1 // SPDX-License-Identifier: GPL-2.0
12 #include "disk-io.h"
13 #include "print-tree.h"
15 #include "space-info.h"
17 #include "root-tree.h"
21  * Read a root item from the tree. In case we detect a root item smaller then
22  * sizeof(root_item), we know it's an old version of the root structure and
24  * generation numbers as then we know the root was once mounted with an older
25  * kernel that was not aware of the root item structure change.
41 			btrfs_warn(eb->fs_info,  in btrfs_read_root_item()
42 …"mismatching generation and generation_v2 found in root item. This root was probably mounted with …  in btrfs_read_root_item()
49 		generate_random_guid(item->uuid);  in btrfs_read_root_item()
54  * btrfs_find_root - lookup the root by the key.
55  * root: the root of the root tree
58  * root_item: the root item of the tree we look for
59  * root_key: the root key of the tree we look for
61  * If ->offset of 'search_key' is -1ULL, it means we are not sure the offset
62  * of the search key, just lookup the root with the highest offset for a
67 int btrfs_find_root(struct btrfs_root *root, const struct btrfs_key *search_key,  in btrfs_find_root()  argument
76 	ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);  in btrfs_find_root()
80 	if (search_key->offset != -1ULL) {	/* the search key is exact */  in btrfs_find_root()
85 		if (path->slots[0] == 0)  in btrfs_find_root()
87 		path->slots[0]--;  in btrfs_find_root()
91 	l = path->nodes[0];  in btrfs_find_root()
92 	slot = path->slots[0];  in btrfs_find_root()
95 	if (found_key.objectid != search_key->objectid ||  in btrfs_find_root()
113 	btrfs_set_root_bytenr(item, node->start);  in btrfs_set_root_node()
122 		      *root, struct btrfs_key *key, struct btrfs_root_item  in btrfs_update_root()
125 	struct btrfs_fs_info *fs_info = root->fs_info;  in btrfs_update_root()
135 		return -ENOMEM;  in btrfs_update_root()
137 	ret = btrfs_search_slot(trans, root, key, path, 0, 1);  in btrfs_update_root()
143 			"unable to find root key (%llu %u %llu) in tree %llu",  in btrfs_update_root()
144 			key->objectid, key->type, key->offset,  in btrfs_update_root()
145 			root->root_key.objectid);  in btrfs_update_root()
146 		ret = -EUCLEAN;  in btrfs_update_root()
151 	l = path->nodes[0];  in btrfs_update_root()
152 	slot = path->slots[0];  in btrfs_update_root()
157 	 * If this is the first time we update the root item which originated  in btrfs_update_root()
163 		ret = btrfs_search_slot(trans, root, key, path,  in btrfs_update_root()
164 				-1, 1);  in btrfs_update_root()
170 		ret = btrfs_del_item(trans, root, path);  in btrfs_update_root()
176 		ret = btrfs_insert_empty_item(trans, root, path,  in btrfs_update_root()
182 		l = path->nodes[0];  in btrfs_update_root()
183 		slot = path->slots[0];  in btrfs_update_root()
188 	 * Update generation_v2 so at the next mount we know the new root  in btrfs_update_root()
194 	btrfs_mark_buffer_dirty(trans, path->nodes[0]);  in btrfs_update_root()
200 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,  in btrfs_insert_root()  argument
207 	return btrfs_insert_item(trans, root, key, item, sizeof(*item));  in btrfs_insert_root()
212 	struct btrfs_root *tree_root = fs_info->tree_root;  in btrfs_find_orphan_roots()
216 	struct btrfs_root *root;  in btrfs_find_orphan_roots()  local
222 		return -ENOMEM;  in btrfs_find_orphan_roots()
237 		leaf = path->nodes[0];  in btrfs_find_orphan_roots()
238 		if (path->slots[0] >= btrfs_header_nritems(leaf)) {  in btrfs_find_orphan_roots()
244 			leaf = path->nodes[0];  in btrfs_find_orphan_roots()
247 		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);  in btrfs_find_orphan_roots()
257 		root = btrfs_get_fs_root(fs_info, root_objectid, false);  in btrfs_find_orphan_roots()
258 		err = PTR_ERR_OR_ZERO(root);  in btrfs_find_orphan_roots()
259 		if (err && err != -ENOENT) {  in btrfs_find_orphan_roots()
261 		} else if (err == -ENOENT) {  in btrfs_find_orphan_roots()
278 					    "Failed to delete root orphan item");  in btrfs_find_orphan_roots()
284 		WARN_ON(!test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state));  in btrfs_find_orphan_roots()
285 		if (btrfs_root_refs(&root->root_item) == 0) {  in btrfs_find_orphan_roots()
288 			btrfs_disk_key_to_cpu(&drop_key, &root->root_item.drop_progress);  in btrfs_find_orphan_roots()
