Staging: zram: Rename ramzswap to zram in code

Automated renames in code:
 - rzs* -> zram*
 - RZS* -> ZRAM*
 - ramzswap* -> zram*

Manual changes:
 - Edited comments/messages mentioning "swap"

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/zram/zram_drv.c

@@ -1,5 +1,5 @@
 /*
- * Compressed RAM based swap device
+ * Compressed RAM block device
  *
  * Copyright (C) 2008, 2009, 2010  Nitin Gupta
  *
@@ -12,7 +12,7 @@
  * Project home: http://compcache.googlecode.com
  */
 
-#define KMSG_COMPONENT "ramzswap"
+#define KMSG_COMPONENT "zram"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/module.h>
@@ -26,35 +26,33 @@
 #include <linux/slab.h>
 #include <linux/lzo.h>
 #include <linux/string.h>
-#include <linux/swap.h>
-#include <linux/swapops.h>
 #include <linux/vmalloc.h>
 
 #include "zram_drv.h"
 
 /* Globals */
-static int ramzswap_major;
-static struct ramzswap *devices;
+static int zram_major;
+static struct zram *devices;
 
 /* Module params (documentation at end) */
 static unsigned int num_devices;
 
-static int rzs_test_flag(struct ramzswap *rzs, u32 index,
-			enum rzs_pageflags flag)
+static int zram_test_flag(struct zram *zram, u32 index,
+			enum zram_pageflags flag)
 {
-	return rzs->table[index].flags & BIT(flag);
+	return zram->table[index].flags & BIT(flag);
 }
 
-static void rzs_set_flag(struct ramzswap *rzs, u32 index,
-			enum rzs_pageflags flag)
+static void zram_set_flag(struct zram *zram, u32 index,
+			enum zram_pageflags flag)
 {
-	rzs->table[index].flags |= BIT(flag);
+	zram->table[index].flags |= BIT(flag);
 }
 
-static void rzs_clear_flag(struct ramzswap *rzs, u32 index,
-			enum rzs_pageflags flag)
+static void zram_clear_flag(struct zram *zram, u32 index,
+			enum zram_pageflags flag)
 {
-	rzs->table[index].flags &= ~BIT(flag);
+	zram->table[index].flags &= ~BIT(flag);
 }
 
 static int page_zero_filled(void *ptr)
@@ -72,50 +70,50 @@ static int page_zero_filled(void *ptr)
 	return 1;
 }
 
-static void ramzswap_set_disksize(struct ramzswap *rzs, size_t totalram_bytes)
+static void zram_set_disksize(struct zram *zram, size_t totalram_bytes)
 {
-	if (!rzs->disksize) {
+	if (!zram->disksize) {
 		pr_info(
 		"disk size not provided. You can use disksize_kb module "
 		"param to specify size.\nUsing default: (%u%% of RAM).\n",
 		default_disksize_perc_ram
 		);
-		rzs->disksize = default_disksize_perc_ram *
+		zram->disksize = default_disksize_perc_ram *
 					(totalram_bytes / 100);
 	}
 
-	if (rzs->disksize > 2 * (totalram_bytes)) {
+	if (zram->disksize > 2 * (totalram_bytes)) {
 		pr_info(
-		"There is little point creating a ramzswap of greater than "
+		"There is little point creating a zram of greater than "
 		"twice the size of memory since we expect a 2:1 compression "
-		"ratio. Note that ramzswap uses about 0.1%% of the size of "
-		"the swap device when not in use so a huge ramzswap is "
+		"ratio. Note that zram uses about 0.1%% of the size of "
+		"the disk when not in use so a huge zram is "
 		"wasteful.\n"
 		"\tMemory Size: %zu kB\n"
 		"\tSize you selected: %zu kB\n"
 		"Continuing anyway ...\n",
-		totalram_bytes >> 10, rzs->disksize
+		totalram_bytes >> 10, zram->disksize
 		);
 	}
 
-	rzs->disksize &= PAGE_MASK;
+	zram->disksize &= PAGE_MASK;
 }
 
-static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
-			struct ramzswap_ioctl_stats *s)
+static void zram_ioctl_get_stats(struct zram *zram,
+			struct zram_ioctl_stats *s)
 {
-	s->disksize = rzs->disksize;
+	s->disksize = zram->disksize;
 
-#if defined(CONFIG_RAMZSWAP_STATS)
+#if defined(CONFIG_ZRAM_STATS)
 	{
-	struct ramzswap_stats *rs = &rzs->stats;
+	struct zram_stats *rs = &zram->stats;
 	size_t succ_writes, mem_used;
 	unsigned int good_compress_perc = 0, no_compress_perc = 0;
 
-	mem_used = xv_get_total_size_bytes(rzs->mem_pool)
+	mem_used = xv_get_total_size_bytes(zram->mem_pool)
 			+ (rs->pages_expand << PAGE_SHIFT);
-	succ_writes = rzs_stat64_read(rzs, &rs->num_writes) -
-			rzs_stat64_read(rzs, &rs->failed_writes);
+	succ_writes = zram_stat64_read(zram, &rs->num_writes) -
+			zram_stat64_read(zram, &rs->failed_writes);
 
 	if (succ_writes && rs->pages_stored) {
 		good_compress_perc = rs->good_compress * 100
@@ -124,12 +122,12 @@ static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
 					/ rs->pages_stored;
 	}
 
