From 072623de1f964c7ff01c46a9101af1c822fd2873 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Sat, 9 Apr 2016 12:48:18 -0400 Subject: [PATCH 1/2] dm: fix dm_target_io leak if clone_bio() returns an error Commit c80914e81ec5b08 ("dm: return error if bio_integrity_clone() fails in clone_bio()") changed clone_bio() such that if it does return error then the alloc_tio() created resources (both the bio that was allocated to be a clone and the containing dm_target_io struct) will leak. Fix this by calling free_tio() in __clone_and_map_data_bio()'s clone_bio() error path. Fixes: c80914e81ec5b08 ("dm: return error if bio_integrity_clone() fails in clone_bio()") Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index be4905769a45..3d3ac13287a4 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1662,8 +1662,10 @@ static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti, tio = alloc_tio(ci, ti, target_bio_nr); tio->len_ptr = len; r = clone_bio(tio, bio, sector, *len); - if (r < 0) + if (r < 0) { + free_tio(ci->md, tio); break; + } __map_bio(tio); } From 9567366fefddeaea4ed1d713270535d93a3b3c76 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 12 Apr 2016 12:14:46 -0400 Subject: [PATCH 2/2] 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 Signed-off-by: Mike Snitzer Fixes: d14fcf3dd79 ("dm cache: make sure every metadata function checks fail_io") Cc: stable@vger.kernel.org --- drivers/md/dm-cache-metadata.c | 64 +++++++++++++++++++++------------- 1 file 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) {