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 * lookup the root with the highest offset for a given objectid. The key we do
26 * find is copied into 'key'. If we find something return 0, otherwise 1, < 0
29 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
30 struct btrfs_root_item *item, struct btrfs_key *key)
32 struct btrfs_path *path;
33 struct btrfs_key search_key;
34 struct btrfs_key found_key;
35 struct extent_buffer *l;
39 search_key.objectid = objectid;
40 search_key.type = BTRFS_ROOT_ITEM_KEY;
41 search_key.offset = (u64)-1;
43 path = btrfs_alloc_path();
46 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
51 if (path->slots[0] == 0) {
56 slot = path->slots[0] - 1;
57 btrfs_item_key_to_cpu(l, &found_key, slot);
58 if (found_key.objectid != objectid ||
59 found_key.type != BTRFS_ROOT_ITEM_KEY) {
64 read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
67 memcpy(key, &found_key, sizeof(found_key));
70 btrfs_free_path(path);
74 void btrfs_set_root_node(struct btrfs_root_item *item,
75 struct extent_buffer *node)
77 btrfs_set_root_bytenr(item, node->start);
78 btrfs_set_root_level(item, btrfs_header_level(node));
79 btrfs_set_root_generation(item, btrfs_header_generation(node));
83 * copy the data in 'item' into the btree
85 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
86 *root, struct btrfs_key *key, struct btrfs_root_item
89 struct btrfs_path *path;
90 struct extent_buffer *l;
95 path = btrfs_alloc_path();
97 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
102 btrfs_print_leaf(root, path->nodes[0]);
103 printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
104 (unsigned long long)key->objectid, key->type,
105 (unsigned long long)key->offset);
110 slot = path->slots[0];
111 ptr = btrfs_item_ptr_offset(l, slot);
112 write_extent_buffer(l, item, ptr, sizeof(*item));
113 btrfs_mark_buffer_dirty(path->nodes[0]);
115 btrfs_free_path(path);
119 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
120 *root, struct btrfs_key *key, struct btrfs_root_item
124 ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
129 * at mount time we want to find all the old transaction snapshots that were in
130 * the process of being deleted if we crashed. This is any root item with an
131 * offset lower than the latest root. They need to be queued for deletion to
132 * finish what was happening when we crashed.
134 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid)
136 struct btrfs_root *dead_root;
137 struct btrfs_root_item *ri;
138 struct btrfs_key key;
139 struct btrfs_key found_key;
140 struct btrfs_path *path;
143 struct extent_buffer *leaf;
146 key.objectid = objectid;
147 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
149 path = btrfs_alloc_path();
154 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
158 leaf = path->nodes[0];
159 nritems = btrfs_header_nritems(leaf);
160 slot = path->slots[0];
161 if (slot >= nritems) {
162 ret = btrfs_next_leaf(root, path);
165 leaf = path->nodes[0];
166 nritems = btrfs_header_nritems(leaf);
167 slot = path->slots[0];
169 btrfs_item_key_to_cpu(leaf, &key, slot);
170 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
173 if (key.objectid < objectid)
176 if (key.objectid > objectid)
179 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
180 if (btrfs_disk_root_refs(leaf, ri) != 0)
183 memcpy(&found_key, &key, sizeof(key));
185 btrfs_release_path(path);
187 btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
189 if (IS_ERR(dead_root)) {
190 ret = PTR_ERR(dead_root);
194 ret = btrfs_add_dead_root(dead_root);
204 btrfs_free_path(path);
208 int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
210 struct extent_buffer *leaf;
211 struct btrfs_path *path;
212 struct btrfs_key key;
213 struct btrfs_key root_key;
214 struct btrfs_root *root;
218 path = btrfs_alloc_path();
222 key.objectid = BTRFS_ORPHAN_OBJECTID;
223 key.type = BTRFS_ORPHAN_ITEM_KEY;
226 root_key.type = BTRFS_ROOT_ITEM_KEY;
227 root_key.offset = (u64)-1;
230 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
236 leaf = path->nodes[0];
237 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
238 ret = btrfs_next_leaf(tree_root, path);
243 leaf = path->nodes[0];
246 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
