Pull md updates from Neil Brown:
"All bug fixes, two tagged for -stable"
* tag 'md/3.14' of git://neil.brown.name/md:
md/raid5: close recently introduced race in stripe_head management.
md/raid5: fix long-standing problem with bitmap handling on write failure.
md: check command validity early in md_ioctl().
md: ensure metadata is writen after raid level change.
md/raid10: avoid fullsync when not necessary.
md: allow a partially recovered device to be hot-added to an array.
md: Change handling of save_raid_disk and metadata update during recovery.