290 			 * If we have a non-zero drop_progress then we know we  in btrfs_find_orphan_roots()
297 				set_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags);  in btrfs_find_orphan_roots()
298 				set_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);  in btrfs_find_orphan_roots()
301 			set_bit(BTRFS_ROOT_DEAD_TREE, &root->state);  in btrfs_find_orphan_roots()
302 			btrfs_add_dead_root(root);  in btrfs_find_orphan_roots()
304 		btrfs_put_root(root);  in btrfs_find_orphan_roots()
311 /* drop the root item for 'key' from the tree root */
315 	struct btrfs_root *root = trans->fs_info->tree_root;  in btrfs_del_root()  local
321 		return -ENOMEM;  in btrfs_del_root()
322 	ret = btrfs_search_slot(trans, root, key, path, -1, 1);  in btrfs_del_root()
328 	ret = btrfs_del_item(trans, root, path);  in btrfs_del_root()
338 	struct btrfs_root *tree_root = trans->fs_info->tree_root;  in btrfs_del_root_ref()
348 		return -ENOMEM;  in btrfs_del_root_ref()
354 	ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);  in btrfs_del_root_ref()
358 		leaf = path->nodes[0];  in btrfs_del_root_ref()
359 		ref = btrfs_item_ptr(leaf, path->slots[0],  in btrfs_del_root_ref()
363 		    (btrfs_root_ref_name_len(leaf, ref) != name->len) ||  in btrfs_del_root_ref()
364 		    memcmp_extent_buffer(leaf, name->name, ptr, name->len)) {  in btrfs_del_root_ref()
365 			ret = -ENOENT;  in btrfs_del_root_ref()
374 		ret = -ENOENT;  in btrfs_del_root_ref()
396  * that is referencing the root.
399  * the root and ref_id is the id of the subvol  or snapshot.
404  * Will return 0, -ENOMEM, or anything from the CoW path
410 	struct btrfs_root *tree_root = trans->fs_info->tree_root;  in btrfs_add_root_ref()
420 		return -ENOMEM;  in btrfs_add_root_ref()
427 				      sizeof(*ref) + name->len);  in btrfs_add_root_ref()
434 	leaf = path->nodes[0];  in btrfs_add_root_ref()
435 	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);  in btrfs_add_root_ref()
438 	btrfs_set_root_ref_name_len(leaf, ref, name->len);  in btrfs_add_root_ref()
440 	write_extent_buffer(leaf, name->name, ptr, name->len);  in btrfs_add_root_ref()
456  * Old btrfs forgets to init root_item->flags and root_item->byte_limit
458  * root_item->inode_item->flags, and use it to indicate if those fields
463 	u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);  in btrfs_check_and_init_root_item()
467 		btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);  in btrfs_check_and_init_root_item()
474 			     struct btrfs_root *root)  in btrfs_update_root_times()  argument
476 	struct btrfs_root_item *item = &root->root_item;  in btrfs_update_root_times()
480 	spin_lock(&root->root_item_lock);  in btrfs_update_root_times()
481 	btrfs_set_root_ctransid(item, trans->transid);  in btrfs_update_root_times()
482 	btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);  in btrfs_update_root_times()
483 	btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);  in btrfs_update_root_times()
484 	spin_unlock(&root->root_item_lock);  in btrfs_update_root_times()
488  * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
489  * root: the root of the parent directory
497  * and root tree, the number of items that the qgroup reserves is
501 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,  in btrfs_subvolume_reserve_metadata()  argument
508 	struct btrfs_fs_info *fs_info = root->fs_info;  in btrfs_subvolume_reserve_metadata()
509 	struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;  in btrfs_subvolume_reserve_metadata()
511 	if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {  in btrfs_subvolume_reserve_metadata()
513 		qgroup_num_bytes = 3 * fs_info->nodesize;  in btrfs_subvolume_reserve_metadata()
514 		ret = btrfs_qgroup_reserve_meta_prealloc(root,  in btrfs_subvolume_reserve_metadata()
522 	rsv->space_info = btrfs_find_space_info(fs_info,  in btrfs_subvolume_reserve_metadata()
527 	if (ret == -ENOSPC && use_global_rsv)  in btrfs_subvolume_reserve_metadata()
531 		btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);  in btrfs_subvolume_reserve_metadata()
534 		spin_lock(&rsv->lock);  in btrfs_subvolume_reserve_metadata()
535 		rsv->qgroup_rsv_reserved += qgroup_num_bytes;  in btrfs_subvolume_reserve_metadata()
536 		spin_unlock(&rsv->lock);  in btrfs_subvolume_reserve_metadata()