remote_eph_pages_unsucc_get();
-		else
-			inc_ramster_remote_pers_pages_unsucc_get();
-		obj = NULL;
-		pampd = NULL;
-		ret = -EEXIST;
-		goto finish;
-	} else if (size == 0) {
-		/* no remote data, delete the local is_remote pampd */
-		pampd = NULL;
-		if (eph)
-			inc_ramster_remote_eph_pages_unsucc_get();
-		else
-			BUG();
-		delete = true;
-		goto finish;
-	}
-	if (pampd_is_intransit(pampd)) {
-		/*
-		 *  a pampd is marked intransit if it is remote and space has
-		 *  been allocated for it locally (note, only happens for
-		 *  persistent pages, in which case the remote copy is freed)
-		 */
-		BUG_ON(eph);
-		pampd = pampd_mask_intransit_and_remote(pampd);
-		zbud_copy_to_zbud(pampd, data, size);
-	} else {
-		/*
-		 * setting pampd to NULL tells tmem_localify_finish to leave
-		 * pampd alone... meaning it is left pointing to the
-		 * remote copy
-		 */
-		pampd = NULL;
-		obj = NULL;
-	}
-	/*
-	 * but in all cases, we decompress direct-to-memory to complete
-	 * the remotify and return success
-	 */
-	BUG_ON(extra == NULL);
-	zcache_decompress_to_page(data, size, (struct page *)extra);
-	if (eph)
-		inc_ramster_remote_eph_pages_succ_get();
-	else
-		inc_ramster_remote_pers_pages_succ_get();
-	ret = 0;
-finish:
-	tmem_localify_finish(obj, index, pampd, saved_hb, delete);
-	zcache_put_pool(pool);
-	local_irq_restore(flags);
-out:
-	return ret;
-}
-
-void ramster_pampd_new_obj(struct tmem_obj *obj)
-{
-	obj->extra = NULL;
-}
-
-void ramster_pampd_free_obj(struct tmem_pool *pool, struct tmem_obj *obj,
-				bool pool_destroy)
-{
-	struct flushlist_node *flnode;
-
-	BUG_ON(preemptible());
-	if (obj->extra == NULL)
-		return;
-	if (pool_destroy && is_ephemeral(pool))
-		/* FIXME don't bother with remote eph data for now */
-		return;
-	BUG_ON(!pampd_is_remote(obj->extra));
-	flnode = ramster_flnode_alloc(pool);
-	flnode->xh.client_id = pampd_remote_node(obj->extra);
-	flnode->xh.pool_id = pool->pool_id;
-	flnode->xh.oid = obj->oid;
-	flnode->xh.index = FLUSH_ENTIRE_OBJECT;
-	flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_OBJ;
-	spin_lock(&ramster_rem_op_list_lock);
-	list_add(&flnode->rem_op.list, &ramster_rem_op_list);
-	spin_unlock(&ramster_rem_op_list_lock);
-}
-
-/*
- * Called on a remote persistent tmem_get to attempt to preallocate
- * local storage for the data contained in the remote persistent page.
- * If successfully preallocated, returns the pampd, marked as remote and
- * in_transit.  Else returns NULL.  Note that the appropriate tmem data
- * structure must be locked.
- */
-void *ramster_pampd_repatriate_preload(void *pampd, struct tmem_pool *pool,
-					struct tmem_oid *oidp, uint32_t index,
-					bool *intransit)
-{
-	int clen = pampd_remote_size(pampd), c;
-	void *ret_pampd = NULL;
-	unsigned long flags;
-	struct tmem_handle th;
-
-	BUG_ON(!pampd_is_remote(pampd));
-	BUG_ON(is_ephemeral(pool));
-	if (use_frontswap_exclusive_gets)
-		/* don't need local storage */
-		goto out;
-	if (pampd_is_intransit(pampd)) {
-		/*
-		 * to avoid multiple allocations (and maybe a memory leak)
-		 * don't preallocate if already in the process of being
-		 * repatriated
-		 */
-		*intransit = true;
-		goto out;
-	}
-	*intransit = false;
-	local_irq_save(flags);
-	th.client_id = pampd_remote_node(pampd);
-	th.pool_id = pool->pool_id;
-	th.oid = *oidp;
-	th.index = index;
-	ret_pampd = zcache_pampd_create(NULL, clen, true, false, &th);
-	if (ret_pampd != NULL) {
-		/*
-		 *  a pampd is marked intransit if it is remote and space has
-		 *  been allocated for it locally (note, only happens for
-		 *  persistent pages, in which case the remote copy is freed)
-		 */
-		ret_pampd = pampd_mark_intransit(ret_pampd);
-		c = atomic_dec_return(&ramster_remote_pers_pages);
-		WARN_ON_ONCE(c < 0);
-	} else {
-		inc_ramster_pers_pages_remote_nomem();
-	}
-	local_irq_restore(flags);
-out:
-	return ret_pampd;
-}
-
-/*
- * Called on a remote tmem_get to invoke a message to fetch the page.
- * Might sleep so no tmem locks can be held.  "extra" is passed
- * all the way through the round-trip messaging to ramster_localify.
- */
-int ramster_pampd_repatriate(void *fake_pampd, void *real_pampd,
-				struct tmem_pool *pool,
-				struct tmem_oid *oid, uint32_t index,
-				bool free, void *extra)
-{
-	struct tmem_xhandle xh;
-	int ret;
-
-	if (pampd_is_intransit(real_pampd))
-		/* have local space pre-reserved, so free remote copy */
-		free = true;
-	xh = tmem_xhandle_fill(LOCAL_CLIENT, pool, oid, index);
-	/* unreliable request/response for now */
-	ret = r2net_remote_async_get(&xh, free,
-					pampd_remote_node(fake_pampd),
-					pampd_remote_size(fake_pampd),
-					pampd_remote_cksum(fake_pampd),
-					extra);
-	return ret;
-}
-
-bool ramster_pampd_is_remote(void *pampd)
-{
-	return pampd_is_remote(pampd);
-}
-
-int ramster_pampd_replace_in_obj(void *new_pampd, struct tmem_obj *obj)
-{
-	int ret = -1;
-
-	if (new_pampd != NULL) {
-		if (obj->extra == NULL)
-			obj->extra = new_pampd;
-		/* enforce that all remote pages in an object reside
-		 * in the same node! */
-		else if (pampd_remote_node(new_pampd) !=
-				pampd_remote_node((void *)(obj->extra)))
-			BUG();
-		ret = 0;
-	}
-	return ret;
-}
-
-void *ramster_pampd_free(void *pampd, struct tmem_pool *pool,
-			      struct tmem_oid *oid, uint32_t index, bool acct)
-{
-	bool eph = is_ephemeral(pool);
-	void *local_pampd = NULL;
-	int c;
-
-	BUG_ON(preemptible());
-	BUG_ON(!pampd_is_remote(pampd));
-	WARN_ON(acct == false);
-	if (oid == NULL) {
-		/*
-		 * a NULL oid means to ignore this pampd free
-		 * as the remote freeing will be handled elsewhere
-		 */
-	} else if (eph) {
-		/* FIXME remote flush optional but probably good idea */
-	} else if (pampd_is_intransit(pampd)) {
-		/* did a pers remote get_and_free, so just free local */
-		local_pampd = pampd_mask_intransit_and_remote(pampd);
-	} else {
-		struct flushlist_node *flnode =
-			ramster_flnode_alloc(pool);
-
-		flnode->xh.client_id = pampd_remote_node(pampd);
-		flnode->xh.pool_id = pool->pool_id;
-		flnode->xh.oid = *oid;
-		flnode->xh.index = index;
-		flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_PAGE;
-		spin_lock(&ramster_rem_op_list_lock);
-		list_add(&flnode->rem_op.list, &ramster_rem_op_list);
-		spin_unlock(&ramster_rem_op_list_lock);
-		c = atomic_dec_return(&ramster_remote_pers_pages);
-		WARN_ON_ONCE(c < 0);
-	}
-	return local_pampd;
-}
-EXPORT_SYMBOL_GPL(ramster_pampd_free);
-
-void ramster_count_foreign_pages(bool eph, int count)
-{
-	BUG_ON(count != 1 && count != -1);
-	if (eph) {
-		if (count > 0) {
-			inc_ramster_foreign_eph_pages();
-		} else {
-			dec_ramster_foreign_eph_pages();
-#ifdef CONFIG_RAMSTER_DEBUG
-			WARN_ON_ONCE(ramster_foreign_eph_pages < 0);
-#endif
-		}
-	} else {
-		if (count > 0) {
-			inc_ramster_foreign_pers_pages();
-		} else {
-			dec_ramster_foreign_pers_pages();
-#ifdef CONFIG_RAMSTER_DEBUG
-			WARN_ON_ONCE(ramster_foreign_pers_pages < 0);
-#endif
-		}
-	}
-}
-EXPORT_SYMBOL_GPL(ramster_count_foreign_pages);
-
-/*
- * For now, just push over a few pages every few seconds to
- * ensure that it basically works
- */
-static struct workqueue_struct *ramster_remotify_workqueue;
-static void ramster_remotify_process(struct work_struct *work);
-static DECLARE_DELAYED_WORK(ramster_remotify_worker,
-		ramster_remotify_process);
-
-static void ramster_remotify_queue_delayed_work(unsigned long delay)
-{
-	if (!queue_delayed_work(ramster_remotify_workqueue,
-				&ramster_remotify_worker, delay))
-		pr_err("ramster_remotify: bad workqueue\n");
-}
-
-static void ramster_remote_flush_page(struct flushlist_node *flnode)
-{
-	struct tmem_xhandle *xh;
-	int remotenode, ret;
-
-	preempt_disable();
-	xh = &flnode->xh;
-	remotenode = flnode->xh.client_id;
-	ret = r2net_remote_flush(xh, remotenode);
-	if (ret >= 0)
-		inc_ramster_remote_pages_flushed();
-	else
-		inc_ramster_remote_page_flushes_failed();
-	preempt_enable_no_resched();
-	ramster_flnode_free(flnode, NULL);
-}
-
-static void ramster_remote_flush_object(struct flushlist_node *flnode)
-{
-	struct tmem_xhandle *xh;
-	int remotenode, ret;
-
-	preempt_disable();
-	xh = &flnode->xh;
-	remotenode = flnode->xh.client_id;
-	ret = r2net_remote_flush_object(xh, remotenode);
-	if (ret >= 0)
-		inc_ramster_remote_objects_flushed();
-	else
-		inc_ramster_remote_object_flushes_failed();
-	preempt_enable_no_resched();
-	ramster_flnode_free(flnode, NULL);
-}
-
-int ramster_remotify_pageframe(bool eph)
-{
-	struct tmem_xhandle xh;
-	unsigned int size;
-	int remotenode, ret, zbuds;
-	struct tmem_pool *pool;
-	unsigned long flags;
-	unsigned char cksum;
-	char *p;
-	int i, j;
-	unsigned char *tmpmem[2];
-	struct tmem_handle th[2];
-	unsigned int zsize[2];
-
-	tmpmem[0] = __get_cpu_var(ramster_remoteputmem1);
-	tmpmem[1] = __get_cpu_var(ramster_remoteputmem2);
-	local_bh_disable();
-	zbuds = zbud_make_zombie_lru(&th[0], &tmpmem[0], &zsize[0], eph);
-	/* now OK to release lock set in caller */
-	local_bh_enable();
-	if (zbuds == 0)
-		goto out;
-	BUG_ON(zbuds > 2);
-	for (i = 0; i < zbuds; i++) {
-		xh.client_id = th[i].client_id;
-		xh.pool_id = th[i].pool_id;
-		xh.oid = th[i].oid;
-		xh.index = th[i].index;
-		size = zsize[i];
-		BUG_ON(size == 0 || size > zbud_max_buddy_size());
-		for (p = tmpmem[i], cksum = 0, j = 0; j < size; j++)
-			cksum += *p++;
-		ret = r2net_remote_put(&xh, tmpmem[i], size, eph, &remotenode);
-		if (ret != 0) {
-		/*
-		 * This is some form of a memory leak... if the remote put
-		 * fails, there will never be another attempt to remotify
-		 * this page.  But since we've dropped the zv pointer,
-		 * the page may have been freed or the data replaced
-		 * so we can't just "put it back" in the remote op list.
-		 * Even if we could, not sure where to put it in the list
-		 * because there may be flushes that must be strictly
-		 * ordered vs the put.  So leave this as a FIXME for now.
-		 * But count them so we know if it becomes a problem.
-		 */
-			if (eph)
-				inc_ramster_eph_pages_remote_failed();
-			else
-				inc_ramster_pers_pages_remote_failed();
-			break;
-		} else {
-			if (!eph)
-				atomic_inc(&ramster_remote_pers_pages);
-		}
-		if (eph)
-			inc_ramster_eph_pages_remoted();
-		else
-			inc_ramster_pers_pages_remoted();
-		/*
-		 * data was successfully remoted so change the local version to
-		 * point to the remote node where it landed
-		 */
-		local_bh_disable();
-		pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh.pool_id);
-		local_irq_save(flags);
-		(void)tmem_replace(pool, &xh.oid, xh.index,
-				pampd_make_remote(remotenode, size, cksum));
-		local_irq_restore(flags);
-		zcache_put_pool(pool);
-		local_bh_enable();
-	}
-out:
-	return zbuds;
-}
-
-static void zcache_do_remotify_flushes(void)
-{
-	struct ramster_remotify_hdr *rem_op;
-	union remotify_list_node *u;
-
-	while (1) {
-		spin_lock(&ramster_rem_op_list_lock);
-		if (list_empty(&ramster_rem_op_list)) {
-			spin_unlock(&ramster_rem_op_list_lock);
-			goto out;
-		}
-		rem_op = list_first_entry(&ramster_rem_op_list,
-				struct ramster_remotify_hdr, list);
-		list_del_init(&rem_op->list);
-		spin_unlock(&ramster_rem_op_list_lock);
-		u = (union remotify_list_node *)rem_op;
-		switch (rem_op->op) {
-		case RAMSTER_REMOTIFY_FLUSH_PAGE:
-			ramster_remote_flush_page((struct flushlist_node *)u);
-			break;
-		case RAMSTER_REMOTIFY_FLUSH_OBJ:
-			ramster_remote_flush_object((struct flushlist_node *)u);
-			break;
-		default:
-			BUG();
-		}
-	}
-out:
-	return;
-}
-
-static void ramster_remotify_process(struct work_struct *work)
-{
-	static bool remotify_in_progress;
-	int i;
-
-	BUG_ON(irqs_disabled());
-	if (remotify_in_progress)
-		goto requeue;
-	if (ramster_remote_target_nodenum == -1)
-		goto requeue;
-	remotify_in_progress = true;
-	if (use_cleancache && ramster_eph_remotify_enable) {
-		for (i = 0; i < 100; i++) {
-			zcache_do_remotify_flushes();
-			(void)ramster_remotify_pageframe(true);
-		}
-	}
-	if (use_frontswap && ramster_pers_remotify_enable) {
-		for (i = 0; i < 100; i++) {
-			zcache_do_remotify_flushes();
-			(void)ramster_remotify_pageframe(false);
-		}
-	}
-	remotify_in_progress = false;
-requeue:
-	ramster_remotify_queue_delayed_work(HZ);
-}
-
-void ramster_remotify_init(void)
-{
-	unsigned long n = 60UL;
-	ramster_remotify_workqueue =
-		create_singlethread_workqueue("ramster_remotify");
-	ramster_remotify_queue_delayed_work(n * HZ);
-}
-
-static ssize_t ramster_manual_node_up_show(struct kobject *kobj,
-				struct kobj_attribute *attr, char *buf)
-{
-	int i;
-	char *p = buf;
-	for (i = 0; i < MANUAL_NODES; i++)
-		if (ramster_nodes_manual_up[i])
-			p += sprintf(p, "%d ", i);
-	p += sprintf(p, "\n");
-	return p - buf;
-}
-
-static ssize_t ramster_manual_node_up_store(struct kobject *kobj,
-		struct kobj_attribute *attr, const char *buf, size_t count)
-{
-	int err;
-	unsigned long node_num;
-
-	err = kstrtoul(buf, 10, &node_num);
-	if (err) {
-		pr_err("ramster: bad strtoul?\n");
-		return -EINVAL;
-	}
-	if (node_num >= MANUAL_NODES) {
-		pr_err("ramster: bad node_num=%lu?\n", node_num);
-		return -EINVAL;
-	}
-	if (ramster_nodes_manual_up[node_num]) {
-		pr_err("ramster: node %d already up, ignoring\n",
-							(int)node_num);
-	} else {
-		ramster_nodes_manual_up[node_num] = true;
-		r2net_hb_node_up_manual((int)node_num);
-	}
-	return count;
-}
-
-static struct kobj_attribute ramster_manual_node_up_attr = {
-	.attr = { .name = "manual_node_up", .mode = 0644 },
-	.show = ramster_manual_node_up_show,
-	.store = ramster_manual_node_up_store,
-};
-
-static ssize_t ramster_remote_target_nodenum_show(struct kobject *kobj,
-				struct kobj_attribute *attr, char *buf)
-{
-	if (ramster_remote_target_nodenum == -1UL)
-		return sprintf(buf, "unset\n");
-	else
-		return sprintf(buf, "%d\n", ramster_remote_target_nodenum);
-}
-
-static ssize_t ramster_remote_target_nodenum_store(struct kobject *kobj,
-		struct kobj_attribute *attr, const char *buf, size_t count)
-{
-	int err;
-	unsigned long node_num;
-
-	err = kstrtoul(buf, 10, &node_num);
-	if (err) {
-		pr_err("ramster: bad strtoul?\n");
-		return -EINVAL;
-	} else if (node_num == -1UL) {
-		pr_err("ramster: disabling all remotification, "
-			"data may still reside on remote nodes however\n");
-		return -EINVAL;
-	} else if (node_num >= MANUAL_NODES) {
-		pr_err("ramster: bad node_num=%lu?\n", node_num);
-		return -EINVAL;
-	} else if (!ramster_nodes_manual_up[node_num]) {
-		pr_err("ramster: node %d not up, ignoring setting "
-			"of remotification target\n", (int)node_num);
-	} else if (r2net_remote_target_node_set((int)node_num) >= 0) {
-		pr_info("ramster: node %d set as remotification target\n",
-				(int)node_num);
-		ramster_remote_target_nodenum = (int)node_num;
-	} else {
-		pr_err("ramster: bad num to node node_num=%d?\n",
-				(int)node_num);
-		return -EINVAL;
-	}
-	return count;
-}
-
-static struct kobj_attribute ramster_remote_target_nodenum_attr = {
-	.attr = { .name = "remote_target_nodenum", .mode = 0644 },
-	.show = ramster_remote_target_nodenum_show,
-	.store = ramster_remote_target_nodenum_store,
-};
-
-#define RAMSTER_SYSFS_RO(_name) \
-	static ssize_t ramster_##_name##_show(struct kobject *kobj, \
-				struct kobj_attribute *attr, char *buf) \
-	{ \
-		return sprintf(buf, "%lu\n", ramster_##_name); \
-	} \
-	static struct kobj_attribute ramster_##_name##_attr = { \
-		.attr = { .name = __stringify(_name), .mode = 0444 }, \
-		.show = ramster_##_name##_show, \
-	}
-
-#define RAMSTER_SYSFS_RW(_name) \
-	static ssize_t ramster_##_name##_show(struct kobject *kobj, \
-				struct kobj_attribute *attr, char *buf) \
-	{ \
-		return sprintf(buf, "%lu\n", ramster_##_name); \
-	} \
-	static ssize_t ramster_##_name##_store(struct kobject *kobj, \
-		struct kobj_attribute *attr, const char *buf, size_t count) \
-	{ \
-		int err; \
-		unsigned long enable; \
-		err = kstrtoul(buf, 10, &enable); \
-		if (err) \
-			return -EINVAL; \
-		ramster_##_name = enable; \
-		return count; \
-	} \
-	static struct kobj_attribute ramster_##_name##_attr = { \
-		.attr = { .name = __stringify(_name), .mode = 0644 }, \
-		.show = ramster_##_name##_show, \
-		.store = ramster_##_name##_store, \
-	}
-
-#define RAMSTER_SYSFS_RO_ATOMIC(_name) \
-	static ssize_t ramster_##_name##_show(struct kobject *kobj, \
-				struct kobj_attribute *attr, char *buf) \
-	{ \
-	    return sprintf(buf, "%d\n", atomic_read(&ramster_##_name)); \
-	} \
-	static struct kobj_attribute ramster_##_name##_attr = { \
-		.attr = { .name = __stringify(_name), .mode = 0444 }, \
-		.show = ramster_##_name##_show, \
-	}
-
-RAMSTER_SYSFS_RO(interface_revision);
-RAMSTER_SYSFS_RO_ATOMIC(remote_pers_pages);
-RAMSTER_SYSFS_RW(pers_remotify_enable);
-RAMSTER_SYSFS_RW(eph_remotify_enable);
-
-static struct attribute *ramster_attrs[] = {
-	&ramster_interface_revision_attr.attr,
-	&ramster_remote_pers_pages_attr.attr,
-	&ramster_manual_node_up_attr.attr,
-	&ramster_remote_target_nodenum_attr.attr,
-	&ramster_pers_remotify_enable_attr.attr,
-	&ramster_eph_remotify_enable_attr.attr,
-	NULL,
-};
-
-static struct attribute_group ramster_attr_group = {
-	.attrs = ramster_attrs,
-	.name = "ramster",
-};
-
-/*
- * frontswap selfshrinking
- */
-
-/* In HZ, controls frequency of worker invocation. */
-static unsigned int selfshrink_interval __read_mostly = 5;
-/* Enable/disable with sysfs. */
-static bool frontswap_selfshrinking __read_mostly;
-
-static void selfshrink_process(struct work_struct *work);
-static DECLARE_DELAYED_WORK(selfshrink_worker, selfshrink_process);
-
-#ifndef CONFIG_RAMSTER_MODULE
-/* Enable/disable with kernel boot option. */
-static bool use_frontswap_selfshrink = true;
-#endif
-
-/*
- * The default values for the following parameters were deemed reasonable
- * by experimentation, may be workload-dependent, and can all be
- * adjusted via sysfs.
- */
-
-/* Control rate for frontswap shrinking. Higher hysteresis is slower. */
-static unsigned int frontswap_hysteresis __read_mostly = 20;
-
-/*
- * Number of selfshrink worker invocations to wait before observing that
- * frontswap selfshrinking should commence. Note that selfshrinking does
- * not use a separate worker thread.
- */
-static unsigned int frontswap_inertia __read_mostly = 3;
-
-/* Countdown to next invocation of frontswap_shrink() */
-static unsigned long frontswap_inertia_counter;
-
-/*
- * Invoked by the selfshrink worker thread, uses current number of pages
- * in frontswap (frontswap_curr_pages()), previous status, and control
- * values (hysteresis and inertia) to determine if frontswap should be
- * shrunk and what the new frontswap size should be.  Note that
- * frontswap_shrink is essentially a partial swapoff that immediately
- * transfers pages from the "swap device" (frontswap) back into kernel
- * RAM; despite the name, frontswap "shrinking" is very different from
- * the "shrinker" interface used by the kernel MM subsystem to reclaim
- * memory.
- */
-static void frontswap_selfshrink(void)
-{
-	static unsigned long cur_frontswap_pages;
-	static unsigned long last_frontswap_pages;
-	static unsigned long tgt_frontswap_pages;
-
-	last_frontswap_pages = cur_frontswap_pages;
-	cur_frontswap_pages = frontswap_curr_pages();
-	if (!cur_frontswap_pages ||
-			(cur_frontswap_pages > last_frontswap_pages)) {
-		frontswap_inertia_counter = frontswap_inertia;
-		return;
-	}
-	if (frontswap_inertia_counter && --frontswap_inertia_counter)
-		return;
-	if (cur_frontswap_pages <= frontswap_hysteresis)
-		tgt_frontswap_pages = 0;
-	else
-		tgt_frontswap_pages = cur_frontswap_pages -
-			(cur_frontswap_pages / frontswap_hysteresis);
-	frontswap_shrink(tgt_frontswap_pages);
-}
-
-#ifndef CONFIG_RAMSTER_MODULE
-static int __init ramster_nofrontswap_selfshrink_setup(char *s)
-{
-	use_frontswap_selfshrink = false;
-	return 1;
-}
-
-__setup("noselfshrink", ramster_nofrontswap_selfshrink_setup);
-#endif
-
-static void selfshrink_process(struct work_struct *work)
-{
-	if (frontswap_selfshrinking && frontswap_enabled) {
-		frontswap_selfshrink();
-		schedule_delayed_work(&selfshrink_worker,
-			selfshrink_interval * HZ);
-	}
-}
-
-void ramster_cpu_up(int cpu)
-{
-	unsigned char *p1 = kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT);
-	unsigned char *p2 = kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT);
-	BUG_ON(!p1 || !p2);
-	per_cpu(ramster_remoteputmem1, cpu) = p1;
-	per_cpu(ramster_remoteputmem2, cpu) = p2;
-}
-EXPORT_SYMBOL_GPL(ramster_cpu_up);
-
-void ramster_cpu_down(int cpu)
-{
-	struct ramster_preload *kp;
-
-	kfree(per_cpu(ramster_remoteputmem1, cpu));
-	per_cpu(ramster_remoteputmem1, cpu) = NULL;
-	kfree(per_cpu(ramster_remoteputmem2, cpu));
-	per_cpu(ramster_remoteputmem2, cpu) = NULL;
-	kp = &per_cpu(ramster_preloads, cpu);
-	if (kp->flnode) {
-		kmem_cache_free(ramster_flnode_cache, kp->flnode);
-		kp->flnode = NULL;
-	}
-}
-EXPORT_SYMBOL_GPL(ramster_cpu_down);
-
-void ramster_register_pamops(struct tmem_pamops *pamops)
-{
-	pamops->free_obj = ramster_pampd_free_obj;
-	pamops->new_obj = ramster_pampd_new_obj;
-	pamops->replace_in_obj = ramster_pampd_replace_in_obj;
-	pamops->is_remote = ramster_pampd_is_remote;
-	pamops->repatriate = ramster_pampd_repatriate;
-	pamops->repatriate_preload = ramster_pampd_repatriate_preload;
-}
-EXPORT_SYMBOL_GPL(ramster_register_pamops);
-
-void ramster_init(bool cleancache, bool frontswap,
-				bool frontswap_exclusive_gets,
-				bool frontswap_selfshrink)
-{
-	int ret = 0;
-
-	if (cleancache)
-		use_cleancache = true;
-	if (frontswap)
-		use_frontswap = true;
-	if (frontswap_exclusive_gets)
-		use_frontswap_exclusive_gets = true;
-	ramster_debugfs_init();
-	ret = sysfs_create_group(mm_kobj, &ramster_attr_group);
-	if (ret)
-		pr_err("ramster: can't create sysfs for ramster\n");
-	(void)r2net_register_handlers();
-#ifdef CONFIG_RAMSTER_MODULE
-	ret = r2nm_init();
-	if (ret)
-		pr_err("ramster: can't init r2net\n");
-	frontswap_selfshrinking = frontswap_selfshrink;
-#else
-	frontswap_selfshrinking = use_frontswap_selfshrink;
-#endif
-	INIT_LIST_HEAD(&ramster_rem_op_list);
-	ramster_flnode_cache = kmem_cache_create("ramster_flnode",
-				sizeof(struct flushlist_node), 0, 0, NULL);
-	if (frontswap_selfshrinking) {
-		pr_info("ramster: Initializing frontswap selfshrink driver.\n");
-		schedule_delayed_work(&selfshrink_worker,
-					selfshrink_interval * HZ);
-	}
-	ramster_remotify_init();
-}
-EXPORT_SYMBOL_GPL(ramster_init);

drivers/staging/zcache/ramster/ramster.h

@@ -1,161 +0,0 @@
-/*
- * ramster.h
- *
- * Peer-to-peer transcendent memory
- *
- * Copyright (c) 2009-2012, Dan Magenheimer, Oracle Corp.
- */
-
-#ifndef _RAMSTER_RAMSTER_H_
-#define _RAMSTER_RAMSTER_H_
-
-#include "../tmem.h"
-
-enum ramster_remotify_op {
-	RAMSTER_REMOTIFY_FLUSH_PAGE,
-	RAMSTER_REMOTIFY_FLUSH_OBJ,
-};
-
-struct ramster_remotify_hdr {
-	enum ramster_remotify_op op;
-	struct list_head list;
-};
-
-struct flushlist_node {
-	struct ramster_remotify_hdr rem_op;
-	struct tmem_xhandle xh;
-};
-
-struct ramster_preload {
-	struct flushlist_node *flnode;
-};
-
-union remotify_list_node {
-	struct ramster_remotify_hdr rem_op;
-	struct {
-		struct ramster_remotify_hdr rem_op;
-		struct tmem_handle th;
-	} zbud_hdr;
-	struct flushlist_node flist;
-};
-
-/*
- * format of remote pampd:
- *   bit 0 is reserved for zbud (in-page buddy selection)
- *   bit 1 == intransit
- *   bit 2 == is_remote... if this bit is set, then
- *   bit 3-10 == remotenode
- *   bit 11-23 == size
- *   bit 24-31 == cksum
- */
-#define FAKE_PAMPD_INTRANSIT_BITS	1
-#define FAKE_PAMPD_ISREMOTE_BITS	1
-#define FAKE_PAMPD_REMOTENODE_BITS	8
-#define FAKE_PAMPD_REMOTESIZE_BITS	13
-#define FAKE_PAMPD_CHECKSUM_BITS	8
-
-#define FAKE_PAMPD_INTRANSIT_SHIFT	1
-#define FAKE_PAMPD_ISREMOTE_SHIFT	(FAKE_PAMPD_INTRANSIT_SHIFT + \
-					 FAKE_PAMPD_INTRANSIT_BITS)
-#define FAKE_PAMPD_REMOTENODE_SHIFT	(FAKE_PAMPD_ISREMOTE_SHIFT + \
-					 FAKE_PAMPD_ISREMOTE_BITS)
-#define FAKE_PAMPD_REMOTESIZE_SHIFT	(FAKE_PAMPD_REMOTENODE_SHIFT + \
-					 FAKE_PAMPD_REMOTENODE_BITS)
-#define FAKE_PAMPD_CHECKSUM_SHIFT	(FAKE_PAMPD_REMOTESIZE_SHIFT + \
-					 FAKE_PAMPD_REMOTESIZE_BITS)
-
-#define FAKE_PAMPD_MASK(x)		((1UL << (x)) - 1)
-
-static inline void *pampd_make_remote(int remotenode, size_t size,
-					unsigned char cksum)
-{
-	unsigned long fake_pampd = 0;
-	fake_pampd |= 1UL << FAKE_PAMPD_ISREMOTE_SHIFT;
-	fake_pampd |= ((unsigned long)remotenode &
-			FAKE_PAMPD_MASK(FAKE_PAMPD_REMOTENODE_BITS)) <<
-				FAKE_PAMPD_REMOTENODE_SHIFT;
-	fake_pampd |= ((unsigned long)size &
-			FAKE_PAMPD_MASK(FAKE_PAMPD_REMOTESIZE_BITS)) <<
-				FAKE_PAMPD_REMOTESIZE_SHIFT;
-	fake_pampd |= ((unsigned long)cksum &
-			FAKE_PAMPD_MASK(FAKE_PAMPD_CHECKSUM_BITS)) <<
-				FAKE_PAMPD_CHECKSUM_SHIFT;
-	return (void *)fake_pampd;
-}
-
-static inline unsigned int pampd_remote_node(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-	return (fake_pampd >> FAKE_PAMPD_REMOTENODE_SHIFT) &
-		FAKE_PAMPD_MASK(FAKE_PAMPD_REMOTENODE_BITS);
-}
-
-static inline unsigned int pampd_remote_size(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-	return (fake_pampd >> FAKE_PAMPD_REMOTESIZE_SHIFT) &
-		FAKE_PAMPD_MASK(FAKE_PAMPD_REMOTESIZE_BITS);
-}
-
-static inline unsigned char pampd_remote_cksum(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-	return (fake_pampd >> FAKE_PAMPD_CHECKSUM_SHIFT) &
-		FAKE_PAMPD_MASK(FAKE_PAMPD_CHECKSUM_BITS);
-}
-
-static inline bool pampd_is_remote(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-	return (fake_pampd >> FAKE_PAMPD_ISREMOTE_SHIFT) &
-		FAKE_PAMPD_MASK(FAKE_PAMPD_ISREMOTE_BITS);
-}
-
-static inline bool pampd_is_intransit(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-	return (fake_pampd >> FAKE_PAMPD_INTRANSIT_SHIFT) &
-		FAKE_PAMPD_MASK(FAKE_PAMPD_INTRANSIT_BITS);
-}
-
-/* note that it is a BUG for intransit to be set without isremote also set */
-static inline void *pampd_mark_intransit(void *pampd)
-{
-	unsigned long fake_pampd = (unsigned long)pampd;
-
-	fake_pampd |= 1UL << FAKE_PAMPD_ISREMOTE_SHIFT;
-	fake_pampd |= 1UL << FAKE_PAMPD_INTRANSIT_SHIFT;
-	return (void *)fake_pampd;
-}
-
-static inline void *pampd_mask_intransit_and_remote(void *marked_pampd)
-{
-	unsigned long pampd = (unsigned long)marked_pampd;
-
-	pampd &= ~(1UL << FAKE_PAMPD_INTRANSIT_SHIFT);
-	pampd &= ~(1UL << FAKE_PAMPD_ISREMOTE_SHIFT);
-	return (void *)pampd;
-}
-
-extern int r2net_remote_async_get(struct tmem_xhandle *,
-				bool, int, size_t, uint8_t, void *extra);
-extern int r2net_remote_put(struct tmem_xhandle *, char *, size_t,
-				bool, int *);
-extern int r2net_remote_flush(struct tmem_xhandle *, int);
-extern int r2net_remote_flush_object(struct tmem_xhandle *, int);
-extern int r2net_register_handlers(void);
-extern int r2net_remote_target_node_set(int);
-
-extern int ramster_remotify_pageframe(bool);
-extern void ramster_init(bool, bool, bool, bool);
-extern void ramster_register_pamops(struct tmem_pamops *);
-extern int ramster_localify(int, struct tmem_oid *oidp, uint32_t, char *,
-				unsigned int, void *);
-extern void *ramster_pampd_free(void *, struct tmem_pool *, struct tmem_oid *,
-				uint32_t, bool);
-extern void ramster_count_foreign_pages(bool, int);
-extern int ramster_do_preload_flnode(struct tmem_pool *);
-extern void ramster_cpu_up(int);
-extern void ramster_cpu_down(int);
-
-#endif /* _RAMSTER_RAMSTER_H */

