btrfs: false BUG_ON when degraded

In degraded mode the struct btrfs_device of missing devs don't have
device->name set. A kstrdup of NULL correctly returns NULL. Don't
BUG in this case.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c48214ef5c09611100590c75f1eed8c8f0547e04..da541dfca2e335c2419242b44d7a3fbaa9ccc300 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -504,7 +504,7 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                BUG_ON(!new_device);
                memcpy(new_device, device, sizeof(*new_device));
                new_device->name = kstrdup(device->name, GFP_NOFS);
-               BUG_ON(!new_device->name);
+               BUG_ON(device->name && !new_device->name);
                new_device->bdev = NULL;
                new_device->writeable = 0;
                new_device->in_fs_metadata = 0;