tree 4a634f1d55ebe090060c35b1b09a36cfdb10516f
parent c56f7949fc574c6648f9a53c801538b7ea2db263
author Yu Kuai <yukuai3@huawei.com> 1679467282 +0800
committer Song Liu <song@kernel.org> 1680047479 -0700

md: enhance checking in md_check_recovery()

For md_check_recovery():

1) if 'MD_RECOVERY_RUNING' is not set, register new sync_thread.
2) if 'MD_RECOVERY_RUNING' is set:
 a) if 'MD_RECOVERY_DONE' is not set, don't do anything, wait for
   md_do_sync() to be done.
 b) if 'MD_RECOVERY_DONE' is set, unregister sync_thread. Current code
   expects that sync_thread is not NULL, otherwise new sync_thread will
   be registered, which will corrupt raid.

This patch add a WARN_ON_ONCE() in the above corruption, and make sure
md_check_recovery() won't register new sync_thread if 'MD_RECOVERY_RUNING'
is still set.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230322064122.2384589-7-yukuai1@huaweicloud.com