diff options
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 76 |
1 files changed, 75 insertions, 1 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index eb7f7655e9d5..e9be3abcb368 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -84,7 +84,7 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, int slot; search_key.objectid = objectid; - search_key.type = (u8)-1; + search_key.type = BTRFS_ROOT_ITEM_KEY; search_key.offset = (u64)-1; path = btrfs_alloc_path(); @@ -275,3 +275,77 @@ out: btrfs_free_path(path); return ret; } + +int btrfs_del_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id) +{ + struct btrfs_key key; + int ret; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + + key.objectid = root_id; + key.type = type; + key.offset = ref_id; + + ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); + BUG_ON(ret); + + ret = btrfs_del_item(trans, tree_root, path); + BUG_ON(ret); + + btrfs_free_path(path); + return ret; +} + +/* + * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY + * or BTRFS_ROOT_BACKREF_KEY. + * + * The dirid, sequence, name and name_len refer to the directory entry + * that is referencing the root. + * + * For a forward ref, the root_id is the id of the tree referencing + * the root and ref_id is the id of the subvol or snapshot. + * + * For a back ref the root_id is the id of the subvol or snapshot and + * ref_id is the id of the tree referencing it. + */ +int btrfs_add_root_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *tree_root, + u64 root_id, u8 type, u64 ref_id, + u64 dirid, u64 sequence, + const char *name, int name_len) +{ + struct btrfs_key key; + int ret; + struct btrfs_path *path; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + unsigned long ptr; + + + path = btrfs_alloc_path(); + + key.objectid = root_id; + key.type = type; + key.offset = ref_id; + + ret = btrfs_insert_empty_item(trans, tree_root, path, &key, + sizeof(*ref) + name_len); + BUG_ON(ret); + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + btrfs_set_root_ref_dirid(leaf, ref, dirid); + btrfs_set_root_ref_sequence(leaf, ref, sequence); + btrfs_set_root_ref_name_len(leaf, ref, name_len); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(leaf, name, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + + btrfs_free_path(path); + return ret; +} |