md: be more careful setting MD_CHANGE_CLEAN
When MD_CHANGE_CLEAN is set we might block in md_write_start.
So we should only set it when fairly sure that something will clear
it.
There are two places where it is set so as to encourage a metadata
update to record the progress of resync/recovery. This should only
be done if the internal metadata update mechanisms are in use, which
can be tested by by inspecting '->persistent'.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9007651..d636b0a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6753,7 +6753,8 @@
atomic_read(&mddev->recovery_active) == 0);
mddev->curr_resync_completed =
mddev->curr_resync;
- set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+ if (mddev->persistent)
+ set_bit(MD_CHANGE_CLEAN, &mddev->flags);
sysfs_notify(&mddev->kobj, NULL, "sync_completed");
}