-	s->num_reads = rzs_stat64_read(rzs, &rs->num_reads);
-	s->num_writes = rzs_stat64_read(rzs, &rs->num_writes);
-	s->failed_reads = rzs_stat64_read(rzs, &rs->failed_reads);
-	s->failed_writes = rzs_stat64_read(rzs, &rs->failed_writes);
-	s->invalid_io = rzs_stat64_read(rzs, &rs->invalid_io);
-	s->notify_free = rzs_stat64_read(rzs, &rs->notify_free);
+	s->num_reads = zram_stat64_read(zram, &rs->num_reads);
+	s->num_writes = zram_stat64_read(zram, &rs->num_writes);
+	s->failed_reads = zram_stat64_read(zram, &rs->failed_reads);
+	s->failed_writes = zram_stat64_read(zram, &rs->failed_writes);
+	s->invalid_io = zram_stat64_read(zram, &rs->invalid_io);
+	s->notify_free = zram_stat64_read(zram, &rs->notify_free);
 	s->pages_zero = rs->pages_zero;
 
 	s->good_compress_pct = good_compress_perc;
@@ -141,34 +139,34 @@ static void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
 	s->compr_data_size = rs->compr_size;
 	s->mem_used_total = mem_used;
 	}
-#endif /* CONFIG_RAMZSWAP_STATS */
+#endif /* CONFIG_ZRAM_STATS */
 }
 
-static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
+static void zram_free_page(struct zram *zram, size_t index)
 {
 	u32 clen;
 	void *obj;
 
-	struct page *page = rzs->table[index].page;
-	u32 offset = rzs->table[index].offset;
+	struct page *page = zram->table[index].page;
+	u32 offset = zram->table[index].offset;
 
 	if (unlikely(!page)) {
 		/*
 		 * No memory is allocated for zero filled pages.
 		 * Simply clear zero page flag.
 		 */
-		if (rzs_test_flag(rzs, index, RZS_ZERO)) {
-			rzs_clear_flag(rzs, index, RZS_ZERO);
-			rzs_stat_dec(&rzs->stats.pages_zero);
+		if (zram_test_flag(zram, index, ZRAM_ZERO)) {
+			zram_clear_flag(zram, index, ZRAM_ZERO);
+			zram_stat_dec(&zram->stats.pages_zero);
 		}
 		return;
 	}
 
-	if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) {
+	if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
 		clen = PAGE_SIZE;
 		__free_page(page);
-		rzs_clear_flag(rzs, index, RZS_UNCOMPRESSED);
-		rzs_stat_dec(&rzs->stats.pages_expand);
+		zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED);
+		zram_stat_dec(&zram->stats.pages_expand);
 		goto out;
 	}
 
@@ -176,16 +174,16 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
 	clen = xv_get_object_size(obj) - sizeof(struct zobj_header);
 	kunmap_atomic(obj, KM_USER0);
 
-	xv_free(rzs->mem_pool, page, offset);
+	xv_free(zram->mem_pool, page, offset);
 	if (clen <= PAGE_SIZE / 2)
-		rzs_stat_dec(&rzs->stats.good_compress);
+		zram_stat_dec(&zram->stats.good_compress);
 
 out:
-	rzs->stats.compr_size -= clen;
-	rzs_stat_dec(&rzs->stats.pages_stored);
+	zram->stats.compr_size -= clen;
+	zram_stat_dec(&zram->stats.pages_stored);
 
-	rzs->table[index].page = NULL;
-	rzs->table[index].offset = 0;
+	zram->table[index].page = NULL;
+	zram->table[index].offset = 0;
 }
 
 static void handle_zero_page(struct page *page)
@@ -199,14 +197,14 @@ static void handle_zero_page(struct page *page)
 	flush_dcache_page(page);
 }
 
-static void handle_uncompressed_page(struct ramzswap *rzs,
+static void handle_uncompressed_page(struct zram *zram,
 				struct page *page, u32 index)
 {
 	unsigned char *user_mem, *cmem;
 
 	user_mem = kmap_atomic(page, KM_USER0);
-	cmem = kmap_atomic(rzs->table[index].page, KM_USER1) +
-			rzs->table[index].offset;
+	cmem = kmap_atomic(zram->table[index].page, KM_USER1) +
+			zram->table[index].offset;
 
 	memcpy(user_mem, cmem, PAGE_SIZE);
 	kunmap_atomic(user_mem, KM_USER0);
@@ -215,14 +213,14 @@ static void handle_uncompressed_page(struct ramzswap *rzs,
 	flush_dcache_page(page);
 }
 
-static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
+static int zram_read(struct zram *zram, struct bio *bio)
 {
 
 	int i;
 	u32 index;
 	struct bio_vec *bvec;
 
-	rzs_stat64_inc(rzs, &rzs->stats.num_reads);
+	zram_stat64_inc(zram, &zram->stats.num_reads);
 
 	index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
 	bio_for_each_segment(bvec, bio, i) {
@@ -234,13 +232,13 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
 
 		page = bvec->bv_page;
 
