From 7f47aea487df2dc281c7f64ff7430aff3b260af0 Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Thu, 10 Mar 2016 16:20:58 +0000 Subject: dm cache: make sure every metadata function checks fail_io commit d14fcf3dd79c0b8a8d0ba469c44a6b04f3a1403b upstream. Otherwise operations may be attempted that will only ever go on to crash (since the metadata device is either missing or unreliable if 'fail_io' is set). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-metadata.c | 98 +++++++++++++++++++++++++----------------- 1 file changed, 59 insertions(+), 39 deletions(-) (limited to 'drivers/md/dm-cache-metadata.c') diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index f6543f3a970f..27f2ef300f8b 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -867,19 +867,40 @@ static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, return 0; } -#define WRITE_LOCK(cmd) \ - if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \ +#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; \ - down_write(&cmd->root_lock) + } #define WRITE_LOCK_VOID(cmd) \ - if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) \ + down_write(&cmd->root_lock); \ + if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { \ + up_write(&cmd->root_lock); \ return; \ - down_write(&cmd->root_lock) + } #define WRITE_UNLOCK(cmd) \ 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; \ + } + +#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_UNLOCK(cmd) \ + up_read(&cmd->root_lock) + int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) { int r; @@ -1015,22 +1036,20 @@ int dm_cache_load_discards(struct dm_cache_metadata *cmd, { int r; - down_read(&cmd->root_lock); + READ_LOCK(cmd); r = __load_discards(cmd, fn, context); - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); return r; } -dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd) +int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result) { - dm_cblock_t r; + READ_LOCK(cmd); + *result = cmd->cache_blocks; + READ_UNLOCK(cmd); - down_read(&cmd->root_lock); - r = cmd->cache_blocks; - up_read(&cmd->root_lock); - - return r; + return 0; } static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) @@ -1188,9 +1207,9 @@ int dm_cache_load_mappings(struct dm_cache_metadata *cmd, { int r; - down_read(&cmd->root_lock); + READ_LOCK(cmd); r = __load_mappings(cmd, policy, fn, context); - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); return r; } @@ -1215,18 +1234,18 @@ static int __dump_mappings(struct dm_cache_metadata *cmd) void dm_cache_dump(struct dm_cache_metadata *cmd) { - down_read(&cmd->root_lock); + READ_LOCK_VOID(cmd); __dump_mappings(cmd); - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); } int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) { int r; - down_read(&cmd->root_lock); + READ_LOCK(cmd); r = cmd->changed; - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); return r; } @@ -1276,9 +1295,9 @@ int dm_cache_set_dirty(struct dm_cache_metadata *cmd, void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, struct dm_cache_statistics *stats) { - down_read(&cmd->root_lock); + READ_LOCK_VOID(cmd); *stats = cmd->stats; - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); } void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, @@ -1312,9 +1331,9 @@ int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, { int r = -EINVAL; - down_read(&cmd->root_lock); + READ_LOCK(cmd); r = dm_sm_get_nr_free(cmd->metadata_sm, result); - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); return r; } @@ -1324,9 +1343,9 @@ int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, { int r = -EINVAL; - down_read(&cmd->root_lock); + READ_LOCK(cmd); r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); - up_read(&cmd->root_lock); + READ_UNLOCK(cmd); return r; } @@ -1417,7 +1436,13 @@ int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy * int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) { - return blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); + int r; + + READ_LOCK(cmd); + r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); + READ_UNLOCK(cmd); + + return r; } void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd) @@ -1440,10 +1465,7 @@ int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) struct dm_block *sblock; struct cache_disk_superblock *disk_super; - /* - * We ignore fail_io for this function. - */ - down_write(&cmd->root_lock); + WRITE_LOCK(cmd); set_bit(NEEDS_CHECK, &cmd->flags); r = superblock_lock(cmd, &sblock); @@ -1458,19 +1480,17 @@ int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) dm_bm_unlock(sblock); out: - up_write(&cmd->root_lock); + WRITE_UNLOCK(cmd); return r; } -bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd) +int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result) { - bool needs_check; + READ_LOCK(cmd); + *result = !!test_bit(NEEDS_CHECK, &cmd->flags); + READ_UNLOCK(cmd); - down_read(&cmd->root_lock); - needs_check = !!test_bit(NEEDS_CHECK, &cmd->flags); - up_read(&cmd->root_lock); - - return needs_check; + return 0; } int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) -- cgit v1.2.3 From 9d58f322ee18ffaca1e0b67d90ab811ad75e62a6 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 12 Apr 2016 12:14:46 -0400 Subject: dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros commit 9567366fefddeaea4ed1d713270535d93a3b3c76 upstream. 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") Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-metadata.c | 64 ++++++++++++++++++++++++++---------------- 1 file changed, 40 insertions(+), 24 deletions(-) (limited to 'drivers/md/dm-cache-metadata.c') 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) { -- cgit v1.2.3 From be5cbaf31cd318f8aaeeff901f6d27232dfa965f Mon Sep 17 00:00:00 2001 From: Ahmed Samy Date: Sun, 17 Apr 2016 05:37:09 +0000 Subject: dm cache metadata: fix cmd_read_lock() acquiring write lock commit 6545b60baaf880b0cd29a5e89dbe745a06027e89 upstream. Commit 9567366fefdd ("dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros") uses down_write() instead of down_read() in cmd_read_lock(), yet up_read() is used to release the lock in READ_UNLOCK(). Fix it. Fixes: 9567366fefdd ("dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros") Signed-off-by: Ahmed Samy Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-metadata.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/md/dm-cache-metadata.c') diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 65ce6985f87a..3970cda10080 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -894,9 +894,9 @@ static bool cmd_write_lock(struct dm_cache_metadata *cmd) static bool cmd_read_lock(struct dm_cache_metadata *cmd) { - down_write(&cmd->root_lock); + down_read(&cmd->root_lock); if (cmd->fail_io) { - up_write(&cmd->root_lock); + up_read(&cmd->root_lock); return false; } return true; -- cgit v1.2.3