Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md...

Merge branch 'md-next' of https://git./linux/kernel/git/song/md into for-5.14/drivers

Pull MD changes from Song:

"1) iostats rewrite by Guoqing Jiang;
 2) raid5 lock contention optimization by Gal Ofri."

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md/raid5: avoid device_lock in read_one_chunk()
  md: add comments in md_integrity_register
  md: check level before create and exit io_acct_set
  md: Constify attribute_group structs
  md: mark some personalities as deprecated
  md/raid10: enable io accounting
  md/raid1: enable io accounting
  md/raid1: rename print_msg with r1bio_existed
  md/raid5: avoid redundant bio clone in raid5_read_one_chunk
  md/raid5: move checking badblock before clone bio in raid5_read_one_chunk
  md: add io accounting for raid0 and raid5
  md: revert io stats accounting