-		if (rzs_test_flag(rzs, index, RZS_ZERO)) {
+		if (zram_test_flag(zram, index, ZRAM_ZERO)) {
 			handle_zero_page(page);
 			continue;
 		}
 
 		/* Requested page is not present in compressed area */
-		if (unlikely(!rzs->table[index].page)) {
+		if (unlikely(!zram->table[index].page)) {
 			pr_debug("Read before write: sector=%lu, size=%u",
 				(ulong)(bio->bi_sector), bio->bi_size);
 			/* Do nothing */
@@ -248,16 +246,16 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
 		}
 
 		/* Page is stored uncompressed since it's incompressible */
-		if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) {
-			handle_uncompressed_page(rzs, page, index);
+		if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
+			handle_uncompressed_page(zram, page, index);
 			continue;
 		}
 
 		user_mem = kmap_atomic(page, KM_USER0);
 		clen = PAGE_SIZE;
 
-		cmem = kmap_atomic(rzs->table[index].page, KM_USER1) +
-				rzs->table[index].offset;
+		cmem = kmap_atomic(zram->table[index].page, KM_USER1) +
+				zram->table[index].offset;
 
 		ret = lzo1x_decompress_safe(
 			cmem + sizeof(*zheader),
@@ -271,7 +269,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
 		if (unlikely(ret != LZO_E_OK)) {
 			pr_err("Decompression failed! err=%d, page=%u\n",
 				ret, index);
-			rzs_stat64_inc(rzs, &rzs->stats.failed_reads);
+			zram_stat64_inc(zram, &zram->stats.failed_reads);
 			goto out;
 		}
 
@@ -288,13 +286,13 @@ out:
 	return 0;
 }
 
-static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
+static int zram_write(struct zram *zram, struct bio *bio)
 {
 	int i;
 	u32 index;
 	struct bio_vec *bvec;
 
-	rzs_stat64_inc(rzs, &rzs->stats.num_writes);
+	zram_stat64_inc(zram, &zram->stats.num_writes);
 
 	index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT;
 
@@ -307,82 +305,83 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
 		unsigned char *user_mem, *cmem, *src;
 
 		page = bvec->bv_page;
-		src = rzs->compress_buffer;
+		src = zram->compress_buffer;
 
 		/*
 		 * System overwrites unused sectors. Free memory associated
 		 * with this sector now.
 		 */
-		if (rzs->table[index].page ||
-				rzs_test_flag(rzs, index, RZS_ZERO))
-			ramzswap_free_page(rzs, index);
+		if (zram->table[index].page ||
+				zram_test_flag(zram, index, ZRAM_ZERO))
+			zram_free_page(zram, index);
 
-		mutex_lock(&rzs->lock);
+		mutex_lock(&zram->lock);
 
 		user_mem = kmap_atomic(page, KM_USER0);
 		if (page_zero_filled(user_mem)) {
 			kunmap_atomic(user_mem, KM_USER0);
-			mutex_unlock(&rzs->lock);
-			rzs_stat_inc(&rzs->stats.pages_zero);
-			rzs_set_flag(rzs, index, RZS_ZERO);
+			mutex_unlock(&zram->lock);
+			zram_stat_inc(&zram->stats.pages_zero);
+			zram_set_flag(zram, index, ZRAM_ZERO);
 			continue;
 		}
 
 		ret = lzo1x_1_compress(user_mem, PAGE_SIZE, src, &clen,
-					rzs->compress_workmem);
+					zram->compress_workmem);
 
 		kunmap_atomic(user_mem, KM_USER0);
 
 		if (unlikely(ret != LZO_E_OK)) {
-			mutex_unlock(&rzs->lock);
+			mutex_unlock(&zram->lock);
 			pr_err("Compression failed! err=%d\n", ret);
-			rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
+			zram_stat64_inc(zram, &zram->stats.failed_writes);
 			goto out;
 		}
 
 		/*
 		 * Page is incompressible. Store it as-is (uncompressed)
-		 * since we do not want to return too many swap write
+		 * since we do not want to return too many disk write
 		 * errors which has side effect of hanging the system.
 		 */
 		if (unlikely(clen > max_zpage_size)) {
 			clen = PAGE_SIZE;
 			page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM);
 			if (unlikely(!page_store)) {
-				mutex_unlock(&rzs->lock);
+				mutex_unlock(&zram->lock);
 				pr_info("Error allocating memory for "
 					"incompressible page: %u\n", index);
-				rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
+				zram_stat64_inc(zram,
+					&zram->stats.failed_writes);
 				goto out;
 			}
 
 			offset = 0;
-			rzs_set_flag(rzs, index, RZS_UNCOMPRESSED);
-			rzs_stat_inc(&rzs->stats.pages_expand);
-			rzs->table[index].page = page_store;
+			zram_set_flag(zram, index, ZRAM_UNCOMPRESSED);
+			zram_stat_inc(&zram->stats.pages_expand);
+			zram->table[index].page = page_store;
 			src = kmap_atomic(page, KM_USER0);
 			goto memstore;
 		}
 
