From d7f9553680b36ca8a0a0bee6695e91634be4f0f2 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 27 Feb 2019 14:58:58 +0100
Subject: [PATCH] Revert "loop: Fix double mutex_unlock(&loop_ctl_mutex) in
 loop_control_ioctl()"

This reverts commit d2762edcb6af99fc9322bab0b1d4e71a427760e8 which is
commit 628bd85947091830a8c4872adfd5ed1d515a9cf2 upstream.

It does not work properly in the 4.14.y tree and causes more problems
than it fixes, so revert it.

Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Reported-by: Jan Kara <jack@suse.cz>
Cc: syzbot <syzbot+c0138741c2290fc5e63f@syzkaller.appspotmail.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/block/loop.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7910dd8b1d3a..ceb62579eb21 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1996,10 +1996,12 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
 			break;
 		if (lo->lo_state != Lo_unbound) {
 			ret = -EBUSY;
+			mutex_unlock(&loop_ctl_mutex);
 			break;
 		}
 		if (atomic_read(&lo->lo_refcnt) > 0) {
 			ret = -EBUSY;
+			mutex_unlock(&loop_ctl_mutex);
 			break;
 		}
 		lo->lo_disk->private_data = NULL;
-- 
2.50.1