From: Alex Elder <elder@dreamhost.com>
Date: Thu, 12 Jan 2012 03:42:15 +0000 (-0800)
Subject: rbd: initialize snap_rwsem in rbd_add()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0e805a1d857799352e51e8697c0b1a30aec16913;p=linux-beck.git

rbd: initialize snap_rwsem in rbd_add()

New rbd device structures get initialized in rbd_add().  Many of
the fields rely on being initially zero-filled.  However we lockdep
was noticing that the rw_semaphore embedded in the header field
was not getting properly initialized.  Fix that.

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
---

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 148ab944378d..3fd31dec8c9c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2184,6 +2184,8 @@ static ssize_t rbd_add(struct bus_type *bus,
 	INIT_LIST_HEAD(&rbd_dev->node);
 	INIT_LIST_HEAD(&rbd_dev->snaps);
 
+	init_rwsem(&rbd_dev->header.snap_rwsem);
+
 	/* generate unique id: find highest unique id, add one */
 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);