-		if (xv_malloc(rzs->mem_pool, clen + sizeof(*zheader),
-				&rzs->table[index].page, &offset,
+		if (xv_malloc(zram->mem_pool, clen + sizeof(*zheader),
+				&zram->table[index].page, &offset,
 				GFP_NOIO | __GFP_HIGHMEM)) {
-			mutex_unlock(&rzs->lock);
+			mutex_unlock(&zram->lock);
 			pr_info("Error allocating memory for compressed "
 				"page: %u, size=%zu\n", index, clen);
-			rzs_stat64_inc(rzs, &rzs->stats.failed_writes);
+			zram_stat64_inc(zram, &zram->stats.failed_writes);
 			goto out;
 		}
 
 memstore:
-		rzs->table[index].offset = offset;
+		zram->table[index].offset = offset;
 
-		cmem = kmap_atomic(rzs->table[index].page, KM_USER1) +
-				rzs->table[index].offset;
+		cmem = kmap_atomic(zram->table[index].page, KM_USER1) +
+				zram->table[index].offset;
 
 #if 0
 		/* Back-reference needed for memory defragmentation */
-		if (!rzs_test_flag(rzs, index, RZS_UNCOMPRESSED)) {
+		if (!zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)) {
 			zheader = (struct zobj_header *)cmem;
 			zheader->table_idx = index;
 			cmem += sizeof(*zheader);
@@ -392,16 +391,16 @@ memstore:
 		memcpy(cmem, src, clen);
 
 		kunmap_atomic(cmem, KM_USER1);
-		if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED)))
+		if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)))
 			kunmap_atomic(src, KM_USER0);
 
 		/* Update stats */
-		rzs->stats.compr_size += clen;
-		rzs_stat_inc(&rzs->stats.pages_stored);
+		zram->stats.compr_size += clen;
+		zram_stat_inc(&zram->stats.pages_stored);
 		if (clen <= PAGE_SIZE / 2)
-			rzs_stat_inc(&rzs->stats.good_compress);
+			zram_stat_inc(&zram->stats.good_compress);
 
-		mutex_unlock(&rzs->lock);
+		mutex_unlock(&zram->lock);
 		index++;
 	}
 
@@ -417,10 +416,10 @@ out:
 /*
  * Check if request is within bounds and page aligned.
  */
-static inline int valid_io_request(struct ramzswap *rzs, struct bio *bio)
+static inline int valid_io_request(struct zram *zram, struct bio *bio)
 {
 	if (unlikely(
-		(bio->bi_sector >= (rzs->disksize >> SECTOR_SHIFT)) ||
+		(bio->bi_sector >= (zram->disksize >> SECTOR_SHIFT)) ||
 		(bio->bi_sector & (SECTORS_PER_PAGE - 1)) ||
 		(bio->bi_size & (PAGE_SIZE - 1)))) {
 
@@ -432,160 +431,160 @@ static inline int valid_io_request(struct ramzswap *rzs, struct bio *bio)
 }
 
 /*
- * Handler function for all ramzswap I/O requests.
+ * Handler function for all zram I/O requests.
  */
-static int ramzswap_make_request(struct request_queue *queue, struct bio *bio)
+static int zram_make_request(struct request_queue *queue, struct bio *bio)
 {
 	int ret = 0;
-	struct ramzswap *rzs = queue->queuedata;
+	struct zram *zram = queue->queuedata;
 
-	if (unlikely(!rzs->init_done)) {
+	if (unlikely(!zram->init_done)) {
 		bio_io_error(bio);
 		return 0;
 	}
 
-	if (!valid_io_request(rzs, bio)) {
-		rzs_stat64_inc(rzs, &rzs->stats.invalid_io);
+	if (!valid_io_request(zram, bio)) {
+		zram_stat64_inc(zram, &zram->stats.invalid_io);
 		bio_io_error(bio);
 		return 0;
 	}
 
 	switch (bio_data_dir(bio)) {
 	case READ:
-		ret = ramzswap_read(rzs, bio);
+		ret = zram_read(zram, bio);
 		break;
 
 	case WRITE:
-		ret = ramzswap_write(rzs, bio);
+		ret = zram_write(zram, bio);
 		break;
 	}
 
 	return ret;
 }
 
-static void reset_device(struct ramzswap *rzs)
+static void reset_device(struct zram *zram)
 {
 	size_t index;
 
 	/* Do not accept any new I/O request */
-	rzs->init_done = 0;
+	zram->init_done = 0;
 
 	/* Free various per-device buffers */
-	kfree(rzs->compress_workmem);
-	free_pages((unsigned long)rzs->compress_buffer, 1);
+	kfree(zram->compress_workmem);
+	free_pages((unsigned long)zram->compress_buffer, 1);
 
-	rzs->compress_workmem = NULL;
-	rzs->compress_buffer = NULL;
+	zram->compress_workmem = NULL;
+	zram->compress_buffer = NULL;
 
-	/* Free all pages that are still in this ramzswap device */
-	for (index = 0; index < rzs->disksize >> PAGE_SHIFT; index++) {
+	/* Free all pages that are still in this zram device */
+	for (index = 0; index < zram->disksize >> PAGE_SHIFT; index++) {
 		struct page *page;
 		u16 offset;
 
-		page = rzs->table[index].page;
-		offset = rzs->table[index].offset;
+		page = zram->table[index].page;
+		offset = zram->table[index].offset;
 
 		if (!page)
 			continue;
 
