btrfs: don't try to notify udev about missing devices

If we remove a missing device, bdev is null, and if we
send that off to btrfs_kobject_uevent we'll panic.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5cce6aa74012..485a5423e3c6 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1556,7 +1556,8 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
         ret = 0;
 
         /* Notify udev that device has changed */
-        btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
+        if (bdev)
+                btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
 
 error_brelse:
         brelse(bh);