2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include "transaction.h"
22 #include "print-tree.h"
25 * search forward for a root, starting with objectid 'search_start'
26 * if a root key is found, the objectid we find is filled into 'found_objectid'
27 * and 0 is returned. < 0 is returned on error, 1 if there is nothing
30 int btrfs_search_root(struct btrfs_root *root, u64 search_start,
33 struct btrfs_path *path;
34 struct btrfs_key search_key;
37 root = root->fs_info->tree_root;
38 search_key.objectid = search_start;
39 search_key.type = (u8)-1;
40 search_key.offset = (u64)-1;
42 path = btrfs_alloc_path();
45 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
52 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
53 ret = btrfs_next_leaf(root, path);
57 btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]);
58 if (search_key.type != BTRFS_ROOT_ITEM_KEY) {
60 btrfs_release_path(root, path);
64 *found_objectid = search_key.objectid;
67 btrfs_free_path(path);
72 * lookup the root with the highest offset for a given objectid. The key we do
73 * find is copied into 'key'. If we find something return 0, otherwise 1, < 0
76 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
77 struct btrfs_root_item *item, struct btrfs_key *key)
79 struct btrfs_path *path;
80 struct btrfs_key search_key;
81 struct btrfs_key found_key;
82 struct extent_buffer *l;
86 search_key.objectid = objectid;
87 search_key.type = BTRFS_ROOT_ITEM_KEY;
88 search_key.offset = (u64)-1;
90 path = btrfs_alloc_path();
92 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
97 if (path->slots[0] == 0) {
102 slot = path->slots[0] - 1;
103 btrfs_item_key_to_cpu(l, &found_key, slot);
104 if (found_key.objectid != objectid ||
105 found_key.type != BTRFS_ROOT_ITEM_KEY) {
110 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
113 memcpy(key, &found_key, sizeof(found_key));
116 btrfs_free_path(path);
120 int btrfs_set_root_node(struct btrfs_root_item *item,
121 struct extent_buffer *node)
123 btrfs_set_root_bytenr(item, node->start);
124 btrfs_set_root_level(item, btrfs_header_level(node));
125 btrfs_set_root_generation(item, btrfs_header_generation(node));
130 * copy the data in 'item' into the btree
132 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
133 *root, struct btrfs_key *key, struct btrfs_root_item
136 struct btrfs_path *path;
137 struct extent_buffer *l;
142 path = btrfs_alloc_path();
144 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
149 btrfs_print_leaf(root, path->nodes[0]);
150 printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
151 (unsigned long long)key->objectid, key->type,
152 (unsigned long long)key->offset);
157 slot = path->slots[0];
158 ptr = btrfs_item_ptr_offset(l, slot);
159 write_extent_buffer(l, item, ptr, sizeof(*item));
160 btrfs_mark_buffer_dirty(path->nodes[0]);
162 btrfs_free_path(path);
166 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
167 *root, struct btrfs_key *key, struct btrfs_root_item
171 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
176 * at mount time we want to find all the old transaction snapshots that were in
177 * the process of being deleted if we crashed. This is any root item with an
178 * offset lower than the latest root. They need to be queued for deletion to
179 * finish what was happening when we crashed.