-		if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED)))
+		if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)))
 			__free_page(page);
 		else
-			xv_free(rzs->mem_pool, page, offset);
+			xv_free(zram->mem_pool, page, offset);
 	}
 
-	vfree(rzs->table);
-	rzs->table = NULL;
+	vfree(zram->table);
+	zram->table = NULL;
 
-	xv_destroy_pool(rzs->mem_pool);
-	rzs->mem_pool = NULL;
+	xv_destroy_pool(zram->mem_pool);
+	zram->mem_pool = NULL;
 
 	/* Reset stats */
-	memset(&rzs->stats, 0, sizeof(rzs->stats));
+	memset(&zram->stats, 0, sizeof(zram->stats));
 
-	rzs->disksize = 0;
+	zram->disksize = 0;
 }
 
-static int ramzswap_ioctl_init_device(struct ramzswap *rzs)
+static int zram_ioctl_init_device(struct zram *zram)
 {
 	int ret;
 	size_t num_pages;
 
-	if (rzs->init_done) {
+	if (zram->init_done) {
 		pr_info("Device already initialized!\n");
 		return -EBUSY;
 	}
 
-	ramzswap_set_disksize(rzs, totalram_pages << PAGE_SHIFT);
+	zram_set_disksize(zram, totalram_pages << PAGE_SHIFT);
 
-	rzs->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
-	if (!rzs->compress_workmem) {
+	zram->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
+	if (!zram->compress_workmem) {
 		pr_err("Error allocating compressor working memory!\n");
 		ret = -ENOMEM;
 		goto fail;
 	}
 
-	rzs->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1);
-	if (!rzs->compress_buffer) {
+	zram->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1);
+	if (!zram->compress_buffer) {
 		pr_err("Error allocating compressor buffer space\n");
 		ret = -ENOMEM;
 		goto fail;
 	}
 
-	num_pages = rzs->disksize >> PAGE_SHIFT;
-	rzs->table = vmalloc(num_pages * sizeof(*rzs->table));
-	if (!rzs->table) {
-		pr_err("Error allocating ramzswap address table\n");
+	num_pages = zram->disksize >> PAGE_SHIFT;
+	zram->table = vmalloc(num_pages * sizeof(*zram->table));
+	if (!zram->table) {
+		pr_err("Error allocating zram address table\n");
 		/* To prevent accessing table entries during cleanup */
-		rzs->disksize = 0;
+		zram->disksize = 0;
 		ret = -ENOMEM;
 		goto fail;
 	}
-	memset(rzs->table, 0, num_pages * sizeof(*rzs->table));
+	memset(zram->table, 0, num_pages * sizeof(*zram->table));
 
-	set_capacity(rzs->disk, rzs->disksize >> SECTOR_SHIFT);
+	set_capacity(zram->disk, zram->disksize >> SECTOR_SHIFT);
 
-	/* ramzswap devices sort of resembles non-rotational disks */
-	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, rzs->disk->queue);
+	/* zram devices sort of resembles non-rotational disks */
+	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue);
 
-	rzs->mem_pool = xv_create_pool();
-	if (!rzs->mem_pool) {
+	zram->mem_pool = xv_create_pool();
+	if (!zram->mem_pool) {
 		pr_err("Error creating memory pool\n");
 		ret = -ENOMEM;
 		goto fail;
 	}
 
-	rzs->init_done = 1;
+	zram->init_done = 1;
 
 	pr_debug("Initialization done!\n");
 	return 0;
 
 fail:
-	reset_device(rzs);
+	reset_device(zram);
 
 	pr_err("Initialization failed: err=%d\n", ret);
 	return ret;
 }
 
-static int ramzswap_ioctl_reset_device(struct ramzswap *rzs)
+static int zram_ioctl_reset_device(struct zram *zram)
 {
-	if (rzs->init_done)
-		reset_device(rzs);
+	if (zram->init_done)
+		reset_device(zram);
 
 	return 0;
 }
 
-static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
+static int zram_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned int cmd, unsigned long arg)
 {
 	int ret = 0;
 	size_t disksize_kb;
 
-	struct ramzswap *rzs = bdev->bd_disk->private_data;
+	struct zram *zram = bdev->bd_disk->private_data;
 
 	switch (cmd) {
-	case RZSIO_SET_DISKSIZE_KB:
-		if (rzs->init_done) {
+	case ZRAMIO_SET_DISKSIZE_KB:
+		if (zram->init_done) {
 			ret = -EBUSY;
 			goto out;
 		}
@@ -594,14 +593,14 @@ static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
 			ret = -EFAULT;
 			goto out;
 		}
-		rzs->disksize = disksize_kb << 10;
+		zram->disksize = disksize_kb << 10;
 		pr_info("Disk size set to %zu kB\n", disksize_kb);
 		break;
 
-	case RZSIO_GET_STATS:
+	case ZRAMIO_GET_STATS:
 	{
-		struct ramzswap_ioctl_stats *stats;
-		if (!rzs->init_done) {
+		struct zram_ioctl_stats *stats;
+		if (!zram->init_done) {
 			ret = -ENOTTY;
 			goto out;
 		}
@@ -610,7 +609,7 @@ static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
 			ret = -ENOMEM;
 			goto out;
 		}
-		ramzswap_ioctl_get_stats(rzs, stats);
+		zram_ioctl_get_stats(zram, stats);
 		if (copy_to_user((void *)arg, stats, sizeof(*stats))) {
 			kfree(stats);
 			ret = -EFAULT;
@@ -619,11 +618,11 @@ static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
 		kfree(stats);
 		break;
 	}
-	case RZSIO_INIT:
-		ret = ramzswap_ioctl_init_device(rzs);
+	case ZRAMIO_INIT:
+		ret = zram_ioctl_init_device(zram);
 		break;
 