drivers/staging/zcache/ramster/ramster_nodemanager.h

@@ -1,41 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * ramster_nodemanager.h
- *
- * Header describing the interface between userspace and the kernel
- * for the ramster_nodemanager module.
- *
- * Copyright (C) 2002, 2004, 2012 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- */
-
-#ifndef _RAMSTER_NODEMANAGER_H
-#define _RAMSTER_NODEMANAGER_H
-
-#define R2NM_API_VERSION	5
-
-#define R2NM_MAX_NODES		255
-#define R2NM_INVALID_NODE_NUM	255
-
-/* host name, group name, cluster name all 64 bytes */
-#define R2NM_MAX_NAME_LEN        64    /* __NEW_UTS_LEN */
-
-extern int r2nm_init(void);
-
-#endif /* _RAMSTER_NODEMANAGER_H */

drivers/staging/zcache/ramster/tcp.c

@@ -1,2251 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- *
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- * ----
- *
- * Callers for this were originally written against a very simple synchronus
- * API.  This implementation reflects those simple callers.  Some day I'm sure
- * we'll need to move to a more robust posting/callback mechanism.
- *
- * Transmit calls pass in kernel virtual addresses and block copying this into
- * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
- * for a failed socket to timeout.  TX callers can also pass in a poniter to an
- * 'int' which gets filled with an errno off the wire in response to the
- * message they send.
- *
- * Handlers for unsolicited messages are registered.  Each socket has a page
- * that incoming data is copied into.  First the header, then the data.
- * Handlers are called from only one thread with a reference to this per-socket
- * page.  This page is destroyed after the handler call, so it can't be
- * referenced beyond the call.  Handlers may block but are discouraged from
- * doing so.
- *
- * Any framing errors (bad magic, large payload lengths) close a connection.
- *
- * Our sock_container holds the state we associate with a socket.  It's current
- * framing state is held there as well as the refcounting we do around when it
- * is safe to tear down the socket.  The socket is only finally torn down from
- * the container when the container loses all of its references -- so as long
- * as you hold a ref on the container you can trust that the socket is valid
- * for use with kernel socket APIs.
- *
- * Connections are initiated between a pair of nodes when the node with the
- * higher node number gets a heartbeat callback which indicates that the lower
- * numbered node has started heartbeating.  The lower numbered node is passive
- * and only accepts the connection if the higher numbered node is heartbeating.
- */
-
-#include <linux/kernel.h>
-#include <linux/jiffies.h>
-#include <linux/slab.h>
-#include <linux/idr.h>
-#include <linux/kref.h>
-#include <linux/net.h>
-#include <linux/export.h>
-#include <linux/uaccess.h>
-#include <net/tcp.h>
-
-
-#include "heartbeat.h"
-#include "tcp.h"
-#include "nodemanager.h"
-#define MLOG_MASK_PREFIX ML_TCP
-#include "masklog.h"
-
-#include "tcp_internal.h"
-
-#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
-
-/*
- * In the following two log macros, the whitespace after the ',' just
- * before ##args is intentional. Otherwise, gcc 2.95 will eat the
- * previous token if args expands to nothing.
- */
-#define msglog(hdr, fmt, args...) do {					\
-	typeof(hdr) __hdr = (hdr);					\
-	mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "	\
-	     "key %08x num %u] " fmt,					\
-	be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len),	\
-	     be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),	\
-	     be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),	\
-	     be32_to_cpu(__hdr->msg_num) ,  ##args);			\
-} while (0)
-
-#define sclog(sc, fmt, args...) do {					\
-	typeof(sc) __sc = (sc);						\
-	mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "	\
-	     "pg_off %zu] " fmt, __sc,					\
-	     atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock,	\
-	    __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,	\
-	    ##args);							\
-} while (0)
-
-static DEFINE_RWLOCK(r2net_handler_lock);
-static struct rb_root r2net_handler_tree = RB_ROOT;
-
-static struct r2net_node r2net_nodes[R2NM_MAX_NODES];
-
-/* XXX someday we'll need better accounting */
-static struct socket *r2net_listen_sock;
-
-/*
- * listen work is only queued by the listening socket callbacks on the
- * r2net_wq.  teardown detaches the callbacks before destroying the workqueue.
- * quorum work is queued as sock containers are shutdown.. stop_listening
- * tears down all the node's sock containers, preventing future shutdowns
- * and queued quorum work, before canceling delayed quorum work and
- * destroying the work queue.
- */
-static struct workqueue_struct *r2net_wq;
-static struct work_struct r2net_listen_work;
-
-static struct r2hb_callback_func r2net_hb_up, r2net_hb_down;
-#define R2NET_HB_PRI 0x1
-
-static struct r2net_handshake *r2net_hand;
-static struct r2net_msg *r2net_keep_req, *r2net_keep_resp;
-
-static int r2net_sys_err_translations[R2NET_ERR_MAX] = {
-		[R2NET_ERR_NONE]	= 0,
-		[R2NET_ERR_NO_HNDLR]	= -ENOPROTOOPT,
-		[R2NET_ERR_OVERFLOW]	= -EOVERFLOW,
-		[R2NET_ERR_DIED]	= -EHOSTDOWN,};
-
-/* can't quite avoid *all* internal declarations :/ */
-static void r2net_sc_connect_completed(struct work_struct *work);
-static void r2net_rx_until_empty(struct work_struct *work);
-static void r2net_shutdown_sc(struct work_struct *work);
-static void r2net_listen_data_ready(struct sock *sk, int bytes);
-static void r2net_sc_send_keep_req(struct work_struct *work);
-static void r2net_idle_timer(unsigned long data);
-static void r2net_sc_postpone_idle(struct r2net_sock_container *sc);
-static void r2net_sc_reset_idle_timer(struct r2net_sock_container *sc);
-
-#ifdef CONFIG_DEBUG_FS
-static void r2net_init_nst(struct r2net_send_tracking *nst, u32 msgtype,
-			   u32 msgkey, struct task_struct *task, u8 node)
-{
-	INIT_LIST_HEAD(&nst->st_net_debug_item);
-	nst->st_task = task;
-	nst->st_msg_type = msgtype;
-	nst->st_msg_key = msgkey;
-	nst->st_node = node;
-}
-
-static inline void r2net_set_nst_sock_time(struct r2net_send_tracking *nst)
-{
-	nst->st_sock_time = ktime_get();
-}
-
-static inline void r2net_set_nst_send_time(struct r2net_send_tracking *nst)
-{
-	nst->st_send_time = ktime_get();
-}
-
-static inline void r2net_set_nst_status_time(struct r2net_send_tracking *nst)
-{
-	nst->st_status_time = ktime_get();
-}
-
-static inline void r2net_set_nst_sock_container(struct r2net_send_tracking *nst,
-						struct r2net_sock_container *sc)
-{
-	nst->st_sc = sc;
-}
-
-static inline void r2net_set_nst_msg_id(struct r2net_send_tracking *nst,
-					u32 msg_id)
-{
-	nst->st_id = msg_id;
-}
-
-static inline void r2net_set_sock_timer(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_timer = ktime_get();
-}
-
-static inline void r2net_set_data_ready_time(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_data_ready = ktime_get();
-}
-
-static inline void r2net_set_advance_start_time(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_advance_start = ktime_get();
-}
-
-static inline void r2net_set_advance_stop_time(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_advance_stop = ktime_get();
-}
-
-static inline void r2net_set_func_start_time(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_func_start = ktime_get();
-}
-
-static inline void r2net_set_func_stop_time(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_func_stop = ktime_get();
-}
-
-#else  /* CONFIG_DEBUG_FS */
-# define r2net_init_nst(a, b, c, d, e)
-# define r2net_set_nst_sock_time(a)
-# define r2net_set_nst_send_time(a)
-# define r2net_set_nst_status_time(a)
-# define r2net_set_nst_sock_container(a, b)
-# define r2net_set_nst_msg_id(a, b)
-# define r2net_set_sock_timer(a)
-# define r2net_set_data_ready_time(a)
-# define r2net_set_advance_start_time(a)
-# define r2net_set_advance_stop_time(a)
-# define r2net_set_func_start_time(a)
-# define r2net_set_func_stop_time(a)
-#endif /* CONFIG_DEBUG_FS */
-
-#ifdef CONFIG_RAMSTER_FS_STATS
-static ktime_t r2net_get_func_run_time(struct r2net_sock_container *sc)
-{
-	return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
-}
-
-static void r2net_update_send_stats(struct r2net_send_tracking *nst,
-				    struct r2net_sock_container *sc)
-{
-	sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
-					   ktime_sub(ktime_get(),
-						     nst->st_status_time));
-	sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
-					 ktime_sub(nst->st_status_time,
-						   nst->st_send_time));
-	sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
-					    ktime_sub(nst->st_send_time,
-						      nst->st_sock_time));
-	sc->sc_send_count++;
-}
-
-static void r2net_update_recv_stats(struct r2net_sock_container *sc)
-{
-	sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
-					    r2net_get_func_run_time(sc));
-	sc->sc_recv_count++;
-}
-
-#else
-
-# define r2net_update_send_stats(a, b)
-
-# define r2net_update_recv_stats(sc)
-
-#endif /* CONFIG_RAMSTER_FS_STATS */
-
-static inline int r2net_reconnect_delay(void)
-{
-	return r2nm_single_cluster->cl_reconnect_delay_ms;
-}
-
-static inline int r2net_keepalive_delay(void)
-{
-	return r2nm_single_cluster->cl_keepalive_delay_ms;
-}
-
-static inline int r2net_idle_timeout(void)
-{
-	return r2nm_single_cluster->cl_idle_timeout_ms;
-}
-
-static inline int r2net_sys_err_to_errno(enum r2net_system_error err)
-{
-	int trans;
-	BUG_ON(err >= R2NET_ERR_MAX);
-	trans = r2net_sys_err_translations[err];
-
-	/* Just in case we mess up the translation table above */
-	BUG_ON(err != R2NET_ERR_NONE && trans == 0);
-	return trans;
-}
-
-struct r2net_node *r2net_nn_from_num(u8 node_num)
-{
-	BUG_ON(node_num >= ARRAY_SIZE(r2net_nodes));
-	return &r2net_nodes[node_num];
-}
-
-static u8 r2net_num_from_nn(struct r2net_node *nn)
-{
-	BUG_ON(nn == NULL);
-	return nn - r2net_nodes;
-}
-
-/* ------------------------------------------------------------ */
-
-static int r2net_prep_nsw(struct r2net_node *nn, struct r2net_status_wait *nsw)
-{
-	int ret;
-
-	spin_lock(&nn->nn_lock);
-	ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
-	if (ret >= 0) {
-		nsw->ns_id = ret;
-		list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
-	}
-	spin_unlock(&nn->nn_lock);
-
-	if (ret >= 0) {
-		init_waitqueue_head(&nsw->ns_wq);
-		nsw->ns_sys_status = R2NET_ERR_NONE;
-		nsw->ns_status = 0;
-		return 0;
-	}
-	return ret;
-}
-
-static void r2net_complete_nsw_locked(struct r2net_node *nn,
-				      struct r2net_status_wait *nsw,
-				      enum r2net_system_error sys_status,
-				      s32 status)
-{
-	assert_spin_locked(&nn->nn_lock);
-
-	if (!list_empty(&nsw->ns_node_item)) {
-		list_del_init(&nsw->ns_node_item);
-		nsw->ns_sys_status = sys_status;
-		nsw->ns_status = status;
-		idr_remove(&nn->nn_status_idr, nsw->ns_id);
-		wake_up(&nsw->ns_wq);
-	}
-}
-
-static void r2net_complete_nsw(struct r2net_node *nn,
-			       struct r2net_status_wait *nsw,
-			       u64 id, enum r2net_system_error sys_status,
-			       s32 status)
-{
-	spin_lock(&nn->nn_lock);
-	if (nsw == NULL) {
-		if (id > INT_MAX)
-			goto out;
-
-		nsw = idr_find(&nn->nn_status_idr, id);
-		if (nsw == NULL)
-			goto out;
-	}
-
-	r2net_complete_nsw_locked(nn, nsw, sys_status, status);
-
-out:
-	spin_unlock(&nn->nn_lock);
-	return;
-}
-
-static void r2net_complete_nodes_nsw(struct r2net_node *nn)
-{
-	struct r2net_status_wait *nsw, *tmp;
-	unsigned int num_kills = 0;
-
-	assert_spin_locked(&nn->nn_lock);
-
-	list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
-		r2net_complete_nsw_locked(nn, nsw, R2NET_ERR_DIED, 0);
-		num_kills++;
-	}
-
-	mlog(0, "completed %d messages for node %u\n", num_kills,
-	     r2net_num_from_nn(nn));
-}
-
-static int r2net_nsw_completed(struct r2net_node *nn,
-			       struct r2net_status_wait *nsw)
-{
-	int completed;
-	spin_lock(&nn->nn_lock);
-	completed = list_empty(&nsw->ns_node_item);
-	spin_unlock(&nn->nn_lock);
-	return completed;
-}
-
-/* ------------------------------------------------------------ */
-
-static void sc_kref_release(struct kref *kref)
-{
-	struct r2net_sock_container *sc = container_of(kref,
-					struct r2net_sock_container, sc_kref);
-	BUG_ON(timer_pending(&sc->sc_idle_timeout));
-
-	sclog(sc, "releasing\n");
-
-	if (sc->sc_sock) {
-		sock_release(sc->sc_sock);
-		sc->sc_sock = NULL;
-	}
-
-	r2nm_undepend_item(&sc->sc_node->nd_item);
-	r2nm_node_put(sc->sc_node);
-	sc->sc_node = NULL;
-
-	r2net_debug_del_sc(sc);
-
-	if (sc->sc_page)
-		__free_page(sc->sc_page);
-	kfree(sc);
-}
-
-static void sc_put(struct r2net_sock_container *sc)
-{
-	sclog(sc, "put\n");
-	kref_put(&sc->sc_kref, sc_kref_release);
-}
-static void sc_get(struct r2net_sock_container *sc)
-{
-	sclog(sc, "get\n");
-	kref_get(&sc->sc_kref);
-}
-static struct r2net_sock_container *sc_alloc(struct r2nm_node *node)
-{
-	struct r2net_sock_container *sc, *ret = NULL;
-	struct page *page = NULL;
-	int status = 0;
-
-	page = alloc_page(GFP_NOFS);
-	sc = kzalloc(sizeof(*sc), GFP_NOFS);
-	if (sc == NULL || page == NULL)
-		goto out;
-
-	kref_init(&sc->sc_kref);
-	r2nm_node_get(node);
-	sc->sc_node = node;
-
-	/* pin the node item of the remote node */
-	status = r2nm_depend_item(&node->nd_item);
-	if (status) {
-		mlog_errno(status);
-		r2nm_node_put(node);
-		goto out;
-	}
-	INIT_WORK(&sc->sc_connect_work, r2net_sc_connect_completed);
-	INIT_WORK(&sc->sc_rx_work, r2net_rx_until_empty);
-	INIT_WORK(&sc->sc_shutdown_work, r2net_shutdown_sc);
-	INIT_DELAYED_WORK(&sc->sc_keepalive_work, r2net_sc_send_keep_req);
-
-	init_timer(&sc->sc_idle_timeout);
-	sc->sc_idle_timeout.function = r2net_idle_timer;
-	sc->sc_idle_timeout.data = (unsigned long)sc;
-
-	sclog(sc, "alloced\n");
-
-	ret = sc;
-	sc->sc_page = page;
-	r2net_debug_add_sc(sc);
-	sc = NULL;
-	page = NULL;
-
-out:
-	if (page)
-		__free_page(page);
-	kfree(sc);
-
-	return ret;
-}
-
-/* ------------------------------------------------------------ */
-
-static void r2net_sc_queue_work(struct r2net_sock_container *sc,
-				struct work_struct *work)
-{
-	sc_get(sc);
-	if (!queue_work(r2net_wq, work))
-		sc_put(sc);
-}
-static void r2net_sc_queue_delayed_work(struct r2net_sock_container *sc,
-					struct delayed_work *work,
-					int delay)
-{
-	sc_get(sc);
-	if (!queue_delayed_work(r2net_wq, work, delay))
-		sc_put(sc);
-}
-static void r2net_sc_cancel_delayed_work(struct r2net_sock_container *sc,
-					 struct delayed_work *work)
-{
-	if (cancel_delayed_work(work))
-		sc_put(sc);
-}
-
-static atomic_t r2net_connected_peers = ATOMIC_INIT(0);
-
-int r2net_num_connected_peers(void)
-{
-	return atomic_read(&r2net_connected_peers);
-}
-
-static void r2net_set_nn_state(struct r2net_node *nn,
-			       struct r2net_sock_container *sc,
-			       unsigned valid, int err)
-{
-	int was_valid = nn->nn_sc_valid;
-	int was_err = nn->nn_persistent_error;
-	struct r2net_sock_container *old_sc = nn->nn_sc;
-
-	assert_spin_locked(&nn->nn_lock);
-
-	if (old_sc && !sc)
-		atomic_dec(&r2net_connected_peers);
-	else if (!old_sc && sc)
-		atomic_inc(&r2net_connected_peers);
-
-	/* the node num comparison and single connect/accept path should stop
-	 * an non-null sc from being overwritten with another */
-	BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
-	mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
-	mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
-
-	if (was_valid && !valid && err == 0)
-		err = -ENOTCONN;
-
-	mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
-	     r2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
-	     nn->nn_persistent_error, err);
-
-	nn->nn_sc = sc;
-	nn->nn_sc_valid = valid ? 1 : 0;
-	nn->nn_persistent_error = err;
-
-	/* mirrors r2net_tx_can_proceed() */
-	if (nn->nn_persistent_error || nn->nn_sc_valid)
-		wake_up(&nn->nn_sc_wq);
-
-	if (!was_err && nn->nn_persistent_error) {
-		queue_delayed_work(r2net_wq, &nn->nn_still_up,
-				   msecs_to_jiffies(R2NET_QUORUM_DELAY_MS));
-	}
-
-	if (was_valid && !valid) {
-		pr_notice("ramster: No longer connected to " SC_NODEF_FMT "\n",
-			old_sc->sc_node->nd_name, old_sc->sc_node->nd_num,
-			&old_sc->sc_node->nd_ipv4_address,
-			ntohs(old_sc->sc_node->nd_ipv4_port));
-		r2net_complete_nodes_nsw(nn);
-	}
-
-	if (!was_valid && valid) {
-		cancel_delayed_work(&nn->nn_connect_expired);
-		pr_notice("ramster: %s " SC_NODEF_FMT "\n",
-		       r2nm_this_node() > sc->sc_node->nd_num ?
-		       "Connected to" : "Accepted connection from",
-		       sc->sc_node->nd_name, sc->sc_node->nd_num,
-			&sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port));
-	}
-
-	/* trigger the connecting worker func as long as we're not valid,
-	 * it will back off if it shouldn't connect.  This can be called
-	 * from node config teardown and so needs to be careful about
-	 * the work queue actually being up. */
-	if (!valid && r2net_wq) {
-		unsigned long delay;
-		/* delay if we're within a RECONNECT_DELAY of the
-		 * last attempt */
-		delay = (nn->nn_last_connect_attempt +
-			 msecs_to_jiffies(r2net_reconnect_delay()))
-			- jiffies;
-		if (delay > msecs_to_jiffies(r2net_reconnect_delay()))
-			delay = 0;
-		mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
-		queue_delayed_work(r2net_wq, &nn->nn_connect_work, delay);
-
-		/*
-		 * Delay the expired work after idle timeout.
-		 *
-		 * We might have lots of failed connection attempts that run
-		 * through here but we only cancel the connect_expired work when
-		 * a connection attempt succeeds.  So only the first enqueue of
-		 * the connect_expired work will do anything.  The rest will see
-		 * that it's already queued and do nothing.
-		 */
-		delay += msecs_to_jiffies(r2net_idle_timeout());
-		queue_delayed_work(r2net_wq, &nn->nn_connect_expired, delay);
-	}
-
-	/* keep track of the nn's sc ref for the caller */
-	if ((old_sc == NULL) && sc)
-		sc_get(sc);
-	if (old_sc && (old_sc != sc)) {
-		r2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
-		sc_put(old_sc);
-	}
-}
-
-/* see r2net_register_callbacks() */
-static void r2net_data_ready(struct sock *sk, int bytes)
-{
-	void (*ready)(struct sock *sk, int bytes);
-
-	read_lock(&sk->sk_callback_lock);
-	if (sk->sk_user_data) {
-		struct r2net_sock_container *sc = sk->sk_user_data;
-		sclog(sc, "data_ready hit\n");
-		r2net_set_data_ready_time(sc);
-		r2net_sc_queue_work(sc, &sc->sc_rx_work);
-		ready = sc->sc_data_ready;
-	} else {
-		ready = sk->sk_data_ready;
-	}
-	read_unlock(&sk->sk_callback_lock);
-
-	ready(sk, bytes);
-}
-
-/* see r2net_register_callbacks() */
-static void r2net_state_change(struct sock *sk)
-{
-	void (*state_change)(struct sock *sk);
-	struct r2net_sock_container *sc;
-
-	read_lock(&sk->sk_callback_lock);
-	sc = sk->sk_user_data;
-	if (sc == NULL) {
-		state_change = sk->sk_state_change;
-		goto out;
-	}
-
-	sclog(sc, "state_change to %d\n", sk->sk_state);
-
-	state_change = sc->sc_state_change;
-
-	switch (sk->sk_state) {
-
-	/* ignore connecting sockets as they make progress */
-	case TCP_SYN_SENT:
-	case TCP_SYN_RECV:
-		break;
-	case TCP_ESTABLISHED:
-		r2net_sc_queue_work(sc, &sc->sc_connect_work);
-		break;
-	default:
-		pr_info("ramster: Connection to "
-			SC_NODEF_FMT " shutdown, state %d\n",
-			sc->sc_node->nd_name, sc->sc_node->nd_num,
-			&sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port), sk->sk_state);
-		r2net_sc_queue_work(sc, &sc->sc_shutdown_work);
-		break;
-
-	}
-out:
-	read_unlock(&sk->sk_callback_lock);
-	state_change(sk);
-}
-
-/*
- * we register callbacks so we can queue work on events before calling
- * the original callbacks.  our callbacks are careful to test user_data
- * to discover when they've reaced with r2net_unregister_callbacks().
- */
-static void r2net_register_callbacks(struct sock *sk,
-				     struct r2net_sock_container *sc)
-{
-	write_lock_bh(&sk->sk_callback_lock);
-
-	/* accepted sockets inherit the old listen socket data ready */
-	if (sk->sk_data_ready == r2net_listen_data_ready) {
-		sk->sk_data_ready = sk->sk_user_data;
-		sk->sk_user_data = NULL;
-	}
-
-	BUG_ON(sk->sk_user_data != NULL);
-	sk->sk_user_data = sc;
-	sc_get(sc);
-
-	sc->sc_data_ready = sk->sk_data_ready;
-	sc->sc_state_change = sk->sk_state_change;
-	sk->sk_data_ready = r2net_data_ready;
-	sk->sk_state_change = r2net_state_change;
-
-	mutex_init(&sc->sc_send_lock);
-
-	write_unlock_bh(&sk->sk_callback_lock);
-}
-
-static int r2net_unregister_callbacks(struct sock *sk,
-					struct r2net_sock_container *sc)
-{
-	int ret = 0;
-
-	write_lock_bh(&sk->sk_callback_lock);
-	if (sk->sk_user_data == sc) {
-		ret = 1;
-		sk->sk_user_data = NULL;
-		sk->sk_data_ready = sc->sc_data_ready;
-		sk->sk_state_change = sc->sc_state_change;
-	}
-	write_unlock_bh(&sk->sk_callback_lock);
-
-	return ret;
-}
-
-/*
- * this is a little helper that is called by callers who have seen a problem
- * with an sc and want to detach it from the nn if someone already hasn't beat
- * them to it.  if an error is given then the shutdown will be persistent
- * and pending transmits will be canceled.
- */
-static void r2net_ensure_shutdown(struct r2net_node *nn,
-					struct r2net_sock_container *sc,
-				   int err)
-{
-	spin_lock(&nn->nn_lock);
-	if (nn->nn_sc == sc)
-		r2net_set_nn_state(nn, NULL, 0, err);
-	spin_unlock(&nn->nn_lock);
-}
-
-/*
- * This work queue function performs the blocking parts of socket shutdown.  A
- * few paths lead here.  set_nn_state will trigger this callback if it sees an
- * sc detached from the nn.  state_change will also trigger this callback
- * directly when it sees errors.  In that case we need to call set_nn_state
- * ourselves as state_change couldn't get the nn_lock and call set_nn_state
- * itself.
- */
-static void r2net_shutdown_sc(struct work_struct *work)
-{
-	struct r2net_sock_container *sc =
-		container_of(work, struct r2net_sock_container,
-			     sc_shutdown_work);
-	struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-
-	sclog(sc, "shutting down\n");
-
-	/* drop the callbacks ref and call shutdown only once */
-	if (r2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
-		/* we shouldn't flush as we're in the thread, the
-		 * races with pending sc work structs are harmless */
-		del_timer_sync(&sc->sc_idle_timeout);
-		r2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
-		sc_put(sc);
-		kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
-	}
-
-	/* not fatal so failed connects before the other guy has our
-	 * heartbeat can be retried */
-	r2net_ensure_shutdown(nn, sc, 0);
-	sc_put(sc);
-}
-
-/* ------------------------------------------------------------ */
-
-static int r2net_handler_cmp(struct r2net_msg_handler *nmh, u32 msg_type,
-			     u32 key)
-{
-	int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
-
-	if (ret == 0)
-		ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
-
-	return ret;
-}
-
-static struct r2net_msg_handler *
-r2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
-				struct rb_node **ret_parent)
-{
-	struct rb_node **p = &r2net_handler_tree.rb_node;
-	struct rb_node *parent = NULL;
-	struct r2net_msg_handler *nmh, *ret = NULL;
-	int cmp;
-
-	while (*p) {
-		parent = *p;
-		nmh = rb_entry(parent, struct r2net_msg_handler, nh_node);
-		cmp = r2net_handler_cmp(nmh, msg_type, key);
-
-		if (cmp < 0)
-			p = &(*p)->rb_left;
-		else if (cmp > 0)
-			p = &(*p)->rb_right;
-		else {
-			ret = nmh;
-			break;
-		}
-	}
-
-	if (ret_p != NULL)
-		*ret_p = p;
-	if (ret_parent != NULL)
-		*ret_parent = parent;
-
-	return ret;
-}
-
-static void r2net_handler_kref_release(struct kref *kref)
-{
-	struct r2net_msg_handler *nmh;
-	nmh = container_of(kref, struct r2net_msg_handler, nh_kref);
-
-	kfree(nmh);
-}
-
-static void r2net_handler_put(struct r2net_msg_handler *nmh)
-{
-	kref_put(&nmh->nh_kref, r2net_handler_kref_release);
-}
-
-/* max_len is protection for the handler func.  incoming messages won't
- * be given to the handler if their payload is longer than the max. */
-int r2net_register_handler(u32 msg_type, u32 key, u32 max_len,
-			   r2net_msg_handler_func *func, void *data,
-			   r2net_post_msg_handler_func *post_func,
-			   struct list_head *unreg_list)
-{
-	struct r2net_msg_handler *nmh = NULL;
-	struct rb_node **p, *parent;
-	int ret = 0;
-
-	if (max_len > R2NET_MAX_PAYLOAD_BYTES) {
-		mlog(0, "max_len for message handler out of range: %u\n",
-			max_len);
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (!msg_type) {
-		mlog(0, "no message type provided: %u, %p\n", msg_type, func);
-		ret = -EINVAL;
-		goto out;
-
-	}
-	if (!func) {
-		mlog(0, "no message handler provided: %u, %p\n",
-		       msg_type, func);
-		ret = -EINVAL;
-		goto out;
-	}
-
-	nmh = kzalloc(sizeof(struct r2net_msg_handler), GFP_NOFS);
-	if (nmh == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	nmh->nh_func = func;
-	nmh->nh_func_data = data;
-	nmh->nh_post_func = post_func;
-	nmh->nh_msg_type = msg_type;
-	nmh->nh_max_len = max_len;
-	nmh->nh_key = key;
-	/* the tree and list get this ref.. they're both removed in
-	 * unregister when this ref is dropped */
-	kref_init(&nmh->nh_kref);
-	INIT_LIST_HEAD(&nmh->nh_unregister_item);
-
-	write_lock(&r2net_handler_lock);
-	if (r2net_handler_tree_lookup(msg_type, key, &p, &parent))
-		ret = -EEXIST;
-	else {
-		rb_link_node(&nmh->nh_node, parent, p);
-		rb_insert_color(&nmh->nh_node, &r2net_handler_tree);
-		list_add_tail(&nmh->nh_unregister_item, unreg_list);
-
-		mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
-		     func, msg_type, key);
-		/* we've had some trouble with handlers seemingly vanishing. */
-		mlog_bug_on_msg(r2net_handler_tree_lookup(msg_type, key, &p,
-							  &parent) == NULL,
-				"couldn't find handler we *just* registered "
-				"for type %u key %08x\n", msg_type, key);
-	}
-	write_unlock(&r2net_handler_lock);
-	if (ret)
-		goto out;
-
-out:
-	if (ret)
-		kfree(nmh);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(r2net_register_handler);
-
-void r2net_unregister_handler_list(struct list_head *list)
-{
-	struct r2net_msg_handler *nmh, *n;
-
-	write_lock(&r2net_handler_lock);
-	list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
-		mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
-		     nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
-		rb_erase(&nmh->nh_node, &r2net_handler_tree);
-		list_del_init(&nmh->nh_unregister_item);
-		kref_put(&nmh->nh_kref, r2net_handler_kref_release);
-	}
-	write_unlock(&r2net_handler_lock);
-}
-EXPORT_SYMBOL_GPL(r2net_unregister_handler_list);
-
-static struct r2net_msg_handler *r2net_handler_get(u32 msg_type, u32 key)
-{
-	struct r2net_msg_handler *nmh;
-
-	read_lock(&r2net_handler_lock);
-	nmh = r2net_handler_tree_lookup(msg_type, key, NULL, NULL);
-	if (nmh)
-		kref_get(&nmh->nh_kref);
-	read_unlock(&r2net_handler_lock);
-
-	return nmh;
-}
-
-/* ------------------------------------------------------------ */
-
-static int r2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
-{
-	int ret;
-	mm_segment_t oldfs;
-	struct kvec vec = {
-		.iov_len = len,
-		.iov_base = data,
-	};
-	struct msghdr msg = {
-		.msg_iovlen = 1,
-		.msg_iov = (struct iovec *)&vec,
-		.msg_flags = MSG_DONTWAIT,
-	};
-
-	oldfs = get_fs();
-	set_fs(get_ds());
-	ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
-	set_fs(oldfs);
-
-	return ret;
-}
-
-static int r2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
-			      size_t veclen, size_t total)
-{
-	int ret;
-	mm_segment_t oldfs;
-	struct msghdr msg = {
-		.msg_iov = (struct iovec *)vec,
-		.msg_iovlen = veclen,
-	};
-
-	if (sock == NULL) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	oldfs = get_fs();
-	set_fs(get_ds());
-	ret = sock_sendmsg(sock, &msg, total);
-	set_fs(oldfs);
-	if (ret != total) {
-		mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
-		     total);
-		if (ret >= 0)
-			ret = -EPIPE; /* should be smarter, I bet */
-		goto out;
-	}
-
-	ret = 0;
-out:
-	if (ret < 0)
-		mlog(0, "returning error: %d\n", ret);
-	return ret;
-}
-
-static void r2net_sendpage(struct r2net_sock_container *sc,
-			   void *kmalloced_virt,
-			   size_t size)
-{
-	struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-	ssize_t ret;
-
-	while (1) {
-		mutex_lock(&sc->sc_send_lock);
-		ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
-					virt_to_page(kmalloced_virt),
-					(long)kmalloced_virt & ~PAGE_MASK,
-					size, MSG_DONTWAIT);
-		mutex_unlock(&sc->sc_send_lock);
-		if (ret == size)
-			break;
-		if (ret == (ssize_t)-EAGAIN) {
-			mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
-			     " returned EAGAIN\n", size, sc->sc_node->nd_name,
-				sc->sc_node->nd_num,
-				&sc->sc_node->nd_ipv4_address,
-				ntohs(sc->sc_node->nd_ipv4_port));
-			cond_resched();
-			continue;
-		}
-		mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
-		     " failed with %zd\n", size, sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port), ret);
-		r2net_ensure_shutdown(nn, sc, 0);
-		break;
-	}
-}
-
-static void r2net_init_msg(struct r2net_msg *msg, u16 data_len,
-				u16 msg_type, u32 key)
-{
-	memset(msg, 0, sizeof(struct r2net_msg));
-	msg->magic = cpu_to_be16(R2NET_MSG_MAGIC);
-	msg->data_len = cpu_to_be16(data_len);
-	msg->msg_type = cpu_to_be16(msg_type);
-	msg->sys_status = cpu_to_be32(R2NET_ERR_NONE);
-	msg->status = 0;
-	msg->key = cpu_to_be32(key);
-}
-
-static int r2net_tx_can_proceed(struct r2net_node *nn,
-				struct r2net_sock_container **sc_ret,
-				int *error)
-{
-	int ret = 0;
-
-	spin_lock(&nn->nn_lock);
-	if (nn->nn_persistent_error) {
-		ret = 1;
-		*sc_ret = NULL;
-		*error = nn->nn_persistent_error;
-	} else if (nn->nn_sc_valid) {
-		kref_get(&nn->nn_sc->sc_kref);
-
-		ret = 1;
-		*sc_ret = nn->nn_sc;
-		*error = 0;
-	}
-	spin_unlock(&nn->nn_lock);
-
-	return ret;
-}
-
-/* Get a map of all nodes to which this node is currently connected to */
-void r2net_fill_node_map(unsigned long *map, unsigned bytes)
-{
-	struct r2net_sock_container *sc;
-	int node, ret;
-
-	BUG_ON(bytes < (BITS_TO_LONGS(R2NM_MAX_NODES) * sizeof(unsigned long)));
-
-	memset(map, 0, bytes);
-	for (node = 0; node < R2NM_MAX_NODES; ++node) {
-		r2net_tx_can_proceed(r2net_nn_from_num(node), &sc, &ret);
-		if (!ret) {
-			set_bit(node, map);
-			sc_put(sc);
-		}
-	}
-}
-EXPORT_SYMBOL_GPL(r2net_fill_node_map);
-
-int r2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
-			   size_t caller_veclen, u8 target_node, int *status)
-{
-	int ret = 0;
-	struct r2net_msg *msg = NULL;
-	size_t veclen, caller_bytes = 0;
-	struct kvec *vec = NULL;
-	struct r2net_sock_container *sc = NULL;
-	struct r2net_node *nn = r2net_nn_from_num(target_node);
-	struct r2net_status_wait nsw = {
-		.ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
-	};
-	struct r2net_send_tracking nst;
-
-	/* this may be a general bug fix */
-	init_waitqueue_head(&nsw.ns_wq);
-
-	r2net_init_nst(&nst, msg_type, key, current, target_node);
-
-	if (r2net_wq == NULL) {
-		mlog(0, "attempt to tx without r2netd running\n");
-		ret = -ESRCH;
-		goto out;
-	}
-
-	if (caller_veclen == 0) {
-		mlog(0, "bad kvec array length\n");
-		ret = -EINVAL;
-		goto out;
-	}
-
-	caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
-	if (caller_bytes > R2NET_MAX_PAYLOAD_BYTES) {
-		mlog(0, "total payload len %zu too large\n", caller_bytes);
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (target_node == r2nm_this_node()) {
-		ret = -ELOOP;
-		goto out;
-	}
-
-	r2net_debug_add_nst(&nst);
-
-	r2net_set_nst_sock_time(&nst);
-
-	wait_event(nn->nn_sc_wq, r2net_tx_can_proceed(nn, &sc, &ret));
-	if (ret)
-		goto out;
-
-	r2net_set_nst_sock_container(&nst, sc);
-
-	veclen = caller_veclen + 1;
-	vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
-	if (vec == NULL) {
-		mlog(0, "failed to %zu element kvec!\n", veclen);
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	msg = kmalloc(sizeof(struct r2net_msg), GFP_ATOMIC);
-	if (!msg) {
-		mlog(0, "failed to allocate a r2net_msg!\n");
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	r2net_init_msg(msg, caller_bytes, msg_type, key);
-
-	vec[0].iov_len = sizeof(struct r2net_msg);
