From: Alexander Beregalov <a.beregalov@gmail.com>
Date: Tue, 7 Apr 2009 11:48:21 +0000 (+0200)
Subject: loop: mutex already unlocked in loop_clr_fd()
X-Git-Tag: firefly_0821_release~14581^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ffcd7dca3ab78f9f425971756e5e90024157f6be;p=firefly-linux-kernel-4.4.55.git

loop: mutex already unlocked in loop_clr_fd()

mount/1865 is trying to release lock (&lo->lo_ctl_mutex) at:
but there are no more locks to release!

mutex is already unlocked in loop_clr_fd(), we should not
try to unlock it in lo_release() again.

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 40b17d3b55a1..ddae80825899 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1431,6 +1431,7 @@ static int lo_open(struct block_device *bdev, fmode_t mode)
 static int lo_release(struct gendisk *disk, fmode_t mode)
 {
 	struct loop_device *lo = disk->private_data;
+	int err;
 
 	mutex_lock(&lo->lo_ctl_mutex);
 
@@ -1442,7 +1443,9 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
 		 * In autoclear mode, stop the loop thread
 		 * and remove configuration after last close.
 		 */
-		loop_clr_fd(lo, NULL);
+		err = loop_clr_fd(lo, NULL);
+		if (!err)
+			goto out_unlocked;
 	} else {
 		/*
 		 * Otherwise keep thread (if running) and config,
@@ -1453,7 +1456,7 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
 
 out:
 	mutex_unlock(&lo->lo_ctl_mutex);
-
+out_unlocked:
 	return 0;
 }