-	case RZSIO_RESET:
+	case ZRAMIO_RESET:
 		/* Do not reset an active device! */
 		if (bdev->bd_holders) {
 			ret = -EBUSY;
@@ -634,7 +633,7 @@ static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode,
 		if (bdev)
 			fsync_bdev(bdev);
 
-		ret = ramzswap_ioctl_reset_device(rzs);
+		ret = zram_ioctl_reset_device(zram);
 		break;
 
 	default:
@@ -646,88 +645,88 @@ out:
 	return ret;
 }
 
-void ramzswap_slot_free_notify(struct block_device *bdev, unsigned long index)
+void zram_slot_free_notify(struct block_device *bdev, unsigned long index)
 {
-	struct ramzswap *rzs;
+	struct zram *zram;
 
-	rzs = bdev->bd_disk->private_data;
-	ramzswap_free_page(rzs, index);
-	rzs_stat64_inc(rzs, &rzs->stats.notify_free);
+	zram = bdev->bd_disk->private_data;
+	zram_free_page(zram, index);
+	zram_stat64_inc(zram, &zram->stats.notify_free);
 }
 
-static const struct block_device_operations ramzswap_devops = {
-	.ioctl = ramzswap_ioctl,
-	.swap_slot_free_notify = ramzswap_slot_free_notify,
+static const struct block_device_operations zram_devops = {
+	.ioctl = zram_ioctl,
+	.swap_slot_free_notify = zram_slot_free_notify,
 	.owner = THIS_MODULE
 };
 
-static int create_device(struct ramzswap *rzs, int device_id)
+static int create_device(struct zram *zram, int device_id)
 {
 	int ret = 0;
 
-	mutex_init(&rzs->lock);
-	spin_lock_init(&rzs->stat64_lock);
+	mutex_init(&zram->lock);
+	spin_lock_init(&zram->stat64_lock);
 
-	rzs->queue = blk_alloc_queue(GFP_KERNEL);
-	if (!rzs->queue) {
+	zram->queue = blk_alloc_queue(GFP_KERNEL);
+	if (!zram->queue) {
 		pr_err("Error allocating disk queue for device %d\n",
 			device_id);
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	blk_queue_make_request(rzs->queue, ramzswap_make_request);
-	rzs->queue->queuedata = rzs;
+	blk_queue_make_request(zram->queue, zram_make_request);
+	zram->queue->queuedata = zram;
 
 	 /* gendisk structure */
-	rzs->disk = alloc_disk(1);
-	if (!rzs->disk) {
-		blk_cleanup_queue(rzs->queue);
+	zram->disk = alloc_disk(1);
+	if (!zram->disk) {
+		blk_cleanup_queue(zram->queue);
 		pr_warning("Error allocating disk structure for device %d\n",
 			device_id);
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	rzs->disk->major = ramzswap_major;
-	rzs->disk->first_minor = device_id;
-	rzs->disk->fops = &ramzswap_devops;
-	rzs->disk->queue = rzs->queue;
-	rzs->disk->private_data = rzs;
-	snprintf(rzs->disk->disk_name, 16, "ramzswap%d", device_id);
+	zram->disk->major = zram_major;
+	zram->disk->first_minor = device_id;
+	zram->disk->fops = &zram_devops;
+	zram->disk->queue = zram->queue;
+	zram->disk->private_data = zram;
+	snprintf(zram->disk->disk_name, 16, "zram%d", device_id);
 
-	/* Actual capacity set using RZSIO_SET_DISKSIZE_KB ioctl */
-	set_capacity(rzs->disk, 0);
+	/* Actual capacity set using ZRAMIO_SET_DISKSIZE_KB ioctl */
+	set_capacity(zram->disk, 0);
 
 	/*
 	 * To ensure that we always get PAGE_SIZE aligned
 	 * and n*PAGE_SIZED sized I/O requests.
 	 */
-	blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE);
-	blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE);
-	blk_queue_io_min(rzs->disk->queue, PAGE_SIZE);
-	blk_queue_io_opt(rzs->disk->queue, PAGE_SIZE);
+	blk_queue_physical_block_size(zram->disk->queue, PAGE_SIZE);
+	blk_queue_logical_block_size(zram->disk->queue, PAGE_SIZE);
+	blk_queue_io_min(zram->disk->queue, PAGE_SIZE);
+	blk_queue_io_opt(zram->disk->queue, PAGE_SIZE);
 
-	add_disk(rzs->disk);
+	add_disk(zram->disk);
 
-	rzs->init_done = 0;
+	zram->init_done = 0;
 
 out:
 	return ret;
 }
 
-static void destroy_device(struct ramzswap *rzs)
+static void destroy_device(struct zram *zram)
 {
-	if (rzs->disk) {
-		del_gendisk(rzs->disk);
-		put_disk(rzs->disk);
+	if (zram->disk) {
+		del_gendisk(zram->disk);
+		put_disk(zram->disk);
 	}
 