-	vec[0].iov_base = msg;
-	memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
-
-	ret = r2net_prep_nsw(nn, &nsw);
-	if (ret)
-		goto out;
-
-	msg->msg_num = cpu_to_be32(nsw.ns_id);
-	r2net_set_nst_msg_id(&nst, nsw.ns_id);
-
-	r2net_set_nst_send_time(&nst);
-
-	/* finally, convert the message header to network byte-order
-	 * and send */
-	mutex_lock(&sc->sc_send_lock);
-	ret = r2net_send_tcp_msg(sc->sc_sock, vec, veclen,
-				 sizeof(struct r2net_msg) + caller_bytes);
-	mutex_unlock(&sc->sc_send_lock);
-	msglog(msg, "sending returned %d\n", ret);
-	if (ret < 0) {
-		mlog(0, "error returned from r2net_send_tcp_msg=%d\n", ret);
-		goto out;
-	}
-
-	/* wait on other node's handler */
-	r2net_set_nst_status_time(&nst);
-	wait_event(nsw.ns_wq, r2net_nsw_completed(nn, &nsw) ||
-			nn->nn_persistent_error || !nn->nn_sc_valid);
-
-	r2net_update_send_stats(&nst, sc);
-
-	/* Note that we avoid overwriting the callers status return
-	 * variable if a system error was reported on the other
-	 * side. Callers beware. */
-	ret = r2net_sys_err_to_errno(nsw.ns_sys_status);
-	if (status && !ret)
-		*status = nsw.ns_status;
-
-	mlog(0, "woken, returning system status %d, user status %d\n",
-	     ret, nsw.ns_status);
-out:
-	r2net_debug_del_nst(&nst); /* must be before dropping sc and node */
-	if (sc)
-		sc_put(sc);
-	kfree(vec);
-	kfree(msg);
-	r2net_complete_nsw(nn, &nsw, 0, 0, 0);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(r2net_send_message_vec);
-
-int r2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
-		       u8 target_node, int *status)
-{
-	struct kvec vec = {
-		.iov_base = data,
-		.iov_len = len,
-	};
-	return r2net_send_message_vec(msg_type, key, &vec, 1,
-				      target_node, status);
-}
-EXPORT_SYMBOL_GPL(r2net_send_message);
-
-static int r2net_send_status_magic(struct socket *sock, struct r2net_msg *hdr,
-				   enum r2net_system_error syserr, int err)
-{
-	struct kvec vec = {
-		.iov_base = hdr,
-		.iov_len = sizeof(struct r2net_msg),
-	};
-
-	BUG_ON(syserr >= R2NET_ERR_MAX);
-
-	/* leave other fields intact from the incoming message, msg_num
-	 * in particular */
-	hdr->sys_status = cpu_to_be32(syserr);
-	hdr->status = cpu_to_be32(err);
-	/* twiddle the magic */
-	hdr->magic = cpu_to_be16(R2NET_MSG_STATUS_MAGIC);
-	hdr->data_len = 0;
-
-	msglog(hdr, "about to send status magic %d\n", err);
-	/* hdr has been in host byteorder this whole time */
-	return r2net_send_tcp_msg(sock, &vec, 1, sizeof(struct r2net_msg));
-}
-
-/*
- * "data magic" is a long version of "status magic" where the message
- * payload actually contains data to be passed in reply to certain messages
- */
-static int r2net_send_data_magic(struct r2net_sock_container *sc,
-			  struct r2net_msg *hdr,
-			  void *data, size_t data_len,
-			  enum r2net_system_error syserr, int err)
-{
-	struct kvec vec[2];
-	int ret;
-
-	vec[0].iov_base = hdr;
-	vec[0].iov_len = sizeof(struct r2net_msg);
-	vec[1].iov_base = data;
-	vec[1].iov_len = data_len;
-
-	BUG_ON(syserr >= R2NET_ERR_MAX);
-
-	/* leave other fields intact from the incoming message, msg_num
-	 * in particular */
-	hdr->sys_status = cpu_to_be32(syserr);
-	hdr->status = cpu_to_be32(err);
-	hdr->magic = cpu_to_be16(R2NET_MSG_DATA_MAGIC);  /* twiddle magic */
-	hdr->data_len = cpu_to_be16(data_len);
-
-	msglog(hdr, "about to send data magic %d\n", err);
-	/* hdr has been in host byteorder this whole time */
-	ret = r2net_send_tcp_msg(sc->sc_sock, vec, 2,
-			sizeof(struct r2net_msg) + data_len);
-	return ret;
-}
-
-/*
- * called by a message handler to convert an otherwise normal reply
- * message into a "data magic" message
- */
-void r2net_force_data_magic(struct r2net_msg *hdr, u16 msgtype, u32 msgkey)
-{
-	hdr->magic = cpu_to_be16(R2NET_MSG_DATA_MAGIC);
-	hdr->msg_type = cpu_to_be16(msgtype);
-	hdr->key = cpu_to_be32(msgkey);
-}
-
-/* this returns -errno if the header was unknown or too large, etc.
- * after this is called the buffer us reused for the next message */
-static int r2net_process_message(struct r2net_sock_container *sc,
-				 struct r2net_msg *hdr)
-{
-	struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-	int ret = 0, handler_status;
-	enum  r2net_system_error syserr;
-	struct r2net_msg_handler *nmh = NULL;
-	void *ret_data = NULL;
-	int data_magic = 0;
-
-	msglog(hdr, "processing message\n");
-
-	r2net_sc_postpone_idle(sc);
-
-	switch (be16_to_cpu(hdr->magic)) {
-
-	case R2NET_MSG_STATUS_MAGIC:
-		/* special type for returning message status */
-		r2net_complete_nsw(nn, NULL, be32_to_cpu(hdr->msg_num),
-						be32_to_cpu(hdr->sys_status),
-						be32_to_cpu(hdr->status));
-		goto out;
-	case R2NET_MSG_KEEP_REQ_MAGIC:
-		r2net_sendpage(sc, r2net_keep_resp, sizeof(*r2net_keep_resp));
-		goto out;
-	case R2NET_MSG_KEEP_RESP_MAGIC:
-		goto out;
-	case R2NET_MSG_MAGIC:
-		break;
-	case R2NET_MSG_DATA_MAGIC:
-		/*
-		 * unlike a normal status magic, a data magic DOES
-		 * (MUST) have a handler, so the control flow is
-		 * a little funky here as a result
-		 */
-		data_magic = 1;
-		break;
-	default:
-		msglog(hdr, "bad magic\n");
-		ret = -EINVAL;
-		goto out;
-		break;
-	}
-
-	/* find a handler for it */
-	handler_status = 0;
-	nmh = r2net_handler_get(be16_to_cpu(hdr->msg_type),
-				be32_to_cpu(hdr->key));
-	if (!nmh) {
-		mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
-		     be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
-		syserr = R2NET_ERR_NO_HNDLR;
-		goto out_respond;
-	}
-
-	syserr = R2NET_ERR_NONE;
-
-	if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
-		syserr = R2NET_ERR_OVERFLOW;
-
-	if (syserr != R2NET_ERR_NONE) {
-		pr_err("ramster_r2net, message length problem\n");
-		goto out_respond;
-	}
-
-	r2net_set_func_start_time(sc);
-	sc->sc_msg_key = be32_to_cpu(hdr->key);
-	sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
-	handler_status = (nmh->nh_func)(hdr, sizeof(struct r2net_msg) +
-					     be16_to_cpu(hdr->data_len),
-					nmh->nh_func_data, &ret_data);
-	if (data_magic) {
-		/*
-		 * handler handled data sent in reply to request
-		 * so complete the transaction
-		 */
-		r2net_complete_nsw(nn, NULL, be32_to_cpu(hdr->msg_num),
-			be32_to_cpu(hdr->sys_status), handler_status);
-		goto out;
-	}
-	/*
-	 * handler changed magic to DATA_MAGIC to reply to request for data,
-	 * implies ret_data points to data to return and handler_status
-	 * is the number of bytes of data
-	 */
-	if (be16_to_cpu(hdr->magic) == R2NET_MSG_DATA_MAGIC) {
-		ret = r2net_send_data_magic(sc, hdr,
-						ret_data, handler_status,
-						syserr, 0);
-		hdr = NULL;
-		mlog(0, "sending data reply %d, syserr %d returned %d\n",
-			handler_status, syserr, ret);
-		r2net_set_func_stop_time(sc);
-
-		r2net_update_recv_stats(sc);
-		goto out;
-	}
-	r2net_set_func_stop_time(sc);
-
-	r2net_update_recv_stats(sc);
-
-out_respond:
-	/* this destroys the hdr, so don't use it after this */
-	mutex_lock(&sc->sc_send_lock);
-	ret = r2net_send_status_magic(sc->sc_sock, hdr, syserr,
-				      handler_status);
-	mutex_unlock(&sc->sc_send_lock);
-	hdr = NULL;
-	mlog(0, "sending handler status %d, syserr %d returned %d\n",
-	     handler_status, syserr, ret);
-
-	if (nmh) {
-		BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
-		if (nmh->nh_post_func)
-			(nmh->nh_post_func)(handler_status, nmh->nh_func_data,
-					    ret_data);
-	}
-
-out:
-	if (nmh)
-		r2net_handler_put(nmh);
-	return ret;
-}
-
-static int r2net_check_handshake(struct r2net_sock_container *sc)
-{
-	struct r2net_handshake *hand = page_address(sc->sc_page);
-	struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-
-	if (hand->protocol_version != cpu_to_be64(R2NET_PROTOCOL_VERSION)) {
-		pr_notice("ramster: " SC_NODEF_FMT " Advertised net "
-		       "protocol version %llu but %llu is required. "
-		       "Disconnecting.\n", sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port),
-		       (unsigned long long)be64_to_cpu(hand->protocol_version),
-		       R2NET_PROTOCOL_VERSION);
-
-		/* don't bother reconnecting if its the wrong version. */
-		r2net_ensure_shutdown(nn, sc, -ENOTCONN);
-		return -1;
-	}
-
-	/*
-	 * Ensure timeouts are consistent with other nodes, otherwise
-	 * we can end up with one node thinking that the other must be down,
-	 * but isn't. This can ultimately cause corruption.
-	 */
-	if (be32_to_cpu(hand->r2net_idle_timeout_ms) !=
-				r2net_idle_timeout()) {
-		pr_notice("ramster: " SC_NODEF_FMT " uses a network "
-		       "idle timeout of %u ms, but we use %u ms locally. "
-		       "Disconnecting.\n", sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port),
-		       be32_to_cpu(hand->r2net_idle_timeout_ms),
-		       r2net_idle_timeout());
-		r2net_ensure_shutdown(nn, sc, -ENOTCONN);
-		return -1;
-	}
-
-	if (be32_to_cpu(hand->r2net_keepalive_delay_ms) !=
-			r2net_keepalive_delay()) {
-		pr_notice("ramster: " SC_NODEF_FMT " uses a keepalive "
-		       "delay of %u ms, but we use %u ms locally. "
-		       "Disconnecting.\n", sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port),
-		       be32_to_cpu(hand->r2net_keepalive_delay_ms),
-		       r2net_keepalive_delay());
-		r2net_ensure_shutdown(nn, sc, -ENOTCONN);
-		return -1;
-	}
-
-	if (be32_to_cpu(hand->r2hb_heartbeat_timeout_ms) !=
-			R2HB_MAX_WRITE_TIMEOUT_MS) {
-		pr_notice("ramster: " SC_NODEF_FMT " uses a heartbeat "
-		       "timeout of %u ms, but we use %u ms locally. "
-		       "Disconnecting.\n", sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port),
-		       be32_to_cpu(hand->r2hb_heartbeat_timeout_ms),
-		       R2HB_MAX_WRITE_TIMEOUT_MS);
-		r2net_ensure_shutdown(nn, sc, -ENOTCONN);
-		return -1;
-	}
-
-	sc->sc_handshake_ok = 1;
-
-	spin_lock(&nn->nn_lock);
-	/* set valid and queue the idle timers only if it hasn't been
-	 * shut down already */
-	if (nn->nn_sc == sc) {
-		r2net_sc_reset_idle_timer(sc);
-		atomic_set(&nn->nn_timeout, 0);
-		r2net_set_nn_state(nn, sc, 1, 0);
-	}
-	spin_unlock(&nn->nn_lock);
-
-	/* shift everything up as though it wasn't there */
-	sc->sc_page_off -= sizeof(struct r2net_handshake);
-	if (sc->sc_page_off)
-		memmove(hand, hand + 1, sc->sc_page_off);
-
-	return 0;
-}
-
-/* this demuxes the queued rx bytes into header or payload bits and calls
- * handlers as each full message is read off the socket.  it returns -error,
- * == 0 eof, or > 0 for progress made.*/
-static int r2net_advance_rx(struct r2net_sock_container *sc)
-{
-	struct r2net_msg *hdr;
-	int ret = 0;
-	void *data;
-	size_t datalen;
-
-	sclog(sc, "receiving\n");
-	r2net_set_advance_start_time(sc);
-
-	if (unlikely(sc->sc_handshake_ok == 0)) {
-		if (sc->sc_page_off < sizeof(struct r2net_handshake)) {
-			data = page_address(sc->sc_page) + sc->sc_page_off;
-			datalen = sizeof(struct r2net_handshake) -
-							sc->sc_page_off;
-			ret = r2net_recv_tcp_msg(sc->sc_sock, data, datalen);
-			if (ret > 0)
-				sc->sc_page_off += ret;
-		}
-
-		if (sc->sc_page_off == sizeof(struct r2net_handshake)) {
-			r2net_check_handshake(sc);
-			if (unlikely(sc->sc_handshake_ok == 0))
-				ret = -EPROTO;
-		}
-		goto out;
-	}
-
-	/* do we need more header? */
-	if (sc->sc_page_off < sizeof(struct r2net_msg)) {
-		data = page_address(sc->sc_page) + sc->sc_page_off;
-		datalen = sizeof(struct r2net_msg) - sc->sc_page_off;
-		ret = r2net_recv_tcp_msg(sc->sc_sock, data, datalen);
-		if (ret > 0) {
-			sc->sc_page_off += ret;
-			/* only swab incoming here.. we can
-			 * only get here once as we cross from
-			 * being under to over */
-			if (sc->sc_page_off == sizeof(struct r2net_msg)) {
-				hdr = page_address(sc->sc_page);
-				if (be16_to_cpu(hdr->data_len) >
-				    R2NET_MAX_PAYLOAD_BYTES)
-					ret = -EOVERFLOW;
-				WARN_ON_ONCE(ret == -EOVERFLOW);
-			}
-		}
-		if (ret <= 0)
-			goto out;
-	}
-
-	if (sc->sc_page_off < sizeof(struct r2net_msg)) {
-		/* oof, still don't have a header */
-		goto out;
-	}
-
-	/* this was swabbed above when we first read it */
-	hdr = page_address(sc->sc_page);
-
-	msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
-
-	/* do we need more payload? */
-	if (sc->sc_page_off - sizeof(struct r2net_msg) <
-					be16_to_cpu(hdr->data_len)) {
-		/* need more payload */
-		data = page_address(sc->sc_page) + sc->sc_page_off;
-		datalen = (sizeof(struct r2net_msg) +
-				be16_to_cpu(hdr->data_len)) -
-				sc->sc_page_off;
-		ret = r2net_recv_tcp_msg(sc->sc_sock, data, datalen);
-		if (ret > 0)
-			sc->sc_page_off += ret;
-		if (ret <= 0)
-			goto out;
-	}
-
-	if (sc->sc_page_off - sizeof(struct r2net_msg) ==
-						be16_to_cpu(hdr->data_len)) {
-		/* we can only get here once, the first time we read
-		 * the payload.. so set ret to progress if the handler
-		 * works out. after calling this the message is toast */
-		ret = r2net_process_message(sc, hdr);
-		if (ret == 0)
-			ret = 1;
-		sc->sc_page_off = 0;
-	}
-
-out:
-	sclog(sc, "ret = %d\n", ret);
-	r2net_set_advance_stop_time(sc);
-	return ret;
-}
-
-/* this work func is triggerd by data ready.  it reads until it can read no
- * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
- * our work the work struct will be marked and we'll be called again. */
-static void r2net_rx_until_empty(struct work_struct *work)
-{
-	struct r2net_sock_container *sc =
-		container_of(work, struct r2net_sock_container, sc_rx_work);
-	int ret;
-
-	do {
-		ret = r2net_advance_rx(sc);
-	} while (ret > 0);
-
-	if (ret <= 0 && ret != -EAGAIN) {
-		struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-		sclog(sc, "saw error %d, closing\n", ret);
-		/* not permanent so read failed handshake can retry */
-		r2net_ensure_shutdown(nn, sc, 0);
-	}
-	sc_put(sc);
-}
-
-static int r2net_set_nodelay(struct socket *sock)
-{
-	int ret, val = 1;
-	mm_segment_t oldfs;
-
-	oldfs = get_fs();
-	set_fs(KERNEL_DS);
-
-	/*
-	 * Dear unsuspecting programmer,
-	 *
-	 * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
-	 * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
-	 * silently turn into SO_DEBUG.
-	 *
-	 * Yours,
-	 * Keeper of hilariously fragile interfaces.
-	 */
-	ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
-				    (char __user *)&val, sizeof(val));
-
-	set_fs(oldfs);
-	return ret;
-}
-
-static void r2net_initialize_handshake(void)
-{
-	r2net_hand->r2hb_heartbeat_timeout_ms = cpu_to_be32(
-		R2HB_MAX_WRITE_TIMEOUT_MS);
-	r2net_hand->r2net_idle_timeout_ms = cpu_to_be32(r2net_idle_timeout());
-	r2net_hand->r2net_keepalive_delay_ms = cpu_to_be32(
-		r2net_keepalive_delay());
-	r2net_hand->r2net_reconnect_delay_ms = cpu_to_be32(
-		r2net_reconnect_delay());
-}
-
-/* ------------------------------------------------------------ */
-
-/* called when a connect completes and after a sock is accepted.  the
- * rx path will see the response and mark the sc valid */
-static void r2net_sc_connect_completed(struct work_struct *work)
-{
-	struct r2net_sock_container *sc =
-			container_of(work, struct r2net_sock_container,
-			     sc_connect_work);
-
-	mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
-		(unsigned long long)R2NET_PROTOCOL_VERSION,
-		(unsigned long long)be64_to_cpu(r2net_hand->connector_id));
-
-	r2net_initialize_handshake();
-	r2net_sendpage(sc, r2net_hand, sizeof(*r2net_hand));
-	sc_put(sc);
-}
-
-/* this is called as a work_struct func. */
-static void r2net_sc_send_keep_req(struct work_struct *work)
-{
-	struct r2net_sock_container *sc =
-		container_of(work, struct r2net_sock_container,
-			     sc_keepalive_work.work);
-
-	r2net_sendpage(sc, r2net_keep_req, sizeof(*r2net_keep_req));
-	sc_put(sc);
-}
-
-/* socket shutdown does a del_timer_sync against this as it tears down.
- * we can't start this timer until we've got to the point in sc buildup
- * where shutdown is going to be involved */
-static void r2net_idle_timer(unsigned long data)
-{
-	struct r2net_sock_container *sc = (struct r2net_sock_container *)data;
-	struct r2net_node *nn = r2net_nn_from_num(sc->sc_node->nd_num);
-#ifdef CONFIG_DEBUG_FS
-	unsigned long msecs = ktime_to_ms(ktime_get()) -
-		ktime_to_ms(sc->sc_tv_timer);
-#else
-	unsigned long msecs = r2net_idle_timeout();
-#endif
-
-	pr_notice("ramster: Connection to " SC_NODEF_FMT " has been "
-	       "idle for %lu.%lu secs, shutting it down.\n",
-		sc->sc_node->nd_name, sc->sc_node->nd_num,
-		&sc->sc_node->nd_ipv4_address, ntohs(sc->sc_node->nd_ipv4_port),
-	       msecs / 1000, msecs % 1000);
-
-	/*
-	 * Initialize the nn_timeout so that the next connection attempt
-	 * will continue in r2net_start_connect.
-	 */
-	atomic_set(&nn->nn_timeout, 1);
-	r2net_sc_queue_work(sc, &sc->sc_shutdown_work);
-}
-
-static void r2net_sc_reset_idle_timer(struct r2net_sock_container *sc)
-{
-	r2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
-	r2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
-		      msecs_to_jiffies(r2net_keepalive_delay()));
-	r2net_set_sock_timer(sc);
-	mod_timer(&sc->sc_idle_timeout,
-	       jiffies + msecs_to_jiffies(r2net_idle_timeout()));
-}
-
-static void r2net_sc_postpone_idle(struct r2net_sock_container *sc)
-{
-	/* Only push out an existing timer */
-	if (timer_pending(&sc->sc_idle_timeout))
-		r2net_sc_reset_idle_timer(sc);
-}
-
-/* this work func is kicked whenever a path sets the nn state which doesn't
- * have valid set.  This includes seeing hb come up, losing a connection,
- * having a connect attempt fail, etc. This centralizes the logic which decides
- * if a connect attempt should be made or if we should give up and all future
- * transmit attempts should fail */
-static void r2net_start_connect(struct work_struct *work)
-{
-	struct r2net_node *nn =
-		container_of(work, struct r2net_node, nn_connect_work.work);
-	struct r2net_sock_container *sc = NULL;
-	struct r2nm_node *node = NULL, *mynode = NULL;
-	struct socket *sock = NULL;
-	struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
-	int ret = 0, stop;
-	unsigned int timeout;
-
-	/* if we're greater we initiate tx, otherwise we accept */
-	if (r2nm_this_node() <= r2net_num_from_nn(nn))
-		goto out;
-
-	/* watch for racing with tearing a node down */
-	node = r2nm_get_node_by_num(r2net_num_from_nn(nn));
-	if (node == NULL) {
-		ret = 0;
-		goto out;
-	}
-
-	mynode = r2nm_get_node_by_num(r2nm_this_node());
-	if (mynode == NULL) {
-		ret = 0;
-		goto out;
-	}
-
-	spin_lock(&nn->nn_lock);
-	/*
-	 * see if we already have one pending or have given up.
-	 * For nn_timeout, it is set when we close the connection
-	 * because of the idle time out. So it means that we have
-	 * at least connected to that node successfully once,
-	 * now try to connect to it again.
-	 */
-	timeout = atomic_read(&nn->nn_timeout);
-	stop = (nn->nn_sc ||
-		(nn->nn_persistent_error &&
-		(nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
-	spin_unlock(&nn->nn_lock);
-	if (stop)
-		goto out;
-
-	nn->nn_last_connect_attempt = jiffies;
-
-	sc = sc_alloc(node);
-	if (sc == NULL) {
-		mlog(0, "couldn't allocate sc\n");
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
-	if (ret < 0) {
-		mlog(0, "can't create socket: %d\n", ret);
-		goto out;
-	}
-	sc->sc_sock = sock; /* freed by sc_kref_release */
-
-	sock->sk->sk_allocation = GFP_ATOMIC;
-
-	myaddr.sin_family = AF_INET;
-	myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
-	myaddr.sin_port = htons(0); /* any port */
-
-	ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
-			      sizeof(myaddr));
-	if (ret) {
-		mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
-		     ret, &mynode->nd_ipv4_address);
-		goto out;
-	}
-
-	ret = r2net_set_nodelay(sc->sc_sock);
-	if (ret) {
-		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
-		goto out;
-	}
-
-	r2net_register_callbacks(sc->sc_sock->sk, sc);
-
-	spin_lock(&nn->nn_lock);
-	/* handshake completion will set nn->nn_sc_valid */
-	r2net_set_nn_state(nn, sc, 0, 0);
-	spin_unlock(&nn->nn_lock);
-
-	remoteaddr.sin_family = AF_INET;
-	remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
-	remoteaddr.sin_port = node->nd_ipv4_port;
-
-	ret = sc->sc_sock->ops->connect(sc->sc_sock,
-					(struct sockaddr *)&remoteaddr,
-					sizeof(remoteaddr),
-					O_NONBLOCK);
-	if (ret == -EINPROGRESS)
-		ret = 0;
-
-out:
-	if (ret) {
-		pr_notice("ramster: Connect attempt to " SC_NODEF_FMT
-		       " failed with errno %d\n", sc->sc_node->nd_name,
-			sc->sc_node->nd_num, &sc->sc_node->nd_ipv4_address,
-			ntohs(sc->sc_node->nd_ipv4_port), ret);
-		/* 0 err so that another will be queued and attempted
-		 * from set_nn_state */
-		if (sc)
-			r2net_ensure_shutdown(nn, sc, 0);
-	}
-	if (sc)
-		sc_put(sc);
-	if (node)
-		r2nm_node_put(node);
-	if (mynode)
-		r2nm_node_put(mynode);
-
-	return;
-}
-
-static void r2net_connect_expired(struct work_struct *work)
-{
-	struct r2net_node *nn =
-		container_of(work, struct r2net_node, nn_connect_expired.work);
-
-	spin_lock(&nn->nn_lock);
-	if (!nn->nn_sc_valid) {
-		pr_notice("ramster: No connection established with "
-		       "node %u after %u.%u seconds, giving up.\n",
-		     r2net_num_from_nn(nn),
-		     r2net_idle_timeout() / 1000,
-		     r2net_idle_timeout() % 1000);
-
-		r2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
-	}
-	spin_unlock(&nn->nn_lock);
-}
-
-static void r2net_still_up(struct work_struct *work)
-{
-}
-
-/* ------------------------------------------------------------ */
-
-void r2net_disconnect_node(struct r2nm_node *node)
-{
-	struct r2net_node *nn = r2net_nn_from_num(node->nd_num);
-
-	/* don't reconnect until it's heartbeating again */
-	spin_lock(&nn->nn_lock);
-	atomic_set(&nn->nn_timeout, 0);
-	r2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
-	spin_unlock(&nn->nn_lock);
-
-	if (r2net_wq) {
-		cancel_delayed_work(&nn->nn_connect_expired);
-		cancel_delayed_work(&nn->nn_connect_work);
-		cancel_delayed_work(&nn->nn_still_up);
-		flush_workqueue(r2net_wq);
-	}
-}
-
-static void r2net_hb_node_down_cb(struct r2nm_node *node, int node_num,
-				  void *data)
-{
-	if (!node)
-		return;
-
-	if (node_num != r2nm_this_node())
-		r2net_disconnect_node(node);
-
-	BUG_ON(atomic_read(&r2net_connected_peers) < 0);
-}
-
-static void r2net_hb_node_up_cb(struct r2nm_node *node, int node_num,
-				void *data)
-{
-	struct r2net_node *nn = r2net_nn_from_num(node_num);
-
-	BUG_ON(!node);
-
-	/* ensure an immediate connect attempt */
-	nn->nn_last_connect_attempt = jiffies -
-		(msecs_to_jiffies(r2net_reconnect_delay()) + 1);
-
-	if (node_num != r2nm_this_node()) {
-		/* believe it or not, accept and node hearbeating testing
-		 * can succeed for this node before we got here.. so
-		 * only use set_nn_state to clear the persistent error
-		 * if that hasn't already happened */
-		spin_lock(&nn->nn_lock);
-		atomic_set(&nn->nn_timeout, 0);
-		if (nn->nn_persistent_error)
-			r2net_set_nn_state(nn, NULL, 0, 0);
-		spin_unlock(&nn->nn_lock);
-	}
-}
-
-void r2net_unregister_hb_callbacks(void)
-{
-	r2hb_unregister_callback(NULL, &r2net_hb_up);
-	r2hb_unregister_callback(NULL, &r2net_hb_down);
-}
-
-int r2net_register_hb_callbacks(void)
-{
-	int ret;
-
-	r2hb_setup_callback(&r2net_hb_down, R2HB_NODE_DOWN_CB,
-			    r2net_hb_node_down_cb, NULL, R2NET_HB_PRI);
-	r2hb_setup_callback(&r2net_hb_up, R2HB_NODE_UP_CB,
-			    r2net_hb_node_up_cb, NULL, R2NET_HB_PRI);
-
-	ret = r2hb_register_callback(NULL, &r2net_hb_up);
-	if (ret == 0)
-		ret = r2hb_register_callback(NULL, &r2net_hb_down);
-
-	if (ret)
-		r2net_unregister_hb_callbacks();
-
-	return ret;
-}
-
-/* ------------------------------------------------------------ */
-
-static int r2net_accept_one(struct socket *sock)
-{
-	int ret, slen;
-	struct sockaddr_in sin;
-	struct socket *new_sock = NULL;
-	struct r2nm_node *node = NULL;
-	struct r2nm_node *local_node = NULL;
-	struct r2net_sock_container *sc = NULL;
-	struct r2net_node *nn;
-
-	BUG_ON(sock == NULL);
-	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
-			       sock->sk->sk_protocol, &new_sock);
-	if (ret)
-		goto out;
-
-	new_sock->type = sock->type;
-	new_sock->ops = sock->ops;
-	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
-	if (ret < 0)
-		goto out;
-
-	new_sock->sk->sk_allocation = GFP_ATOMIC;
-
-	ret = r2net_set_nodelay(new_sock);
-	if (ret) {
-		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
-		goto out;
-	}
-
-	slen = sizeof(sin);
-	ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
-				       &slen, 1);
-	if (ret < 0)
-		goto out;
-
-	node = r2nm_get_node_by_ip(sin.sin_addr.s_addr);
-	if (node == NULL) {
-		pr_notice("ramster: Attempt to connect from unknown "
-		       "node at %pI4:%d\n", &sin.sin_addr.s_addr,
-		       ntohs(sin.sin_port));
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (r2nm_this_node() >= node->nd_num) {
-		local_node = r2nm_get_node_by_num(r2nm_this_node());
-		pr_notice("ramster: Unexpected connect attempt seen "
-		       "at node '%s' (%u, %pI4:%d) from node '%s' (%u, "
-		       "%pI4:%d)\n", local_node->nd_name, local_node->nd_num,
-		       &(local_node->nd_ipv4_address),
-		       ntohs(local_node->nd_ipv4_port), node->nd_name,
-		       node->nd_num, &sin.sin_addr.s_addr, ntohs(sin.sin_port));
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/* this happens all the time when the other node sees our heartbeat
-	 * and tries to connect before we see their heartbeat */
-	if (!r2hb_check_node_heartbeating_from_callback(node->nd_num)) {
-		mlog(ML_CONN, "attempt to connect from node '%s' at "
-		     "%pI4:%d but it isn't heartbeating\n",
-		     node->nd_name, &sin.sin_addr.s_addr,
-		     ntohs(sin.sin_port));
-		ret = -EINVAL;
-		goto out;
-	}
-
-	nn = r2net_nn_from_num(node->nd_num);
-
-	spin_lock(&nn->nn_lock);
-	if (nn->nn_sc)
-		ret = -EBUSY;
-	else
-		ret = 0;
-	spin_unlock(&nn->nn_lock);
-	if (ret) {
-		pr_notice("ramster: Attempt to connect from node '%s' "
-		       "at %pI4:%d but it already has an open connection\n",
-		       node->nd_name, &sin.sin_addr.s_addr,
-		       ntohs(sin.sin_port));
-		goto out;
-	}
-
-	sc = sc_alloc(node);
-	if (sc == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	sc->sc_sock = new_sock;
-	new_sock = NULL;
-
-	spin_lock(&nn->nn_lock);
-	atomic_set(&nn->nn_timeout, 0);
-	r2net_set_nn_state(nn, sc, 0, 0);
-	spin_unlock(&nn->nn_lock);
-
-	r2net_register_callbacks(sc->sc_sock->sk, sc);
-	r2net_sc_queue_work(sc, &sc->sc_rx_work);
-
-	r2net_initialize_handshake();
-	r2net_sendpage(sc, r2net_hand, sizeof(*r2net_hand));
-
-out:
-	if (new_sock)
-		sock_release(new_sock);
-	if (node)
-		r2nm_node_put(node);
-	if (local_node)
-		r2nm_node_put(local_node);
-	if (sc)
-		sc_put(sc);
-	return ret;
-}
-
-static void r2net_accept_many(struct work_struct *work)
-{
-	struct socket *sock = r2net_listen_sock;
-	while (r2net_accept_one(sock) == 0)
-		cond_resched();
-}
-
-static void r2net_listen_data_ready(struct sock *sk, int bytes)
-{
-	void (*ready)(struct sock *sk, int bytes);
-
-	read_lock(&sk->sk_callback_lock);
-	ready = sk->sk_user_data;
-	if (ready == NULL) { /* check for teardown race */
-		ready = sk->sk_data_ready;
-		goto out;
-	}
-
-	/* ->sk_data_ready is also called for a newly established child socket
-	 * before it has been accepted and the acceptor has set up their
-	 * data_ready.. we only want to queue listen work for our listening
-	 * socket */
-	if (sk->sk_state == TCP_LISTEN) {
-		mlog(ML_TCP, "bytes: %d\n", bytes);
-		queue_work(r2net_wq, &r2net_listen_work);
-	}
-
-out:
-	read_unlock(&sk->sk_callback_lock);
-	ready(sk, bytes);
-}
-
-static int r2net_open_listening_sock(__be32 addr, __be16 port)
-{
-	struct socket *sock = NULL;
-	int ret;
-	struct sockaddr_in sin = {
-		.sin_family = PF_INET,
-		.sin_addr = { .s_addr = addr },
-		.sin_port = port,
-	};
-
-	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
-	if (ret < 0) {
-		pr_err("ramster: Error %d while creating socket\n", ret);
-		goto out;
-	}
-
-	sock->sk->sk_allocation = GFP_ATOMIC;
-
-	write_lock_bh(&sock->sk->sk_callback_lock);
-	sock->sk->sk_user_data = sock->sk->sk_data_ready;
-	sock->sk->sk_data_ready = r2net_listen_data_ready;
-	write_unlock_bh(&sock->sk->sk_callback_lock);
-
-	r2net_listen_sock = sock;
-	INIT_WORK(&r2net_listen_work, r2net_accept_many);
-
-	sock->sk->sk_reuse = /* SK_CAN_REUSE FIXME FOR 3.4 */ 1;
-	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
-	if (ret < 0) {
-		pr_err("ramster: Error %d while binding socket at %pI4:%u\n",
-			ret, &addr, ntohs(port));
-		goto out;
-	}
-
-	ret = sock->ops->listen(sock, 64);
-	if (ret < 0)
-		pr_err("ramster: Error %d while listening on %pI4:%u\n",
-		       ret, &addr, ntohs(port));
-
-out:
-	if (ret) {
-		r2net_listen_sock = NULL;
-		if (sock)
-			sock_release(sock);
-	}
-	return ret;
-}
-
-/*
- * called from node manager when we should bring up our network listening
- * socket.  node manager handles all the serialization to only call this
- * once and to match it with r2net_stop_listening().  note,
- * r2nm_this_node() doesn't work yet as we're being called while it
- * is being set up.
- */
-int r2net_start_listening(struct r2nm_node *node)
-{
-	int ret = 0;
-
-	BUG_ON(r2net_wq != NULL);
-	BUG_ON(r2net_listen_sock != NULL);
-
-	mlog(ML_KTHREAD, "starting r2net thread...\n");
-	r2net_wq = create_singlethread_workqueue("r2net");
-	if (r2net_wq == NULL) {
-		mlog(ML_ERROR, "unable to launch r2net thread\n");
-		return -ENOMEM; /* ? */
-	}
-
-	ret = r2net_open_listening_sock(node->nd_ipv4_address,
-					node->nd_ipv4_port);
-	if (ret) {
-		destroy_workqueue(r2net_wq);
-		r2net_wq = NULL;
-	}
-
-	return ret;
-}
-
-/* again, r2nm_this_node() doesn't work here as we're involved in
- * tearing it down */
-void r2net_stop_listening(struct r2nm_node *node)
-{
-	struct socket *sock = r2net_listen_sock;
-	size_t i;
-
-	BUG_ON(r2net_wq == NULL);
-	BUG_ON(r2net_listen_sock == NULL);
-
-	/* stop the listening socket from generating work */
-	write_lock_bh(&sock->sk->sk_callback_lock);
-	sock->sk->sk_data_ready = sock->sk->sk_user_data;
-	sock->sk->sk_user_data = NULL;
-	write_unlock_bh(&sock->sk->sk_callback_lock);
-
-	for (i = 0; i < ARRAY_SIZE(r2net_nodes); i++) {
-		struct r2nm_node *node = r2nm_get_node_by_num(i);
-		if (node) {
-			r2net_disconnect_node(node);
-			r2nm_node_put(node);
-		}
-	}
-
-	/* finish all work and tear down the work queue */
-	mlog(ML_KTHREAD, "waiting for r2net thread to exit....\n");
-	destroy_workqueue(r2net_wq);
-	r2net_wq = NULL;
-
-	sock_release(r2net_listen_sock);
-	r2net_listen_sock = NULL;
-}
-
-void r2net_hb_node_up_manual(int node_num)
-{
-	struct r2nm_node dummy;
-	if (r2nm_single_cluster == NULL)
-		pr_err("ramster: cluster not alive, node_up_manual ignored\n");
-	else {
-		r2hb_manual_set_node_heartbeating(node_num);
-		r2net_hb_node_up_cb(&dummy, node_num, NULL);
-	}
-}
-
-/* ------------------------------------------------------------ */
-
-int r2net_init(void)
-{
-	unsigned long i;
-
-	if (r2net_debugfs_init())
-		return -ENOMEM;
-
-	r2net_hand = kzalloc(sizeof(struct r2net_handshake), GFP_KERNEL);
-	r2net_keep_req = kzalloc(sizeof(struct r2net_msg), GFP_KERNEL);
-	r2net_keep_resp = kzalloc(sizeof(struct r2net_msg), GFP_KERNEL);
-	if (!r2net_hand || !r2net_keep_req || !r2net_keep_resp) {
-		kfree(r2net_hand);
-		kfree(r2net_keep_req);
-		kfree(r2net_keep_resp);
-		return -ENOMEM;
-	}
-
-	r2net_hand->protocol_version = cpu_to_be64(R2NET_PROTOCOL_VERSION);
-	r2net_hand->connector_id = cpu_to_be64(1);
-
-	r2net_keep_req->magic = cpu_to_be16(R2NET_MSG_KEEP_REQ_MAGIC);
-	r2net_keep_resp->magic = cpu_to_be16(R2NET_MSG_KEEP_RESP_MAGIC);
-
-	for (i = 0; i < ARRAY_SIZE(r2net_nodes); i++) {
-		struct r2net_node *nn = r2net_nn_from_num(i);
-
-		atomic_set(&nn->nn_timeout, 0);
-		spin_lock_init(&nn->nn_lock);
-		INIT_DELAYED_WORK(&nn->nn_connect_work, r2net_start_connect);
-		INIT_DELAYED_WORK(&nn->nn_connect_expired,
-				  r2net_connect_expired);
-		INIT_DELAYED_WORK(&nn->nn_still_up, r2net_still_up);
-		/* until we see hb from a node we'll return einval */
-		nn->nn_persistent_error = -ENOTCONN;
-		init_waitqueue_head(&nn->nn_sc_wq);
-		idr_init(&nn->nn_status_idr);
-		INIT_LIST_HEAD(&nn->nn_status_list);
-	}
-
-	return 0;
-}
-
-void r2net_exit(void)
-{
-	kfree(r2net_hand);
-	kfree(r2net_keep_req);
-	kfree(r2net_keep_resp);
-	r2net_debugfs_exit();
-}

