kernel/git/stable/linux.git/drivers/md/dm-cache-metadata.c, branch linux-4.6.y

dm cache metadata: fix cmd_read_lock() acquiring write lock

2016-04-17T15:24:46+00:00

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

2016-04-14T21:34:49+00:00

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

2016-03-10T22:12:12+00:00

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

Merge tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2015-11-05T05:19:53+00:00

Pull device mapper updates from Mike Snitzer: "Smaller set of DM changes for this merge. I've based these changes on Jens' for-4.4/reservations branch because the associated DM changes required it. - Revert a dm-multipath change that caused a regression for unprivledged users (e.g. kvm guests) that issued ioctls when a multipath device had no available paths. - Include Christoph's refactoring of DM's ioctl handling and add support for passing through persistent reservations with DM multipath. - All other changes are very simple cleanups" * tag 'dm-4.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm switch: simplify conditional in alloc_region_table() dm delay: document that offsets are specified in sectors dm delay: capitalize the start of an delay_ctr() error message dm delay: Use DM_MAPIO macros instead of open-coded equivalents dm linear: remove redundant target name from error messages dm persistent data: eliminate unnecessary return values dm: eliminate unused "bioset" process for each bio-based DM device dm: convert ffs to __ffs dm: drop NULL test before kmem_cache_destroy() and mempool_destroy() dm: add support for passing through persistent reservations dm: refactor ioctl handling Revert "dm mpath: fix stalls when handling invalid ioctls" dm: initialize non-blk-mq queue data before queue is used

dm persistent data: eliminate unnecessary return values

2015-10-31T23:06:02+00:00

dm_bm_unlock and dm_tm_unlock return an integer value but the returned value is always 0. The calling code sometimes checks the return value and sometimes doesn't. Eliminate these unnecessary return values and also the checks for them. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm cache: the CLEAN_SHUTDOWN flag was not being set

2015-10-23T18:02:56+00:00

If the CLEAN_SHUTDOWN flag is not set when a cache is loaded then all cache blocks are marked as dirty and a full writeback occurs. __commit_transaction() is responsible for setting/clearing CLEAN_SHUTDOWN (based the flags_mutator that is passed in). Fix this issue, of the cache's on-disk flags being wrong, by making sure __commit_transaction() does not reset the flags after the mutator has altered the flags in preparation for them being serialized to disk. before: sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags); disk_super->flags = cpu_to_le32(cmd->flags); after: disk_super->flags = cpu_to_le32(cmd->flags); sb_flags = mutator(le32_to_cpu(disk_super->flags)); disk_super->flags = cpu_to_le32(sb_flags); Reported-by: Bogdan Vasiliev Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm cache: add fail io mode and needs_check flag

2015-06-11T21:13:00+00:00

If a cache metadata operation fails (e.g. transaction commit) the cache's metadata device will abort the current transaction, set a new needs_check flag, and the cache will transition to "read-only" mode. If aborting the transaction or setting the needs_check flag fails the cache will transition to "fail-io" mode. Once needs_check is set the cache device will not be allowed to activate. Activation requires write access to metadata. Future work is needed to add proper support for running the cache in read-only mode. Once in fail-io mode the cache will report a status of "Fail". Also, add commit() wrapper that will disallow commits if in read_only or fail mode. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer

dm cache: fix missing ERR_PTR returns and handling

2015-01-28T14:59:20+00:00

Commit 9b1cc9f251 ("dm cache: share cache-metadata object across inactive and active DM tables") mistakenly ignored the use of ERR_PTR returns. Restore missing IS_ERR checks and ERR_PTR returns where appropriate. Reported-by: Dan Carpenter Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm cache: share cache-metadata object across inactive and active DM tables

2015-01-23T15:57:15+00:00

If a DM table is reloaded with an inactive table when the device is not suspended (normal procedure for LVM2), then there will be two dm-bufio objects that can diverge. This can lead to a situation where the inactive table uses bufio to read metadata at the same time the active table writes metadata -- resulting in the inactive table having stale metadata buffers once it is promoted to the active table slot. Fix this by using reference counting and a global list of cache metadata objects to ensure there is only one metadata object per metadata device. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org

dm cache: revert "remove remainder of distinct discard block size"

2014-11-10T20:25:30+00:00

This reverts commit 64ab346a360a4b15c28fb8531918d4a01f4eabd9 because we actually do want to allow the discard blocksize to be larger than the cache blocksize. Further dm-cache discard changes will make this possible. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer