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();
93 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
98 if (path->slots[0] == 0) {
103 slot = path->slots[0] - 1;
104 btrfs_item_key_to_cpu(l, &found_key, slot);
105 if (found_key.objectid != objectid ||
106 found_key.type != BTRFS_ROOT_ITEM_KEY) {
111 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
114 memcpy(key, &found_key, sizeof(found_key));
117 btrfs_free_path(path);
121 int btrfs_set_root_node(struct btrfs_root_item *item,
122 struct extent_buffer *node)
124 btrfs_set_root_bytenr(item, node->start);
125 btrfs_set_root_level(item, btrfs_header_level(node));
126 btrfs_set_root_generation(item, btrfs_header_generation(node));
131 * copy the data in 'item' into the btree
133 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
134 *root, struct btrfs_key *key, struct btrfs_root_item
137 struct btrfs_path *path;
138 struct extent_buffer *l;
143 path = btrfs_alloc_path();
145 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
150 btrfs_print_leaf(root, path->nodes[0]);
151 printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
152 (unsigned long long)key->objectid, key->type,
153 (unsigned long long)key->offset);
158 slot = path->slots[0];
159 ptr = btrfs_item_ptr_offset(l, slot);
160 write_extent_buffer(l, item, ptr, sizeof(*item));
161 btrfs_mark_buffer_dirty(path->nodes[0]);
163 btrfs_free_path(path);
167 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
168 *root, struct btrfs_key *key, struct btrfs_root_item
172 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
177 * at mount time we want to find all the old transaction snapshots that were in
178 * the process of being deleted if we crashed. This is any root item with an
179 * offset lower than the latest root. They need to be queued for deletion to
180 * finish what was happening when we crashed.
182 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
184 struct btrfs_root *dead_root;
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 btrfs_item_key_to_cpu(leaf, &key, slot);
218 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
221 if (key.objectid < objectid)
224 if (key.objectid > objectid)
227 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
228 if (btrfs_disk_root_refs(leaf, ri) != 0)
231 memcpy(&found_key, &key, sizeof(key));
233 btrfs_release_path(root, path);
235 btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
237 if (IS_ERR(dead_root)) {
238 ret = PTR_ERR(dead_root);
242 ret = btrfs_add_dead_root(dead_root);
252 btrfs_free_path(path);
256 int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
258 struct extent_buffer *leaf;
259 struct btrfs_path *path;
260 struct btrfs_key key;
261 struct btrfs_key root_key;
262 struct btrfs_root *root;
266 path = btrfs_alloc_path();
270 key.objectid = BTRFS_ORPHAN_OBJECTID;
271 key.type = BTRFS_ORPHAN_ITEM_KEY;
274 root_key.type = BTRFS_ROOT_ITEM_KEY;
275 root_key.offset = (u64)-1;
278 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
284 leaf = path->nodes[0];
285 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
286 ret = btrfs_next_leaf(tree_root, path);
291 leaf = path->nodes[0];
294 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
295 btrfs_release_path(tree_root, path);
297 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
298 key.type != BTRFS_ORPHAN_ITEM_KEY)
301 root_key.objectid = key.offset;
304 root = btrfs_read_fs_root_no_name(tree_root->fs_info,
310 if (ret != -ENOENT) {
315 ret = btrfs_find_dead_roots(tree_root, root_key.objectid);
322 btrfs_free_path(path);
326 /* drop the root item for 'key' from 'root' */
327 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
328 struct btrfs_key *key)
330 struct btrfs_path *path;
332 struct btrfs_root_item *ri;
333 struct extent_buffer *leaf;
335 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);
478 * Old btrfs forgets to init root_item->flags and root_item->byte_limit
479 * for subvolumes. To work around this problem, we steal a bit from
480 * root_item->inode_item->flags, and use it to indicate if those fields
481 * have been properly initialized.
483 void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
485 u64 inode_flags = le64_to_cpu(root_item->inode.flags);
487 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
488 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
489 root_item->inode.flags = cpu_to_le64(inode_flags);
490 root_item->flags = 0;
491 root_item->byte_limit = 0;