From: Alex Elder <elder@inktank.com>
Date: Fri, 10 Aug 2012 20:12:07 +0000 (-0700)
Subject: rbd: drop dev reference on error in rbd_open()
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=340c7a2b2c9a2da640af28a8c196356484ac8b50;p=deliverable%2Flinux.git

rbd: drop dev reference on error in rbd_open()

If a read-only rbd device is opened for writing in rbd_open(), it
returns without dropping the just-acquired device reference.

Fix this by moving the read-only check before getting the reference.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
---

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 9917943a3572..54a55f03115d 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -246,13 +246,12 @@ static int rbd_open(struct block_device *bdev, fmode_t mode)
 {
 	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 
-	rbd_get_dev(rbd_dev);
-
-	set_device_ro(bdev, rbd_dev->read_only);
-
 	if ((mode & FMODE_WRITE) && rbd_dev->read_only)
 		return -EROFS;
 
+	rbd_get_dev(rbd_dev);
+	set_device_ro(bdev, rbd_dev->read_only);
+
 	return 0;
 }