Pull device mapper fixes from Mike Snitzer:
- Fix dm core to use more efficient bio_split() instead of
bio_clone_bioset(). Also fixes splitting bio that has integrity
payload.
- Three fixes related to properly validating DAX capabilities of a
stacked DM device that will advertise DAX support.
- Update DM writecache target to use 2-factor allocator arguments. Kees
says this is the last related change for 4.18.
- Fix DM zoned target to use GFP_NOIO to avoid triggering reclaim
during IO submission (caught by lockdep).
- Fix DM thinp to gracefully recover from running out of data space
while a previous async discard completes (whereby freeing space).
- Fix DM thinp's metadata transaction commit to avoid needless work.
* tag 'for-4.18/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm: prevent DAX mounts if not supported
dax: check for QUEUE_FLAG_DAX in bdev_dax_supported()
pmem: only set QUEUE_FLAG_DAX for fsdax mode
dm thin: handle running out of data space vs concurrent discard
dm raid: don't use 'const' in function return
dm zoned: avoid triggering reclaim from inside dmz_map()
dm writecache: use 2-factor allocator arguments
dm thin metadata: remove needless work from __commit_transaction
dm: use bio_split() when splitting out the already processed bio