Pull MD fixes from Shaohua Li:
"There are several bug fixes queued:
- fix raid5-cache recovery bugs
- fix discard IO error handling for raid1/10
- fix array sync writes bogus position to superblock
- fix IO error handling for raid array with external metadata"
* tag 'md/4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md: be careful not lot leak internal curr_resync value into metadata. -- (all)
raid1: handle read error also in readonly mode
raid5-cache: correct condition for empty metadata write
md: report 'write_pending' state when array in sync
md/raid5: write an empty meta-block when creating log super-block
md/raid5: initialize next_checkpoint field before use
RAID10: ignore discard error
RAID1: ignore discard error