247 btrfs_release_path(path);
249 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
250 key.type != BTRFS_ORPHAN_ITEM_KEY)
253 root_key.objectid = key.offset;
256 root = btrfs_read_fs_root_no_name(tree_root->fs_info,
262 if (ret != -ENOENT) {
267 ret = btrfs_find_dead_roots(tree_root, root_key.objectid);
274 btrfs_free_path(path);
278 /* drop the root item for 'key' from 'root' */
279 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
280 struct btrfs_key *key)
282 struct btrfs_path *path;
284 struct btrfs_root_item *ri;
285 struct extent_buffer *leaf;
287 path = btrfs_alloc_path();
290 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
295 leaf = path->nodes[0];
296 ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
298 ret = btrfs_del_item(trans, root, path);
300 btrfs_free_path(path);
304 int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
305 struct btrfs_root *tree_root,
306 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
307 const char *name, int name_len)
310 struct btrfs_path *path;
311 struct btrfs_root_ref *ref;
312 struct extent_buffer *leaf;
313 struct btrfs_key key;
318 path = btrfs_alloc_path();
322 key.objectid = root_id;
323 key.type = BTRFS_ROOT_BACKREF_KEY;
326 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
329 leaf = path->nodes[0];
330 ref = btrfs_item_ptr(leaf, path->slots[0],
331 struct btrfs_root_ref);
333 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
334 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
335 ptr = (unsigned long)(ref + 1);
336 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
337 *sequence = btrfs_root_ref_sequence(leaf, ref);
339 ret = btrfs_del_item(trans, tree_root, path);
347 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
348 btrfs_release_path(path);
349 key.objectid = ref_id;
350 key.type = BTRFS_ROOT_REF_KEY;
351 key.offset = root_id;
356 btrfs_free_path(path);
360 int btrfs_find_root_ref(struct btrfs_root *tree_root,
361 struct btrfs_path *path,
362 u64 root_id, u64 ref_id)
364 struct btrfs_key key;
367 key.objectid = root_id;
368 key.type = BTRFS_ROOT_REF_KEY;
371 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
376 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
377 * or BTRFS_ROOT_BACKREF_KEY.
379 * The dirid, sequence, name and name_len refer to the directory entry
380 * that is referencing the root.
382 * For a forward ref, the root_id is the id of the tree referencing
383 * the root and ref_id is the id of the subvol or snapshot.
385 * For a back ref the root_id is the id of the subvol or snapshot and
386 * ref_id is the id of the tree referencing it.
388 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
389 struct btrfs_root *tree_root,
390 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
391 const char *name, int name_len)
393 struct btrfs_key key;
395 struct btrfs_path *path;
396 struct btrfs_root_ref *ref;
397 struct extent_buffer *leaf;
400 path = btrfs_alloc_path();
404 key.objectid = root_id;
405 key.type = BTRFS_ROOT_BACKREF_KEY;
408 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
409 sizeof(*ref) + name_len);
412 leaf = path->nodes[0];
413 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
414 btrfs_set_root_ref_dirid(leaf, ref, dirid);
415 btrfs_set_root_ref_sequence(leaf, ref, sequence);
416 btrfs_set_root_ref_name_len(leaf, ref, name_len);
417 ptr = (unsigned long)(ref + 1);
418 write_extent_buffer(leaf, name, ptr, name_len);
419 btrfs_mark_buffer_dirty(leaf);
421 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
422 btrfs_release_path(path);
423 key.objectid = ref_id;
424 key.type = BTRFS_ROOT_REF_KEY;
425 key.offset = root_id;
429 btrfs_free_path(path);
434 * Old btrfs forgets to init root_item->flags and root_item->byte_limit
435 * for subvolumes. To work around this problem, we steal a bit from
436 * root_item->inode_item->flags, and use it to indicate if those fields
437 * have been properly initialized.
439 void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
441 u64 inode_flags = le64_to_cpu(root_item->inode.flags);
443 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
444 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
445 root_item->inode.flags = cpu_to_le64(inode_flags);
446 root_item->flags = 0;
447 root_item->byte_limit = 0;