drivers/staging/zcache/ramster/tcp.h

@@ -1,159 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * tcp.h
- *
- * Function prototypes
- *
- * Copyright (C) 2004 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- */
-
-#ifndef R2CLUSTER_TCP_H
-#define R2CLUSTER_TCP_H
-
-#include <linux/socket.h>
-#ifdef __KERNEL__
-#include <net/sock.h>
-#include <linux/tcp.h>
-#else
-#include <sys/socket.h>
-#endif
-#include <linux/inet.h>
-#include <linux/in.h>
-
-struct r2net_msg {
-	__be16 magic;
-	__be16 data_len;
-	__be16 msg_type;
-	__be16 pad1;
-	__be32 sys_status;
-	__be32 status;
-	__be32 key;
-	__be32 msg_num;
-	__u8  buf[0];
-};
-
-typedef int (r2net_msg_handler_func)(struct r2net_msg *msg, u32 len, void *data,
-				     void **ret_data);
-typedef void (r2net_post_msg_handler_func)(int status, void *data,
-					   void *ret_data);
-
-#define R2NET_MAX_PAYLOAD_BYTES  (4096 - sizeof(struct r2net_msg))
-
-/* same as hb delay, we're waiting for another node to recognize our hb */
-#define R2NET_RECONNECT_DELAY_MS_DEFAULT	2000
-
-#define R2NET_KEEPALIVE_DELAY_MS_DEFAULT	2000
-#define R2NET_IDLE_TIMEOUT_MS_DEFAULT		30000
-
-
-/* TODO: figure this out.... */
-static inline int r2net_link_down(int err, struct socket *sock)
-{
-	if (sock) {
-		if (sock->sk->sk_state != TCP_ESTABLISHED &&
-			sock->sk->sk_state != TCP_CLOSE_WAIT)
-			return 1;
-	}
-
-	if (err >= 0)
-		return 0;
-	switch (err) {
-
-	/* ????????????????????????? */
-	case -ERESTARTSYS:
-	case -EBADF:
-	/* When the server has died, an ICMP port unreachable
-	 * message prompts ECONNREFUSED. */
-	case -ECONNREFUSED:
-	case -ENOTCONN:
-	case -ECONNRESET:
-	case -EPIPE:
-		return 1;
-
-	}
-	return 0;
-}
-
-enum {
-	R2NET_DRIVER_UNINITED,
-	R2NET_DRIVER_READY,
-};
-
-int r2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
-		       u8 target_node, int *status);
-int r2net_send_message_vec(u32 msg_type, u32 key, struct kvec *vec,
-			   size_t veclen, u8 target_node, int *status);
-
-int r2net_register_handler(u32 msg_type, u32 key, u32 max_len,
-			   r2net_msg_handler_func *func, void *data,
-			   r2net_post_msg_handler_func *post_func,
-			   struct list_head *unreg_list);
-void r2net_unregister_handler_list(struct list_head *list);
-
-void r2net_fill_node_map(unsigned long *map, unsigned bytes);
-
-void r2net_force_data_magic(struct r2net_msg *, u16, u32);
-void r2net_hb_node_up_manual(int);
-struct r2net_node *r2net_nn_from_num(u8);
-
-struct r2nm_node;
-int r2net_register_hb_callbacks(void);
-void r2net_unregister_hb_callbacks(void);
-int r2net_start_listening(struct r2nm_node *node);
-void r2net_stop_listening(struct r2nm_node *node);
-void r2net_disconnect_node(struct r2nm_node *node);
-int r2net_num_connected_peers(void);
-
-int r2net_init(void);
-void r2net_exit(void);
-
-struct r2net_send_tracking;
-struct r2net_sock_container;
-
-#if 0
-int r2net_debugfs_init(void);
-void r2net_debugfs_exit(void);
-void r2net_debug_add_nst(struct r2net_send_tracking *nst);
-void r2net_debug_del_nst(struct r2net_send_tracking *nst);
-void r2net_debug_add_sc(struct r2net_sock_container *sc);
-void r2net_debug_del_sc(struct r2net_sock_container *sc);
-#else
-static inline int r2net_debugfs_init(void)
-{
-	return 0;
-}
-static inline void r2net_debugfs_exit(void)
-{
-}
-static inline void r2net_debug_add_nst(struct r2net_send_tracking *nst)
-{
-}
-static inline void r2net_debug_del_nst(struct r2net_send_tracking *nst)
-{
-}
-static inline void r2net_debug_add_sc(struct r2net_sock_container *sc)
-{
-}
-static inline void r2net_debug_del_sc(struct r2net_sock_container *sc)
-{
-}
-#endif	/* CONFIG_DEBUG_FS */
-
-#endif /* R2CLUSTER_TCP_H */

drivers/staging/zcache/ramster/tcp_internal.h

@@ -1,248 +0,0 @@
-/* -*- mode: c; c-basic-offset: 8; -*-
- * vim: noexpandtab sw=8 ts=8 sts=0:
- *
- * Copyright (C) 2005 Oracle.  All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#ifndef R2CLUSTER_TCP_INTERNAL_H
-#define R2CLUSTER_TCP_INTERNAL_H
-
-#define R2NET_MSG_MAGIC           ((u16)0xfa55)
-#define R2NET_MSG_STATUS_MAGIC    ((u16)0xfa56)
-#define R2NET_MSG_KEEP_REQ_MAGIC  ((u16)0xfa57)
-#define R2NET_MSG_KEEP_RESP_MAGIC ((u16)0xfa58)
-/*
- * "data magic" is a long version of "status magic" where the message
- * payload actually contains data to be passed in reply to certain messages
- */
-#define R2NET_MSG_DATA_MAGIC      ((u16)0xfa59)
-
-/* we're delaying our quorum decision so that heartbeat will have timed
- * out truly dead nodes by the time we come around to making decisions
- * on their number */
-#define R2NET_QUORUM_DELAY_MS	\
-		((r2hb_dead_threshold + 2) * R2HB_REGION_TIMEOUT_MS)
-
-/*
- * This version number represents quite a lot, unfortunately.  It not
- * only represents the raw network message protocol on the wire but also
- * locking semantics of the file system using the protocol.  It should
- * be somewhere else, I'm sure, but right now it isn't.
- *
- * With version 11, we separate out the filesystem locking portion.  The
- * filesystem now has a major.minor version it negotiates.  Version 11
- * introduces this negotiation to the r2dlm protocol, and as such the
- * version here in tcp_internal.h should not need to be bumped for
- * filesystem locking changes.
- *
- * New in version 11
- *	- Negotiation of filesystem locking in the dlm join.
- *
- * New in version 10:
- *	- Meta/data locks combined
- *
- * New in version 9:
- *	- All votes removed
- *
- * New in version 8:
- *	- Replace delete inode votes with a cluster lock
- *
- * New in version 7:
- *	- DLM join domain includes the live nodemap
- *
- * New in version 6:
- *	- DLM lockres remote refcount fixes.
- *
- * New in version 5:
- *	- Network timeout checking protocol
- *
- * New in version 4:
- *	- Remove i_generation from lock names for better stat performance.
- *
- * New in version 3:
- *	- Replace dentry votes with a cluster lock
- *
- * New in version 2:
- *	- full 64 bit i_size in the metadata lock lvbs
- *	- introduction of "rw" lock and pushing meta/data locking down
- */
-#define R2NET_PROTOCOL_VERSION 11ULL
-struct r2net_handshake {
-	__be64	protocol_version;
-	__be64	connector_id;
-	__be32  r2hb_heartbeat_timeout_ms;
-	__be32  r2net_idle_timeout_ms;
-	__be32  r2net_keepalive_delay_ms;
-	__be32  r2net_reconnect_delay_ms;
-};
-
-struct r2net_node {
-	/* this is never called from int/bh */
-	spinlock_t			nn_lock;
-
-	/* set the moment an sc is allocated and a connect is started */
-	struct r2net_sock_container	*nn_sc;
-	/* _valid is only set after the handshake passes and tx can happen */
-	unsigned			nn_sc_valid:1;
-	/* if this is set tx just returns it */
-	int				nn_persistent_error;
-	/* It is only set to 1 after the idle time out. */
-	atomic_t			nn_timeout;
-
-	/* threads waiting for an sc to arrive wait on the wq for generation
-	 * to increase.  it is increased when a connecting socket succeeds
-	 * or fails or when an accepted socket is attached. */
-	wait_queue_head_t		nn_sc_wq;
-
-	struct idr			nn_status_idr;
-	struct list_head		nn_status_list;
-
-	/* connects are attempted from when heartbeat comes up until either hb
-	 * goes down, the node is unconfigured, no connect attempts succeed
-	 * before R2NET_CONN_IDLE_DELAY, or a connect succeeds.  connect_work
-	 * is queued from set_nn_state both from hb up and from itself if a
-	 * connect attempt fails and so can be self-arming.  shutdown is
-	 * careful to first mark the nn such that no connects will be attempted
-	 * before canceling delayed connect work and flushing the queue. */
-	struct delayed_work		nn_connect_work;
-	unsigned long			nn_last_connect_attempt;
-
-	/* this is queued as nodes come up and is canceled when a connection is
-	 * established.  this expiring gives up on the node and errors out
-	 * transmits */
-	struct delayed_work		nn_connect_expired;
-
-	/* after we give up on a socket we wait a while before deciding
-	 * that it is still heartbeating and that we should do some
-	 * quorum work */
-	struct delayed_work		nn_still_up;
-};
-
-struct r2net_sock_container {
-	struct kref		sc_kref;
-	/* the next two are valid for the life time of the sc */
-	struct socket		*sc_sock;
-	struct r2nm_node	*sc_node;
-
-	/* all of these sc work structs hold refs on the sc while they are
-	 * queued.  they should not be able to ref a freed sc.  the teardown
-	 * race is with r2net_wq destruction in r2net_stop_listening() */
-
-	/* rx and connect work are generated from socket callbacks.  sc
-	 * shutdown removes the callbacks and then flushes the work queue */
-	struct work_struct	sc_rx_work;
-	struct work_struct	sc_connect_work;
-	/* shutdown work is triggered in two ways.  the simple way is
-	 * for a code path calls ensure_shutdown which gets a lock, removes
-	 * the sc from the nn, and queues the work.  in this case the
-	 * work is single-shot.  the work is also queued from a sock
-	 * callback, though, and in this case the work will find the sc
-	 * still on the nn and will call ensure_shutdown itself.. this
-	 * ends up triggering the shutdown work again, though nothing
-	 * will be done in that second iteration.  so work queue teardown
-	 * has to be careful to remove the sc from the nn before waiting
-	 * on the work queue so that the shutdown work doesn't remove the
-	 * sc and rearm itself.
-	 */
-	struct work_struct	sc_shutdown_work;
-
-	struct timer_list	sc_idle_timeout;
-	struct delayed_work	sc_keepalive_work;
-
-	unsigned		sc_handshake_ok:1;
-
-	struct page		*sc_page;
-	size_t			sc_page_off;
-
-	/* original handlers for the sockets */
-	void			(*sc_state_change)(struct sock *sk);
-	void			(*sc_data_ready)(struct sock *sk, int bytes);
-
-	u32			sc_msg_key;
-	u16			sc_msg_type;
-
-#ifdef CONFIG_DEBUG_FS
-	struct list_head        sc_net_debug_item;
-	ktime_t			sc_tv_timer;
-	ktime_t			sc_tv_data_ready;
-	ktime_t			sc_tv_advance_start;
-	ktime_t			sc_tv_advance_stop;
-	ktime_t			sc_tv_func_start;
-	ktime_t			sc_tv_func_stop;
-#endif
-#ifdef CONFIG_RAMSTER_FS_STATS
-	ktime_t			sc_tv_acquiry_total;
-	ktime_t			sc_tv_send_total;
-	ktime_t			sc_tv_status_total;
-	u32			sc_send_count;
-	u32			sc_recv_count;
-	ktime_t			sc_tv_process_total;
-#endif
-	struct mutex		sc_send_lock;
-};
-
-struct r2net_msg_handler {
-	struct rb_node		nh_node;
-	u32			nh_max_len;
-	u32			nh_msg_type;
-	u32			nh_key;
-	r2net_msg_handler_func	*nh_func;
-	r2net_msg_handler_func	*nh_func_data;
-	r2net_post_msg_handler_func
-				*nh_post_func;
-	struct kref		nh_kref;
-	struct list_head	nh_unregister_item;
-};
-
-enum r2net_system_error {
-	R2NET_ERR_NONE = 0,
-	R2NET_ERR_NO_HNDLR,
-	R2NET_ERR_OVERFLOW,
-	R2NET_ERR_DIED,
-	R2NET_ERR_MAX
-};
-
-struct r2net_status_wait {
-	enum r2net_system_error	ns_sys_status;
-	s32			ns_status;
-	int			ns_id;
-	wait_queue_head_t	ns_wq;
-	struct list_head	ns_node_item;
-};
-
-#ifdef CONFIG_DEBUG_FS
-/* just for state dumps */
-struct r2net_send_tracking {
-	struct list_head		st_net_debug_item;
-	struct task_struct		*st_task;
-	struct r2net_sock_container	*st_sc;
-	u32				st_id;
-	u32				st_msg_type;
-	u32				st_msg_key;
-	u8				st_node;
-	ktime_t				st_sock_time;
-	ktime_t				st_send_time;
-	ktime_t				st_status_time;
-};
-#else
-struct r2net_send_tracking {
-	u32	dummy;
-};
-#endif	/* CONFIG_DEBUG_FS */
-
-#endif /* R2CLUSTER_TCP_INTERNAL_H */