-	if (rzs->queue)
-		blk_cleanup_queue(rzs->queue);
+	if (zram->queue)
+		blk_cleanup_queue(zram->queue);
 }
 
-static int __init ramzswap_init(void)
+static int __init zram_init(void)
 {
 	int ret, dev_id;
 
@@ -738,8 +737,8 @@ static int __init ramzswap_init(void)
 		goto out;
 	}
 
-	ramzswap_major = register_blkdev(0, "ramzswap");
-	if (ramzswap_major <= 0) {
+	zram_major = register_blkdev(0, "zram");
+	if (zram_major <= 0) {
 		pr_warning("Unable to get major number\n");
 		ret = -EBUSY;
 		goto out;
@@ -752,7 +751,7 @@ static int __init ramzswap_init(void)
 
 	/* Allocate the device array and initialize each one */
 	pr_info("Creating %u devices ...\n", num_devices);
-	devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL);
+	devices = kzalloc(num_devices * sizeof(struct zram), GFP_KERNEL);
 	if (!devices) {
 		ret = -ENOMEM;
 		goto unregister;
@@ -770,36 +769,36 @@ free_devices:
 	while (dev_id)
 		destroy_device(&devices[--dev_id]);
 unregister:
-	unregister_blkdev(ramzswap_major, "ramzswap");
+	unregister_blkdev(zram_major, "zram");
 out:
 	return ret;
 }
 
-static void __exit ramzswap_exit(void)
+static void __exit zram_exit(void)
 {
 	int i;
-	struct ramzswap *rzs;
+	struct zram *zram;
 
 	for (i = 0; i < num_devices; i++) {
-		rzs = &devices[i];
+		zram = &devices[i];
 
-		destroy_device(rzs);
-		if (rzs->init_done)
-			reset_device(rzs);
+		destroy_device(zram);
+		if (zram->init_done)
+			reset_device(zram);
 	}
 
-	unregister_blkdev(ramzswap_major, "ramzswap");
+	unregister_blkdev(zram_major, "zram");
 
 	kfree(devices);
 	pr_debug("Cleanup done!\n");
 }
 
 module_param(num_devices, uint, 0);
-MODULE_PARM_DESC(num_devices, "Number of ramzswap devices");
+MODULE_PARM_DESC(num_devices, "Number of zram devices");
 
-module_init(ramzswap_init);
-module_exit(ramzswap_exit);
+module_init(zram_init);
+module_exit(zram_exit);
 
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>");
-MODULE_DESCRIPTION("Compressed RAM Based Swap Device");
+MODULE_DESCRIPTION("Compressed RAM Block Device");

drivers/staging/zram/zram_drv.h

@@ -1,5 +1,5 @@
 /*
- * Compressed RAM based swap device
+ * Compressed RAM block device
  *
  * Copyright (C) 2008, 2009, 2010  Nitin Gupta
  *
@@ -12,8 +12,8 @@
  * Project home: http://compcache.googlecode.com
  */
 
-#ifndef _RAMZSWAP_DRV_H_
-#define _RAMZSWAP_DRV_H_
+#ifndef _ZRAM_DRV_H_
+#define _ZRAM_DRV_H_
 
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
@@ -41,7 +41,7 @@ struct zobj_header {
 
 /*-- Configurable parameters */
 
-/* Default ramzswap disk size: 25% of total RAM */
+/* Default zram disk size: 25% of total RAM */
 static const unsigned default_disksize_perc_ram = 25;
 
 /*
@@ -63,23 +63,20 @@ static const unsigned max_zpage_size = PAGE_SIZE / 4 * 3;
 #define SECTORS_PER_PAGE_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
 #define SECTORS_PER_PAGE	(1 << SECTORS_PER_PAGE_SHIFT)
 
-/* Flags for ramzswap pages (table[page_no].flags) */
-enum rzs_pageflags {
+/* Flags for zram pages (table[page_no].flags) */
+enum zram_pageflags {
 	/* Page is stored uncompressed */
-	RZS_UNCOMPRESSED,
+	ZRAM_UNCOMPRESSED,
 
 	/* Page consists entirely of zeros */
-	RZS_ZERO,
+	ZRAM_ZERO,
 
-	__NR_RZS_PAGEFLAGS,
+	__NR_ZRAM_PAGEFLAGS,
 };
 
 /*-- Data structures */
 
-/*
- * Allocated for each swap slot, indexed by page no.
- * These table entries must fit exactly in a page.
- */
+/* Allocated for each disk page */
 struct table {
 	struct page *page;
 	u16 offset;
@@ -87,17 +84,17 @@ struct table {
 	u8 flags;
 } __attribute__((aligned(4)));
 
