4.2.8-ckt7 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------ From: Joe Thornber <[email protected]> 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 <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> Signed-off-by: Kamal Mostafa <[email protected]> --- drivers/md/dm-cache-metadata.c | 98 +++++++++++++++++++++++++----------------- drivers/md/dm-cache-metadata.h | 4 +- drivers/md/dm-cache-target.c | 12 +++++- 3 files changed, 71 insertions(+), 43 deletions(-) diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c index 0a17d1b..1ed4ab1 100644 --- a/drivers/md/dm-cache-metadata.c +++ b/drivers/md/dm-cache-metadata.c @@ -863,19 +863,40 @@ 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; @@ -1011,22 +1032,20 @@ 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) @@ -1184,9 +1203,9 @@ 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; } @@ -1211,18 +1230,18 @@ 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; } @@ -1272,9 +1291,9 @@ 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, @@ -1308,9 +1327,9 @@ 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; } @@ -1320,9 +1339,9 @@ 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; } @@ -1413,7 +1432,13 @@ 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) @@ -1436,10 +1461,7 @@ 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); @@ -1454,19 +1476,17 @@ 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) diff --git a/drivers/md/dm-cache-metadata.h b/drivers/md/dm-cache-metadata.h index 2ffee21..8528744 100644 --- a/drivers/md/dm-cache-metadata.h +++ b/drivers/md/dm-cache-metadata.h @@ -66,7 +66,7 @@ void dm_cache_metadata_close(struct dm_cache_metadata *cmd); * origin blocks to map to. */ int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size); -dm_cblock_t dm_cache_size(struct dm_cache_metadata *cmd); +int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result); int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, sector_t discard_block_size, @@ -137,7 +137,7 @@ 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); -bool dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd); +int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result); int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd); void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd); void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd); diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 9d0672b..6ad5ddf 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -988,9 +988,14 @@ static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mod static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode) { - bool needs_check = dm_cache_metadata_needs_check(cache->cmd); + bool needs_check; enum cache_metadata_mode old_mode = get_cache_mode(cache); + if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) { + DMERR("unable to read needs_check flag, setting failure mode"); + new_mode = CM_FAIL; + } + if (new_mode == CM_WRITE && needs_check) { DMERR("%s: unable to switch cache to write mode until repaired.", cache_device_name(cache)); @@ -3517,6 +3522,7 @@ static void cache_status(struct dm_target *ti, status_type_t type, char buf[BDEVNAME_SIZE]; struct cache *cache = ti->private; dm_cblock_t residency; + bool needs_check; switch (type) { case STATUSTYPE_INFO: @@ -3590,7 +3596,9 @@ static void cache_status(struct dm_target *ti, status_type_t type, else DMEMIT("rw "); - if (dm_cache_metadata_needs_check(cache->cmd)) + r = dm_cache_metadata_needs_check(cache->cmd, &needs_check); + + if (r || needs_check) DMEMIT("needs_check "); else DMEMIT("- "); -- 2.7.4