drivers/staging/zcache/tmem.c

@@ -1,898 +0,0 @@
-/*
- * In-kernel transcendent memory (generic implementation)
- *
- * Copyright (c) 2009-2012, Dan Magenheimer, Oracle Corp.
- *
- * The primary purpose of Transcedent Memory ("tmem") is to map object-oriented
- * "handles" (triples containing a pool id, and object id, and an index), to
- * pages in a page-accessible memory (PAM).  Tmem references the PAM pages via
- * an abstract "pampd" (PAM page-descriptor), which can be operated on by a
- * set of functions (pamops).  Each pampd contains some representation of
- * PAGE_SIZE bytes worth of data. For those familiar with key-value stores,
- * the tmem handle is a three-level hierarchical key, and the value is always
- * reconstituted (but not necessarily stored) as PAGE_SIZE bytes and is
- * referenced in the datastore by the pampd.  The hierarchy is required
- * to ensure that certain invalidation functions can be performed efficiently
- * (i.e. flush all indexes associated with this object_id, or
- * flush all objects associated with this pool).
- *
- * Tmem must support potentially millions of pages and must be able to insert,
- * find, and delete these pages at a potential frequency of thousands per
- * second concurrently across many CPUs, (and, if used with KVM, across many
- * vcpus across many guests).  Tmem is tracked with a hierarchy of data
- * structures, organized by the elements in the handle-tuple: pool_id,
- * object_id, and page index.  One or more "clients" (e.g. guests) each
- * provide one or more tmem_pools.  Each pool, contains a hash table of
- * rb_trees of tmem_objs.  Each tmem_obj contains a radix-tree-like tree
- * of pointers, with intermediate nodes called tmem_objnodes.  Each leaf
- * pointer in this tree points to a pampd, which is accessible only through
- * a small set of callbacks registered by the PAM implementation (see
- * tmem_register_pamops). Tmem only needs to memory allocation for objs
- * and objnodes and this is done via a set of callbacks that must be
- * registered by the tmem host implementation (e.g. see tmem_register_hostops).
- */
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <linux/atomic.h>
-#include <linux/export.h>
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-#include <linux/delay.h>
-#endif
-
-#include "tmem.h"
-
-/* data structure sentinels used for debugging... see tmem.h */
-#define POOL_SENTINEL 0x87658765
-#define OBJ_SENTINEL 0x12345678
-#define OBJNODE_SENTINEL 0xfedcba09
-
-/*
- * A tmem host implementation must use this function to register callbacks
- * for memory allocation.
- */
-static struct tmem_hostops tmem_hostops;
-
-static void tmem_objnode_tree_init(void);
-
-void tmem_register_hostops(struct tmem_hostops *m)
-{
-	tmem_objnode_tree_init();
-	tmem_hostops = *m;
-}
-
-/*
- * A tmem host implementation must use this function to register
- * callbacks for a page-accessible memory (PAM) implementation.
- */
-static struct tmem_pamops tmem_pamops;
-
-void tmem_register_pamops(struct tmem_pamops *m)
-{
-	tmem_pamops = *m;
-}
-
-/*
- * Oid's are potentially very sparse and tmem_objs may have an indeterminately
- * short life, being added and deleted at a relatively high frequency.
- * So an rb_tree is an ideal data structure to manage tmem_objs.  But because
- * of the potentially huge number of tmem_objs, each pool manages a hashtable
- * of rb_trees to reduce search, insert, delete, and rebalancing time.
- * Each hashbucket also has a lock to manage concurrent access and no
- * searches, inserts, or deletions can be performed unless the lock is held.
- * As a result, care must be taken to ensure tmem routines are not called
- * recursively; the vast majority of the time, a recursive call may work
- * but a deadlock will occur a small fraction of the time due to the
- * hashbucket lock.
- *
- * The following routines manage tmem_objs.  In all of these routines,
- * the hashbucket lock is already held.
- */
-
-/* Search for object==oid in pool, returns object if found. */
-static struct tmem_obj *__tmem_obj_find(struct tmem_hashbucket *hb,
-					struct tmem_oid *oidp,
-					struct rb_node **parent,
-					struct rb_node ***link)
-{
-	struct rb_node *_parent = NULL, **rbnode;
-	struct tmem_obj *obj = NULL;
-
-	rbnode = &hb->obj_rb_root.rb_node;
-	while (*rbnode) {
-		BUG_ON(RB_EMPTY_NODE(*rbnode));
-		_parent = *rbnode;
-		obj = rb_entry(*rbnode, struct tmem_obj,
-			       rb_tree_node);
-		switch (tmem_oid_compare(oidp, &obj->oid)) {
-		case 0: /* equal */
-			goto out;
-		case -1:
-			rbnode = &(*rbnode)->rb_left;
-			break;
-		case 1:
-			rbnode = &(*rbnode)->rb_right;
-			break;
-		}
-	}
-
-	if (parent)
-		*parent = _parent;
-	if (link)
-		*link = rbnode;
-	obj = NULL;
-out:
-	return obj;
-}
-
-static struct tmem_obj *tmem_obj_find(struct tmem_hashbucket *hb,
-					struct tmem_oid *oidp)
-{
-	return __tmem_obj_find(hb, oidp, NULL, NULL);
-}
-
-static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *, bool);
-
-/* Free an object that has no more pampds in it. */
-static void tmem_obj_free(struct tmem_obj *obj, struct tmem_hashbucket *hb)
-{
-	struct tmem_pool *pool;
-
-	BUG_ON(obj == NULL);
-	ASSERT_SENTINEL(obj, OBJ);
-	BUG_ON(obj->pampd_count > 0);
-	pool = obj->pool;
-	BUG_ON(pool == NULL);
-	if (obj->objnode_tree_root != NULL) /* may be "stump" with no leaves */
-		tmem_pampd_destroy_all_in_obj(obj, false);
-	BUG_ON(obj->objnode_tree_root != NULL);
-	BUG_ON((long)obj->objnode_count != 0);
-	atomic_dec(&pool->obj_count);
-	BUG_ON(atomic_read(&pool->obj_count) < 0);
-	INVERT_SENTINEL(obj, OBJ);
-	obj->pool = NULL;
-	tmem_oid_set_invalid(&obj->oid);
-	rb_erase(&obj->rb_tree_node, &hb->obj_rb_root);
-}
-
-/*
- * Initialize, and insert an tmem_object_root (called only if find failed).
- */
-static void tmem_obj_init(struct tmem_obj *obj, struct tmem_hashbucket *hb,
-					struct tmem_pool *pool,
-					struct tmem_oid *oidp)
-{
-	struct rb_root *root = &hb->obj_rb_root;
-	struct rb_node **new = NULL, *parent = NULL;
-
-	BUG_ON(pool == NULL);
-	atomic_inc(&pool->obj_count);
-	obj->objnode_tree_height = 0;
-	obj->objnode_tree_root = NULL;
-	obj->pool = pool;
-	obj->oid = *oidp;
-	obj->objnode_count = 0;
-	obj->pampd_count = 0;
-#ifdef CONFIG_RAMSTER
-	if (tmem_pamops.new_obj != NULL)
-		(*tmem_pamops.new_obj)(obj);
-#endif
-	SET_SENTINEL(obj, OBJ);
-
-	if (__tmem_obj_find(hb, oidp, &parent, &new))
-		BUG();
-
-	rb_link_node(&obj->rb_tree_node, parent, new);
-	rb_insert_color(&obj->rb_tree_node, root);
-}
-
-/*
- * Tmem is managed as a set of tmem_pools with certain attributes, such as
- * "ephemeral" vs "persistent".  These attributes apply to all tmem_objs
- * and all pampds that belong to a tmem_pool.  A tmem_pool is created
- * or deleted relatively rarely (for example, when a filesystem is
- * mounted or unmounted).
- */
-
-/* flush all data from a pool and, optionally, free it */
-static void tmem_pool_flush(struct tmem_pool *pool, bool destroy)
-{
-	struct rb_node *rbnode;
-	struct tmem_obj *obj;
-	struct tmem_hashbucket *hb = &pool->hashbucket[0];
-	int i;
-
-	BUG_ON(pool == NULL);
-	for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) {
-		spin_lock(&hb->lock);
-		rbnode = rb_first(&hb->obj_rb_root);
-		while (rbnode != NULL) {
-			obj = rb_entry(rbnode, struct tmem_obj, rb_tree_node);
-			rbnode = rb_next(rbnode);
-			tmem_pampd_destroy_all_in_obj(obj, true);
-			tmem_obj_free(obj, hb);
-			(*tmem_hostops.obj_free)(obj, pool);
-		}
-		spin_unlock(&hb->lock);
-	}
-	if (destroy)
-		list_del(&pool->pool_list);
-}
-
-/*
- * A tmem_obj contains a radix-tree-like tree in which the intermediate
- * nodes are called tmem_objnodes.  (The kernel lib/radix-tree.c implementation
- * is very specialized and tuned for specific uses and is not particularly
- * suited for use from this code, though some code from the core algorithms has
- * been reused, thus the copyright notices below).  Each tmem_objnode contains
- * a set of pointers which point to either a set of intermediate tmem_objnodes
- * or a set of of pampds.
- *
- * Portions Copyright (C) 2001 Momchil Velikov
- * Portions Copyright (C) 2001 Christoph Hellwig
- * Portions Copyright (C) 2005 SGI, Christoph Lameter <clameter@sgi.com>
- */
-
-struct tmem_objnode_tree_path {
-	struct tmem_objnode *objnode;
-	int offset;
-};
-
-/* objnode height_to_maxindex translation */
-static unsigned long tmem_objnode_tree_h2max[OBJNODE_TREE_MAX_PATH + 1];
-
-static void tmem_objnode_tree_init(void)
-{
-	unsigned int ht, tmp;
-
-	for (ht = 0; ht < ARRAY_SIZE(tmem_objnode_tree_h2max); ht++) {
-		tmp = ht * OBJNODE_TREE_MAP_SHIFT;
-		if (tmp >= OBJNODE_TREE_INDEX_BITS)
-			tmem_objnode_tree_h2max[ht] = ~0UL;
-		else
-			tmem_objnode_tree_h2max[ht] =
-			    (~0UL >> (OBJNODE_TREE_INDEX_BITS - tmp - 1)) >> 1;
-	}
-}
-
-static struct tmem_objnode *tmem_objnode_alloc(struct tmem_obj *obj)
-{
-	struct tmem_objnode *objnode;
-
-	ASSERT_SENTINEL(obj, OBJ);
-	BUG_ON(obj->pool == NULL);
-	ASSERT_SENTINEL(obj->pool, POOL);
-	objnode = (*tmem_hostops.objnode_alloc)(obj->pool);
-	if (unlikely(objnode == NULL))
-		goto out;
-	objnode->obj = obj;
-	SET_SENTINEL(objnode, OBJNODE);
-	memset(&objnode->slots, 0, sizeof(objnode->slots));
-	objnode->slots_in_use = 0;
-	obj->objnode_count++;
-out:
-	return objnode;
-}
-
-static void tmem_objnode_free(struct tmem_objnode *objnode)
-{
-	struct tmem_pool *pool;
-	int i;
-
-	BUG_ON(objnode == NULL);
-	for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++)
-		BUG_ON(objnode->slots[i] != NULL);
-	ASSERT_SENTINEL(objnode, OBJNODE);
-	INVERT_SENTINEL(objnode, OBJNODE);
-	BUG_ON(objnode->obj == NULL);
-	ASSERT_SENTINEL(objnode->obj, OBJ);
-	pool = objnode->obj->pool;
-	BUG_ON(pool == NULL);
-	ASSERT_SENTINEL(pool, POOL);
-	objnode->obj->objnode_count--;
-	objnode->obj = NULL;
-	(*tmem_hostops.objnode_free)(objnode, pool);
-}
-
-/*
- * Lookup index in object and return associated pampd (or NULL if not found).
- */
-static void **__tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
-{
-	unsigned int height, shift;
-	struct tmem_objnode **slot = NULL;
-
-	BUG_ON(obj == NULL);
-	ASSERT_SENTINEL(obj, OBJ);
-	BUG_ON(obj->pool == NULL);
-	ASSERT_SENTINEL(obj->pool, POOL);
-
-	height = obj->objnode_tree_height;
-	if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height])
-		goto out;
-	if (height == 0 && obj->objnode_tree_root) {
-		slot = &obj->objnode_tree_root;
-		goto out;
-	}
-	shift = (height-1) * OBJNODE_TREE_MAP_SHIFT;
-	slot = &obj->objnode_tree_root;
-	while (height > 0) {
-		if (*slot == NULL)
-			goto out;
-		slot = (struct tmem_objnode **)
-			((*slot)->slots +
-			 ((index >> shift) & OBJNODE_TREE_MAP_MASK));
-		shift -= OBJNODE_TREE_MAP_SHIFT;
-		height--;
-	}
-out:
-	return slot != NULL ? (void **)slot : NULL;
-}
-
-static void *tmem_pampd_lookup_in_obj(struct tmem_obj *obj, uint32_t index)
-{
-	struct tmem_objnode **slot;
-
-	slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
-	return slot != NULL ? *slot : NULL;
-}
-
-#ifdef CONFIG_RAMSTER
-static void *tmem_pampd_replace_in_obj(struct tmem_obj *obj, uint32_t index,
-					void *new_pampd, bool no_free)
-{
-	struct tmem_objnode **slot;
-	void *ret = NULL;
-
-	slot = (struct tmem_objnode **)__tmem_pampd_lookup_in_obj(obj, index);
-	if ((slot != NULL) && (*slot != NULL)) {
-		void *old_pampd = *(void **)slot;
-		*(void **)slot = new_pampd;
-		if (!no_free)
-			(*tmem_pamops.free)(old_pampd, obj->pool,
-						NULL, 0, false);
-		ret = new_pampd;
-	}
-	return ret;
-}
-#endif
-
-static int tmem_pampd_add_to_obj(struct tmem_obj *obj, uint32_t index,
-					void *pampd)
-{
-	int ret = 0;
-	struct tmem_objnode *objnode = NULL, *newnode, *slot;
-	unsigned int height, shift;
-	int offset = 0;
-
-	/* if necessary, extend the tree to be higher  */
-	if (index > tmem_objnode_tree_h2max[obj->objnode_tree_height]) {
-		height = obj->objnode_tree_height + 1;
-		if (index > tmem_objnode_tree_h2max[height])
-			while (index > tmem_objnode_tree_h2max[height])
-				height++;
-		if (obj->objnode_tree_root == NULL) {
-			obj->objnode_tree_height = height;
-			goto insert;
-		}
-		do {
-			newnode = tmem_objnode_alloc(obj);
-			if (!newnode) {
-				ret = -ENOMEM;
-				goto out;
-			}
-			newnode->slots[0] = obj->objnode_tree_root;
-			newnode->slots_in_use = 1;
-			obj->objnode_tree_root = newnode;
-			obj->objnode_tree_height++;
-		} while (height > obj->objnode_tree_height);
-	}
-insert:
-	slot = obj->objnode_tree_root;
-	height = obj->objnode_tree_height;
-	shift = (height-1) * OBJNODE_TREE_MAP_SHIFT;
-	while (height > 0) {
-		if (slot == NULL) {
-			/* add a child objnode.  */
-			slot = tmem_objnode_alloc(obj);
-			if (!slot) {
-				ret = -ENOMEM;
-				goto out;
-			}
-			if (objnode) {
-
-				objnode->slots[offset] = slot;
-				objnode->slots_in_use++;
-			} else
-				obj->objnode_tree_root = slot;
-		}
-		/* go down a level */
-		offset = (index >> shift) & OBJNODE_TREE_MAP_MASK;
-		objnode = slot;
-		slot = objnode->slots[offset];
-		shift -= OBJNODE_TREE_MAP_SHIFT;
-		height--;
-	}
-	BUG_ON(slot != NULL);
-	if (objnode) {
-		objnode->slots_in_use++;
-		objnode->slots[offset] = pampd;
-	} else
-		obj->objnode_tree_root = pampd;
-	obj->pampd_count++;
-out:
-	return ret;
-}
-
-static void *tmem_pampd_delete_from_obj(struct tmem_obj *obj, uint32_t index)
-{
-	struct tmem_objnode_tree_path path[OBJNODE_TREE_MAX_PATH + 1];
-	struct tmem_objnode_tree_path *pathp = path;
-	struct tmem_objnode *slot = NULL;
-	unsigned int height, shift;
-	int offset;
-
-	BUG_ON(obj == NULL);
-	ASSERT_SENTINEL(obj, OBJ);
-	BUG_ON(obj->pool == NULL);
-	ASSERT_SENTINEL(obj->pool, POOL);
-	height = obj->objnode_tree_height;
-	if (index > tmem_objnode_tree_h2max[height])
-		goto out;
-	slot = obj->objnode_tree_root;
-	if (height == 0 && obj->objnode_tree_root) {
-		obj->objnode_tree_root = NULL;
-		goto out;
-	}
-	shift = (height - 1) * OBJNODE_TREE_MAP_SHIFT;
-	pathp->objnode = NULL;
-	do {
-		if (slot == NULL)
-			goto out;
-		pathp++;
-		offset = (index >> shift) & OBJNODE_TREE_MAP_MASK;
-		pathp->offset = offset;
-		pathp->objnode = slot;
-		slot = slot->slots[offset];
-		shift -= OBJNODE_TREE_MAP_SHIFT;
-		height--;
-	} while (height > 0);
-	if (slot == NULL)
-		goto out;
-	while (pathp->objnode) {
-		pathp->objnode->slots[pathp->offset] = NULL;
-		pathp->objnode->slots_in_use--;
-		if (pathp->objnode->slots_in_use) {
-			if (pathp->objnode == obj->objnode_tree_root) {
-				while (obj->objnode_tree_height > 0 &&
-				  obj->objnode_tree_root->slots_in_use == 1 &&
-				  obj->objnode_tree_root->slots[0]) {
-					struct tmem_objnode *to_free =
-						obj->objnode_tree_root;
-
-					obj->objnode_tree_root =
-							to_free->slots[0];
-					obj->objnode_tree_height--;
-					to_free->slots[0] = NULL;
-					to_free->slots_in_use = 0;
-					tmem_objnode_free(to_free);
-				}
-			}
-			goto out;
-		}
-		tmem_objnode_free(pathp->objnode); /* 0 slots used, free it */
-		pathp--;
-	}
-	obj->objnode_tree_height = 0;
-	obj->objnode_tree_root = NULL;
-
-out:
-	if (slot != NULL)
-		obj->pampd_count--;
-	BUG_ON(obj->pampd_count < 0);
-	return slot;
-}
-
-/* Recursively walk the objnode_tree destroying pampds and objnodes. */
-static void tmem_objnode_node_destroy(struct tmem_obj *obj,
-					struct tmem_objnode *objnode,
-					unsigned int ht)
-{
-	int i;
-
-	if (ht == 0)
-		return;
-	for (i = 0; i < OBJNODE_TREE_MAP_SIZE; i++) {
-		if (objnode->slots[i]) {
-			if (ht == 1) {
-				obj->pampd_count--;
-				(*tmem_pamops.free)(objnode->slots[i],
-						obj->pool, NULL, 0, true);
-				objnode->slots[i] = NULL;
-				continue;
-			}
-			tmem_objnode_node_destroy(obj, objnode->slots[i], ht-1);
-			tmem_objnode_free(objnode->slots[i]);
-			objnode->slots[i] = NULL;
-		}
-	}
-}
-
-static void tmem_pampd_destroy_all_in_obj(struct tmem_obj *obj,
-						bool pool_destroy)
-{
-	if (obj->objnode_tree_root == NULL)
-		return;
-	if (obj->objnode_tree_height == 0) {
-		obj->pampd_count--;
-		(*tmem_pamops.free)(obj->objnode_tree_root,
-					obj->pool, NULL, 0, true);
-	} else {
-		tmem_objnode_node_destroy(obj, obj->objnode_tree_root,
-					obj->objnode_tree_height);
-		tmem_objnode_free(obj->objnode_tree_root);
-		obj->objnode_tree_height = 0;
-	}
-	obj->objnode_tree_root = NULL;
-#ifdef CONFIG_RAMSTER
-	if (tmem_pamops.free_obj != NULL)
-		(*tmem_pamops.free_obj)(obj->pool, obj, pool_destroy);
-#endif
-}
-
-/*
- * Tmem is operated on by a set of well-defined actions:
- * "put", "get", "flush", "flush_object", "new pool" and "destroy pool".
- * (The tmem ABI allows for subpages and exchanges but these operations
- * are not included in this implementation.)
- *
- * These "tmem core" operations are implemented in the following functions.
- */
-
-/*
- * "Put" a page, e.g. associate the passed pampd with the passed handle.
- * Tmem_put is complicated by a corner case: What if a page with matching
- * handle already exists in tmem?  To guarantee coherency, one of two
- * actions is necessary: Either the data for the page must be overwritten,
- * or the page must be "flushed" so that the data is not accessible to a
- * subsequent "get".  Since these "duplicate puts" are relatively rare,
- * this implementation always flushes for simplicity.
- */
-int tmem_put(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
-		bool raw, void *pampd_to_use)
-{
-	struct tmem_obj *obj = NULL, *objfound = NULL, *objnew = NULL;
-	void *pampd = NULL, *pampd_del = NULL;
-	int ret = -ENOMEM;
-	struct tmem_hashbucket *hb;
-
-	hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-	spin_lock(&hb->lock);
-	obj = objfound = tmem_obj_find(hb, oidp);
-	if (obj != NULL) {
-		pampd = tmem_pampd_lookup_in_obj(objfound, index);
-		if (pampd != NULL) {
-			/* if found, is a dup put, flush the old one */
-			pampd_del = tmem_pampd_delete_from_obj(obj, index);
-			BUG_ON(pampd_del != pampd);
-			(*tmem_pamops.free)(pampd, pool, oidp, index, true);
-			if (obj->pampd_count == 0) {
-				objnew = obj;
-				objfound = NULL;
-			}
-			pampd = NULL;
-		}
-	} else {
-		obj = objnew = (*tmem_hostops.obj_alloc)(pool);
-		if (unlikely(obj == NULL)) {
-			ret = -ENOMEM;
-			goto out;
-		}
-		tmem_obj_init(obj, hb, pool, oidp);
-	}
-	BUG_ON(obj == NULL);
-	BUG_ON(((objnew != obj) && (objfound != obj)) || (objnew == objfound));
-	pampd = pampd_to_use;
-	BUG_ON(pampd_to_use == NULL);
-	ret = tmem_pampd_add_to_obj(obj, index, pampd);
-	if (unlikely(ret == -ENOMEM))
-		/* may have partially built objnode tree ("stump") */
-		goto delete_and_free;
-	(*tmem_pamops.create_finish)(pampd, is_ephemeral(pool));
-	goto out;
-
-delete_and_free:
-	(void)tmem_pampd_delete_from_obj(obj, index);
-	if (pampd)
-		(*tmem_pamops.free)(pampd, pool, NULL, 0, true);
-	if (objnew) {
-		tmem_obj_free(objnew, hb);
-		(*tmem_hostops.obj_free)(objnew, pool);
-	}
-out:
-	spin_unlock(&hb->lock);
-	return ret;
-}
-
-#ifdef CONFIG_RAMSTER
-/*
- * For ramster only:  The following routines provide a two-step sequence
- * to allow the caller to replace a pampd in the tmem data structures with
- * another pampd. Here, we lookup the passed handle and, if found, return the
- * associated pampd and object, leaving the hashbucket locked and returning
- * a reference to it.  The caller is expected to immediately call the
- * matching tmem_localify_finish routine which will handles the replacement
- * and unlocks the hashbucket.
- */
-void *tmem_localify_get_pampd(struct tmem_pool *pool, struct tmem_oid *oidp,
-				uint32_t index, struct tmem_obj **ret_obj,
-				void **saved_hb)
-{
-	struct tmem_hashbucket *hb;
-	struct tmem_obj *obj = NULL;
-	void *pampd = NULL;
-
-	hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-	spin_lock(&hb->lock);
-	obj = tmem_obj_find(hb, oidp);
-	if (likely(obj != NULL))
-		pampd = tmem_pampd_lookup_in_obj(obj, index);
-	*ret_obj = obj;
-	*saved_hb = (void *)hb;
-	/* note, hashbucket remains locked */
-	return pampd;
-}
-EXPORT_SYMBOL_GPL(tmem_localify_get_pampd);
-
-void tmem_localify_finish(struct tmem_obj *obj, uint32_t index,
-			  void *pampd, void *saved_hb, bool delete)
-{
-	struct tmem_hashbucket *hb = (struct tmem_hashbucket *)saved_hb;
-
-	BUG_ON(!spin_is_locked(&hb->lock));
-	if (pampd != NULL) {
-		BUG_ON(obj == NULL);
-		(void)tmem_pampd_replace_in_obj(obj, index, pampd, 1);
-		(*tmem_pamops.create_finish)(pampd, is_ephemeral(obj->pool));
-	} else if (delete) {
-		BUG_ON(obj == NULL);
-		(void)tmem_pampd_delete_from_obj(obj, index);
-	}
-	spin_unlock(&hb->lock);
-}
-EXPORT_SYMBOL_GPL(tmem_localify_finish);
-
-/*
- * For ramster only.  Helper function to support asynchronous tmem_get.
- */
-static int tmem_repatriate(void **ppampd, struct tmem_hashbucket *hb,
-				struct tmem_pool *pool, struct tmem_oid *oidp,
-				uint32_t index, bool free, char *data)
-{
-	void *old_pampd = *ppampd, *new_pampd = NULL;
-	bool intransit = false;
-	int ret = 0;
-
-	if (!is_ephemeral(pool))
-		new_pampd = (*tmem_pamops.repatriate_preload)(
-				old_pampd, pool, oidp, index, &intransit);
-	if (intransit)
-		ret = -EAGAIN;
-	else if (new_pampd != NULL)
-		*ppampd = new_pampd;
-	/* must release the hb->lock else repatriate can't sleep */
-	spin_unlock(&hb->lock);
-	if (!intransit)
-		ret = (*tmem_pamops.repatriate)(old_pampd, new_pampd, pool,
-						oidp, index, free, data);
-	if (ret == -EAGAIN) {
-		/* rare I think, but should cond_resched()??? */
-		usleep_range(10, 1000);
-	} else if (ret == -ENOTCONN || ret == -EHOSTDOWN) {
-		ret = -1;
-	} else if (ret != 0 && ret != -ENOENT) {
-		ret = -1;
-	}
-	/* note hb->lock has now been unlocked */
-	return ret;
-}
-
-/*
- * For ramster only.  If a page in tmem matches the handle, replace the
- * page so that any subsequent "get" gets the new page.  Returns 0 if
- * there was a page to replace, else returns -1.
- */
-int tmem_replace(struct tmem_pool *pool, struct tmem_oid *oidp,
-			uint32_t index, void *new_pampd)
-{
-	struct tmem_obj *obj;
-	int ret = -1;
-	struct tmem_hashbucket *hb;
-
-	hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-	spin_lock(&hb->lock);
-	obj = tmem_obj_find(hb, oidp);
-	if (obj == NULL)
-		goto out;
-	new_pampd = tmem_pampd_replace_in_obj(obj, index, new_pampd, 0);
-	/* if we bug here, pamops wasn't properly set up for ramster */
-	BUG_ON(tmem_pamops.replace_in_obj == NULL);
-	ret = (*tmem_pamops.replace_in_obj)(new_pampd, obj);
-out:
-	spin_unlock(&hb->lock);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(tmem_replace);
-#endif
-
-/*
- * "Get" a page, e.g. if a pampd can be found matching the passed handle,
- * use a pamops callback to recreated the page from the pampd with the
- * matching handle.  By tmem definition, when a "get" is successful on
- * an ephemeral page, the page is "flushed", and when a "get" is successful
- * on a persistent page, the page is retained in tmem.  Note that to preserve
- * coherency, "get" can never be skipped if tmem contains the data.
- * That is, if a get is done with a certain handle and fails, any
- * subsequent "get" must also fail (unless of course there is a
- * "put" done with the same handle).
- */
-int tmem_get(struct tmem_pool *pool, struct tmem_oid *oidp, uint32_t index,
-		char *data, size_t *sizep, bool raw, int get_and_free)
-{
-	struct tmem_obj *obj;
-	void *pampd = NULL;
-	bool ephemeral = is_ephemeral(pool);
-	int ret = -1;
-	struct tmem_hashbucket *hb;
-	bool free = (get_and_free == 1) || ((get_and_free == 0) && ephemeral);
-	bool lock_held = false;
-	void **ppampd;
-
-	do {
-		hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-		spin_lock(&hb->lock);
-		lock_held = true;
-		obj = tmem_obj_find(hb, oidp);
-		if (obj == NULL)
-			goto out;
-		ppampd = __tmem_pampd_lookup_in_obj(obj, index);
-		if (ppampd == NULL)
-			goto out;
-#ifdef CONFIG_RAMSTER
-		if ((tmem_pamops.is_remote != NULL) &&
-		     tmem_pamops.is_remote(*ppampd)) {
-			ret = tmem_repatriate(ppampd, hb, pool, oidp,
-						index, free, data);
-			/* tmem_repatriate releases hb->lock */
-			lock_held = false;
-			*sizep = PAGE_SIZE;
-			if (ret != -EAGAIN)
-				goto out;
-		}
-#endif
-	} while (ret == -EAGAIN);
-	if (free)
-		pampd = tmem_pampd_delete_from_obj(obj, index);
-	else
-		pampd = tmem_pampd_lookup_in_obj(obj, index);
-	if (pampd == NULL)
-		goto out;
-	if (free) {
-		if (obj->pampd_count == 0) {
-			tmem_obj_free(obj, hb);
-			(*tmem_hostops.obj_free)(obj, pool);
-			obj = NULL;
-		}
-	}
-	if (free)
-		ret = (*tmem_pamops.get_data_and_free)(
-				data, sizep, raw, pampd, pool, oidp, index);
-	else
-		ret = (*tmem_pamops.get_data)(
-				data, sizep, raw, pampd, pool, oidp, index);
-	if (ret < 0)
-		goto out;
-	ret = 0;
-out:
-	if (lock_held)
-		spin_unlock(&hb->lock);
-	return ret;
-}
-
-/*
- * If a page in tmem matches the handle, "flush" this page from tmem such
- * that any subsequent "get" does not succeed (unless, of course, there
- * was another "put" with the same handle).
- */
-int tmem_flush_page(struct tmem_pool *pool,
-				struct tmem_oid *oidp, uint32_t index)
-{
-	struct tmem_obj *obj;
-	void *pampd;
-	int ret = -1;
-	struct tmem_hashbucket *hb;
-
-	hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-	spin_lock(&hb->lock);
-	obj = tmem_obj_find(hb, oidp);
-	if (obj == NULL)
-		goto out;
-	pampd = tmem_pampd_delete_from_obj(obj, index);
-	if (pampd == NULL)
-		goto out;
-	(*tmem_pamops.free)(pampd, pool, oidp, index, true);
-	if (obj->pampd_count == 0) {
-		tmem_obj_free(obj, hb);
-		(*tmem_hostops.obj_free)(obj, pool);
-	}
-	ret = 0;
-
-out:
-	spin_unlock(&hb->lock);
-	return ret;
-}
-
-/*
- * "Flush" all pages in tmem matching this oid.
- */
-int tmem_flush_object(struct tmem_pool *pool, struct tmem_oid *oidp)
-{
-	struct tmem_obj *obj;
-	struct tmem_hashbucket *hb;
-	int ret = -1;
-
-	hb = &pool->hashbucket[tmem_oid_hash(oidp)];
-	spin_lock(&hb->lock);
-	obj = tmem_obj_find(hb, oidp);
-	if (obj == NULL)
-		goto out;
-	tmem_pampd_destroy_all_in_obj(obj, false);
-	tmem_obj_free(obj, hb);
-	(*tmem_hostops.obj_free)(obj, pool);
-	ret = 0;
-
-out:
-	spin_unlock(&hb->lock);
-	return ret;
-}
-
-/*
- * "Flush" all pages (and tmem_objs) from this tmem_pool and disable
- * all subsequent access to this tmem_pool.
- */
-int tmem_destroy_pool(struct tmem_pool *pool)
-{
-	int ret = -1;
-
-	if (pool == NULL)
-		goto out;
-	tmem_pool_flush(pool, 1);
-	ret = 0;
-out:
-	return ret;
-}
-
-static LIST_HEAD(tmem_global_pool_list);
-
-/*
- * Create a new tmem_pool with the provided flag and return
- * a pool id provided by the tmem host implementation.
- */
-void tmem_new_pool(struct tmem_pool *pool, uint32_t flags)
-{
-	int persistent = flags & TMEM_POOL_PERSIST;
-	int shared = flags & TMEM_POOL_SHARED;
-	struct tmem_hashbucket *hb = &pool->hashbucket[0];
-	int i;
-
-	for (i = 0; i < TMEM_HASH_BUCKETS; i++, hb++) {
-		hb->obj_rb_root = RB_ROOT;
-		spin_lock_init(&hb->lock);
-	}
-	INIT_LIST_HEAD(&pool->pool_list);
-	atomic_set(&pool->obj_count, 0);
-	SET_SENTINEL(pool, POOL);
-	list_add_tail(&pool->pool_list, &tmem_global_pool_list);
-	pool->persistent = persistent;
-	pool->shared = shared;
-}

drivers/staging/zcache/tmem.h

@@ -1,259 +0,0 @@
-/*
- * tmem.h
- *
- * Transcendent memory
- *
- * Copyright (c) 2009-2012, Dan Magenheimer, Oracle Corp.
- */
-
-#ifndef _TMEM_H_
-#define _TMEM_H_
-
-#include <linux/types.h>
-#include <linux/highmem.h>
-#include <linux/hash.h>
-#include <linux/atomic.h>
-
-/*
- * These are defined by the Xen<->Linux ABI so should remain consistent
- */
-#define TMEM_POOL_PERSIST		1
-#define TMEM_POOL_SHARED		2
-#define TMEM_POOL_PRECOMPRESSED		4
-#define TMEM_POOL_PAGESIZE_SHIFT	4
-#define TMEM_POOL_PAGESIZE_MASK		0xf
-#define TMEM_POOL_RESERVED_BITS		0x00ffff00
-
-/*
- * sentinels have proven very useful for debugging but can be removed
- * or disabled before final merge.
- */
-#undef SENTINELS
-#ifdef SENTINELS
-#define DECL_SENTINEL uint32_t sentinel;
-#define SET_SENTINEL(_x, _y) (_x->sentinel = _y##_SENTINEL)
-#define INVERT_SENTINEL(_x, _y) (_x->sentinel = ~_y##_SENTINEL)
-#define ASSERT_SENTINEL(_x, _y) WARN_ON(_x->sentinel != _y##_SENTINEL)
-#define ASSERT_INVERTED_SENTINEL(_x, _y) WARN_ON(_x->sentinel != ~_y##_SENTINEL)
-#else
-#define DECL_SENTINEL
-#define SET_SENTINEL(_x, _y) do { } while (0)
-#define INVERT_SENTINEL(_x, _y) do { } while (0)
-#define ASSERT_SENTINEL(_x, _y) do { } while (0)
-#define ASSERT_INVERTED_SENTINEL(_x, _y) do { } while (0)
-#endif
-
-#define ASSERT_SPINLOCK(_l)	lockdep_assert_held(_l)
-
-/*
- * A pool is the highest-level data structure managed by tmem and
- * usually corresponds to a large independent set of pages such as
- * a filesystem.  Each pool has an id, and certain attributes and counters.
- * It also contains a set of hash buckets, each of which contains an rbtree
- * of objects and a lock to manage concurrency within the pool.
- */
-
-#define TMEM_HASH_BUCKET_BITS	8
-#define TMEM_HASH_BUCKETS	(1<<TMEM_HASH_BUCKET_BITS)
-
-struct tmem_hashbucket {
-	struct rb_root obj_rb_root;
-	spinlock_t lock;
-};
-
-struct tmem_pool {
-	void *client; /* "up" for some clients, avoids table lookup */
-	struct list_head pool_list;
-	uint32_t pool_id;
-	bool persistent;
-	bool shared;
-	atomic_t obj_count;
-	atomic_t refcount;
-	struct tmem_hashbucket hashbucket[TMEM_HASH_BUCKETS];
-	DECL_SENTINEL
-};
-
-#define is_persistent(_p)  (_p->persistent)
-#define is_ephemeral(_p)   (!(_p->persistent))
-
-/*
- * An object id ("oid") is large: 192-bits (to ensure, for example, files
- * in a modern filesystem can be uniquely identified).
- */
-
-struct tmem_oid {
-	uint64_t oid[3];
-};
-
-static inline void tmem_oid_set_invalid(struct tmem_oid *oidp)
-{
-	oidp->oid[0] = oidp->oid[1] = oidp->oid[2] = -1UL;
-}
-
-static inline bool tmem_oid_valid(struct tmem_oid *oidp)
-{
-	return oidp->oid[0] != -1UL || oidp->oid[1] != -1UL ||
-		oidp->oid[2] != -1UL;
-}
-
-static inline int tmem_oid_compare(struct tmem_oid *left,
-					struct tmem_oid *right)
-{
-	int ret;
-
-	if (left->oid[2] == right->oid[2]) {
-		if (left->oid[1] == right->oid[1]) {
-			if (left->oid[0] == right->oid[0])
-				ret = 0;
-			else if (left->oid[0] < right->oid[0])
-				ret = -1;
-			else
-				return 1;
-		} else if (left->oid[1] < right->oid[1])
-			ret = -1;
-		else
-			ret = 1;
-	} else if (left->oid[2] < right->oid[2])
-		ret = -1;
-	else
-		ret = 1;
-	return ret;
-}
-
-static inline unsigned tmem_oid_hash(struct tmem_oid *oidp)
-{
-	return hash_long(oidp->oid[0] ^ oidp->oid[1] ^ oidp->oid[2],
-				TMEM_HASH_BUCKET_BITS);
-}
-
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-struct tmem_xhandle {
-	uint8_t client_id;
-	uint8_t xh_data_cksum;
-	uint16_t xh_data_size;
-	uint16_t pool_id;
-	struct tmem_oid oid;
-	uint32_t index;
-	void *extra;
-};
-
-static inline struct tmem_xhandle tmem_xhandle_fill(uint16_t client_id,
-					struct tmem_pool *pool,
-					struct tmem_oid *oidp,
-					uint32_t index)
-{
-	struct tmem_xhandle xh;
-	xh.client_id = client_id;
-	xh.xh_data_cksum = (uint8_t)-1;
-	xh.xh_data_size = (uint16_t)-1;
-	xh.pool_id = pool->pool_id;
-	xh.oid = *oidp;
-	xh.index = index;
-	return xh;
-}
-#endif
-
-
-/*
- * A tmem_obj contains an identifier (oid), pointers to the parent
- * pool and the rb_tree to which it belongs, counters, and an ordered
- * set of pampds, structured in a radix-tree-like tree.  The intermediate
- * nodes of the tree are called tmem_objnodes.
- */
-
-struct tmem_objnode;
-
-struct tmem_obj {
-	struct tmem_oid oid;
-	struct tmem_pool *pool;
-	struct rb_node rb_tree_node;
-	struct tmem_objnode *objnode_tree_root;
-	unsigned int objnode_tree_height;
-	unsigned long objnode_count;
-	long pampd_count;
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-	/*
-	 * for current design of ramster, all pages belonging to
-	 * an object reside on the same remotenode and extra is
-	 * used to record the number of the remotenode so a
-	 * flush-object operation can specify it
-	 */
-	void *extra; /* for private use by pampd implementation */
-#endif
-	DECL_SENTINEL
-};
-
-#define OBJNODE_TREE_MAP_SHIFT 6
-#define OBJNODE_TREE_MAP_SIZE (1UL << OBJNODE_TREE_MAP_SHIFT)
-#define OBJNODE_TREE_MAP_MASK (OBJNODE_TREE_MAP_SIZE-1)
-#define OBJNODE_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long))
-#define OBJNODE_TREE_MAX_PATH \
-		(OBJNODE_TREE_INDEX_BITS/OBJNODE_TREE_MAP_SHIFT + 2)
-
-struct tmem_objnode {
-	struct tmem_obj *obj;
-	DECL_SENTINEL
-	void *slots[OBJNODE_TREE_MAP_SIZE];
-	unsigned int slots_in_use;
-};
-
-struct tmem_handle {
-	struct tmem_oid oid; /* 24 bytes */
-	uint32_t index;
-	uint16_t pool_id;
-	uint16_t client_id;
-};
-
-
-/* pampd abstract datatype methods provided by the PAM implementation */
-struct tmem_pamops {
-	void (*create_finish)(void *, bool);
-	int (*get_data)(char *, size_t *, bool, void *, struct tmem_pool *,
-				struct tmem_oid *, uint32_t);
-	int (*get_data_and_free)(char *, size_t *, bool, void *,
-				struct tmem_pool *, struct tmem_oid *,
-				uint32_t);
-	void (*free)(void *, struct tmem_pool *,
-				struct tmem_oid *, uint32_t, bool);
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-	void (*new_obj)(struct tmem_obj *);
-	void (*free_obj)(struct tmem_pool *, struct tmem_obj *, bool);
-	void *(*repatriate_preload)(void *, struct tmem_pool *,
-					struct tmem_oid *, uint32_t, bool *);
-	int (*repatriate)(void *, void *, struct tmem_pool *,
-				struct tmem_oid *, uint32_t, bool, void *);
-	bool (*is_remote)(void *);
-	int (*replace_in_obj)(void *, struct tmem_obj *);
-#endif
-};
-extern void tmem_register_pamops(struct tmem_pamops *m);
-
-/* memory allocation methods provided by the host implementation */
-struct tmem_hostops {
-	struct tmem_obj *(*obj_alloc)(struct tmem_pool *);
-	void (*obj_free)(struct tmem_obj *, struct tmem_pool *);
-	struct tmem_objnode *(*objnode_alloc)(struct tmem_pool *);
-	void (*objnode_free)(struct tmem_objnode *, struct tmem_pool *);
-};
-extern void tmem_register_hostops(struct tmem_hostops *m);
-
-/* core tmem accessor functions */
-extern int tmem_put(struct tmem_pool *, struct tmem_oid *, uint32_t index,
-			bool, void *);
-extern int tmem_get(struct tmem_pool *, struct tmem_oid *, uint32_t index,
-			char *, size_t *, bool, int);
-extern int tmem_flush_page(struct tmem_pool *, struct tmem_oid *,
-			uint32_t index);
-extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *);
-extern int tmem_destroy_pool(struct tmem_pool *);
-extern void tmem_new_pool(struct tmem_pool *, uint32_t);
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index,
-			void *);
-extern void *tmem_localify_get_pampd(struct tmem_pool *, struct tmem_oid *,
-				   uint32_t index, struct tmem_obj **,
-				   void **);
-extern void tmem_localify_finish(struct tmem_obj *, uint32_t index,
-				 void *, void *, bool);
-#endif
-#endif /* _TMEM_H */

