I think this is btrfs using a struct block_device that doesn't have a valid queue pointer in it's gendisk for ->s_bdev. And there are some fishy looking ->s_bdev assignments in the code which I suspect are related to it: fs/btrfs/dev-replace.c: if (fs_info->sb->s_bdev == src_device->bdev) fs/btrfs/dev-replace.c: fs_info->sb->s_bdev = tgt_device->bdev; fs/btrfs/volumes.c: if (device->bdev == root->fs_info->sb->s_bdev) fs/btrfs/volumes.c: root->fs_info->sb->s_bdev = next_device->bdev; fs/btrfs/volumes.c: if (tgtdev->bdev == fs_info->sb->s_bdev) fs/btrfs/volumes.c: fs_info->sb->s_bdev = next_device->bdev; -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html