kernel.git/drivers/md/dm-cache-metadata.c, branch linux-4.9.y

dm cache: Fix ABBA deadlock between shrink_slab and dm_cache_metadata_abort

2023-01-07T11:07:36Z

commit 352b837a5541690d4f843819028cf2b8be83d424 upstream. Same ABBA deadlock pattern fixed in commit 4b60f452ec51 ("dm thin: Fix ABBA deadlock between shrink_slab and dm_pool_abort_metadata") to DM-cache's metadata. Reported-by: Zhihao Cheng Cc: stable@vger.kernel.org Fixes: 028ae9f76f29 ("dm cache: add fail io mode and needs_check flag") Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: Avoid returning cmd->bm wild pointer on error

2020-09-12T09:47:37Z

commit d16ff19e69ab57e08bf908faaacbceaf660249de upstream. Maybe __create_persistent_data_objects() caller will use PTR_ERR as a pointer, it will lead to some strange things. Signed-off-by: Ye Bin Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: ignore hints array being too small during resize

2018-10-13T07:18:55Z

commit 4561ffca88c546f96367f94b8f1e4715a9c62314 upstream. Commit fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock") enabled previously written policy hints to be used after a cache is reactivated. But in doing so the cache metadata's hint array was left exposed to out of bounds access because on resize the metadata's on-disk hint array wasn't ever extended. Fix this by ignoring that there are no on-disk hints associated with the newly added cache blocks. An expanded on-disk hint array is later rewritten upon the next clean shutdown of the cache. Fixes: fd2fa9541 ("dm cache metadata: save in-core policy_hint_size to on-disk superblock") Cc: stable@vger.kernel.org Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: save in-core policy_hint_size to on-disk superblock

2018-09-09T18:01:21Z

commit fd2fa95416188a767a63979296fa3e169a9ef5ec upstream. policy_hint_size starts as 0 during __write_initial_superblock(). It isn't until the policy is loaded that policy_hint_size is set in-core (cmd->policy_hint_size). But it never got recorded in the on-disk superblock because __commit_transaction() didn't deal with transfering the in-core cmd->policy_hint_size to the on-disk superblock. The in-core cmd->policy_hint_size gets initialized by metadata_open()'s __begin_transaction_flags() which re-reads all superblock fields. Because the superblock's policy_hint_size was never properly stored, when the cache was created, hints_array_available() would always return false when re-activating a previously created cache. This means __load_mappings() always considered the hints invalid and never made use of the hints (these hints served to optimize). Another detremental side-effect of this oversight is the cache_check utility would fail with: "invalid hint width: 0" Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: fail operations if fail_io mode has been established

2017-05-25T13:44:33Z

commit 10add84e276432d9dd8044679a1028dd4084117e upstream. Otherwise it is possible to trigger crashes due to the metadata being inaccessible yet these methods don't safely account for that possibility without these checks. Reported-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm cache metadata: switch to using the new cursor api for loading metadata

2016-09-22T15:15:05Z

This change offers a pretty significant performance improvement. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm cache: speed up writing of the hint array

2016-09-22T15:15:02Z

It's far quicker to always delete the hint array and recreate with dm_array_new() because we avoid the copying caused by mutation. Also simplifies the policy interface, replacing the walk_hints() with the simpler get_hint(). Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm cache metadata: fix cmd_read_lock() acquiring write lock

2016-04-17T15:24:46Z

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") Cc: stable@vger.kernel.org Signed-off-by: Ahmed Samy Signed-off-by: Mike Snitzer

dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros

2016-04-14T21:34:49Z

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

dm cache: make sure every metadata function checks fail_io

2016-03-10T22:12:12Z

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 Cc: stable@vger.kernel.org