drivers/staging/zcache/zbud.c

@@ -1,1066 +0,0 @@
-/*
- * zbud.c - Compression buddies allocator
- *
- * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
- *
- * Compression buddies ("zbud") provides for efficiently packing two
- * (or, possibly in the future, more) compressed pages ("zpages") into
- * a single "raw" pageframe and for tracking both zpages and pageframes
- * so that whole pageframes can be easily reclaimed in LRU-like order.
- * It is designed to be used in conjunction with transcendent memory
- * ("tmem"); for example separate LRU lists are maintained for persistent
- * vs. ephemeral pages.
- *
- * A zbudpage is an overlay for a struct page and thus each zbudpage
- * refers to a physical pageframe of RAM.  When the caller passes a
- * struct page from the kernel's page allocator, zbud "transforms" it
- * to a zbudpage which sets/uses a different set of fields than the
- * struct-page and thus must "untransform" it back by reinitializing
- * certain fields before the struct-page can be freed.  The fields
- * of a zbudpage include a page lock for controlling access to the
- * corresponding pageframe, and there is a size field for each zpage.
- * Each zbudpage also lives on two linked lists: a "budlist" which is
- * used to support efficient buddying of zpages; and an "lru" which
- * is used for reclaiming pageframes in approximately least-recently-used
- * order.
- *
- * A zbudpageframe is a pageframe divided up into aligned 64-byte "chunks"
- * which contain the compressed data for zero, one, or two zbuds.  Contained
- * with the compressed data is a tmem_handle which is a key to allow
- * the same data to be found via the tmem interface so the zpage can
- * be invalidated (for ephemeral pages) or repatriated to the swap cache
- * (for persistent pages).  The contents of a zbudpageframe must never
- * be accessed without holding the page lock for the corresponding
- * zbudpage and, to accomodate highmem machines, the contents may
- * only be examined or changes when kmapped.  Thus, when in use, a
- * kmapped zbudpageframe is referred to in the zbud code as "void *zbpg".
- *
- * Note that the term "zbud" refers to the combination of a zpage and
- * a tmem_handle that is stored as one of possibly two "buddied" zpages;
- * it also generically refers to this allocator... sorry for any confusion.
- *
- * A zbudref is a pointer to a struct zbudpage (which can be cast to a
- * struct page), with the LSB either cleared or set to indicate, respectively,
- * the first or second zpage in the zbudpageframe. Since a zbudref can be
- * cast to a pointer, it is used as the tmem "pampd" pointer and uniquely
- * references a stored tmem page and so is the only zbud data structure
- * externally visible to zbud.c/zbud.h.
- *
- * Since we wish to reclaim entire pageframes but zpages may be randomly
- * added and deleted to any given pageframe, we approximate LRU by
- * promoting a pageframe to MRU when a zpage is added to it, but
- * leaving it at the current place in the list when a zpage is deleted
- * from it.  As a side effect, zpages that are difficult to buddy (e.g.
- * very large paages) will be reclaimed faster than average, which seems
- * reasonable.
- *
- * In the current implementation, no more than two zpages may be stored in
- * any pageframe and no zpage ever crosses a pageframe boundary.  While
- * other zpage allocation mechanisms may allow greater density, this two
- * zpage-per-pageframe limit both ensures simple reclaim of pageframes
- * (including garbage collection of references to the contents of those
- * pageframes from tmem data structures) AND avoids the need for compaction.
- * With additional complexity, zbud could be modified to support storing
- * up to three zpages per pageframe or, to handle larger average zpages,
- * up to three zpages per pair of pageframes, but it is not clear if the
- * additional complexity would be worth it.  So consider it an exercise
- * for future developers.
- *
- * Note also that zbud does no page allocation or freeing.  This is so
- * that the caller has complete control over and, for accounting, visibility
- * into if/when pages are allocated and freed.
- *
- * Finally, note that zbud limits the size of zpages it can store; the
- * caller must check the zpage size with zbud_max_buddy_size before
- * storing it, else BUGs will result.  User beware.
- */
-
-#include <linux/module.h>
-#include <linux/highmem.h>
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <linux/pagemap.h>
-#include <linux/atomic.h>
-#include <linux/bug.h>
-#include "tmem.h"
-#include "zcache.h"
-#include "zbud.h"
-
-/*
- * We need to ensure that a struct zbudpage is never larger than a
- * struct page.  This is checked with a BUG_ON in zbud_init.
- *
- * The unevictable field indicates that a zbud is being added to the
- * zbudpage.  Since this is a two-phase process (due to tmem locking),
- * this field locks the zbudpage against eviction when a zbud match
- * or creation is in process.  Since this addition process may occur
- * in parallel for two zbuds in one zbudpage, the field is a counter
- * that must not exceed two.
- */
-struct zbudpage {
-	union {
-		struct page page;
-		struct {
-			unsigned long space_for_flags;
-			struct {
-				unsigned zbud0_size:PAGE_SHIFT;
-				unsigned zbud1_size:PAGE_SHIFT;
-				unsigned unevictable:2;
-			};
-			struct list_head budlist;
-			struct list_head lru;
-		};
-	};
-};
-#if (PAGE_SHIFT * 2) + 2 > BITS_PER_LONG
-#error "zbud won't work for this arch, PAGE_SIZE is too large"
-#endif
-
-struct zbudref {
-	union {
-		struct zbudpage *zbudpage;
-		unsigned long zbudref;
-	};
-};
-
-#define CHUNK_SHIFT	6
-#define CHUNK_SIZE	(1 << CHUNK_SHIFT)
-#define CHUNK_MASK	(~(CHUNK_SIZE-1))
-#define NCHUNKS		(PAGE_SIZE >> CHUNK_SHIFT)
-#define MAX_CHUNK	(NCHUNKS-1)
-
-/*
- * The following functions deal with the difference between struct
- * page and struct zbudpage.  Note the hack of using the pageflags
- * from struct page; this is to avoid duplicating all the complex
- * pageflag macros.
- */
-static inline void zbudpage_spin_lock(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	while (unlikely(test_and_set_bit_lock(PG_locked, &page->flags))) {
-		do {
-			cpu_relax();
-		} while (test_bit(PG_locked, &page->flags));
-	}
-}
-
-static inline void zbudpage_spin_unlock(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	clear_bit(PG_locked, &page->flags);
-}
-
-static inline int zbudpage_spin_trylock(struct zbudpage *zbudpage)
-{
-	return trylock_page((struct page *)zbudpage);
-}
-
-static inline int zbudpage_is_locked(struct zbudpage *zbudpage)
-{
-	return PageLocked((struct page *)zbudpage);
-}
-
-static inline void *kmap_zbudpage_atomic(struct zbudpage *zbudpage)
-{
-	return kmap_atomic((struct page *)zbudpage);
-}
-
-/*
- * A dying zbudpage is an ephemeral page in the process of being evicted.
- * Any data contained in the zbudpage is invalid and we are just waiting for
- * the tmem pampds to be invalidated before freeing the page
- */
-static inline int zbudpage_is_dying(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	return test_bit(PG_reclaim, &page->flags);
-}
-
-static inline void zbudpage_set_dying(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	set_bit(PG_reclaim, &page->flags);
-}
-
-static inline void zbudpage_clear_dying(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	clear_bit(PG_reclaim, &page->flags);
-}
-
-/*
- * A zombie zbudpage is a persistent page in the process of being evicted.
- * The data contained in the zbudpage is valid and we are just waiting for
- * the tmem pampds to be invalidated before freeing the page
- */
-static inline int zbudpage_is_zombie(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	return test_bit(PG_dirty, &page->flags);
-}
-
-static inline void zbudpage_set_zombie(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	set_bit(PG_dirty, &page->flags);
-}
-
-static inline void zbudpage_clear_zombie(struct zbudpage *zbudpage)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	clear_bit(PG_dirty, &page->flags);
-}
-
-static inline void kunmap_zbudpage_atomic(void *zbpg)
-{
-	kunmap_atomic(zbpg);
-}
-
-/*
- * zbud "translation" and helper functions
- */
-
-static inline struct zbudpage *zbudref_to_zbudpage(struct zbudref *zref)
-{
-	unsigned long zbud = (unsigned long)zref;
-	zbud &= ~1UL;
-	return (struct zbudpage *)zbud;
-}
-
-static inline struct zbudref *zbudpage_to_zbudref(struct zbudpage *zbudpage,
-							unsigned budnum)
-{
-	unsigned long zbud = (unsigned long)zbudpage;
-	BUG_ON(budnum > 1);
-	zbud |= budnum;
-	return (struct zbudref *)zbud;
-}
-
-static inline int zbudref_budnum(struct zbudref *zbudref)
-{
-	unsigned long zbud = (unsigned long)zbudref;
-	return zbud & 1UL;
-}
-
-static inline unsigned zbud_max_size(void)
-{
-	return MAX_CHUNK << CHUNK_SHIFT;
-}
-
-static inline unsigned zbud_size_to_chunks(unsigned size)
-{
-	BUG_ON(size == 0 || size > zbud_max_size());
-	return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT;
-}
-
-/* can only be used between kmap_zbudpage_atomic/kunmap_zbudpage_atomic! */
-static inline char *zbud_data(void *zbpg,
-			unsigned budnum, unsigned size)
-{
-	char *p;
-
-	BUG_ON(size == 0 || size > zbud_max_size());
-	p = (char *)zbpg;
-	if (budnum == 1)
-		p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK);
-	return p;
-}
-
-/*
- * These are all informative and exposed through debugfs... except for
- * the arrays... anyone know how to do that?  To avoid confusion for
- * debugfs viewers, some of these should also be atomic_long_t, but
- * I don't know how to expose atomics via debugfs either...
- */
-static ssize_t zbud_eph_pageframes;
-static ssize_t zbud_pers_pageframes;
-static ssize_t zbud_eph_zpages;
-static ssize_t zbud_pers_zpages;
-static u64 zbud_eph_zbytes;
-static u64 zbud_pers_zbytes;
-static ssize_t zbud_eph_evicted_pageframes;
-static ssize_t zbud_pers_evicted_pageframes;
-static ssize_t zbud_eph_cumul_zpages;
-static ssize_t zbud_pers_cumul_zpages;
-static u64 zbud_eph_cumul_zbytes;
-static u64 zbud_pers_cumul_zbytes;
-static ssize_t zbud_eph_cumul_chunk_counts[NCHUNKS];
-static ssize_t zbud_pers_cumul_chunk_counts[NCHUNKS];
-static ssize_t zbud_eph_buddied_count;
-static ssize_t zbud_pers_buddied_count;
-static ssize_t zbud_eph_unbuddied_count;
-static ssize_t zbud_pers_unbuddied_count;
-static ssize_t zbud_eph_zombie_count;
-static ssize_t zbud_pers_zombie_count;
-static atomic_t zbud_eph_zombie_atomic;
-static atomic_t zbud_pers_zombie_atomic;
-
-#ifdef CONFIG_DEBUG_FS
-#include <linux/debugfs.h>
-#define	zdfs	debugfs_create_size_t
-#define	zdfs64	debugfs_create_u64
-static int zbud_debugfs_init(void)
-{
-	struct dentry *root = debugfs_create_dir("zbud", NULL);
-	if (root == NULL)
-		return -ENXIO;
-
-	/*
-	 * would be nice to dump the sizes of the unbuddied
-	 * arrays, like was done with sysfs, but it doesn't
-	 * look like debugfs is flexible enough to do that
-	 */
-	zdfs64("eph_zbytes", S_IRUGO, root, &zbud_eph_zbytes);
-	zdfs64("eph_cumul_zbytes", S_IRUGO, root, &zbud_eph_cumul_zbytes);
-	zdfs64("pers_zbytes", S_IRUGO, root, &zbud_pers_zbytes);
-	zdfs64("pers_cumul_zbytes", S_IRUGO, root, &zbud_pers_cumul_zbytes);
-	zdfs("eph_cumul_zpages", S_IRUGO, root, &zbud_eph_cumul_zpages);
-	zdfs("eph_evicted_pageframes", S_IRUGO, root,
-				&zbud_eph_evicted_pageframes);
-	zdfs("eph_zpages", S_IRUGO, root, &zbud_eph_zpages);
-	zdfs("eph_pageframes", S_IRUGO, root, &zbud_eph_pageframes);
-	zdfs("eph_buddied_count", S_IRUGO, root, &zbud_eph_buddied_count);
-	zdfs("eph_unbuddied_count", S_IRUGO, root, &zbud_eph_unbuddied_count);
-	zdfs("pers_cumul_zpages", S_IRUGO, root, &zbud_pers_cumul_zpages);
-	zdfs("pers_evicted_pageframes", S_IRUGO, root,
-				&zbud_pers_evicted_pageframes);
-	zdfs("pers_zpages", S_IRUGO, root, &zbud_pers_zpages);
-	zdfs("pers_pageframes", S_IRUGO, root, &zbud_pers_pageframes);
-	zdfs("pers_buddied_count", S_IRUGO, root, &zbud_pers_buddied_count);
-	zdfs("pers_unbuddied_count", S_IRUGO, root, &zbud_pers_unbuddied_count);
-	zdfs("pers_zombie_count", S_IRUGO, root, &zbud_pers_zombie_count);
-	return 0;
-}
-#undef	zdfs
-#undef	zdfs64
-#else
-static inline int zbud_debugfs_init(void)
-{
-	return 0;
-}
-#endif
-
-/* protects the buddied list and all unbuddied lists */
-static DEFINE_SPINLOCK(zbud_eph_lists_lock);
-static DEFINE_SPINLOCK(zbud_pers_lists_lock);
-
-struct zbud_unbuddied {
-	struct list_head list;
-	unsigned count;
-};
-
-/* list N contains pages with N chunks USED and NCHUNKS-N unused */
-/* element 0 is never used but optimizing that isn't worth it */
-static struct zbud_unbuddied zbud_eph_unbuddied[NCHUNKS];
-static struct zbud_unbuddied zbud_pers_unbuddied[NCHUNKS];
-static LIST_HEAD(zbud_eph_lru_list);
-static LIST_HEAD(zbud_pers_lru_list);
-static LIST_HEAD(zbud_eph_buddied_list);
-static LIST_HEAD(zbud_pers_buddied_list);
-static LIST_HEAD(zbud_eph_zombie_list);
-static LIST_HEAD(zbud_pers_zombie_list);
-
-/*
- * Given a struct page, transform it to a zbudpage so that it can be
- * used by zbud and initialize fields as necessary.
- */
-static inline struct zbudpage *zbud_init_zbudpage(struct page *page, bool eph)
-{
-	struct zbudpage *zbudpage = (struct zbudpage *)page;
-
-	BUG_ON(page == NULL);
-	INIT_LIST_HEAD(&zbudpage->budlist);
-	INIT_LIST_HEAD(&zbudpage->lru);
-	zbudpage->zbud0_size = 0;
-	zbudpage->zbud1_size = 0;
-	zbudpage->unevictable = 0;
-	if (eph)
-		zbud_eph_pageframes++;
-	else
-		zbud_pers_pageframes++;
-	return zbudpage;
-}
-
-/* "Transform" a zbudpage back to a struct page suitable to free. */
-static inline struct page *zbud_unuse_zbudpage(struct zbudpage *zbudpage,
-								bool eph)
-{
-	struct page *page = (struct page *)zbudpage;
-
-	BUG_ON(!list_empty(&zbudpage->budlist));
-	BUG_ON(!list_empty(&zbudpage->lru));
-	BUG_ON(zbudpage->zbud0_size != 0);
-	BUG_ON(zbudpage->zbud1_size != 0);
-	BUG_ON(!PageLocked(page));
-	BUG_ON(zbudpage->unevictable != 0);
-	BUG_ON(zbudpage_is_dying(zbudpage));
-	BUG_ON(zbudpage_is_zombie(zbudpage));
-	if (eph)
-		zbud_eph_pageframes--;
-	else
-		zbud_pers_pageframes--;
-	zbudpage_spin_unlock(zbudpage);
-	page_mapcount_reset(page);
-	init_page_count(page);
-	page->index = 0;
-	return page;
-}
-
-/* Mark a zbud as unused and do accounting */
-static inline void zbud_unuse_zbud(struct zbudpage *zbudpage,
-					int budnum, bool eph)
-{
-	unsigned size;
-
-	BUG_ON(!zbudpage_is_locked(zbudpage));
-	if (budnum == 0) {
-		size = zbudpage->zbud0_size;
-		zbudpage->zbud0_size = 0;
-	} else {
-		size = zbudpage->zbud1_size;
-		zbudpage->zbud1_size = 0;
-	}
-	if (eph) {
-		zbud_eph_zbytes -= size;
-		zbud_eph_zpages--;
-	} else {
-		zbud_pers_zbytes -= size;
-		zbud_pers_zpages--;
-	}
-}
-
-/*
- * Given a zbudpage/budnum/size, a tmem handle, and a kmapped pointer
- * to some data, set up the zbud appropriately including data copying
- * and accounting.  Note that if cdata is NULL, the data copying is
- * skipped.  (This is useful for lazy writes such as for RAMster.)
- */
-static void zbud_init_zbud(struct zbudpage *zbudpage, struct tmem_handle *th,
-				bool eph, void *cdata,
-				unsigned budnum, unsigned size)
-{
-	char *to;
-	void *zbpg;
-	struct tmem_handle *to_th;
-	unsigned nchunks = zbud_size_to_chunks(size);
-
-	BUG_ON(!zbudpage_is_locked(zbudpage));
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	to = zbud_data(zbpg, budnum, size);
-	to_th = (struct tmem_handle *)to;
-	to_th->index = th->index;
-	to_th->oid = th->oid;
-	to_th->pool_id = th->pool_id;
-	to_th->client_id = th->client_id;
-	to += sizeof(struct tmem_handle);
-	if (cdata != NULL)
-		memcpy(to, cdata, size - sizeof(struct tmem_handle));
-	kunmap_zbudpage_atomic(zbpg);
-	if (budnum == 0)
-		zbudpage->zbud0_size = size;
-	else
-		zbudpage->zbud1_size = size;
-	if (eph) {
-		zbud_eph_cumul_chunk_counts[nchunks]++;
-		zbud_eph_zpages++;
-		zbud_eph_cumul_zpages++;
-		zbud_eph_zbytes += size;
-		zbud_eph_cumul_zbytes += size;
-	} else {
-		zbud_pers_cumul_chunk_counts[nchunks]++;
-		zbud_pers_zpages++;
-		zbud_pers_cumul_zpages++;
-		zbud_pers_zbytes += size;
-		zbud_pers_cumul_zbytes += size;
-	}
-}
-
-/*
- * Given a locked dying zbudpage, read out the tmem handles from the data,
- * unlock the page, then use the handles to tell tmem to flush out its
- * references
- */
-static void zbud_evict_tmem(struct zbudpage *zbudpage)
-{
-	int i, j;
-	uint32_t pool_id[2], client_id[2];
-	uint32_t index[2];
-	struct tmem_oid oid[2];
-	struct tmem_pool *pool;
-	void *zbpg;
-	struct tmem_handle *th;
-	unsigned size;
-
-	/* read out the tmem handles from the data and set aside */
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	for (i = 0, j = 0; i < 2; i++) {
-		size = (i == 0) ? zbudpage->zbud0_size : zbudpage->zbud1_size;
-		if (size) {
-			th = (struct tmem_handle *)zbud_data(zbpg, i, size);
-			client_id[j] = th->client_id;
-			pool_id[j] = th->pool_id;
-			oid[j] = th->oid;
-			index[j] = th->index;
-			j++;
-			zbud_unuse_zbud(zbudpage, i, true);
-		}
-	}
-	kunmap_zbudpage_atomic(zbpg);
-	zbudpage_spin_unlock(zbudpage);
-	/* zbudpage is now an unlocked dying... tell tmem to flush pointers */
-	for (i = 0; i < j; i++) {
-		pool = zcache_get_pool_by_id(client_id[i], pool_id[i]);
-		if (pool != NULL) {
-			tmem_flush_page(pool, &oid[i], index[i]);
-			zcache_put_pool(pool);
-		}
-	}
-}
-
-/*
- * Externally callable zbud handling routines.
- */
-
-/*
- * Return the maximum size compressed page that can be stored (secretly
- * setting aside space for the tmem handle.
- */
-unsigned int zbud_max_buddy_size(void)
-{
-	return zbud_max_size() - sizeof(struct tmem_handle);
-}
-
-/*
- * Given a zbud reference, free the corresponding zbud from all lists,
- * mark it as unused, do accounting, and if the freeing of the zbud
- * frees up an entire pageframe, return it to the caller (else NULL).
- */
-struct page *zbud_free_and_delist(struct zbudref *zref, bool eph,
-				  unsigned int *zsize, unsigned int *zpages)
-{
-	unsigned long budnum = zbudref_budnum(zref);
-	struct zbudpage *zbudpage = zbudref_to_zbudpage(zref);
-	struct page *page = NULL;
-	unsigned chunks, bud_size, other_bud_size;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-	struct zbud_unbuddied *unbud =
-		eph ? zbud_eph_unbuddied : zbud_pers_unbuddied;
-
-
-	spin_lock(lists_lock);
-	zbudpage_spin_lock(zbudpage);
-	if (zbudpage_is_dying(zbudpage)) {
-		/* ignore dying zbudpage... see zbud_evict_pageframe_lru() */
-		zbudpage_spin_unlock(zbudpage);
-		spin_unlock(lists_lock);
-		*zpages = 0;
-		*zsize = 0;
-		goto out;
-	}
-	if (budnum == 0) {
-		bud_size = zbudpage->zbud0_size;
-		other_bud_size = zbudpage->zbud1_size;
-	} else {
-		bud_size = zbudpage->zbud1_size;
-		other_bud_size = zbudpage->zbud0_size;
-	}
-	*zsize = bud_size - sizeof(struct tmem_handle);
-	*zpages = 1;
-	zbud_unuse_zbud(zbudpage, budnum, eph);
-	if (other_bud_size == 0) { /* was unbuddied: unlist and free */
-		chunks = zbud_size_to_chunks(bud_size) ;
-		if (zbudpage_is_zombie(zbudpage)) {
-			if (eph)
-				zbud_pers_zombie_count =
-				  atomic_dec_return(&zbud_eph_zombie_atomic);
-			else
-				zbud_pers_zombie_count =
-				  atomic_dec_return(&zbud_pers_zombie_atomic);
-			zbudpage_clear_zombie(zbudpage);
-		} else {
-			BUG_ON(list_empty(&unbud[chunks].list));
-			list_del_init(&zbudpage->budlist);
-			unbud[chunks].count--;
-		}
-		list_del_init(&zbudpage->lru);
-		spin_unlock(lists_lock);
-		if (eph)
-			zbud_eph_unbuddied_count--;
-		else
-			zbud_pers_unbuddied_count--;
-		page = zbud_unuse_zbudpage(zbudpage, eph);
-	} else { /* was buddied: move remaining buddy to unbuddied list */
-		chunks = zbud_size_to_chunks(other_bud_size) ;
-		if (!zbudpage_is_zombie(zbudpage)) {
-			list_del_init(&zbudpage->budlist);
-			list_add_tail(&zbudpage->budlist, &unbud[chunks].list);
-			unbud[chunks].count++;
-		}
-		if (eph) {
-			zbud_eph_buddied_count--;
-			zbud_eph_unbuddied_count++;
-		} else {
-			zbud_pers_unbuddied_count++;
-			zbud_pers_buddied_count--;
-		}
-		/* don't mess with lru, no need to move it */
-		zbudpage_spin_unlock(zbudpage);
-		spin_unlock(lists_lock);
-	}
-out:
-	return page;
-}
-
-/*
- * Given a tmem handle, and a kmapped pointer to compressed data of
- * the given size, try to find an unbuddied zbudpage in which to
- * create a zbud. If found, put it there, mark the zbudpage unevictable,
- * and return a zbudref to it.  Else return NULL.
- */
-struct zbudref *zbud_match_prep(struct tmem_handle *th, bool eph,
-				void *cdata, unsigned size)
-{
-	struct zbudpage *zbudpage = NULL, *zbudpage2;
-	unsigned long budnum = 0UL;
-	unsigned nchunks;
-	int i, found_good_buddy = 0;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-	struct zbud_unbuddied *unbud =
-		eph ? zbud_eph_unbuddied : zbud_pers_unbuddied;
-
-	size += sizeof(struct tmem_handle);
-	nchunks = zbud_size_to_chunks(size);
-	for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) {
-		spin_lock(lists_lock);
-		if (!list_empty(&unbud[i].list)) {
-			list_for_each_entry_safe(zbudpage, zbudpage2,
-				    &unbud[i].list, budlist) {
-				if (zbudpage_spin_trylock(zbudpage)) {
-					found_good_buddy = i;
-					goto found_unbuddied;
-				}
-			}
-		}
-		spin_unlock(lists_lock);
-	}
-	zbudpage = NULL;
-	goto out;
-
-found_unbuddied:
-	BUG_ON(!zbudpage_is_locked(zbudpage));
-	BUG_ON(!((zbudpage->zbud0_size == 0) ^ (zbudpage->zbud1_size == 0)));
-	if (zbudpage->zbud0_size == 0)
-		budnum = 0UL;
-	else if (zbudpage->zbud1_size == 0)
-		budnum = 1UL;
-	list_del_init(&zbudpage->budlist);
-	if (eph) {
-		list_add_tail(&zbudpage->budlist, &zbud_eph_buddied_list);
-		unbud[found_good_buddy].count--;
-		zbud_eph_unbuddied_count--;
-		zbud_eph_buddied_count++;
-		/* "promote" raw zbudpage to most-recently-used */
-		list_del_init(&zbudpage->lru);
-		list_add_tail(&zbudpage->lru, &zbud_eph_lru_list);
-	} else {
-		list_add_tail(&zbudpage->budlist, &zbud_pers_buddied_list);
-		unbud[found_good_buddy].count--;
-		zbud_pers_unbuddied_count--;
-		zbud_pers_buddied_count++;
-		/* "promote" raw zbudpage to most-recently-used */
-		list_del_init(&zbudpage->lru);
-		list_add_tail(&zbudpage->lru, &zbud_pers_lru_list);
-	}
-	zbud_init_zbud(zbudpage, th, eph, cdata, budnum, size);
-	zbudpage->unevictable++;
-	BUG_ON(zbudpage->unevictable == 3);
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-out:
-	return zbudpage_to_zbudref(zbudpage, budnum);
-
-}
-
-/*
- * Given a tmem handle, and a kmapped pointer to compressed data of
- * the given size, and a newly allocated struct page, create an unevictable
- * zbud in that new page and return a zbudref to it.
- */
-struct zbudref *zbud_create_prep(struct tmem_handle *th, bool eph,
-					void *cdata, unsigned size,
-					struct page *newpage)
-{
-	struct zbudpage *zbudpage;
-	unsigned long budnum = 0;
-	unsigned nchunks;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-	struct zbud_unbuddied *unbud =
-		eph ? zbud_eph_unbuddied : zbud_pers_unbuddied;
-
-#if 0
-	/* this may be worth it later to support decompress-in-place? */
-	static unsigned long counter;
-	budnum = counter++ & 1;	/* alternate using zbud0 and zbud1 */
-#endif
-
-	if (size  > zbud_max_buddy_size())
-		return NULL;
-	if (newpage == NULL)
-		return NULL;
-
-	size += sizeof(struct tmem_handle);
-	nchunks = zbud_size_to_chunks(size) ;
-	spin_lock(lists_lock);
-	zbudpage = zbud_init_zbudpage(newpage, eph);
-	zbudpage_spin_lock(zbudpage);
-	list_add_tail(&zbudpage->budlist, &unbud[nchunks].list);
-	if (eph) {
-		list_add_tail(&zbudpage->lru, &zbud_eph_lru_list);
-		zbud_eph_unbuddied_count++;
-	} else {
-		list_add_tail(&zbudpage->lru, &zbud_pers_lru_list);
-		zbud_pers_unbuddied_count++;
-	}
-	unbud[nchunks].count++;
-	zbud_init_zbud(zbudpage, th, eph, cdata, budnum, size);
-	zbudpage->unevictable++;
-	BUG_ON(zbudpage->unevictable == 3);
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-	return zbudpage_to_zbudref(zbudpage, budnum);
-}
-
-/*
- * Finish creation of a zbud by, assuming another zbud isn't being created
- * in parallel, marking it evictable.
- */
-void zbud_create_finish(struct zbudref *zref, bool eph)
-{
-	struct zbudpage *zbudpage = zbudref_to_zbudpage(zref);
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-
-	spin_lock(lists_lock);
-	zbudpage_spin_lock(zbudpage);
-	BUG_ON(zbudpage_is_dying(zbudpage));
-	zbudpage->unevictable--;
-	BUG_ON((int)zbudpage->unevictable < 0);
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-}
-
-/*
- * Given a zbudref and a struct page, decompress the data from
- * the zbud into the physical page represented by the struct page
- * by upcalling to zcache_decompress
- */
-int zbud_decompress(struct page *data_page, struct zbudref *zref, bool eph,
-			void (*decompress)(char *, unsigned int, char *))
-{
-	struct zbudpage *zbudpage = zbudref_to_zbudpage(zref);
-	unsigned long budnum = zbudref_budnum(zref);
-	void *zbpg;
-	char *to_va, *from_va;
-	unsigned size;
-	int ret = -1;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-
-	spin_lock(lists_lock);
-	zbudpage_spin_lock(zbudpage);
-	if (zbudpage_is_dying(zbudpage)) {
-		/* ignore dying zbudpage... see zbud_evict_pageframe_lru() */
-		goto out;
-	}
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	to_va = kmap_atomic(data_page);
-	if (budnum == 0)
-		size = zbudpage->zbud0_size;
-	else
-		size = zbudpage->zbud1_size;
-	BUG_ON(size == 0 || size > zbud_max_size());
-	from_va = zbud_data(zbpg, budnum, size);
-	from_va += sizeof(struct tmem_handle);
-	size -= sizeof(struct tmem_handle);
-	decompress(from_va, size, to_va);
-	kunmap_atomic(to_va);
-	kunmap_zbudpage_atomic(zbpg);
-	ret = 0;
-out:
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-	return ret;
-}
-
-/*
- * Given a zbudref and a kernel pointer, copy the data from
- * the zbud to the kernel pointer.
- */
-int zbud_copy_from_zbud(char *to_va, struct zbudref *zref,
-				size_t *sizep, bool eph)
-{
-	struct zbudpage *zbudpage = zbudref_to_zbudpage(zref);
-	unsigned long budnum = zbudref_budnum(zref);
-	void *zbpg;
-	char *from_va;
-	unsigned size;
-	int ret = -1;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-
-	spin_lock(lists_lock);
-	zbudpage_spin_lock(zbudpage);
-	if (zbudpage_is_dying(zbudpage)) {
-		/* ignore dying zbudpage... see zbud_evict_pageframe_lru() */
-		goto out;
-	}
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	if (budnum == 0)
-		size = zbudpage->zbud0_size;
-	else
-		size = zbudpage->zbud1_size;
-	BUG_ON(size == 0 || size > zbud_max_size());
-	from_va = zbud_data(zbpg, budnum, size);
-	from_va += sizeof(struct tmem_handle);
-	size -= sizeof(struct tmem_handle);
-	*sizep = size;
-	memcpy(to_va, from_va, size);
-
-	kunmap_zbudpage_atomic(zbpg);
-	ret = 0;
-out:
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-	return ret;
-}
-
-/*
- * Given a zbudref and a kernel pointer, copy the data from
- * the kernel pointer to the zbud.
- */
-int zbud_copy_to_zbud(struct zbudref *zref, char *from_va, bool eph)
-{
-	struct zbudpage *zbudpage = zbudref_to_zbudpage(zref);
-	unsigned long budnum = zbudref_budnum(zref);
-	void *zbpg;
-	char *to_va;
-	unsigned size;
-	int ret = -1;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-
-	spin_lock(lists_lock);
-	zbudpage_spin_lock(zbudpage);
-	if (zbudpage_is_dying(zbudpage)) {
-		/* ignore dying zbudpage... see zbud_evict_pageframe_lru() */
-		goto out;
-	}
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	if (budnum == 0)
-		size = zbudpage->zbud0_size;
-	else
-		size = zbudpage->zbud1_size;
-	BUG_ON(size == 0 || size > zbud_max_size());
-	to_va = zbud_data(zbpg, budnum, size);
-	to_va += sizeof(struct tmem_handle);
-	size -= sizeof(struct tmem_handle);
-	memcpy(to_va, from_va, size);
-
-	kunmap_zbudpage_atomic(zbpg);
-	ret = 0;
-out:
-	zbudpage_spin_unlock(zbudpage);
-	spin_unlock(lists_lock);
-	return ret;
-}
-
-/*
- * Choose an ephemeral LRU zbudpage that is evictable (not locked), ensure
- * there are no references to it remaining, and return the now unused
- * (and re-init'ed) struct page and the total amount of compressed
- * data that was evicted.
- */
-struct page *zbud_evict_pageframe_lru(unsigned int *zsize, unsigned int *zpages)
-{
-	struct zbudpage *zbudpage = NULL, *zbudpage2;
-	struct zbud_unbuddied *unbud = zbud_eph_unbuddied;
-	struct page *page = NULL;
-	bool irqs_disabled = irqs_disabled();
-
-	/*
-	 * Since this can be called indirectly from cleancache_put, which
-	 * has interrupts disabled, as well as frontswap_put, which does not,
-	 * we need to be able to handle both cases, even though it is ugly.
-	 */
-	if (irqs_disabled)
-		spin_lock(&zbud_eph_lists_lock);
-	else
-		spin_lock_bh(&zbud_eph_lists_lock);
-	*zsize = 0;
-	if (list_empty(&zbud_eph_lru_list))
-		goto unlock_out;
-	list_for_each_entry_safe(zbudpage, zbudpage2, &zbud_eph_lru_list, lru) {
-		/* skip a locked zbudpage */
-		if (unlikely(!zbudpage_spin_trylock(zbudpage)))
-			continue;
-		/* skip an unevictable zbudpage */
-		if (unlikely(zbudpage->unevictable != 0)) {
-			zbudpage_spin_unlock(zbudpage);
-			continue;
-		}
-		/* got a locked evictable page */
-		goto evict_page;
-
-	}
-unlock_out:
-	/* no unlocked evictable pages, give up */
-	if (irqs_disabled)
-		spin_unlock(&zbud_eph_lists_lock);
-	else
-		spin_unlock_bh(&zbud_eph_lists_lock);
-	goto out;
-
-evict_page:
-	list_del_init(&zbudpage->budlist);
-	list_del_init(&zbudpage->lru);
-	zbudpage_set_dying(zbudpage);
-	/*
-	 * the zbudpage is now "dying" and attempts to read, write,
-	 * or delete data from it will be ignored
-	 */
-	if (zbudpage->zbud0_size != 0 && zbudpage->zbud1_size !=  0) {
-		*zsize = zbudpage->zbud0_size + zbudpage->zbud1_size -
-				(2 * sizeof(struct tmem_handle));
-		*zpages = 2;
-	} else if (zbudpage->zbud0_size != 0) {
-		unbud[zbud_size_to_chunks(zbudpage->zbud0_size)].count--;
-		*zsize = zbudpage->zbud0_size - sizeof(struct tmem_handle);
-		*zpages = 1;
-	} else if (zbudpage->zbud1_size != 0) {
-		unbud[zbud_size_to_chunks(zbudpage->zbud1_size)].count--;
-		*zsize = zbudpage->zbud1_size - sizeof(struct tmem_handle);
-		*zpages = 1;
-	} else {
-		BUG();
-	}
-	spin_unlock(&zbud_eph_lists_lock);
-	zbud_eph_evicted_pageframes++;
-	if (*zpages == 1)
-		zbud_eph_unbuddied_count--;
-	else
-		zbud_eph_buddied_count--;
-	zbud_evict_tmem(zbudpage);
-	zbudpage_spin_lock(zbudpage);
-	zbudpage_clear_dying(zbudpage);
-	page = zbud_unuse_zbudpage(zbudpage, true);
-	if (!irqs_disabled)
-		local_bh_enable();
-out:
-	return page;
-}
-
-/*
- * Choose a persistent LRU zbudpage that is evictable (not locked), zombify it,
- * read the tmem_handle(s) out of it into the passed array, and return the
- * number of zbuds.  Caller must perform necessary tmem functions and,
- * indirectly, zbud functions to fetch any valid data and cause the
- * now-zombified zbudpage to eventually be freed.  We track the zombified
- * zbudpage count so it is possible to observe if there is a leak.
- FIXME: describe (ramster) case where data pointers are passed in for memcpy
- */
-unsigned int zbud_make_zombie_lru(struct tmem_handle *th, unsigned char **data,
-					unsigned int *zsize, bool eph)
-{
-	struct zbudpage *zbudpage = NULL, *zbudpag2;
-	struct tmem_handle *thfrom;
-	char *from_va;
-	void *zbpg;
-	unsigned size;
-	int ret = 0, i;
-	spinlock_t *lists_lock =
-		eph ? &zbud_eph_lists_lock : &zbud_pers_lists_lock;
-	struct list_head *lru_list =
-		eph ? &zbud_eph_lru_list : &zbud_pers_lru_list;
-
-	spin_lock_bh(lists_lock);
-	if (list_empty(lru_list))
-		goto out;
-	list_for_each_entry_safe(zbudpage, zbudpag2, lru_list, lru) {
-		/* skip a locked zbudpage */
-		if (unlikely(!zbudpage_spin_trylock(zbudpage)))
-			continue;
-		/* skip an unevictable zbudpage */
-		if (unlikely(zbudpage->unevictable != 0)) {
-			zbudpage_spin_unlock(zbudpage);
-			continue;
-		}
-		/* got a locked evictable page */
-		goto zombify_page;
-	}
-	/* no unlocked evictable pages, give up */
-	goto out;
-
-zombify_page:
-	/* got an unlocked evictable page, zombify it */
-	list_del_init(&zbudpage->budlist);
-	zbudpage_set_zombie(zbudpage);
-	/* FIXME what accounting do I need to do here? */
-	list_del_init(&zbudpage->lru);
-	if (eph) {
-		list_add_tail(&zbudpage->lru, &zbud_eph_zombie_list);
-		zbud_eph_zombie_count =
-				atomic_inc_return(&zbud_eph_zombie_atomic);
-	} else {
-		list_add_tail(&zbudpage->lru, &zbud_pers_zombie_list);
-		zbud_pers_zombie_count =
-				atomic_inc_return(&zbud_pers_zombie_atomic);
-	}
-	/* FIXME what accounting do I need to do here? */
-	zbpg = kmap_zbudpage_atomic(zbudpage);
-	for (i = 0; i < 2; i++) {
-		size = (i == 0) ? zbudpage->zbud0_size : zbudpage->zbud1_size;
-		if (size) {
-			from_va = zbud_data(zbpg, i, size);
-			thfrom = (struct tmem_handle *)from_va;
-			from_va += sizeof(struct tmem_handle);
-			size -= sizeof(struct tmem_handle);
-			if (th != NULL)
-				th[ret] = *thfrom;
-			if (data != NULL)
-				memcpy(data[ret], from_va, size);
-			if (zsize != NULL)
-				*zsize++ = size;
-			ret++;
-		}
-	}
-	kunmap_zbudpage_atomic(zbpg);
-	zbudpage_spin_unlock(zbudpage);
-out:
-	spin_unlock_bh(lists_lock);
-	return ret;
-}
-
-void zbud_init(void)
-{
-	int i;
-
-	zbud_debugfs_init();
-	BUG_ON((sizeof(struct tmem_handle) * 2 > CHUNK_SIZE));
-	BUG_ON(sizeof(struct zbudpage) > sizeof(struct page));
-	for (i = 0; i < NCHUNKS; i++) {
-		INIT_LIST_HEAD(&zbud_eph_unbuddied[i].list);
-		INIT_LIST_HEAD(&zbud_pers_unbuddied[i].list);
-	}
-}

