/* * xattrs work a lot like directories, this inserts an xattr item * into the tree */ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, u16 name_len, const void *data, u16 data_len, u64 dir) { int ret = 0; struct btrfs_path *path; struct btrfs_dir_item *dir_item; unsigned long name_ptr, data_ptr; struct btrfs_key key, location; struct btrfs_disk_key disk_key; struct extent_buffer *leaf; u32 data_size; key.objectid = dir; btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY); key.offset = btrfs_name_hash(name, name_len); path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (name_len + data_len + sizeof(struct btrfs_dir_item) > BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item)) return -ENOSPC; data_size = sizeof(*dir_item) + name_len + data_len; dir_item = insert_with_overflow(trans, root, path, &key, data_size, name, name_len); /* * FIXME: at some point we should handle xattr's that are larger than * what we can fit in our leaf. We set location to NULL b/c we arent * pointing at anything else, that will change if we store the xattr * data in a separate inode. */ BUG_ON(IS_ERR(dir_item)); memset(&location, 0, sizeof(location)); leaf = path->nodes[0]; btrfs_cpu_key_to_disk(&disk_key, &location); btrfs_set_dir_item_key(leaf, dir_item, &disk_key); btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR); btrfs_set_dir_name_len(leaf, dir_item, name_len); btrfs_set_dir_transid(leaf, dir_item, trans->transid); btrfs_set_dir_data_len(leaf, dir_item, data_len); name_ptr = (unsigned long)(dir_item + 1); data_ptr = (unsigned long)((char *)name_ptr + name_len); write_extent_buffer(leaf, name, name_ptr, name_len); write_extent_buffer(leaf, data, data_ptr, data_len); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_free_path(path); return ret; }
/* * xattrs work a lot like directories, this inserts an xattr item * into the tree */ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, const char *name, u16 name_len, const void *data, u16 data_len) { int ret = 0; struct btrfs_dir_item *dir_item; unsigned long name_ptr, data_ptr; struct btrfs_key key, location; struct btrfs_disk_key disk_key; struct extent_buffer *leaf; u32 data_size; if (name_len + data_len > BTRFS_MAX_XATTR_SIZE(root->fs_info)) return -ENOSPC; key.objectid = objectid; key.type = BTRFS_XATTR_ITEM_KEY; key.offset = btrfs_name_hash(name, name_len); data_size = sizeof(*dir_item) + name_len + data_len; dir_item = insert_with_overflow(trans, root, path, &key, data_size, name, name_len); if (IS_ERR(dir_item)) return PTR_ERR(dir_item); memset(&location, 0, sizeof(location)); leaf = path->nodes[0]; btrfs_cpu_key_to_disk(&disk_key, &location); btrfs_set_dir_item_key(leaf, dir_item, &disk_key); btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR); btrfs_set_dir_name_len(leaf, dir_item, name_len); btrfs_set_dir_transid(leaf, dir_item, trans->transid); btrfs_set_dir_data_len(leaf, dir_item, data_len); name_ptr = (unsigned long)(dir_item + 1); data_ptr = (unsigned long)((char *)name_ptr + name_len); write_extent_buffer(leaf, name, name_ptr, name_len); write_extent_buffer(leaf, data, data_ptr, data_len); btrfs_mark_buffer_dirty(path->nodes[0]); return ret; }
/* * insert a directory item in the tree, doing all the magic for * both indexes. 'dir' indicates which objectid to insert it into, * 'location' is the key to stuff into the directory item, 'type' is the * type of the inode we're pointing to, and 'index' is the sequence number * to use for the second index (if one is created). * Will return 0 or -ENOMEM */ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, struct inode *dir, struct btrfs_key *location, u8 type, u64 index) { int ret = 0; int ret2 = 0; struct btrfs_path *path; struct btrfs_dir_item *dir_item; struct extent_buffer *leaf; unsigned long name_ptr; struct btrfs_key key; struct btrfs_disk_key disk_key; u32 data_size; key.objectid = btrfs_ino(dir); btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY); key.offset = btrfs_name_hash(name, name_len); path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; btrfs_cpu_key_to_disk(&disk_key, location); data_size = sizeof(*dir_item) + name_len; dir_item = insert_with_overflow(trans, root, path, &key, data_size, name, name_len); if (IS_ERR(dir_item)) { ret = PTR_ERR(dir_item); if (ret == -EEXIST) goto second_insert; goto