Commit 0c309d66 authored by Boris Burkov's avatar Boris Burkov Committed by David Sterba
Browse files

btrfs: forbid creating subvol qgroups 



Creating a qgroup 0/subvolid leads to various races and it isn't
helpful, because you can't specify a subvol id when creating a subvol,
so you can't be sure it will be the right one. Any requirements on the
automatic subvol can be gratified by using a higher level qgroup and the
inheritance parameters of subvol creation.

Fixes: cecbb533 ("btrfs: record simple quota deltas in delayed refs")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarBoris Burkov <boris@bur.io>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f884a9f9

fs/btrfs/ioctl.c

+5 −0
Original line number Diff line number Diff line
@@ -3806,6 +3806,11 @@ static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg) 
		goto out;

	}



	if (sa->create && is_fstree(sa->qgroupid)) {

		ret = -EINVAL;

		goto out;

	}



	trans = btrfs_join_transaction(root);

	if (IS_ERR(trans)) {

		ret = PTR_ERR(trans);