-struct ramzswap_stats {
+struct zram_stats {
 	/* basic stats */
 	size_t compr_size;	/* compressed size of pages stored -
 				 * needed to enforce memlimit */
 	/* more stats */
-#if defined(CONFIG_RAMZSWAP_STATS)
+#if defined(CONFIG_ZRAM_STATS)
 	u64 num_reads;		/* failed + successful */
 	u64 num_writes;		/* --do-- */
 	u64 failed_reads;	/* should NEVER! happen */
 	u64 failed_writes;	/* can happen when memory is too low */
-	u64 invalid_io;		/* non-swap I/O requests */
+	u64 invalid_io;		/* non-page-aligned I/O requests */
 	u64 notify_free;	/* no. of swap slot free notifications */
 	u32 pages_zero;		/* no. of zero filled pages */
 	u32 pages_stored;	/* no. of pages currently stored */
@@ -106,7 +103,7 @@ struct ramzswap_stats {
 #endif
 };
 
-struct ramzswap {
+struct zram {
 	struct xv_pool *mem_pool;
 	void *compress_workmem;
 	void *compress_buffer;
@@ -118,51 +115,50 @@ struct ramzswap {
 	struct gendisk *disk;
 	int init_done;
 	/*
-	 * This is limit on amount of *uncompressed* worth of data
-	 * we can hold. When backing swap device is provided, it is
-	 * set equal to device size.
+	 * This is the limit on amount of *uncompressed* worth of data
+	 * we can store in a disk.
 	 */
 	size_t disksize;	/* bytes */
 
-	struct ramzswap_stats stats;
+	struct zram_stats stats;
 };
 
 /*-- */
 
 /* Debugging and Stats */
-#if defined(CONFIG_RAMZSWAP_STATS)
-static void rzs_stat_inc(u32 *v)
+#if defined(CONFIG_ZRAM_STATS)
+static void zram_stat_inc(u32 *v)
 {
 	*v = *v + 1;
 }
 
-static void rzs_stat_dec(u32 *v)
+static void zram_stat_dec(u32 *v)
 {
 	*v = *v - 1;
 }
 
-static void rzs_stat64_inc(struct ramzswap *rzs, u64 *v)
+static void zram_stat64_inc(struct zram *zram, u64 *v)
 {
-	spin_lock(&rzs->stat64_lock);
+	spin_lock(&zram->stat64_lock);
 	*v = *v + 1;
-	spin_unlock(&rzs->stat64_lock);
+	spin_unlock(&zram->stat64_lock);
 }
 
-static u64 rzs_stat64_read(struct ramzswap *rzs, u64 *v)
+static u64 zram_stat64_read(struct zram *zram, u64 *v)
 {
 	u64 val;
 
-	spin_lock(&rzs->stat64_lock);
+	spin_lock(&zram->stat64_lock);
 	val = *v;
-	spin_unlock(&rzs->stat64_lock);
+	spin_unlock(&zram->stat64_lock);
 
 	return val;
 }
 #else
-#define rzs_stat_inc(v)
-#define rzs_stat_dec(v)
-#define rzs_stat64_inc(r, v)
-#define rzs_stat64_read(r, v)
-#endif /* CONFIG_RAMZSWAP_STATS */
+#define zram_stat_inc(v)
+#define zram_stat_dec(v)
+#define zram_stat64_inc(r, v)
+#define zram_stat64_read(r, v)
+#endif /* CONFIG_ZRAM_STATS */
 
 #endif

drivers/staging/zram/zram_ioctl.h

@@ -1,5 +1,5 @@
 /*
- * Compressed RAM based swap device
+ * Compressed RAM block device
  *
  * Copyright (C) 2008, 2009, 2010  Nitin Gupta
  *
@@ -12,17 +12,16 @@
  * Project home: http://compcache.googlecode.com
  */
 
-#ifndef _RAMZSWAP_IOCTL_H_
-#define _RAMZSWAP_IOCTL_H_
+#ifndef _ZRAM_IOCTL_H_
+#define _ZRAM_IOCTL_H_
 
-struct ramzswap_ioctl_stats {
-	u64 disksize;		/* user specified or equal to backing swap
-				 * size (if present) */
+struct zram_ioctl_stats {
+	u64 disksize;		/* disksize in bytes (user specifies in KB) */
 	u64 num_reads;		/* failed + successful */
 	u64 num_writes;		/* --do-- */
 	u64 failed_reads;	/* should NEVER! happen */
 	u64 failed_writes;	/* can happen when memory is too low */
-	u64 invalid_io;		/* non-swap I/O requests */
+	u64 invalid_io;		/* non-page-aligned I/O requests */
 	u64 notify_free;	/* no. of swap slot free notifications */
 	u32 pages_zero;		/* no. of zero filled pages */
 	u32 good_compress_pct;	/* no. of pages with compression ratio<=50% */
@@ -34,9 +33,9 @@ struct ramzswap_ioctl_stats {
 	u64 mem_used_total;
 } __attribute__ ((packed, aligned(4)));
 
-#define RZSIO_SET_DISKSIZE_KB	_IOW('z', 0, size_t)
-#define RZSIO_GET_STATS		_IOR('z', 1, struct ramzswap_ioctl_stats)
-#define RZSIO_INIT		_IO('z', 2)
-#define RZSIO_RESET		_IO('z', 3)
+#define ZRAMIO_SET_DISKSIZE_KB	_IOW('z', 0, size_t)
+#define ZRAMIO_GET_STATS	_IOR('z', 1, struct zram_ioctl_stats)
+#define ZRAMIO_INIT		_IO('z', 2)
+#define ZRAMIO_RESET		_IO('z', 3)
 
 #endif