Patch "md/raid10: factor out code from wait_barrier() to stop_waiting_barrier()" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    md/raid10: factor out code from wait_barrier() to stop_waiting_barrier()

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     md-raid10-factor-out-code-from-wait_barrier-to-stop_.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit dad5a7dc4963d82c70930d9b292cf2d105eef29f
Author: Yu Kuai <yukuai3@xxxxxxxxxx>
Date:   Fri Sep 16 19:34:24 2022 +0800

    md/raid10: factor out code from wait_barrier() to stop_waiting_barrier()
    
    [ Upstream commit ed2e063f92c44c891ccd883e289dde6ca870edcc ]
    
    Currently the nasty condition in wait_barrier() is hard to read. This
    patch factors out the condition into a function.
    
    There are no functional changes.
    
    Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
    Acked-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
    Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
    Acked-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>
    Signed-off-by: Song Liu <song@xxxxxxxxxx>
    Stable-dep-of: 72c215ed8731 ("md/raid10: fix task hung in raid10d")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 287bebde2e546..31ecb080851ac 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -952,41 +952,47 @@ static void lower_barrier(struct r10conf *conf)
 	wake_up(&conf->wait_barrier);
 }
 
+static bool stop_waiting_barrier(struct r10conf *conf)
+{
+	struct bio_list *bio_list = current->bio_list;
+
+	/* barrier is dropped */
+	if (!conf->barrier)
+		return true;
+
+	/*
+	 * If there are already pending requests (preventing the barrier from
+	 * rising completely), and the pre-process bio queue isn't empty, then
+	 * don't wait, as we need to empty that queue to get the nr_pending
+	 * count down.
+	 */
+	if (atomic_read(&conf->nr_pending) && bio_list &&
+	    (!bio_list_empty(&bio_list[0]) || !bio_list_empty(&bio_list[1])))
+		return true;
+
+	/* move on if recovery thread is blocked by us */
+	if (conf->mddev->thread->tsk == current &&
+	    test_bit(MD_RECOVERY_RUNNING, &conf->mddev->recovery) &&
+	    conf->nr_queued > 0)
+		return true;
+
+	return false;
+}
+
 static bool wait_barrier(struct r10conf *conf, bool nowait)
 {
 	bool ret = true;
 
 	spin_lock_irq(&conf->resync_lock);
 	if (conf->barrier) {
-		struct bio_list *bio_list = current->bio_list;
 		conf->nr_waiting++;
-		/* Wait for the barrier to drop.
-		 * However if there are already pending
-		 * requests (preventing the barrier from
-		 * rising completely), and the
-		 * pre-process bio queue isn't empty,
-		 * then don't wait, as we need to empty
-		 * that queue to get the nr_pending
-		 * count down.
-		 */
 		/* Return false when nowait flag is set */
 		if (nowait) {
 			ret = false;
 		} else {
 			raid10_log(conf->mddev, "wait barrier");
 			wait_event_lock_irq(conf->wait_barrier,
-					    !conf->barrier ||
-					    (atomic_read(&conf->nr_pending) &&
-					     bio_list &&
-					     (!bio_list_empty(&bio_list[0]) ||
-					      !bio_list_empty(&bio_list[1]))) ||
-					     /* move on if recovery thread is
-					      * blocked by us
-					      */
-					     (conf->mddev->thread->tsk == current &&
-					      test_bit(MD_RECOVERY_RUNNING,
-						       &conf->mddev->recovery) &&
-					      conf->nr_queued > 0),
+					    stop_waiting_barrier(conf),
 					    conf->resync_lock);
 		}
 		conf->nr_waiting--;