. Add dm_accept_partial_bio interface to DM core to allow DM targets
  to only process a portion of a bio, the remainder being sent in the
  next bio.  This enables the old dm snapshot-origin target to only
  split write bios on chunk boundaries, read bios are now sent to the
  origin device unchanged.

. Add DM core support for disabling WRITE SAME if the underlying SCSI
  layer disables it due to command failure.

. Reduce lock contention in DM's bio-prison.

. A few small cleanups and fixes to dm-thin and dm-era.
dm thin: update discard_granularity to reflect the thin-pool blocksize

DM thinp already checks whether the discard_granularity of the data
device is a factor of the thin-pool block size.  But when using the
dm-thin-pool's discard passdown support, DM thinp was not selecting the
max of the underlying data device's discard_granularity and the
thin-pool's block size.

Update set_discard_limits() to set discard_granularity to the max of
these values.  This enables blkdev_issue_discard() to properly align the
discards that are sent to the DM thin device on a full block boundary.
As such each discard will now cover an entire DM thin-pool block and the
block will be reclaimed.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
1 file changed