Pull device-mapper fixes from Alasdair G Kergon:
"Fix reported data loss with discards and thin snapshots; avoid a
deadlock observed in dm verity; fix a race in the new dm cache code
along with some other minor bugs; store the cache policy version on
disk to make the stored hints format future-proof."
* tag 'dm-3.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
dm cache: policy ignore hints if generated by different version
dm cache: policy change version from string to integer set
dm cache: fix race in writethrough implementation
dm cache: metadata clear dirty bits on clean shutdown
dm cache: avoid calling policy destructor twice on error
dm cache: detect cache_create failure
dm cache: avoid 64 bit division on 32 bit
dm verity: avoid deadlock
dm thin: fix non power of two discard granularity calc
dm thin: fix discard corruption
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