FAILED: patch "[PATCH] raid5-cache: Need to do start() part job after adding journal" failed to apply to 4.14-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d9771f5ec46c282d518b453c793635dbdc3a2a94 Mon Sep 17 00:00:00 2001
From: Xiao Ni <xni@redhat.com>
Date: Fri, 14 Jun 2019 15:41:05 -0700
Subject: [PATCH] raid5-cache: Need to do start() part job after adding journal
 device

commit d5d885fd514f ("md: introduce new personality funciton start()")
splits the init job to two parts. The first part run() does the jobs that
do not require the md threads. The second part start() does the jobs that
require the md threads.

Now it just does run() in adding new journal device. It needs to do the
second part start() too.

Fixes: d5d885fd514f ("md: introduce new personality funciton start()")
Cc: stable@vger.kernel.org #v4.9+
Reported-by: Michal Soltys <soltys@ziu.info>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index b83bce2beb66..da94cbaa1a9e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -7672,7 +7672,7 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 {
 	struct r5conf *conf = mddev->private;
-	int err = -EEXIST;
+	int ret, err = -EEXIST;
 	int disk;
 	struct disk_info *p;
 	int first = 0;
@@ -7687,7 +7687,14 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		 * The array is in readonly mode if journal is missing, so no
 		 * write requests running. We should be safe
 		 */
-		log_init(conf, rdev, false);
+		ret = log_init(conf, rdev, false);
+		if (ret)
+			return ret;
+
+		ret = r5l_start(conf->log);
+		if (ret)
+			return ret;
+
 		return 0;
 	}
 	if (mddev->recovery_disabled == conf->recovery_disabled)