Btrfs: check return value of open_bdev_exclusive properly

Hit this problem while testing RAID1 failure stuff.  open_bdev_exclusive
returns ERR_PTR(), not NULL.  So change the return value properly.  This
is important if you accidently specify a device that doesn't exist when
trying to add a new device to an array, you will panic the box
dereferencing bdev.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 66122bdf8bbf..5eb7459e3782 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1434,8 +1434,8 @@ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
                 return -EINVAL;
 
         bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
-        if (!bdev)
-                return -EIO;
+        if (IS_ERR(bdev))
+                return PTR_ERR(bdev);
 
         if (root->fs_info->fs_devices->seeding) {
                 seeding_dev = 1;