user/sven/linux.git/Documentation/device-mapper, branch stable/4.3.y

dm snapshot: add new persistent store option to support overflow

2015-10-09T20:57:03Z

Commit 76c44f6d80 introduced the possibly for "Overflow" to be reported by the snapshot device's status. Older userspace (e.g. lvm2) does not handle the "Overflow" status response. Fix this incompatibility by requiring newer userspace code, that can cope with "Overflow", request the persistent store with overflow support by using "PO" (Persistent with Overflow) for the snapshot store type. Reported-by: Zdenek Kabelac Fixes: 76c44f6d80 ("dm snapshot: don't invalidate on-disk image on snapshot write overflow") Reviewed-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm raid: document RAID 4/5/6 discard support

2015-08-31T19:05:31Z

For RAID 4/5/6 data integrity reasons 'discard_zeroes_data' must work properly. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer

dm stats: report precise_timestamps and histogram in @stats_list output

2015-08-18T21:20:03Z

If the user selected the precise_timestamps or histogram options, report it in the @stats_list message output. If the user didn't select these options, no extra tokens are reported, thus it is backward compatible with old software that doesn't know about precise timestamps and histogram. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 4.2

dm cache: display 'needs_check' in status if it is set

2015-07-16T14:23:50Z

There is currently no way to see that the needs_check flag has been set in the metadata. Display 'needs_check' in the cache status if it is set in the cache metadata. Also, update cache documentation. Signed-off-by: Mike Snitzer

dm thin: display 'needs_check' in status if it is set

2015-07-16T14:23:50Z

There is currently no way to see that the needs_check flag has been set in the metadata. Display 'needs_check' in the thin-pool status if it is set in the thinp metadata. Also, update thinp documentation. Signed-off-by: Mike Snitzer

dm stats: collect and report histogram of IO latencies

2015-06-17T16:40:40Z

Add an option to dm statistics to collect and report a histogram of IO latencies. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm stats: support precise timestamps

2015-06-17T16:40:40Z

Make it possible to use precise timestamps with nanosecond granularity in dm statistics. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer

dm cache: switch the "default" cache replacement policy from mq to smq

2015-06-17T16:40:38Z

The Stochastic multiqueue (SMQ) policy (vs MQ) offers the promise of less memory utilization, improved performance and increased adaptability in the face of changing workloads. SMQ also does not have any cumbersome tuning knobs. Users may switch from "mq" to "smq" simply by appropriately reloading a DM table that is using the cache target. Doing so will cause all of the mq policy's hints to be dropped. Also, performance of the cache may degrade slightly until smq recalculates the origin device's hotspots that should be cached. In the future the "mq" policy will just silently make use of "smq" and the mq code will be removed. Signed-off-by: Mike Snitzer Acked-by: Joe Thornber

dm cache: add fail io mode and needs_check flag

2015-06-11T21:13:00Z

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 raid: add support for the MD RAID0 personality

2015-05-29T18:19:00Z

Add dm-raid access to the MD RAID0 personality to enable single zone striping. The following changes enable that access: - add type definition to raid_types array - make bitmap creation conditonal in super_validate(), because bitmaps are not allowed in raid0 - set rdev->sectors to the data image size in super_validate() to allow the raid0 personality to calculate the MD array size properly - use mdddev(un)lock() functions instead of direct mutex_(un)lock() (wrapped in here because it's a trivial change) - enhance raid_status() to always report full sync for raid0 so that userspace checks for 100% sync will succeed and allow for resize (and takeover/reshape once added in future paches) - enhance raid_resume() to not load bitmap in case of raid0 - add merge function to avoid data corruption (seen with readahead) that resulted from bio payloads that grew too large. This problem did not occur with the other raid levels because it either did not apply without striping (raid1) or was avoided via stripe caching. - raise version to 1.7.0 because of the raid0 API change Signed-off-by: Heinz Mauelshagen Reviewed-by: Jonathan Brassow Signed-off-by: Mike Snitzer