Pull device mapper fixes from Mike Snitzer:
- a revert of a DM mirror commit that has proven to make the code prone
to crash
- a DM io reference count fix that resolves a NULL pointer seen when
issuing discards to a DM mirror target's device whose mirror legs do
not all support discards
- a couple DM integrity fixes
* tag 'for-4.12/dm-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm io: fix duplicate bio completion due to missing ref count
dm integrity: fix to not disable/enable interrupts from interrupt context
Revert "dm mirror: use all available legs on multiple failures"
dm integrity: reject mappings too large for device