drivers/staging/zcache/zbud.h

@@ -1,33 +0,0 @@
-/*
- * zbud.h
- *
- * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
- *
- */
-
-#ifndef _ZBUD_H_
-#define _ZBUD_H_
-
-#include "tmem.h"
-
-struct zbudref;
-
-extern unsigned int zbud_max_buddy_size(void);
-extern struct zbudref *zbud_match_prep(struct tmem_handle *th, bool eph,
-						void *cdata, unsigned size);
-extern struct zbudref *zbud_create_prep(struct tmem_handle *th, bool eph,
-						void *cdata, unsigned size,
-						struct page *newpage);
-extern void zbud_create_finish(struct zbudref *, bool);
-extern int zbud_decompress(struct page *, struct zbudref *, bool,
-				void (*func)(char *, unsigned int, char *));
-extern int zbud_copy_from_zbud(char *, struct zbudref *, size_t *, bool);
-extern int zbud_copy_to_zbud(struct zbudref *, char *, bool);
-extern struct page *zbud_free_and_delist(struct zbudref *, bool eph,
-						unsigned int *, unsigned int *);
-extern struct page *zbud_evict_pageframe_lru(unsigned int *, unsigned int *);
-extern unsigned int zbud_make_zombie_lru(struct tmem_handle *, unsigned char **,
-						unsigned int *, bool);
-extern void zbud_init(void);
-
-#endif /* _ZBUD_H_ */

