FAILED: patch "[PATCH] btrfs: add missing mutex_unlock in" failed to apply to 4.19-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

The patch below does not apply to the 4.19-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@xxxxxxxxxxxxxxx>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 9af503d91298c3f2945e73703f0e00995be08c30
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@xxxxxxxxxxxxxxx>' --in-reply-to '2024051347-kerchief-drainpipe-d49b@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

9af503d91298 ("btrfs: add missing mutex_unlock in btrfs_relocate_sys_chunks()")
7411055db5ce ("btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()")

thanks,

greg k-h

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

>From 9af503d91298c3f2945e73703f0e00995be08c30 Mon Sep 17 00:00:00 2001
From: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx>
Date: Fri, 19 Apr 2024 11:22:48 +0900
Subject: [PATCH] btrfs: add missing mutex_unlock in
 btrfs_relocate_sys_chunks()

The previous patch that replaced BUG_ON by error handling forgot to
unlock the mutex in the error path.

Link: https://lore.kernel.org/all/Zh%2fHpAGFqa7YAFuM@xxxxxxxxxx
Reported-by: Pavel Machek <pavel@xxxxxxx>
Fixes: 7411055db5ce ("btrfs: handle chunk tree lookup error in btrfs_relocate_sys_chunks()")
CC: stable@xxxxxxxxxxxxxxx
Reviewed-by: Pavel Machek <pavel@xxxxxxx>
Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dedec3d9b111..c72c351fe7eb 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3419,6 +3419,7 @@ static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info)
 			 * alignment and size).
 			 */
 			ret = -EUCLEAN;
+			mutex_unlock(&fs_info->reclaim_bgs_lock);
 			goto error;
 		}