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authorMike Snitzer <snitzer@redhat.com>2016-04-12 12:14:46 -0400
committerMike Snitzer <snitzer@redhat.com>2016-04-14 17:34:49 -0400
commit9567366fefddeaea4ed1d713270535d93a3b3c76 (patch)
tree92829c59c613f72cedc01fb14685915bce060468 /drivers/md
parent072623de1f964c7ff01c46a9101af1c822fd2873 (diff)
downloadlinux-9567366fefddeaea4ed1d713270535d93a3b3c76.tar.bz2
dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros
The READ_LOCK macro was incorrectly returning -EINVAL if dm_bm_is_read_only() was true -- it will always be true once the cache metadata transitions to read-only by dm_cache_metadata_set_read_only(). Wrap READ_LOCK and WRITE_LOCK multi-statement macros in do {} while(0). Also, all accesses of the 'cmd' argument passed to these related macros are now encapsulated in parenthesis. A follow-up patch can be developed to eliminate the use of macros in favor of pure C code. Avoiding that now given that this needs to apply to stable@. Reported-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Fixes: d14fcf3dd79 ("dm cache: make sure every metadata function checks fail_io") Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-cache-metadata.c64
1 files changed, 40 insertions, 24 deletions
diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 27f2ef300f8b..65ce6985f87a 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -867,39 +867,55 @@ static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd,
return 0;
}
-#define WRITE_LOCK(cmd) \
- down_write(&cmd->root_lock); \
- if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
- up_write(&cmd->root_lock); \
- return -EINVAL; \
+static bool cmd_write_lock(struct dm_cache_metadata *cmd)
+{
+ down_write(&cmd->root_lock);
+ if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
+ up_write(&cmd->root_lock);
+ return false;
}
+ return true;
+}
-#define WRITE_LOCK_VOID(cmd) \
- down_write(&cmd->root_lock); \
- if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
- up_write(&cmd->root_lock); \
- return; \
- }
+#define WRITE_LOCK(cmd) \
+ do { \
+ if (!cmd_write_lock((cmd))) \
+ return -EINVAL; \
+ } while(0)
+
+#define WRITE_LOCK_VOID(cmd) \
+ do { \
+ if (!cmd_write_lock((cmd))) \
+ return; \
+ } while(0)
#define WRITE_UNLOCK(cmd) \
- up_write(&cmd->root_lock)
+ up_write(&(cmd)->root_lock)
-#define READ_LOCK(cmd) \
- down_read(&cmd->root_lock); \
- if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
- up_read(&cmd->root_lock); \
- return -EINVAL; \
+static bool cmd_read_lock(struct dm_cache_metadata *cmd)
+{
+ down_write(&cmd->root_lock);
+ if (cmd->fail_io) {
+ up_write(&cmd->root_lock);
+ return false;
}
+ return true;
+}
-#define READ_LOCK_VOID(cmd) \
- down_read(&cmd->root_lock); \
- if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \
- up_read(&cmd->root_lock); \
- return; \
- }
+#define READ_LOCK(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return -EINVAL; \
+ } while(0)
+
+#define READ_LOCK_VOID(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return; \
+ } while(0)
#define READ_UNLOCK(cmd) \
- up_read(&cmd->root_lock)
+ up_read(&(cmd)->root_lock)
int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size)
{