From 175a2b871f46272a2aedce5fb3222a72568b84c3 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 12 Aug 2013 15:36:44 -0400 Subject: [PATCH] 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: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/ioctl.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 022d8364e072..317a984fe3c9 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -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;