181 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
183 struct btrfs_root *dead_root;
184 struct btrfs_item *item;
185 struct btrfs_root_item *ri;
186 struct btrfs_key key;
187 struct btrfs_key found_key;
188 struct btrfs_path *path;
191 struct extent_buffer *leaf;
194 key.objectid = objectid;
195 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
197 path = btrfs_alloc_path();
202 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
206 leaf = path->nodes[0];
207 nritems = btrfs_header_nritems(leaf);
208 slot = path->slots[0];
209 if (slot >= nritems) {
210 ret = btrfs_next_leaf(root, path);
213 leaf = path->nodes[0];
214 nritems = btrfs_header_nritems(leaf);
215 slot = path->slots[0];
217 item = btrfs_item_nr(leaf, slot);
218 btrfs_item_key_to_cpu(leaf, &key, slot);
219 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
222 if (key.objectid < objectid)
225 if (key.objectid > objectid)
228 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
229 if (btrfs_disk_root_refs(leaf, ri) != 0)
232 memcpy(&found_key, &key, sizeof(key));
234 btrfs_release_path(root, path);
236 btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
238 if (IS_ERR(dead_root)) {
239 ret = PTR_ERR(dead_root);
243 ret = btrfs_add_dead_root(dead_root);
253 btrfs_free_path(path);
257 int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
259 struct extent_buffer *leaf;
260 struct btrfs_path *path;
261 struct btrfs_key key;
262 struct btrfs_key root_key;
263 struct btrfs_root *root;
267 path = btrfs_alloc_path();
271 key.objectid = BTRFS_ORPHAN_OBJECTID;
272 key.type = BTRFS_ORPHAN_ITEM_KEY;
275 root_key.type = BTRFS_ROOT_ITEM_KEY;
276 root_key.offset = (u64)-1;
279 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
285 leaf = path->nodes[0];
286 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
287 ret = btrfs_next_leaf(tree_root, path);
292 leaf = path->nodes[0];
295 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
296 btrfs_release_path(tree_root, path);
298 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
299 key.type != BTRFS_ORPHAN_ITEM_KEY)
302 root_key.objectid = key.offset;
305 root = btrfs_read_fs_root_no_name(tree_root->fs_info,
311 if (ret != -ENOENT) {
316 ret = btrfs_find_dead_roots(tree_root, root_key.objectid);
323 btrfs_free_path(path);
327 /* drop the root item for 'key' from 'root' */
328 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
329 struct btrfs_key *key)
331 struct btrfs_path *path;
333 struct btrfs_root_item *ri;
334 struct extent_buffer *leaf;
336 path = btrfs_alloc_path();
338 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
343 leaf = path->nodes[0];
344 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
346 ret = btrfs_del_item(trans, root, path);
348 btrfs_free_path(path);
352 int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
353 struct btrfs_root *tree_root,
354 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
355 const char *name, int name_len)
358 struct btrfs_path *path;
359 struct btrfs_root_ref *ref;
360 struct extent_buffer *leaf;
361 struct btrfs_key key;
366 path = btrfs_alloc_path();
370 key.objectid = root_id;
371 key.type = BTRFS_ROOT_BACKREF_KEY;
374 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
377 leaf = path->nodes[0];
378 ref = btrfs_item_ptr(leaf, path->slots[0],
379 struct btrfs_root_ref);
381 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
382 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
383 ptr = (unsigned long)(ref + 1);
384 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
385 *sequence = btrfs_root_ref_sequence(leaf, ref);
387 ret = btrfs_del_item(trans, tree_root, path);
392 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
393 btrfs_release_path(tree_root, path);
394 key.objectid = ref_id;
395 key.type = BTRFS_ROOT_REF_KEY;
396 key.offset = root_id;
400 btrfs_free_path(path);
404 int btrfs_find_root_ref(struct btrfs_root *tree_root,
405 struct btrfs_path *path,
406 u64 root_id, u64 ref_id)
408 struct btrfs_key key;
411 key.objectid = root_id;
412 key.type = BTRFS_ROOT_REF_KEY;
415 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
420 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
421 * or BTRFS_ROOT_BACKREF_KEY.
423 * The dirid, sequence, name and name_len refer to the directory entry
424 * that is referencing the root.
426 * For a forward ref, the root_id is the id of the tree referencing
427 * the root and ref_id is the id of the subvol or snapshot.
429 * For a back ref the root_id is the id of the subvol or snapshot and
430 * ref_id is the id of the tree referencing it.
432 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
433 struct btrfs_root *tree_root,
434 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
435 const char *name, int name_len)
437 struct btrfs_key key;
439 struct btrfs_path *path;
440 struct btrfs_root_ref *ref;
441 struct extent_buffer *leaf;
444 path = btrfs_alloc_path();
448 key.objectid = root_id;
449 key.type = BTRFS_ROOT_BACKREF_KEY;
452 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
453 sizeof(*ref) + name_len);
456 leaf = path->nodes[0];
457 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
458 btrfs_set_root_ref_dirid(leaf, ref, dirid);
459 btrfs_set_root_ref_sequence(leaf, ref, sequence);
460 btrfs_set_root_ref_name_len(leaf, ref, name_len);
461 ptr = (unsigned long)(ref + 1);
462 write_extent_buffer(leaf, name, ptr, name_len);
463 btrfs_mark_buffer_dirty(leaf);
465 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
466 btrfs_release_path(tree_root, path);
467 key.objectid = ref_id;
468 key.type = BTRFS_ROOT_REF_KEY;
469 key.offset = root_id;
473 btrfs_free_path(path);