md/md-bitmap: make method bitmap_ops->daemon_work optional

daemon_work() will be called by daemon thread, on the one hand, daemon
thread doesn't have strict wake-up time; on the other hand, too much
work are put to daemon thread, like handle sync IO, handle failed
or specail normal IO, handle recovery, and so on. Hence daemon thread
may be too busy to clear dirty bits in time.

Make bitmap_ops->daemon_work() optional and following patches will use
separate async work to clear dirty bits for the new bitmap.

Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-11-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Li Nan <linan122@huawei.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index f5d00253798909029b948e7533c25f8830f0a6b4..2f1907f3bc25480bc09f305eed4206bda6511eb7 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9997,7 +9997,7 @@ static void unregister_sync_thread(struct mddev *mddev)
  */
 void md_check_recovery(struct mddev *mddev)
 {
-       if (md_bitmap_enabled(mddev, false))
+       if (md_bitmap_enabled(mddev, false) && mddev->bitmap_ops->daemon_work)
                mddev->bitmap_ops->daemon_work(mddev);
 
        if (signal_pending(current)) {