drivers/staging/zcache/zcache-main.c

@@ -1,1943 +0,0 @@
-/*
- * zcache.c
- *
- * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp.
- * Copyright (c) 2010,2011, Nitin Gupta
- *
- * Zcache provides an in-kernel "host implementation" for transcendent memory
- * ("tmem") and, thus indirectly, for cleancache and frontswap.  Zcache uses
- * lzo1x compression to improve density and an embedded allocator called
- * "zbud" which "buddies" two compressed pages semi-optimally in each physical
- * pageframe.  Zbud is integrally tied into tmem to allow pageframes to
- * be "reclaimed" efficiently.
- */
-
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/highmem.h>
-#include <linux/list.h>
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/types.h>
-#include <linux/string.h>
-#include <linux/atomic.h>
-#include <linux/math64.h>
-#include <linux/crypto.h>
-#include <linux/swap.h>
-#include <linux/swapops.h>
-#include <linux/pagemap.h>
-#include <linux/writeback.h>
-
-#include <linux/cleancache.h>
-#include <linux/frontswap.h>
-#include "tmem.h"
-#include "zcache.h"
-#include "zbud.h"
-#include "ramster.h"
-#include "debug.h"
-#ifdef CONFIG_RAMSTER
-static bool ramster_enabled __read_mostly;
-static int disable_frontswap_selfshrink;
-#else
-#define ramster_enabled false
-#define disable_frontswap_selfshrink 0
-#endif
-
-#ifndef __PG_WAS_ACTIVE
-static inline bool PageWasActive(struct page *page)
-{
-	return true;
-}
-
-static inline void SetPageWasActive(struct page *page)
-{
-}
-#endif
-
-#ifdef FRONTSWAP_HAS_EXCLUSIVE_GETS
-static bool frontswap_has_exclusive_gets __read_mostly = true;
-#else
-static bool frontswap_has_exclusive_gets __read_mostly;
-static inline void frontswap_tmem_exclusive_gets(bool b)
-{
-}
-#endif
-
-/*
- * mark pampd to special value in order that later
- * retrieve will identify zero-filled pages
- */
-#define ZERO_FILLED 0x2
-
-/* enable (or fix code) when Seth's patches are accepted upstream */
-#define zcache_writeback_enabled 0
-
-static bool zcache_enabled __read_mostly;
-static bool disable_cleancache __read_mostly;
-static bool disable_frontswap __read_mostly;
-static bool disable_frontswap_ignore_nonactive __read_mostly;
-static bool disable_cleancache_ignore_nonactive __read_mostly;
-static char *namestr __read_mostly = "zcache";
-
-#define ZCACHE_GFP_MASK \
-	(__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC)
-
-/* crypto API for zcache  */
-#ifdef CONFIG_ZCACHE_MODULE
-static char *zcache_comp_name = "lzo";
-#else
-#define ZCACHE_COMP_NAME_SZ CRYPTO_MAX_ALG_NAME
-static char zcache_comp_name[ZCACHE_COMP_NAME_SZ] __read_mostly;
-#endif
-static struct crypto_comp * __percpu *zcache_comp_pcpu_tfms __read_mostly;
-
-enum comp_op {
-	ZCACHE_COMPOP_COMPRESS,
-	ZCACHE_COMPOP_DECOMPRESS
-};
-
-static inline int zcache_comp_op(enum comp_op op,
-				const u8 *src, unsigned int slen,
-				u8 *dst, unsigned int *dlen)
-{
-	struct crypto_comp *tfm;
-	int ret = -1;
-
-	BUG_ON(!zcache_comp_pcpu_tfms);
-	tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, get_cpu());
-	BUG_ON(!tfm);
-	switch (op) {
-	case ZCACHE_COMPOP_COMPRESS:
-		ret = crypto_comp_compress(tfm, src, slen, dst, dlen);
-		break;
-	case ZCACHE_COMPOP_DECOMPRESS:
-		ret = crypto_comp_decompress(tfm, src, slen, dst, dlen);
-		break;
-	default:
-		ret = -EINVAL;
-	}
-	put_cpu();
-	return ret;
-}
-
-/*
- * policy parameters
- */
-
-/*
- * byte count defining poor compression; pages with greater zsize will be
- * rejected
- */
-static unsigned int zbud_max_zsize __read_mostly = (PAGE_SIZE / 8) * 7;
-/*
- * byte count defining poor *mean* compression; pages with greater zsize
- * will be rejected until sufficient better-compressed pages are accepted
- * driving the mean below this threshold
- */
-static unsigned int zbud_max_mean_zsize __read_mostly = (PAGE_SIZE / 8) * 5;
-
-/*
- * for now, used named slabs so can easily track usage; later can
- * either just use kmalloc, or perhaps add a slab-like allocator
- * to more carefully manage total memory utilization
- */
-static struct kmem_cache *zcache_objnode_cache;
-static struct kmem_cache *zcache_obj_cache;
-
-static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, };
-
-/* Used by debug.c */
-ssize_t zcache_pers_zpages;
-u64 zcache_pers_zbytes;
-ssize_t zcache_eph_pageframes;
-ssize_t zcache_pers_pageframes;
-
-/* Used by this code. */
-ssize_t zcache_last_active_file_pageframes;
-ssize_t zcache_last_inactive_file_pageframes;
-ssize_t zcache_last_active_anon_pageframes;
-ssize_t zcache_last_inactive_anon_pageframes;
-#ifdef CONFIG_ZCACHE_WRITEBACK
-ssize_t zcache_writtenback_pages;
-ssize_t zcache_outstanding_writeback_pages;
-#endif
-/*
- * zcache core code starts here
- */
-
-static struct zcache_client zcache_host;
-static struct zcache_client zcache_clients[MAX_CLIENTS];
-
-static inline bool is_local_client(struct zcache_client *cli)
-{
-	return cli == &zcache_host;
-}
-
-static struct zcache_client *zcache_get_client_by_id(uint16_t cli_id)
-{
-	struct zcache_client *cli = &zcache_host;
-
-	if (cli_id != LOCAL_CLIENT) {
-		if (cli_id >= MAX_CLIENTS)
-			goto out;
-		cli = &zcache_clients[cli_id];
-	}
-out:
-	return cli;
-}
-
-/*
- * Tmem operations assume the poolid implies the invoking client.
- * Zcache only has one client (the kernel itself): LOCAL_CLIENT.
- * RAMster has each client numbered by cluster node, and a KVM version
- * of zcache would have one client per guest and each client might
- * have a poolid==N.
- */
-struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid)
-{
-	struct tmem_pool *pool = NULL;
-	struct zcache_client *cli = NULL;
-
-	cli = zcache_get_client_by_id(cli_id);
-	if (cli == NULL)
-		goto out;
-	if (!is_local_client(cli))
-		atomic_inc(&cli->refcount);
-	if (poolid < MAX_POOLS_PER_CLIENT) {
-		pool = cli->tmem_pools[poolid];
-		if (pool != NULL)
-			atomic_inc(&pool->refcount);
-	}
-out:
-	return pool;
-}
-
-void zcache_put_pool(struct tmem_pool *pool)
-{
-	struct zcache_client *cli = NULL;
-
-	if (pool == NULL)
-		BUG();
-	cli = pool->client;
-	atomic_dec(&pool->refcount);
-	if (!is_local_client(cli))
-		atomic_dec(&cli->refcount);
-}
-
-int zcache_new_client(uint16_t cli_id)
-{
-	struct zcache_client *cli;
-	int ret = -1;
-
-	cli = zcache_get_client_by_id(cli_id);
-	if (cli == NULL)
-		goto out;
-	if (cli->allocated)
-		goto out;
-	cli->allocated = 1;
-	ret = 0;
-out:
-	return ret;
-}
-
-/*
- * zcache implementation for tmem host ops
- */
-
-static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool)
-{
-	struct tmem_objnode *objnode = NULL;
-	struct zcache_preload *kp;
-	int i;
-
-	kp = &__get_cpu_var(zcache_preloads);
-	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
-		objnode = kp->objnodes[i];
-		if (objnode != NULL) {
-			kp->objnodes[i] = NULL;
-			break;
-		}
-	}
-	BUG_ON(objnode == NULL);
-	inc_zcache_objnode_count();
-	return objnode;
-}
-
-static void zcache_objnode_free(struct tmem_objnode *objnode,
-					struct tmem_pool *pool)
-{
-	dec_zcache_objnode_count();
-	kmem_cache_free(zcache_objnode_cache, objnode);
-}
-
-static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool)
-{
-	struct tmem_obj *obj = NULL;
-	struct zcache_preload *kp;
-
-	kp = &__get_cpu_var(zcache_preloads);
-	obj = kp->obj;
-	BUG_ON(obj == NULL);
-	kp->obj = NULL;
-	inc_zcache_obj_count();
-	return obj;
-}
-
-static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool)
-{
-	dec_zcache_obj_count();
-	kmem_cache_free(zcache_obj_cache, obj);
-}
-
-/*
- * Compressing zero-filled pages will waste memory and introduce
- * serious fragmentation, skip it to avoid overhead.
- */
-static bool page_is_zero_filled(struct page *p)
-{
-	unsigned int pos;
-	char *page;
-
-	page = kmap_atomic(p);
-	for (pos = 0; pos < PAGE_SIZE / sizeof(*page); pos++) {
-		if (page[pos]) {
-			kunmap_atomic(page);
-			return false;
-		}
-	}
-	kunmap_atomic(page);
-
-	return true;
-}
-
-static void handle_zero_filled_page(void *p)
-{
-	void *user_mem;
-	struct page *page = (struct page *)p;
-
-	user_mem = kmap_atomic(page);
-	memset(user_mem, 0, PAGE_SIZE);
-	kunmap_atomic(user_mem);
-
-	flush_dcache_page(page);
-}
-
-static struct tmem_hostops zcache_hostops = {
-	.obj_alloc = zcache_obj_alloc,
-	.obj_free = zcache_obj_free,
-	.objnode_alloc = zcache_objnode_alloc,
-	.objnode_free = zcache_objnode_free,
-};
-
-static struct page *zcache_alloc_page(void)
-{
-	struct page *page = alloc_page(ZCACHE_GFP_MASK);
-
-	if (page != NULL)
-		inc_zcache_pageframes_alloced();
-	return page;
-}
-
-static void zcache_free_page(struct page *page)
-{
-	long curr_pageframes;
-	static long max_pageframes, min_pageframes;
-
-	if (page == NULL)
-		BUG();
-	__free_page(page);
-	inc_zcache_pageframes_freed();
-	curr_pageframes = curr_pageframes_count();
-	if (curr_pageframes > max_pageframes)
-		max_pageframes = curr_pageframes;
-	if (curr_pageframes < min_pageframes)
-		min_pageframes = curr_pageframes;
-#ifdef CONFIG_ZCACHE_DEBUG
-	if (curr_pageframes > 2L || curr_pageframes < -2L) {
-		/* pr_info here */
-	}
-#endif
-}
-
-/*
- * zcache implementations for PAM page descriptor ops
- */
-
-/* forward reference */
-static void zcache_compress(struct page *from,
-				void **out_va, unsigned *out_len);
-
-static struct page *zcache_evict_eph_pageframe(void);
-
-static void *zcache_pampd_eph_create(char *data, size_t size, bool raw,
-					struct tmem_handle *th)
-{
-	void *pampd = NULL, *cdata = data;
-	unsigned clen = size;
-	bool zero_filled = false;
-	struct page *page = (struct page *)(data), *newpage;
-
-	if (page_is_zero_filled(page)) {
-		clen = 0;
-		zero_filled = true;
-		inc_zcache_zero_filled_pages();
-		goto got_pampd;
-	}
-
-	if (!raw) {
-		zcache_compress(page, &cdata, &clen);
-		if (clen > zbud_max_buddy_size()) {
-			inc_zcache_compress_poor();
-			goto out;
-		}
-	} else {
-		BUG_ON(clen > zbud_max_buddy_size());
-	}
-
-	/* look for space via an existing match first */
-	pampd = (void *)zbud_match_prep(th, true, cdata, clen);
-	if (pampd != NULL)
-		goto got_pampd;
-
-	/* no match, now we need to find (or free up) a full page */
-	newpage = zcache_alloc_page();
-	if (newpage != NULL)
-		goto create_in_new_page;
-
-	inc_zcache_failed_getfreepages();
-	/* can't allocate a page, evict an ephemeral page via LRU */
-	newpage = zcache_evict_eph_pageframe();
-	if (newpage == NULL) {
-		inc_zcache_eph_ate_tail_failed();
-		goto out;
-	}
-	inc_zcache_eph_ate_tail();
-
-create_in_new_page:
-	pampd = (void *)zbud_create_prep(th, true, cdata, clen, newpage);
-	BUG_ON(pampd == NULL);
-	inc_zcache_eph_pageframes();
-
-got_pampd:
-	inc_zcache_eph_zbytes(clen);
-	inc_zcache_eph_zpages();
-	if (ramster_enabled && raw && !zero_filled)
-		ramster_count_foreign_pages(true, 1);
-	if (zero_filled)
-		pampd = (void *)ZERO_FILLED;
-out:
-	return pampd;
-}
-
-static void *zcache_pampd_pers_create(char *data, size_t size, bool raw,
-					struct tmem_handle *th)
-{
-	void *pampd = NULL, *cdata = data;
-	unsigned clen = size;
-	bool zero_filled = false;
-	struct page *page = (struct page *)(data), *newpage;
-	unsigned long zbud_mean_zsize;
-	unsigned long curr_pers_zpages, total_zsize;
-
-	if (data == NULL) {
-		BUG_ON(!ramster_enabled);
-		goto create_pampd;
-	}
-
-	if (page_is_zero_filled(page)) {
-		clen = 0;
-		zero_filled = true;
-		inc_zcache_zero_filled_pages();
-		goto got_pampd;
-	}
-
-	curr_pers_zpages = zcache_pers_zpages;
-/* FIXME CONFIG_RAMSTER... subtract atomic remote_pers_pages here? */
-	if (!raw)
-		zcache_compress(page, &cdata, &clen);
-	/* reject if compression is too poor */
-	if (clen > zbud_max_zsize) {
-		inc_zcache_compress_poor();
-		goto out;
-	}
-	/* reject if mean compression is too poor */
-	if ((clen > zbud_max_mean_zsize) && (curr_pers_zpages > 0)) {
-		total_zsize = zcache_pers_zbytes;
-		if ((long)total_zsize < 0)
-			total_zsize = 0;
-		zbud_mean_zsize = div_u64(total_zsize,
-					curr_pers_zpages);
-		if (zbud_mean_zsize > zbud_max_mean_zsize) {
-			inc_zcache_mean_compress_poor();
-			goto out;
-		}
-	}
-
-create_pampd:
-	/* look for space via an existing match first */
-	pampd = (void *)zbud_match_prep(th, false, cdata, clen);
-	if (pampd != NULL)
-		goto got_pampd;
-
-	/* no match, now we need to find (or free up) a full page */
-	newpage = zcache_alloc_page();
-	if (newpage != NULL)
-		goto create_in_new_page;
-	/*
-	 * FIXME do the following only if eph is oversized?
-	 * if (zcache_eph_pageframes >
-	 * (global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE) +
-	 * global_page_state(NR_LRU_BASE + LRU_INACTIVE_FILE)))
-	 */
-	inc_zcache_failed_getfreepages();
-	/* can't allocate a page, evict an ephemeral page via LRU */
-	newpage = zcache_evict_eph_pageframe();
-	if (newpage == NULL) {
-		inc_zcache_pers_ate_eph_failed();
-		goto out;
-	}
-	inc_zcache_pers_ate_eph();
-
-create_in_new_page:
-	pampd = (void *)zbud_create_prep(th, false, cdata, clen, newpage);
-	BUG_ON(pampd == NULL);
-	inc_zcache_pers_pageframes();
-
-got_pampd:
-	inc_zcache_pers_zpages();
-	inc_zcache_pers_zbytes(clen);
-	if (ramster_enabled && raw && !zero_filled)
-		ramster_count_foreign_pages(false, 1);
-	if (zero_filled)
-		pampd = (void *)ZERO_FILLED;
-out:
-	return pampd;
-}
-
-/*
- * This is called directly from zcache_put_page to pre-allocate space
- * to store a zpage.
- */
-void *zcache_pampd_create(char *data, unsigned int size, bool raw,
-					int eph, struct tmem_handle *th)
-{
-	void *pampd = NULL;
-	struct zcache_preload *kp;
-	struct tmem_objnode *objnode;
-	struct tmem_obj *obj;
-	int i;
-
-	BUG_ON(!irqs_disabled());
-	/* pre-allocate per-cpu metadata */
-	BUG_ON(zcache_objnode_cache == NULL);
-	BUG_ON(zcache_obj_cache == NULL);
-	kp = &__get_cpu_var(zcache_preloads);
-	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
-		objnode = kp->objnodes[i];
-		if (objnode == NULL) {
-			objnode = kmem_cache_alloc(zcache_objnode_cache,
-							ZCACHE_GFP_MASK);
-			if (unlikely(objnode == NULL)) {
-				inc_zcache_failed_alloc();
-				goto out;
-			}
-			kp->objnodes[i] = objnode;
-		}
-	}
-	if (kp->obj == NULL) {
-		obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK);
-		kp->obj = obj;
-	}
-	if (unlikely(kp->obj == NULL)) {
-		inc_zcache_failed_alloc();
-		goto out;
-	}
-	/*
-	 * ok, have all the metadata pre-allocated, now do the data
-	 * but since how we allocate the data is dependent on ephemeral
-	 * or persistent, we split the call here to different sub-functions
-	 */
-	if (eph)
-		pampd = zcache_pampd_eph_create(data, size, raw, th);
-	else
-		pampd = zcache_pampd_pers_create(data, size, raw, th);
-out:
-	return pampd;
-}
-
-/*
- * This is a pamops called via tmem_put and is necessary to "finish"
- * a pampd creation.
- */
-void zcache_pampd_create_finish(void *pampd, bool eph)
-{
-	if (pampd != (void *)ZERO_FILLED)
-		zbud_create_finish((struct zbudref *)pampd, eph);
-}
-
-/*
- * This is passed as a function parameter to zbud_decompress so that
- * zbud need not be familiar with the details of crypto. It assumes that
- * the bytes from_va and to_va through from_va+size-1 and to_va+size-1 are
- * kmapped.  It must be successful, else there is a logic bug somewhere.
- */
-static void zcache_decompress(char *from_va, unsigned int size, char *to_va)
-{
-	int ret;
-	unsigned int outlen = PAGE_SIZE;
-
-	ret = zcache_comp_op(ZCACHE_COMPOP_DECOMPRESS, from_va, size,
-				to_va, &outlen);
-	BUG_ON(ret);
-	BUG_ON(outlen != PAGE_SIZE);
-}
-
-/*
- * Decompress from the kernel va to a pageframe
- */
-void zcache_decompress_to_page(char *from_va, unsigned int size,
-					struct page *to_page)
-{
-	char *to_va = kmap_atomic(to_page);
-	zcache_decompress(from_va, size, to_va);
-	kunmap_atomic(to_va);
-}
-
-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
-static int zcache_pampd_get_data(char *data, size_t *sizep, bool raw,
-					void *pampd, struct tmem_pool *pool,
-					struct tmem_oid *oid, uint32_t index)
-{
-	int ret;
-	bool eph = !is_persistent(pool);
-
-	BUG_ON(preemptible());
-	BUG_ON(eph);	/* fix later if shared pools get implemented */
-	BUG_ON(pampd_is_remote(pampd));
-
-	if (pampd == (void *)ZERO_FILLED) {
-		handle_zero_filled_page(data);
-		if (!raw)
-			*sizep = PAGE_SIZE;
-		return 0;
-	}
-
-	if (raw)
-		ret = zbud_copy_from_zbud(data, (struct zbudref *)pampd,
-						sizep, eph);
-	else {
-		ret = zbud_decompress((struct page *)(data),
-					(struct zbudref *)pampd, false,
-					zcache_decompress);
-		*sizep = PAGE_SIZE;
-	}
-	return ret;
-}
-
-/*
- * fill the pageframe corresponding to the struct page with the data
- * from the passed pampd
- */
-static int zcache_pampd_get_data_and_free(char *data, size_t *sizep, bool raw,
-					void *pampd, struct tmem_pool *pool,
-					struct tmem_oid *oid, uint32_t index)
-{
-	int ret = 0;
-	bool eph = !is_persistent(pool), zero_filled = false;
-	struct page *page = NULL;
-	unsigned int zsize, zpages;
-
-	BUG_ON(preemptible());
-	BUG_ON(pampd_is_remote(pampd));
-
-	if (pampd == (void *)ZERO_FILLED) {
-		handle_zero_filled_page(data);
-		zero_filled = true;
-		zsize = 0;
-		zpages = 1;
-		if (!raw)
-			*sizep = PAGE_SIZE;
-		dec_zcache_zero_filled_pages();
-		goto zero_fill;
-	}
-
-	if (raw)
-		ret = zbud_copy_from_zbud(data, (struct zbudref *)pampd,
-						sizep, eph);
-	else {
-		ret = zbud_decompress((struct page *)(data),
-					(struct zbudref *)pampd, eph,
-					zcache_decompress);
-		*sizep = PAGE_SIZE;
-	}
-	page = zbud_free_and_delist((struct zbudref *)pampd, eph,
-					&zsize, &zpages);
-zero_fill:
-	if (eph) {
-		if (page)
-			dec_zcache_eph_pageframes();
-		dec_zcache_eph_zpages(zpages);
-		dec_zcache_eph_zbytes(zsize);
-	} else {
-		if (page)
-			dec_zcache_pers_pageframes();
-		dec_zcache_pers_zpages(zpages);
-		dec_zcache_pers_zbytes(zsize);
-	}
-	if (!is_local_client(pool->client) && !zero_filled)
-		ramster_count_foreign_pages(eph, -1);
-	if (page && !zero_filled)
-		zcache_free_page(page);
-	return ret;
-}
-
-/*
- * free the pampd and remove it from any zcache lists
- * pampd must no longer be pointed to from any tmem data structures!
- */
-static void zcache_pampd_free(void *pampd, struct tmem_pool *pool,
-			      struct tmem_oid *oid, uint32_t index, bool acct)
-{
-	struct page *page = NULL;
-	unsigned int zsize, zpages;
-	bool zero_filled = false;
-
-	BUG_ON(preemptible());
-
-	if (pampd == (void *)ZERO_FILLED) {
-		zero_filled = true;
-		zsize = 0;
-		zpages = 1;
-		dec_zcache_zero_filled_pages();
-	}
-
-	if (pampd_is_remote(pampd) && !zero_filled) {
-		BUG_ON(!ramster_enabled);
-		pampd = ramster_pampd_free(pampd, pool, oid, index, acct);
-		if (pampd == NULL)
-			return;
-	}
-	if (is_ephemeral(pool)) {
-		if (!zero_filled)
-			page = zbud_free_and_delist((struct zbudref *)pampd,
-						true, &zsize, &zpages);
-		if (page)
-			dec_zcache_eph_pageframes();
-		dec_zcache_eph_zpages(zpages);
-		dec_zcache_eph_zbytes(zsize);
-		/* FIXME CONFIG_RAMSTER... check acct parameter? */
-	} else {
-		if (!zero_filled)
-			page = zbud_free_and_delist((struct zbudref *)pampd,
-						false, &zsize, &zpages);
-		if (page)
-			dec_zcache_pers_pageframes();
-		dec_zcache_pers_zpages(zpages);
-		dec_zcache_pers_zbytes(zsize);
-	}
-	if (!is_local_client(pool->client) && !zero_filled)
-		ramster_count_foreign_pages(is_ephemeral(pool), -1);
-	if (page && !zero_filled)
-		zcache_free_page(page);
-}
-
-static struct tmem_pamops zcache_pamops = {
-	.create_finish = zcache_pampd_create_finish,
-	.get_data = zcache_pampd_get_data,
-	.get_data_and_free = zcache_pampd_get_data_and_free,
-	.free = zcache_pampd_free,
-};
-
-/*
- * zcache compression/decompression and related per-cpu stuff
- */
-
-static DEFINE_PER_CPU(unsigned char *, zcache_dstmem);
-#define ZCACHE_DSTMEM_ORDER 1
-
-static void zcache_compress(struct page *from, void **out_va, unsigned *out_len)
-{
-	int ret;
-	unsigned char *dmem = __get_cpu_var(zcache_dstmem);
-	char *from_va;
-
-	BUG_ON(!irqs_disabled());
-	/* no buffer or no compressor so can't compress */
-	BUG_ON(dmem == NULL);
-	*out_len = PAGE_SIZE << ZCACHE_DSTMEM_ORDER;
-	from_va = kmap_atomic(from);
-	mb();
-	ret = zcache_comp_op(ZCACHE_COMPOP_COMPRESS, from_va, PAGE_SIZE, dmem,
-				out_len);
-	BUG_ON(ret);
-	*out_va = dmem;
-	kunmap_atomic(from_va);
-}
-
-static int zcache_comp_cpu_up(int cpu)
-{
-	struct crypto_comp *tfm;
-
-	tfm = crypto_alloc_comp(zcache_comp_name, 0, 0);
-	if (IS_ERR(tfm))
-		return NOTIFY_BAD;
-	*per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = tfm;
-	return NOTIFY_OK;
-}
-
-static void zcache_comp_cpu_down(int cpu)
-{
-	struct crypto_comp *tfm;
-
-	tfm = *per_cpu_ptr(zcache_comp_pcpu_tfms, cpu);
-	crypto_free_comp(tfm);
-	*per_cpu_ptr(zcache_comp_pcpu_tfms, cpu) = NULL;
-}
-
-static int zcache_cpu_notifier(struct notifier_block *nb,
-				unsigned long action, void *pcpu)
-{
-	int ret, i, cpu = (long)pcpu;
-	struct zcache_preload *kp;
-
-	switch (action) {
-	case CPU_UP_PREPARE:
-		ret = zcache_comp_cpu_up(cpu);
-		if (ret != NOTIFY_OK) {
-			pr_err("%s: can't allocate compressor xform\n",
-				namestr);
-			return ret;
-		}
-		per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages(
-			GFP_KERNEL | __GFP_REPEAT, ZCACHE_DSTMEM_ORDER);
-		if (ramster_enabled)
-			ramster_cpu_up(cpu);
-		break;
-	case CPU_DEAD:
-	case CPU_UP_CANCELED:
-		zcache_comp_cpu_down(cpu);
-		free_pages((unsigned long)per_cpu(zcache_dstmem, cpu),
-			ZCACHE_DSTMEM_ORDER);
-		per_cpu(zcache_dstmem, cpu) = NULL;
-		kp = &per_cpu(zcache_preloads, cpu);
-		for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
-			if (kp->objnodes[i])
-				kmem_cache_free(zcache_objnode_cache,
-						kp->objnodes[i]);
-		}
-		if (kp->obj) {
-			kmem_cache_free(zcache_obj_cache, kp->obj);
-			kp->obj = NULL;
-		}
-		if (ramster_enabled)
-			ramster_cpu_down(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block zcache_cpu_notifier_block = {
-	.notifier_call = zcache_cpu_notifier
-};
-
-/*
- * The following code interacts with the zbud eviction and zbud
- * zombify code to access LRU pages
- */
-
-static struct page *zcache_evict_eph_pageframe(void)
-{
-	struct page *page;
-	unsigned int zsize = 0, zpages = 0;
-
-	page = zbud_evict_pageframe_lru(&zsize, &zpages);
-	if (page == NULL)
-		goto out;
-	dec_zcache_eph_zbytes(zsize);
-	dec_zcache_eph_zpages(zpages);
-	inc_zcache_evicted_eph_zpages(zpages);
-	dec_zcache_eph_pageframes();
-	inc_zcache_evicted_eph_pageframes();
-out:
-	return page;
-}
-
-#ifdef CONFIG_ZCACHE_WRITEBACK
-
-static atomic_t zcache_outstanding_writeback_pages_atomic = ATOMIC_INIT(0);
-
-static inline void inc_zcache_outstanding_writeback_pages(void)
-{
-	zcache_outstanding_writeback_pages =
-	    atomic_inc_return(&zcache_outstanding_writeback_pages_atomic);
-}
-static inline void dec_zcache_outstanding_writeback_pages(void)
-{
-	zcache_outstanding_writeback_pages =
-	  atomic_dec_return(&zcache_outstanding_writeback_pages_atomic);
-};
-static void unswiz(struct tmem_oid oid, u32 index,
-				unsigned *type, pgoff_t *offset);
-
-/*
- *  Choose an LRU persistent pageframe and attempt to write it back to
- *  the backing swap disk by calling frontswap_writeback on both zpages.
- *
- *  This is work-in-progress.
- */
-
-static void zcache_end_swap_write(struct bio *bio, int err)
-{
-	end_swap_bio_write(bio, err);
-	dec_zcache_outstanding_writeback_pages();
-	zcache_writtenback_pages++;
-}
-
-/*
- * zcache_get_swap_cache_page
- *
- * This is an adaption of read_swap_cache_async()
- *
- * If success, page is returned in retpage
- * Returns 0 if page was already in the swap cache, page is not locked
- * Returns 1 if the new page needs to be populated, page is locked
- */
-static int zcache_get_swap_cache_page(int type, pgoff_t offset,
-				struct page *new_page)
-{
-	struct page *found_page;
-	swp_entry_t entry = swp_entry(type, offset);
-	int err;
-
-	BUG_ON(new_page == NULL);
-	do {
-		/*
-		 * First check the swap cache.  Since this is normally
-		 * called after lookup_swap_cache() failed, re-calling
-		 * that would confuse statistics.
-		 */
-		found_page = find_get_page(&swapper_space, entry.val);
-		if (found_page)
-			return 0;
-
-		/*
-		 * call radix_tree_preload() while we can wait.
-		 */
-		err = radix_tree_preload(GFP_KERNEL);
-		if (err)
-			break;
-
-		/*
-		 * Swap entry may have been freed since our caller observed it.
-		 */
-		err = swapcache_prepare(entry);
-		if (err == -EEXIST) { /* seems racy */
-			radix_tree_preload_end();
-			continue;
-		}
-		if (err) { /* swp entry is obsolete ? */
-			radix_tree_preload_end();
-			break;
-		}
-
-		/* May fail (-ENOMEM) if radix-tree node allocation failed. */
-		__set_page_locked(new_page);
-		SetPageSwapBacked(new_page);
-		err = __add_to_swap_cache(new_page, entry);
-		if (likely(!err)) {
-			radix_tree_preload_end();
-			lru_cache_add_anon(new_page);
-			return 1;
-		}
-		radix_tree_preload_end();
-		ClearPageSwapBacked(new_page);
-		__clear_page_locked(new_page);
-		/*
-		 * add_to_swap_cache() doesn't return -EEXIST, so we can safely
-		 * clear SWAP_HAS_CACHE flag.
-		 */
-		swapcache_free(entry, NULL);
-		/* FIXME: is it possible to get here without err==-ENOMEM?
-		 * If not, we can dispense with the do loop, use goto retry */
-	} while (err != -ENOMEM);
-
-	return -ENOMEM;
-}
-
-/*
- * Given a frontswap zpage in zcache (identified by type/offset) and
- * an empty page, put the page into the swap cache, use frontswap
- * to get the page from zcache into the empty page, then give it
- * to the swap subsystem to send to disk (carefully avoiding the
- * possibility that frontswap might snatch it back).
- * Returns < 0 if error, 0 if successful, and 1 if successful but
- * the newpage passed in not needed and should be freed.
- */
-static int zcache_frontswap_writeback_zpage(int type, pgoff_t offset,
-					struct page *newpage)
-{
-	struct page *page = newpage;
-	int ret;
-	struct writeback_control wbc = {
-		.sync_mode = WB_SYNC_NONE,
-	};
-
-	ret = zcache_get_swap_cache_page(type, offset, page);
-	if (ret < 0)
-		return ret;
-	else if (ret == 0) {
-		/* more uptodate page is already in swapcache */
-		__frontswap_invalidate_page(type, offset);
-		return 1;
-	}
-
-	BUG_ON(!frontswap_has_exclusive_gets); /* load must also invalidate */
-	/* FIXME: how is it possible to get here when page is unlocked? */
-	__frontswap_load(page);
-	SetPageUptodate(page);  /* above does SetPageDirty, is that enough? */
-
-	/* start writeback */
-	SetPageReclaim(page);
-	/*
-	 * Return value is ignored here because it doesn't change anything
-	 * for us.  Page is returned unlocked.
-	 */
-	(void)__swap_writepage(page, &wbc, zcache_end_swap_write);
-	page_cache_release(page);
-	inc_zcache_outstanding_writeback_pages();
-
-	return 0;
-}
-
-/*
- * The following is still a magic number... we want to allow forward progress
- * for writeback because it clears out needed RAM when under pressure, but
- * we don't want to allow writeback to absorb and queue too many GFP_KERNEL
- * pages if the swap device is very slow.
- */
-#define ZCACHE_MAX_OUTSTANDING_WRITEBACK_PAGES 6400
-
-/*
- * Try to allocate two free pages, first using a non-aggressive alloc,
- * then by evicting zcache ephemeral (clean pagecache) pages, and last
- * by aggressive GFP_KERNEL alloc.  We allow zbud to choose a pageframe
- * consisting of 1-2 zbuds/zpages, then call the writeback_zpage helper
- * function above for each.
- */
-static int zcache_frontswap_writeback(void)
-{
-	struct tmem_handle th[2];
-	int ret = 0;
-	int nzbuds, writeback_ret;
-	unsigned type;
-	struct page *znewpage1 = NULL, *znewpage2 = NULL;
-	struct page *evictpage1 = NULL, *evictpage2 = NULL;
-	struct page *newpage1 = NULL, *newpage2 = NULL;
-	struct page *page1 = NULL, *page2 = NULL;
-	pgoff_t offset;
-
-	znewpage1 = alloc_page(ZCACHE_GFP_MASK);
-	znewpage2 = alloc_page(ZCACHE_GFP_MASK);
-	if (znewpage1 == NULL)
-		evictpage1 = zcache_evict_eph_pageframe();
-	if (znewpage2 == NULL)
-		evictpage2 = zcache_evict_eph_pageframe();
-
-	if ((evictpage1 == NULL || evictpage2 == NULL) &&
-	    atomic_read(&zcache_outstanding_writeback_pages_atomic) >
-				ZCACHE_MAX_OUTSTANDING_WRITEBACK_PAGES) {
-		goto free_and_out;
-	}
-	if (znewpage1 == NULL && evictpage1 == NULL)
-		newpage1 = alloc_page(GFP_KERNEL);
-	if (znewpage2 == NULL && evictpage2 == NULL)
-		newpage2 = alloc_page(GFP_KERNEL);
-	if (newpage1 == NULL || newpage2 == NULL)
-			goto free_and_out;
-
-	/* ok, we have two pageframes pre-allocated, get a pair of zbuds */
-	nzbuds = zbud_make_zombie_lru(&th[0], NULL, NULL, false);
-	if (nzbuds == 0) {
-		ret = -ENOENT;
-		goto free_and_out;
-	}
-
-	/* process the first zbud */
-	unswiz(th[0].oid, th[0].index, &type, &offset);
-	page1 = (znewpage1 != NULL) ? znewpage1 :
-			((newpage1 != NULL) ? newpage1 : evictpage1);
-	writeback_ret = zcache_frontswap_writeback_zpage(type, offset, page1);
-	if (writeback_ret < 0) {
-		ret = -ENOMEM;
-		goto free_and_out;
-	}
-	if (evictpage1 != NULL)
-		zcache_pageframes_freed =
-			atomic_inc_return(&zcache_pageframes_freed_atomic);
-	if (writeback_ret == 0) {
-		/* zcache_get_swap_cache_page will free, don't double free */
-		znewpage1 = NULL;
-		newpage1 = NULL;
-		evictpage1 = NULL;
-	}
-	if (nzbuds < 2)
-		goto free_and_out;
-
-	/* if there is a second zbud, process it */
-	unswiz(th[1].oid, th[1].index, &type, &offset);
-	page2 = (znewpage2 != NULL) ? znewpage2 :
-			((newpage2 != NULL) ? newpage2 : evictpage2);
-	writeback_ret = zcache_frontswap_writeback_zpage(type, offset, page2);
-	if (writeback_ret < 0) {
-		ret = -ENOMEM;
-		goto free_and_out;
-	}
-	if (evictpage2 != NULL)
-		zcache_pageframes_freed =
-			atomic_inc_return(&zcache_pageframes_freed_atomic);
-	if (writeback_ret == 0) {
-		znewpage2 = NULL;
-		newpage2 = NULL;
-		evictpage2 = NULL;
-	}
-
-free_and_out:
-	if (znewpage1 != NULL)
-		page_cache_release(znewpage1);
-	if (znewpage2 != NULL)
-		page_cache_release(znewpage2);
-	if (newpage1 != NULL)
-		page_cache_release(newpage1);
-	if (newpage2 != NULL)
-		page_cache_release(newpage2);
-	if (evictpage1 != NULL)
-		zcache_free_page(evictpage1);
-	if (evictpage2 != NULL)
-		zcache_free_page(evictpage2);
-	return ret;
-}
-#endif /* CONFIG_ZCACHE_WRITEBACK */
-
-/*
- * When zcache is disabled ("frozen"), pools can be created and destroyed,
- * but all puts (and thus all other operations that require memory allocation)
- * must fail.  If zcache is unfrozen, accepts puts, then frozen again,
- * data consistency requires all puts while frozen to be converted into
- * flushes.
- */
-static bool zcache_freeze;
-
-/*
- * This zcache shrinker interface reduces the number of ephemeral pageframes
- * used by zcache to approximately the same as the total number of LRU_FILE
- * pageframes in use, and now also reduces the number of persistent pageframes
- * used by zcache to approximately the same as the total number of LRU_ANON
- * pageframes in use.  FIXME POLICY: Probably the writeback should only occur
- * if the eviction doesn't free enough pages.
- */
-static int shrink_zcache_memory(struct shrinker *shrink,
-				struct shrink_control *sc)
-{
-	static bool in_progress;
-	int ret = -1;
-	int nr = sc->nr_to_scan;
-	int nr_evict = 0;
-	int nr_writeback = 0;
-	struct page *page;
-	int  file_pageframes_inuse, anon_pageframes_inuse;
-
-	if (nr <= 0)
-		goto skip_evict;
-
-	/* don't allow more than one eviction thread at a time */
-	if (in_progress)
-		goto skip_evict;
-
-	in_progress = true;
-
-	/* we are going to ignore nr, and target a different value */
-	zcache_last_active_file_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
-	zcache_last_inactive_file_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_INACTIVE_FILE);
-	file_pageframes_inuse = zcache_last_active_file_pageframes +
-				zcache_last_inactive_file_pageframes;
-	if (zcache_eph_pageframes > file_pageframes_inuse)
-		nr_evict = zcache_eph_pageframes - file_pageframes_inuse;
-	else
-		nr_evict = 0;
-	while (nr_evict-- > 0) {
-		page = zcache_evict_eph_pageframe();
-		if (page == NULL)
-			break;
-		zcache_free_page(page);
-	}
-
-	zcache_last_active_anon_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_ACTIVE_ANON);
-	zcache_last_inactive_anon_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_INACTIVE_ANON);
-	anon_pageframes_inuse = zcache_last_active_anon_pageframes +
-				zcache_last_inactive_anon_pageframes;
-	if (zcache_pers_pageframes > anon_pageframes_inuse)
-		nr_writeback = zcache_pers_pageframes - anon_pageframes_inuse;
-	else
-		nr_writeback = 0;
-	while (nr_writeback-- > 0) {
-#ifdef CONFIG_ZCACHE_WRITEBACK
-		int writeback_ret;
-		writeback_ret = zcache_frontswap_writeback();
-		if (writeback_ret == -ENOMEM)
-#endif
-			break;
-	}
-	in_progress = false;
-
-skip_evict:
-	/* resample: has changed, but maybe not all the way yet */
-	zcache_last_active_file_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
-	zcache_last_inactive_file_pageframes =
-		global_page_state(NR_LRU_BASE + LRU_INACTIVE_FILE);
-	ret = zcache_eph_pageframes - zcache_last_active_file_pageframes +
-		zcache_last_inactive_file_pageframes;
-	if (ret < 0)
-		ret = 0;
-	return ret;
-}
-
-static struct shrinker zcache_shrinker = {
-	.shrink = shrink_zcache_memory,
-	.seeks = DEFAULT_SEEKS,
-};
-
-/*
- * zcache shims between cleancache/frontswap ops and tmem
- */
-
-/* FIXME rename these core routines to zcache_tmemput etc? */
-int zcache_put_page(int cli_id, int pool_id, struct tmem_oid *oidp,
-				uint32_t index, void *page,
-				unsigned int size, bool raw, int ephemeral)
-{
-	struct tmem_pool *pool;
-	struct tmem_handle th;
-	int ret = -1;
-	void *pampd = NULL;
-
-	BUG_ON(!irqs_disabled());
-	pool = zcache_get_pool_by_id(cli_id, pool_id);
-	if (unlikely(pool == NULL))
-		goto out;
-	if (!zcache_freeze) {
-		ret = 0;
-		th.client_id = cli_id;
-		th.pool_id = pool_id;
-		th.oid = *oidp;
-		th.index = index;
-		pampd = zcache_pampd_create((char *)page, size, raw,
-				ephemeral, &th);
-		if (pampd == NULL) {
-			ret = -ENOMEM;
-			if (ephemeral)
-				inc_zcache_failed_eph_puts();
-			else
-				inc_zcache_failed_pers_puts();
-		} else {
-			if (ramster_enabled)
-				ramster_do_preload_flnode(pool);
-			ret = tmem_put(pool, oidp, index, 0, pampd);
-			if (ret < 0)
-				BUG();
-		}
-		zcache_put_pool(pool);
-	} else {
-		inc_zcache_put_to_flush();
-		if (ramster_enabled)
-			ramster_do_preload_flnode(pool);
-		if (atomic_read(&pool->obj_count) > 0)
-			/* the put fails whether the flush succeeds or not */
-			(void)tmem_flush_page(pool, oidp, index);
-		zcache_put_pool(pool);
-	}
-out:
-	return ret;
-}
-
-int zcache_get_page(int cli_id, int pool_id, struct tmem_oid *oidp,
-				uint32_t index, void *page,
-				size_t *sizep, bool raw, int get_and_free)
-{
-	struct tmem_pool *pool;
-	int ret = -1;
-	bool eph;
-
-	if (!raw) {
-		BUG_ON(irqs_disabled());
-		BUG_ON(in_softirq());
-	}
-	pool = zcache_get_pool_by_id(cli_id, pool_id);
-	eph = is_ephemeral(pool);
-	if (likely(pool != NULL)) {
-		if (atomic_read(&pool->obj_count) > 0)
-			ret = tmem_get(pool, oidp, index, (char *)(page),
-					sizep, raw, get_and_free);
-		zcache_put_pool(pool);
-	}
-	WARN_ONCE((!is_ephemeral(pool) && (ret != 0)),
-			"zcache_get fails on persistent pool, "
-			"bad things are very likely to happen soon\n");
-#ifdef RAMSTER_TESTING
-	if (ret != 0 && ret != -1 && !(ret == -EINVAL && is_ephemeral(pool)))
-		pr_err("TESTING zcache_get tmem_get returns ret=%d\n", ret);
-#endif
-	return ret;
-}
-
-int zcache_flush_page(int cli_id, int pool_id,
-				struct tmem_oid *oidp, uint32_t index)
-{
-	struct tmem_pool *pool;
-	int ret = -1;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	inc_zcache_flush_total();
-	pool = zcache_get_pool_by_id(cli_id, pool_id);
-	if (ramster_enabled)
-		ramster_do_preload_flnode(pool);
-	if (likely(pool != NULL)) {
-		if (atomic_read(&pool->obj_count) > 0)
-			ret = tmem_flush_page(pool, oidp, index);
-		zcache_put_pool(pool);
-	}
-	if (ret >= 0)
-		inc_zcache_flush_found();
-	local_irq_restore(flags);
-	return ret;
-}
-
-int zcache_flush_object(int cli_id, int pool_id,
-				struct tmem_oid *oidp)
-{
-	struct tmem_pool *pool;
-	int ret = -1;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	inc_zcache_flobj_total();
-	pool = zcache_get_pool_by_id(cli_id, pool_id);
-	if (ramster_enabled)
-		ramster_do_preload_flnode(pool);
-	if (likely(pool != NULL)) {
-		if (atomic_read(&pool->obj_count) > 0)
-			ret = tmem_flush_object(pool, oidp);
-		zcache_put_pool(pool);
-	}
-	if (ret >= 0)
-		inc_zcache_flobj_found();
-	local_irq_restore(flags);
-	return ret;
-}
-
-static int zcache_client_destroy_pool(int cli_id, int pool_id)
-{
-	struct tmem_pool *pool = NULL;
-	struct zcache_client *cli = NULL;
-	int ret = -1;
-
-	if (pool_id < 0)
-		goto out;
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else if ((unsigned int)cli_id < MAX_CLIENTS)
-		cli = &zcache_clients[cli_id];
-	if (cli == NULL)
-		goto out;
-	atomic_inc(&cli->refcount);
-	pool = cli->tmem_pools[pool_id];
-	if (pool == NULL)
-		goto out;
-	cli->tmem_pools[pool_id] = NULL;
-	/* wait for pool activity on other cpus to quiesce */
-	while (atomic_read(&pool->refcount) != 0)
-		;
-	atomic_dec(&cli->refcount);
-	local_bh_disable();
-	ret = tmem_destroy_pool(pool);
-	local_bh_enable();
-	kfree(pool);
-	if (cli_id == LOCAL_CLIENT)
-		pr_info("%s: destroyed local pool id=%d\n", namestr, pool_id);
-	else
-		pr_info("%s: destroyed pool id=%d, client=%d\n",
-				namestr, pool_id, cli_id);
-out:
-	return ret;
-}
-
-int zcache_new_pool(uint16_t cli_id, uint32_t flags)
-{
-	int poolid = -1;
-	struct tmem_pool *pool;
-	struct zcache_client *cli = NULL;
-
-	if (cli_id == LOCAL_CLIENT)
-		cli = &zcache_host;
-	else if ((unsigned int)cli_id < MAX_CLIENTS)
-		cli = &zcache_clients[cli_id];
-	if (cli == NULL)
-		goto out;
-	atomic_inc(&cli->refcount);
-	pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
-	if (pool == NULL)
-		goto out;
-
-	for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++)
-		if (cli->tmem_pools[poolid] == NULL)
-			break;
-	if (poolid >= MAX_POOLS_PER_CLIENT) {
-		pr_info("%s: pool creation failed: max exceeded\n", namestr);
-		kfree(pool);
-		poolid = -1;
-		goto out;
-	}
-	atomic_set(&pool->refcount, 0);
-	pool->client = cli;
-	pool->pool_id = poolid;
-	tmem_new_pool(pool, flags);
-	cli->tmem_pools[poolid] = pool;
-	if (cli_id == LOCAL_CLIENT)
-		pr_info("%s: created %s local tmem pool, id=%d\n", namestr,
-			flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
-			poolid);
-	else
-		pr_info("%s: created %s tmem pool, id=%d, client=%d\n", namestr,
-			flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
-			poolid, cli_id);
-out:
-	if (cli != NULL)
-		atomic_dec(&cli->refcount);
-	return poolid;
-}
-
-static int zcache_local_new_pool(uint32_t flags)
-{
-	return zcache_new_pool(LOCAL_CLIENT, flags);
-}
-
-int zcache_autocreate_pool(unsigned int cli_id, unsigned int pool_id, bool eph)
-{
-	struct tmem_pool *pool;
-	struct zcache_client *cli = NULL;
-	uint32_t flags = eph ? 0 : TMEM_POOL_PERSIST;
-	int ret = -1;
-
-	BUG_ON(!ramster_enabled);
-	if (cli_id == LOCAL_CLIENT)
-		goto out;
-	if (pool_id >= MAX_POOLS_PER_CLIENT)
-		goto out;
-	if (cli_id >= MAX_CLIENTS)
-		goto out;
-
-	cli = &zcache_clients[cli_id];
-	if ((eph && disable_cleancache) || (!eph && disable_frontswap)) {
-		pr_err("zcache_autocreate_pool: pool type disabled\n");
-		goto out;
-	}
-	if (!cli->allocated) {
-		if (zcache_new_client(cli_id)) {
-			pr_err("zcache_autocreate_pool: can't create client\n");
-			goto out;
-		}
-		cli = &zcache_clients[cli_id];
-	}
-	atomic_inc(&cli->refcount);
-	pool = cli->tmem_pools[pool_id];
-	if (pool != NULL) {
-		if (pool->persistent && eph) {
-			pr_err("zcache_autocreate_pool: type mismatch\n");
-			goto out;
-		}
-		ret = 0;
-		goto out;
-	}
-	pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL);
-	if (pool == NULL)
-		goto out;
-
-	atomic_set(&pool->refcount, 0);
-	pool->client = cli;
-	pool->pool_id = pool_id;
-	tmem_new_pool(pool, flags);
-	cli->tmem_pools[pool_id] = pool;
-	pr_info("%s: AUTOcreated %s tmem poolid=%d, for remote client=%d\n",
-		namestr, flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral",
-		pool_id, cli_id);
-	ret = 0;
-out:
-	if (cli != NULL)
-		atomic_dec(&cli->refcount);
-	return ret;
-}
-
-/**********
- * Two kernel functionalities currently can be layered on top of tmem.
- * These are "cleancache" which is used as a second-chance cache for clean
- * page cache pages; and "frontswap" which is used for swap pages
- * to avoid writes to disk.  A generic "shim" is provided here for each
- * to translate in-kernel semantics to zcache semantics.
- */
-
-static void zcache_cleancache_put_page(int pool_id,
-					struct cleancache_filekey key,
-					pgoff_t index, struct page *page)
-{
-	u32 ind = (u32) index;
-	struct tmem_oid oid = *(struct tmem_oid *)&key;
-
-	if (!disable_cleancache_ignore_nonactive && !PageWasActive(page)) {
-		inc_zcache_eph_nonactive_puts_ignored();
-		return;
-	}
-	if (likely(ind == index))
-		(void)zcache_put_page(LOCAL_CLIENT, pool_id, &oid, index,
-					page, PAGE_SIZE, false, 1);
-}
-
-static int zcache_cleancache_get_page(int pool_id,
-					struct cleancache_filekey key,
-					pgoff_t index, struct page *page)
-{
-	u32 ind = (u32) index;
-	struct tmem_oid oid = *(struct tmem_oid *)&key;
-	size_t size;
-	int ret = -1;
-
-	if (likely(ind == index)) {
-		ret = zcache_get_page(LOCAL_CLIENT, pool_id, &oid, index,
-					page, &size, false, 0);
-		BUG_ON(ret >= 0 && size != PAGE_SIZE);
-		if (ret == 0)
-			SetPageWasActive(page);
-	}
-	return ret;
-}
-
-static void zcache_cleancache_flush_page(int pool_id,
-					struct cleancache_filekey key,
-					pgoff_t index)
-{
-	u32 ind = (u32) index;
-	struct tmem_oid oid = *(struct tmem_oid *)&key;
-
-	if (likely(ind == index))
-		(void)zcache_flush_page(LOCAL_CLIENT, pool_id, &oid, ind);
-}
-
-static void zcache_cleancache_flush_inode(int pool_id,
-					struct cleancache_filekey key)
-{
-	struct tmem_oid oid = *(struct tmem_oid *)&key;
-
-	(void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid);
-}
-
-static void zcache_cleancache_flush_fs(int pool_id)
-{
-	if (pool_id >= 0)
-		(void)zcache_client_destroy_pool(LOCAL_CLIENT, pool_id);
-}
-
-static int zcache_cleancache_init_fs(size_t pagesize)
-{
-	BUG_ON(sizeof(struct cleancache_filekey) !=
-				sizeof(struct tmem_oid));
-	BUG_ON(pagesize != PAGE_SIZE);
-	return zcache_local_new_pool(0);
-}
-
-static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize)
-{
-	/* shared pools are unsupported and map to private */
-	BUG_ON(sizeof(struct cleancache_filekey) !=
-				sizeof(struct tmem_oid));
-	BUG_ON(pagesize != PAGE_SIZE);
-	return zcache_local_new_pool(0);
-}
-
-static struct cleancache_ops zcache_cleancache_ops = {
-	.put_page = zcache_cleancache_put_page,
-	.get_page = zcache_cleancache_get_page,
-	.invalidate_page = zcache_cleancache_flush_page,
-	.invalidate_inode = zcache_cleancache_flush_inode,
-	.invalidate_fs = zcache_cleancache_flush_fs,
-	.init_shared_fs = zcache_cleancache_init_shared_fs,
-	.init_fs = zcache_cleancache_init_fs
-};
-
-struct cleancache_ops *zcache_cleancache_register_ops(void)
-{
-	struct cleancache_ops *old_ops =
-		cleancache_register_ops(&zcache_cleancache_ops);
-
-	return old_ops;
-}
-
-/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
-static int zcache_frontswap_poolid __read_mostly = -1;
-
-/*
- * Swizzling increases objects per swaptype, increasing tmem concurrency
- * for heavy swaploads.  Later, larger nr_cpus -> larger SWIZ_BITS
- * Setting SWIZ_BITS to 27 basically reconstructs the swap entry from
- * frontswap_get_page(), but has side-effects. Hence using 8.
- */
-#define SWIZ_BITS		8
-#define SWIZ_MASK		((1 << SWIZ_BITS) - 1)
-#define _oswiz(_type, _ind)	((_type << SWIZ_BITS) | (_ind & SWIZ_MASK))
-#define iswiz(_ind)		(_ind >> SWIZ_BITS)
-
-static inline struct tmem_oid oswiz(unsigned type, u32 ind)
-{
-	struct tmem_oid oid = { .oid = { 0 } };
-	oid.oid[0] = _oswiz(type, ind);
-	return oid;
-}
-
-#ifdef CONFIG_ZCACHE_WRITEBACK
-static void unswiz(struct tmem_oid oid, u32 index,
-				unsigned *type, pgoff_t *offset)
-{
-	*type = (unsigned)(oid.oid[0] >> SWIZ_BITS);
-	*offset = (pgoff_t)((index << SWIZ_BITS) |
-			(oid.oid[0] & SWIZ_MASK));
-}
-#endif
-
-static int zcache_frontswap_put_page(unsigned type, pgoff_t offset,
-					struct page *page)
-{
-	u64 ind64 = (u64)offset;
-	u32 ind = (u32)offset;
-	struct tmem_oid oid = oswiz(type, ind);
-	int ret = -1;
-	unsigned long flags;
-
-	BUG_ON(!PageLocked(page));
-	if (!disable_frontswap_ignore_nonactive && !PageWasActive(page)) {
-		inc_zcache_pers_nonactive_puts_ignored();
-		ret = -ERANGE;
-		goto out;
-	}
-	if (likely(ind64 == ind)) {
-		local_irq_save(flags);
-		ret = zcache_put_page(LOCAL_CLIENT, zcache_frontswap_poolid,
-					&oid, iswiz(ind),
-					page, PAGE_SIZE, false, 0);
-		local_irq_restore(flags);
-	}
-out:
-	return ret;
-}
-
-/* returns 0 if the page was successfully gotten from frontswap, -1 if
- * was not present (should never happen!) */
-static int zcache_frontswap_get_page(unsigned type, pgoff_t offset,
-					struct page *page)
-{
-	u64 ind64 = (u64)offset;
-	u32 ind = (u32)offset;
-	struct tmem_oid oid = oswiz(type, ind);
-	size_t size;
-	int ret = -1, get_and_free;
-
-	if (frontswap_has_exclusive_gets)
-		get_and_free = 1;
-	else
-		get_and_free = -1;
-	BUG_ON(!PageLocked(page));
-	if (likely(ind64 == ind)) {
-		ret = zcache_get_page(LOCAL_CLIENT, zcache_frontswap_poolid,
-					&oid, iswiz(ind),
-					page, &size, false, get_and_free);
-		BUG_ON(ret >= 0 && size != PAGE_SIZE);
-	}
-	return ret;
-}
-
-/* flush a single page from frontswap */
-static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset)
-{
-	u64 ind64 = (u64)offset;
-	u32 ind = (u32)offset;
-	struct tmem_oid oid = oswiz(type, ind);
-
-	if (likely(ind64 == ind))
-		(void)zcache_flush_page(LOCAL_CLIENT, zcache_frontswap_poolid,
-					&oid, iswiz(ind));
-}
-
-/* flush all pages from the passed swaptype */
-static void zcache_frontswap_flush_area(unsigned type)
-{
-	struct tmem_oid oid;
-	int ind;
-
-	for (ind = SWIZ_MASK; ind >= 0; ind--) {
-		oid = oswiz(type, ind);
-		(void)zcache_flush_object(LOCAL_CLIENT,
-						zcache_frontswap_poolid, &oid);
-	}
-}
-
-static void zcache_frontswap_init(unsigned ignored)
-{
-	/* a single tmem poolid is used for all frontswap "types" (swapfiles) */
-	if (zcache_frontswap_poolid < 0)
-		zcache_frontswap_poolid =
-			zcache_local_new_pool(TMEM_POOL_PERSIST);
-}
-
-static struct frontswap_ops zcache_frontswap_ops = {
-	.store = zcache_frontswap_put_page,
-	.load = zcache_frontswap_get_page,
-	.invalidate_page = zcache_frontswap_flush_page,
-	.invalidate_area = zcache_frontswap_flush_area,
-	.init = zcache_frontswap_init
-};
-
-struct frontswap_ops *zcache_frontswap_register_ops(void)
-{
-	struct frontswap_ops *old_ops =
-		frontswap_register_ops(&zcache_frontswap_ops);
-
-	return old_ops;
-}
-
-/*
- * zcache initialization
- * NOTE FOR NOW zcache or ramster MUST BE PROVIDED AS A KERNEL BOOT PARAMETER
- * OR NOTHING HAPPENS!
- */
-
-#ifndef CONFIG_ZCACHE_MODULE
-static int __init enable_zcache(char *s)
-{
-	zcache_enabled = true;
-	return 1;
-}
-__setup("zcache", enable_zcache);
-
-static int __init enable_ramster(char *s)
-{
-	zcache_enabled = true;
-#ifdef CONFIG_RAMSTER
-	ramster_enabled = true;
-#endif
-	return 1;
-}
-__setup("ramster", enable_ramster);
-
-/* allow independent dynamic disabling of cleancache and frontswap */
-
-static int __init no_cleancache(char *s)
-{
-	disable_cleancache = true;
-	return 1;
-}
-
-__setup("nocleancache", no_cleancache);
-
-static int __init no_frontswap(char *s)
-{
-	disable_frontswap = true;
-	return 1;
-}
-
-__setup("nofrontswap", no_frontswap);
-
-static int __init no_frontswap_exclusive_gets(char *s)
-{
-	frontswap_has_exclusive_gets = false;
-	return 1;
-}
-
-__setup("nofrontswapexclusivegets", no_frontswap_exclusive_gets);
-
-static int __init no_frontswap_ignore_nonactive(char *s)
-{
-	disable_frontswap_ignore_nonactive = true;
-	return 1;
-}
-
-__setup("nofrontswapignorenonactive", no_frontswap_ignore_nonactive);
-
-static int __init no_cleancache_ignore_nonactive(char *s)
-{
-	disable_cleancache_ignore_nonactive = true;
-	return 1;
-}
-
-__setup("nocleancacheignorenonactive", no_cleancache_ignore_nonactive);
-
-static int __init enable_zcache_compressor(char *s)
-{
-	strlcpy(zcache_comp_name, s, sizeof(zcache_comp_name));
-	zcache_enabled = true;
-	return 1;
-}
-__setup("zcache=", enable_zcache_compressor);
-#endif
-
-
-static int zcache_comp_init(void)
-{
-	int ret = 0;
-
-	/* check crypto algorithm */
-#ifdef CONFIG_ZCACHE_MODULE
-	ret = crypto_has_comp(zcache_comp_name, 0, 0);
-	if (!ret) {
-		ret = -1;
-		goto out;
-	}
-#else
-	if (*zcache_comp_name != '\0') {
-		ret = crypto_has_comp(zcache_comp_name, 0, 0);
-		if (!ret) {
-			pr_info("zcache: %s not supported\n",
-					zcache_comp_name);
-			ret = 1;
-			goto out;
-		}
-	}
-	if (!ret)
-		strcpy(zcache_comp_name, "lzo");
-	ret = crypto_has_comp(zcache_comp_name, 0, 0);
-	if (!ret) {
-		ret = 1;
-		goto out;
-	}
-#endif
-	pr_info("zcache: using %s compressor\n", zcache_comp_name);
-
-	/* alloc percpu transforms */
-	ret = 0;
-	zcache_comp_pcpu_tfms = alloc_percpu(struct crypto_comp *);
-	if (!zcache_comp_pcpu_tfms)
-		ret = 1;
-out:
-	return ret;
-}
-
-static int zcache_init(void)
-{
-	int ret = 0;
-
-#ifdef CONFIG_ZCACHE_MODULE
-	zcache_enabled = 1;
-#endif
-	if (ramster_enabled) {
-		namestr = "ramster";
-		ramster_register_pamops(&zcache_pamops);
-	}
-	zcache_debugfs_init();
-	if (zcache_enabled) {
-		unsigned int cpu;
-
-		tmem_register_hostops(&zcache_hostops);
-		tmem_register_pamops(&zcache_pamops);
-		ret = register_cpu_notifier(&zcache_cpu_notifier_block);
-		if (ret) {
-			pr_err("%s: can't register cpu notifier\n", namestr);
-			goto out;
-		}
-		ret = zcache_comp_init();
-		if (ret) {
-			pr_err("%s: compressor initialization failed\n",
-				namestr);
-			goto out;
-		}
-		for_each_online_cpu(cpu) {
-			void *pcpu = (void *)(long)cpu;
-			zcache_cpu_notifier(&zcache_cpu_notifier_block,
-				CPU_UP_PREPARE, pcpu);
-		}
-	}
-	zcache_objnode_cache = kmem_cache_create("zcache_objnode",
-				sizeof(struct tmem_objnode), 0, 0, NULL);
-	zcache_obj_cache = kmem_cache_create("zcache_obj",
-				sizeof(struct tmem_obj), 0, 0, NULL);
-	ret = zcache_new_client(LOCAL_CLIENT);
-	if (ret) {
-		pr_err("%s: can't create client\n", namestr);
-		goto out;
-	}
-	zbud_init();
-	if (zcache_enabled && !disable_cleancache) {
-		struct cleancache_ops *old_ops;
-
-		register_shrinker(&zcache_shrinker);
-		old_ops = zcache_cleancache_register_ops();
-		pr_info("%s: cleancache enabled using kernel transcendent "
-			"memory and compression buddies\n", namestr);
-#ifdef CONFIG_ZCACHE_DEBUG
-		pr_info("%s: cleancache: ignorenonactive = %d\n",
-			namestr, !disable_cleancache_ignore_nonactive);
-#endif
-		if (old_ops != NULL)
-			pr_warn("%s: cleancache_ops overridden\n", namestr);
-	}
-	if (zcache_enabled && !disable_frontswap) {
-		struct frontswap_ops *old_ops;
-
-		old_ops = zcache_frontswap_register_ops();
-		if (frontswap_has_exclusive_gets)
-			frontswap_tmem_exclusive_gets(true);
-		pr_info("%s: frontswap enabled using kernel transcendent "
-			"memory and compression buddies\n", namestr);
-#ifdef CONFIG_ZCACHE_DEBUG
-		pr_info("%s: frontswap: excl gets = %d active only = %d\n",
-			namestr, frontswap_has_exclusive_gets,
-			!disable_frontswap_ignore_nonactive);
-#endif
-		if (IS_ERR(old_ops) || old_ops) {
-			if (IS_ERR(old_ops))
-				return PTR_RET(old_ops);
-			pr_warn("%s: frontswap_ops overridden\n", namestr);
-		}
-	}
-	if (ramster_enabled)
-		ramster_init(!disable_cleancache, !disable_frontswap,
-				frontswap_has_exclusive_gets,
-				!disable_frontswap_selfshrink);
-out:
-	return ret;
-}
-
-#ifdef CONFIG_ZCACHE_MODULE
-#ifdef CONFIG_RAMSTER
-module_param(ramster_enabled, bool, S_IRUGO);
-module_param(disable_frontswap_selfshrink, int, S_IRUGO);
-#endif
-module_param(disable_cleancache, bool, S_IRUGO);
-module_param(disable_frontswap, bool, S_IRUGO);
-#ifdef FRONTSWAP_HAS_EXCLUSIVE_GETS
-module_param(frontswap_has_exclusive_gets, bool, S_IRUGO);
-#endif
-module_param(disable_frontswap_ignore_nonactive, bool, S_IRUGO);
-module_param(zcache_comp_name, charp, S_IRUGO);
-module_init(zcache_init);
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Dan Magenheimer <dan.magenheimer@oracle.com>");
-MODULE_DESCRIPTION("In-kernel compression of cleancache/frontswap pages");
-#else
-late_initcall(zcache_init);
-#endif

drivers/staging/zcache/zcache.h

@@ -1,53 +0,0 @@
-
-/*
- * zcache.h
- *
- * Copyright (c) 2012, Dan Magenheimer, Oracle Corp.
- */
-
-#ifndef _ZCACHE_H_
-#define _ZCACHE_H_
-
-struct zcache_preload {
-	struct tmem_obj *obj;
-	struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH];
-};
-
-struct tmem_pool;
-
-#define MAX_POOLS_PER_CLIENT 16
-
-#define MAX_CLIENTS 16
-#define LOCAL_CLIENT ((uint16_t)-1)
-
-struct zcache_client {
-	struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT];
-	bool allocated;
-	atomic_t refcount;
-};
-
-extern struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id,
-							uint16_t poolid);
-extern void zcache_put_pool(struct tmem_pool *pool);
-
-extern int zcache_put_page(int, int, struct tmem_oid *,
-				uint32_t, void *,
-				unsigned int, bool, int);
-extern int zcache_get_page(int, int, struct tmem_oid *, uint32_t,
-				void *, size_t *, bool, int);
-extern int zcache_flush_page(int, int, struct tmem_oid *, uint32_t);
-extern int zcache_flush_object(int, int, struct tmem_oid *);
-extern void zcache_decompress_to_page(char *, unsigned int, struct page *);
-
-#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
-extern void *zcache_pampd_create(char *, unsigned int, bool, int,
-				struct tmem_handle *);
-int zcache_autocreate_pool(unsigned int cli_id, unsigned int pool_id, bool eph);
-#endif
-
-#define MAX_POOLS_PER_CLIENT 16
-
-#define MAX_CLIENTS 16
-#define LOCAL_CLIENT ((uint16_t)-1)
-
-#endif /* _ZCACHE_H_ */