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Commit 175a2b87 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
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Btrfs: don't allow a subvol to be deleted if it is the default subovl 



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: default avatarJosef Bacik <jbacik@fusionio.com>
Signed-off-by: default avatarChris Mason <chris.mason@fusionio.com>
parent a0525414

fs/btrfs/ioctl.c

+15 −0
Original line number Diff line number Diff line
@@ -1726,13 +1726,28 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file, 
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;