Btrfs: don't allow a subvol to be deleted if it is the default subovl (175a2b87) · Commits · 戴 / test

Eric pointed out that btrfs will happily allow you to delete the default subvol. This is a problem obviously since the next time you go to mount the file system it will freak out because it can't find the root. Fix this by adding a check to see if our default subvol points to the subvol we are trying to delete, and if it does not allowing it to happen. Thanks, Signed-off-by:

Josef Bacik <jbacik@fusionio.com> Signed-off-by:

Chris Mason <chris.mason@fusionio.com>

fs/btrfs/ioctl.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -1726,13 +1726,28 @@ out:
		static noinline int may_destroy_subvol(struct btrfs_root *root)
		{
		struct btrfs_path *path;
		struct btrfs_dir_item *di;
		struct btrfs_key key;
		u64 dir_id;
		int ret;

		path = btrfs_alloc_path();
		if (!path)
		return -ENOMEM;

		/* Make sure this root isn't set as the default subvol */
		dir_id = btrfs_super_root_dir(root->fs_info->super_copy);
		di = btrfs_lookup_dir_item(NULL, root->fs_info->tree_root, path,
		dir_id, "default", 7, 0);
		if (di && !IS_ERR(di)) {
		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
		if (key.objectid == root->root_key.objectid) {
		ret = -ENOTEMPTY;
		goto out;
		}
		btrfs_release_path(path);
		}

		key.objectid = root->root_key.objectid;
		key.type = BTRFS_ROOT_REF_KEY;
		key.offset = (u64)-1;

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