Revert "loop: Fold __loop_release into loop_release"

BugLink: https://bugs.launchpad.net/bugs/1818803

This reverts commit 4ee414c3 which is
commit 967d1dc1 upstream.

It is not needed in the 4.4.y tree at this time.
Reported-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/block/loop.c

@@ -1642,15 +1642,12 @@ static int lo_open(struct block_device *bdev, fmode_t mode)
 	return err;
 }
 
-static void lo_release(struct gendisk *disk, fmode_t mode)
+static void __lo_release(struct loop_device *lo)
 {
-	struct loop_device *lo;
 	int err;
 
-	mutex_lock(&loop_index_mutex);
-	lo = disk->private_data;
 	if (atomic_dec_return(&lo->lo_refcnt))
-		goto unlock_index;
+		return;
 
 	mutex_lock(&loop_ctl_mutex);
 	if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
@@ -1660,7 +1657,7 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
 		 */
 		err = loop_clr_fd(lo);
 		if (!err)
-			goto unlock_index;
+			return;
 	} else {
 		/*
 		 * Otherwise keep thread (if running) and config,
@@ -1670,7 +1667,12 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
 	}
 
 	mutex_unlock(&loop_ctl_mutex);
-unlock_index:
+}
+
+static void lo_release(struct gendisk *disk, fmode_t mode)
+{
+	mutex_lock(&loop_index_mutex);
+	__lo_release(disk->private_data);
 	mutex_unlock(&loop_index_mutex);
 }