Merge branch 'dmraid-fix-6.9' into md-6.9

Merge branch 'dmraid-fix-6.9' into md-6.9

This is the second half of fixes for dmraid. The first half is available
at [1].

This set contains fixes:
 - reshape can start unexpected, cause data corruption, patch 1,5,6;
 - deadlocks that reshape concurrent with IO, patch 8;
 - a lockdep warning, patch 9;

For all the dmraid related tests in lvm2 suite, there is no new
regressions compared against 6.6 kernels (which is good baseline before
recent regressions).

[1] https://lore.kernel.org/all/CAPhsuW7u1UKHCDOBDhD7DzOVtkGemDz_QnJ4DUq_kSN-Q3G66Q@mail.gmail.com/

* dmraid-fix-6.9:
  dm-raid: fix lockdep waring in "pers->hot_add_disk"
  dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape
  dm-raid: add a new helper prepare_suspend() in md_personality
  md/dm-raid: don't call md_reap_sync_thread() directly
  dm-raid: really frozen sync_thread during suspend
  md: add a new helper reshape_interrupted()
  md: export helper md_is_rdwr()
  md: export helpers to stop sync_thread
  md: don't clear MD_RECOVERY_FROZEN for new dm-raid until resume