staging: zcache: fix static variables defined in debug.h but used in mutiple C files

After commit 95bdaee214 ("zcache: Move debugfs code out of zcache-main.c file")
be merged, most of knods in zcache debugfs just export zero since these variables
are defined in debug.h but are in use in multiple C files zcache-main.c and debug.c,
in this case variables can't be treated as shared variables.

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/zcache/debug.c

@@ -4,6 +4,38 @@
 #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;
+
 #define ATTR(x)  { .name = #x, .val = &zcache_##x, }
 static struct debug_entry {
 	const char *name;

drivers/staging/zcache/debug.h

@@ -3,9 +3,9 @@
 #ifdef CONFIG_ZCACHE_DEBUG
 
 /* we try to keep these statistics SMP-consistent */
-static ssize_t zcache_obj_count;
+extern ssize_t zcache_obj_count;
 static atomic_t zcache_obj_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_obj_count_max;
+extern ssize_t zcache_obj_count_max;
 static inline void inc_zcache_obj_count(void)
 {
 	zcache_obj_count = atomic_inc_return(&zcache_obj_atomic);
@@ -17,9 +17,9 @@ static inline void dec_zcache_obj_count(void)
 	zcache_obj_count = atomic_dec_return(&zcache_obj_atomic);
 	BUG_ON(zcache_obj_count < 0);
 };
-static ssize_t zcache_objnode_count;
+extern ssize_t zcache_objnode_count;
 static atomic_t zcache_objnode_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_objnode_count_max;
+extern ssize_t zcache_objnode_count_max;
 static inline void inc_zcache_objnode_count(void)
 {
 	zcache_objnode_count = atomic_inc_return(&zcache_objnode_atomic);
@@ -31,9 +31,9 @@ static inline void dec_zcache_objnode_count(void)
 	zcache_objnode_count = atomic_dec_return(&zcache_objnode_atomic);
 	BUG_ON(zcache_objnode_count < 0);
 };
-static u64 zcache_eph_zbytes;
+extern u64 zcache_eph_zbytes;
 static atomic_long_t zcache_eph_zbytes_atomic = ATOMIC_INIT(0);
-static u64 zcache_eph_zbytes_max;
+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);
@@ -46,7 +46,7 @@ static inline void dec_zcache_eph_zbytes(unsigned zsize)
 };
 extern  u64 zcache_pers_zbytes;
 static atomic_long_t zcache_pers_zbytes_atomic = ATOMIC_INIT(0);
-static u64 zcache_pers_zbytes_max;
+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);
@@ -59,7 +59,7 @@ static inline void dec_zcache_pers_zbytes(unsigned zsize)
 }
 extern ssize_t zcache_eph_pageframes;
 static atomic_t zcache_eph_pageframes_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_eph_pageframes_max;
+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);
@@ -72,7 +72,7 @@ static inline void dec_zcache_eph_pageframes(void)
 };
 extern ssize_t zcache_pers_pageframes;
 static atomic_t zcache_pers_pageframes_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_pers_pageframes_max;
+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);
@@ -83,21 +83,21 @@ static inline void dec_zcache_pers_pageframes(void)
 {
 	zcache_pers_pageframes = atomic_dec_return(&zcache_pers_pageframes_atomic);
 }
-static ssize_t zcache_pageframes_alloced;
+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);
 };
-static ssize_t zcache_pageframes_freed;
+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);
 }
-static ssize_t zcache_eph_zpages;
+extern ssize_t zcache_eph_zpages;
 static atomic_t zcache_eph_zpages_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_eph_zpages_max;
+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);
@@ -110,7 +110,7 @@ static inline void dec_zcache_eph_zpages(unsigned zpages)
 }
 extern ssize_t zcache_pers_zpages;
 static atomic_t zcache_pers_zpages_atomic = ATOMIC_INIT(0);
-static ssize_t zcache_pers_zpages_max;
+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);
@@ -130,23 +130,23 @@ static inline unsigned long curr_pageframes_count(void)
 		atomic_read(&zcache_pers_pageframes_atomic);
 };
 /* but for the rest of these, counting races are ok */
-static ssize_t zcache_flush_total;
-static ssize_t zcache_flush_found;
-static ssize_t zcache_flobj_total;
-static ssize_t zcache_flobj_found;
-static ssize_t zcache_failed_eph_puts;
-static ssize_t zcache_failed_pers_puts;
-static ssize_t zcache_failed_getfreepages;
-static ssize_t zcache_failed_alloc;
-static ssize_t zcache_put_to_flush;
-static ssize_t zcache_compress_poor;
-static ssize_t zcache_mean_compress_poor;
-static ssize_t zcache_eph_ate_tail;
-static ssize_t zcache_eph_ate_tail_failed;
-static ssize_t zcache_pers_ate_eph;
-static ssize_t zcache_pers_ate_eph_failed;
-static ssize_t zcache_evicted_eph_zpages;
-static ssize_t zcache_evicted_eph_pageframes;
+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;