diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 3 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 5 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 50 | ||||
| -rw-r--r-- | fs/btrfs/root-tree.c | 16 |
4 files changed, 73 insertions, 1 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index ad2cbe63503..70b3dbb4de1 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1801,6 +1801,9 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, struct extent_buffer *node, struct extent_buffer *parent); /* root-item.c */ +int btrfs_find_root_ref(struct btrfs_root *tree_root, + struct btrfs_path *path, + u64 root_id, u64 ref_id); int btrfs_add_root_ref(struct btrfs_trans_handle *trans, struct btrfs_root *tree_root, u64 root_id, u8 type, u64 ref_id, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 8d7866b733d..e18250a6fd2 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1129,7 +1129,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, kfree(root); return ERR_PTR(ret); } - +#if 0 ret = btrfs_sysfs_add_root(root); if (ret) { free_extent_buffer(root->node); @@ -1137,6 +1137,7 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, kfree(root); return ERR_PTR(ret); } +#endif root->in_sysfs = 1; return root; } @@ -1963,8 +1964,10 @@ int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root) down_write(&root->anon_super.s_umount); kill_anon_super(&root->anon_super); } +#if 0 if (root->in_sysfs) btrfs_sysfs_del_root(root); +#endif if (root->node) free_extent_buffer(root->node); if (root->commit_root) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 536ae883780..8828109fa58 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -284,6 +284,56 @@ static noinline int btrfs_mksubvol(struct path *parent, char *name, * subvolume with specific mode bits. */ if (snap_src) { + struct dentry *dir = dentry->d_parent; + struct dentry *test = dir->d_parent; + struct btrfs_path *path = btrfs_alloc_path(); + int ret; + u64 test_oid; + u64 parent_oid = BTRFS_I(dir->d_inode)->root->root_key.objectid; + + test_oid = snap_src->root_key.objectid; + + ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, + path, parent_oid, test_oid); + if (ret == 0) + goto create; + btrfs_release_path(snap_src->fs_info->tree_root, path); + + /* we need to make sure we aren't creating a directory loop + * by taking a snapshot of something that has our current + * subvol in its directory tree. So, this loops through + * the dentries and checks the forward refs for each subvolume + * to see if is references the subvolume where we are + * placing this new snapshot. + */ + while(1) { + if (!test || + dir == snap_src->fs_info->sb->s_root || + test == snap_src->fs_info->sb->s_root || + test->d_inode->i_sb != snap_src->fs_info->sb) { + break; + } + if (S_ISLNK(test->d_inode->i_mode)) { + printk("Symlink in snapshot path, failed\n"); + error = -EMLINK; + btrfs_free_path(path); + goto out_drop_write; + } + test_oid = + BTRFS_I(test->d_inode)->root->root_key.objectid; + ret = btrfs_find_root_ref(snap_src->fs_info->tree_root, + path, test_oid, parent_oid); + if (ret == 0) { + printk("Snapshot creation failed, looping\n"); + error = -EMLINK; + btrfs_free_path(path); + goto out_drop_write; + } + btrfs_release_path(snap_src->fs_info->tree_root, path); + test = test->d_parent; + } +create: + btrfs_free_path(path); error = create_snapshot(snap_src, dentry, name, namelen); } else { error = create_subvol(BTRFS_I(parent->dentry->d_inode)->root, diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index e9be3abcb36..dbe20d4c6ea 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -300,6 +300,22 @@ int btrfs_del_root_ref(struct btrfs_trans_handle *trans, return ret; } +int btrfs_find_root_ref(struct btrfs_root *tree_root, + struct btrfs_path *path, + u64 root_id, u64 ref_id) +{ + struct btrfs_key key; + int ret; + + key.objectid = root_id; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = ref_id; + + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + return ret; +} + + /* * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY * or BTRFS_ROOT_BACKREF_KEY. |