tree 12cf787a5922610396529d90ae82ccaf223a57d9
parent bcee19f424a0d8c26ecf2607b73c690802658b29
author NeilBrown <neilb@suse.com> 1443067251 +1000
committer NeilBrown <neilb@suse.com> 1443770623 +1000

md: wait for pending superblock updates before switching to read-only

If a superblock update is pending, wait for it to complete before
letting md_set_readonly() switch to readonly.
Otherwise we might lose important information about a device having
failed.

For external arrays, waiting for superblock updates can wait on
user-space, so in that case, just return an error.

Reported-and-tested-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>