16  * Read a root item from the tree. In case we detect a root item smaller then
20  * kernel that was not aware of the root item structure change.
23 				struct btrfs_root_item *item)  in btrfs_read_root_item()  argument
29 	read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),  in btrfs_read_root_item()
30 			   min_t(u32, len, sizeof(*item)));  in btrfs_read_root_item()
31 	if (len < sizeof(*item))  in btrfs_read_root_item()
33 	if (!need_reset && btrfs_root_generation(item)  in btrfs_read_root_item()
34 		!= btrfs_root_generation_v2(item)) {  in btrfs_read_root_item()
35 		if (btrfs_root_generation_v2(item) != 0) {  in btrfs_read_root_item()
37 …"mismatching generation and generation_v2 found in root item. This root was probably mounted with …  in btrfs_read_root_item()
42 		memset(&item->generation_v2, 0,  in btrfs_read_root_item()
43 			sizeof(*item) - offsetof(struct btrfs_root_item,  in btrfs_read_root_item()
46 		generate_random_guid(item->uuid);  in btrfs_read_root_item()
55  * root_item: the root item of the tree we look for
107 void btrfs_set_root_node(struct btrfs_root_item *item,  in btrfs_set_root_node()  argument
110 	btrfs_set_root_bytenr(item, node->start);  in btrfs_set_root_node()
111 	btrfs_set_root_level(item, btrfs_header_level(node));  in btrfs_set_root_node()
112 	btrfs_set_root_generation(item, btrfs_header_generation(node));  in btrfs_set_root_node()
116  * copy the data in 'item' into the btree
120 		      *item)  in btrfs_update_root()
154 	 * If this is the first time we update the root item which originated  in btrfs_update_root()
155 	 * from an older kernel, we need to enlarge the item size to make room  in btrfs_update_root()
158 	if (old_len < sizeof(*item)) {  in btrfs_update_root()
174 				key, sizeof(*item));  in btrfs_update_root()
188 	btrfs_set_root_generation_v2(item, btrfs_root_generation(item));  in btrfs_update_root()
190 	write_extent_buffer(l, item, ptr, sizeof(*item));  in btrfs_update_root()
198 		      const struct btrfs_key *key, struct btrfs_root_item *item)  in btrfs_insert_root()  argument
203 	btrfs_set_root_generation_v2(item, btrfs_root_generation(item));  in btrfs_insert_root()
204 	return btrfs_insert_item(trans, root, key, item, sizeof(*item));  in btrfs_insert_root()
267 					    "Failed to start trans to delete orphan item");  in btrfs_find_orphan_roots()
275 					    "Failed to delete root orphan item");  in btrfs_find_orphan_roots()
293 /* drop the root item for 'key' from the tree root */
375  * add a btrfs_root_ref item.  type is either BTRFS_ROOT_REF_KEY
459 	struct btrfs_root_item *item = &root->root_item;  in btrfs_update_root_times()  local
464 	btrfs_set_root_ctransid(item, trans->transid);  in btrfs_update_root_times()
465 	btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);  in btrfs_update_root_times()
466 	btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);  in btrfs_update_root_times()