out_free; } leaf = path->nodes[0]; btrfs_set_dir_item_key(leaf, dir_item, &disk_key); btrfs_set_dir_type(leaf, dir_item, type); btrfs_set_dir_data_len(leaf, dir_item, 0); btrfs_set_dir_name_len(leaf, dir_item, name_len); btrfs_set_dir_transid(leaf, dir_item, trans->transid); name_ptr = (unsigned long)(dir_item + 1); write_extent_buffer(leaf, name, name_ptr, name_len); btrfs_mark_buffer_dirty(leaf); second_insert: /* FIXME, use some real flag for selecting the extra index */ if (root == root->fs_info->tree_root) { ret = 0; goto out_free; } btrfs_release_path(path); ret2 = btrfs_insert_delayed_dir_index(trans, root, name, name_len, dir, &disk_key, type, index); out_free: btrfs_free_path(path); if (ret) return ret; if (ret2) return ret2; return 0; }
static int do_setxattr(struct btrfs_trans_handle *trans, struct inode *inode, const char *name, const void *value, size_t size, int flags) { struct btrfs_dir_item *di = NULL; struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_path *path; size_t name_len = strlen(name); int ret = 0; if (name_len + size > BTRFS_MAX_XATTR_SIZE(root)) return -ENOSPC; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->skip_release_on_error = 1; if (!value) { di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name, name_len, -1); if (!di && (flags & XATTR_REPLACE)) ret = -ENODATA; else if (IS_ERR(di)) ret = PTR_ERR(di); else if (di) ret = btrfs_delete_one_dir_name(trans, root, path, di); goto out; } /* * For a replace we can't just do the insert blindly. * Do a lookup first (read-only btrfs_search_slot), and return if xattr * doesn't exist. If it exists, fall down below to the insert/replace * path - we can't race with a concurrent xattr delete, because the VFS * locks the inode's i_mutex before calling setxattr or removexattr. */ if (flags & XATTR_REPLACE) { ASSERT(inode_is_locked(inode)); di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name, name_len, 0); if (!di) ret = -ENODATA; else if (IS_ERR(di)) ret = PTR_ERR(di); if (ret) goto out; btrfs_release_path(path); di = NULL; } ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode), name, name_len, value, size); if (ret == -EOVERFLOW) { /* * We have an existing item in a leaf, split_leaf couldn't * expand it. That item might have or not a dir_item that * matches our target xattr, so lets check. */ ret = 0; btrfs_assert_tree_locked(path->nodes[0]); di = btrfs_match_dir_item_name(root, path, name, name_len); if (!di && !(flags & XATTR_REPLACE)) { ret = -ENOSPC; goto out; } } else if (ret == -EEXIST) { ret = 0; di = btrfs_match_dir_item_name(root, path, name, name_len); ASSERT(di); /* logic error */ } else if (ret) { goto out; } if (di && (flags & XATTR_CREATE)) { ret = -EEXIST; goto out; } if (di) { /* * We're doing a replace, and it must be atomic, that is, at * any point in time we have either the old or the new xattr * value in the tree. We don't want readers (getxattr and * listxattrs) to miss a value, this is specially important * for ACLs. */ const int slot = path->slots[0]; struct extent_buffer *leaf = path->nodes[0]; const u16 old_data_len = btrfs_dir_data_len(leaf, di); const u32 item_size = btrfs_item_size_nr(leaf, slot); const u32 data_size = sizeof(*di) + name_len + size; struct btrfs_item *item; unsigned long data_ptr; char *ptr; if (size > old_data_len) { if (btrfs_leaf_free_space(root, leaf) < (size - old_data_len)) { ret = -ENOSPC; goto out; } } if (old_data_len + name_len + sizeof(*di) == item_size) { /* No other xattrs packed in the same leaf item. */ if (size > old_data_len) btrfs_extend_item(root, path, size - old_data_len); else if (size < old_data_len) btrfs_truncate_item(root, path, data_size, 1); } else { /* There are other xattrs packed in the same item. */ ret = btrfs_delete_one_dir_name(trans, root, path, di); if (ret) goto out; btrfs_extend_item(root, path, data_size); } item = btrfs_item_nr(slot); ptr = btrfs_item_ptr(leaf, slot, char); ptr += btrfs_item_size(leaf, item) - data_size; di = (struct btrfs_dir_item *)ptr; btrfs_set_dir_data_len(leaf, di, size); data_ptr = ((unsigned long)(di + 1)) + name_len; write_extent_buffer(leaf, value, data_ptr, size); btrfs_mark_buffer_dirty(leaf); } else { /* * Insert, and we had space for the xattr, so path->slots[0] is * where our xattr dir_item is and btrfs_insert_xattr_item() * filled it. */ }