14  * Read a root item from the tree. In case we detect a root item smaller then
15  * sizeof(root_item), we know it's an old version of the root structure and
17  * generation numbers as then we know the root was once mounted with an older
18  * kernel that was not aware of the root item structure change.
36 …"mismatching generation and generation_v2 found in root item. This root was probably mounted with …  in btrfs_read_root_item()
51  * btrfs_find_root - lookup the root by the key.
52  * root: the root of the root tree
55  * root_item: the root item of the tree we look for
56  * root_key: the root key of the tree we look for
59  * of the search key, just lookup the root with the highest offset for a
64 int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,  in btrfs_find_root()  argument
73 	ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);  in btrfs_find_root()
119 		      *root, struct btrfs_key *key, struct btrfs_root_item  in btrfs_update_root()
122 	struct btrfs_fs_info *fs_info = root->fs_info;  in btrfs_update_root()
134 	ret = btrfs_search_slot(trans, root, key, path, 0, 1);  in btrfs_update_root()
140 			"unable to find root key (%llu %u %llu) in tree %llu",  in btrfs_update_root()
142 			root->root_key.objectid);  in btrfs_update_root()
154 	 * If this is the first time we update the root item which originated  in btrfs_update_root()
160 		ret = btrfs_search_slot(trans, root, key, path,  in btrfs_update_root()
167 		ret = btrfs_del_item(trans, root, path);  in btrfs_update_root()
173 		ret = btrfs_insert_empty_item(trans, root, path,  in btrfs_update_root()
185 	 * Update generation_v2 so at the next mount we know the new root  in btrfs_update_root()
197 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,  in btrfs_insert_root()  argument
204 	return btrfs_insert_item(trans, root, key, item, sizeof(*item));  in btrfs_insert_root()
214 	struct btrfs_root *root;  in btrfs_find_orphan_roots()  local
257 		 * The root might have been inserted already, as before we look  in btrfs_find_orphan_roots()
263 		root = btrfs_lookup_fs_root(fs_info, root_key.objectid);  in btrfs_find_orphan_roots()
264 		if (root) {  in btrfs_find_orphan_roots()
266 					  &root->state));  in btrfs_find_orphan_roots()
267 			if (btrfs_root_refs(&root->root_item) == 0)  in btrfs_find_orphan_roots()
268 				btrfs_add_dead_root(root);  in btrfs_find_orphan_roots()
272 		root = btrfs_read_fs_root(tree_root, &root_key);  in btrfs_find_orphan_roots()
273 		err = PTR_ERR_OR_ZERO(root);  in btrfs_find_orphan_roots()
293 					    "Failed to delete root orphan item");  in btrfs_find_orphan_roots()
299 		err = btrfs_init_fs_root(root);  in btrfs_find_orphan_roots()
301 			btrfs_free_fs_root(root);  in btrfs_find_orphan_roots()
305 		set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);  in btrfs_find_orphan_roots()
307 		err = btrfs_insert_fs_root(fs_info, root);  in btrfs_find_orphan_roots()
310 			btrfs_free_fs_root(root);  in btrfs_find_orphan_roots()
314 		if (btrfs_root_refs(&root->root_item) == 0)  in btrfs_find_orphan_roots()
315 			btrfs_add_dead_root(root);  in btrfs_find_orphan_roots()
322 /* drop the root item for 'key' from the tree root */
326 	struct btrfs_root *root = trans->fs_info->tree_root;  in btrfs_del_root()  local
333 	ret = btrfs_search_slot(trans, root, key, path, -1, 1);  in btrfs_del_root()
339 	ret = btrfs_del_item(trans, root, path);  in btrfs_del_root()
408  * that is referencing the root.
411  * the root and ref_id is the id of the subvol  or snapshot.
486 			     struct btrfs_root *root)  in btrfs_update_root_times()  argument
488 	struct btrfs_root_item *item = &root->root_item;  in btrfs_update_root_times()
492 	spin_lock(&root->root_item_lock);  in btrfs_update_root_times()
496 	spin_unlock(&root->root_item_lock);  in btrfs_update_root_times()