blob: 360a728a639fec403893c6847e1f7859a47dff13 [file] [log] [blame]
Chris Mason6cbd5572007-06-12 09:07:21 -04001/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
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.
7 *
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.
12 *
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.
17 */
18
Sachin Kamat886322e2014-02-17 09:13:57 +053019#include <linux/err.h>
Alexander Block8ea05e32012-07-25 17:35:53 +020020#include <linux/uuid.h>
Chris Mason3768f362007-03-13 16:47:54 -040021#include "ctree.h"
Chris Mason5eda7b52007-06-22 14:16:25 -040022#include "transaction.h"
Chris Mason3768f362007-03-13 16:47:54 -040023#include "disk-io.h"
24#include "print-tree.h"
25
Chris Masonbf4ef672008-05-08 13:26:18 -040026/*
Alexander Block8ea05e32012-07-25 17:35:53 +020027 * Read a root item from the tree. In case we detect a root item smaller then
28 * sizeof(root_item), we know it's an old version of the root structure and
29 * initialize all new fields to zero. The same happens if we detect mismatching
30 * generation numbers as then we know the root was once mounted with an older
31 * kernel that was not aware of the root item structure change.
32 */
Sergei Trofimovich171170c2013-08-14 23:27:46 +030033static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
34 struct btrfs_root_item *item)
Alexander Block8ea05e32012-07-25 17:35:53 +020035{
36 uuid_le uuid;
37 int len;
38 int need_reset = 0;
39
40 len = btrfs_item_size_nr(eb, slot);
41 read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot),
42 min_t(int, len, (int)sizeof(*item)));
43 if (len < sizeof(*item))
44 need_reset = 1;
45 if (!need_reset && btrfs_root_generation(item)
46 != btrfs_root_generation_v2(item)) {
47 if (btrfs_root_generation_v2(item) != 0) {
Frank Holtonefe120a2013-12-20 11:37:06 -050048 printk(KERN_WARNING "BTRFS: mismatching "
Alexander Block8ea05e32012-07-25 17:35:53 +020049 "generation and generation_v2 "
50 "found in root item. This root "
51 "was probably mounted with an "
52 "older kernel. Resetting all "
53 "new fields.\n");
54 }
55 need_reset = 1;
56 }
57 if (need_reset) {
58 memset(&item->generation_v2, 0,
59 sizeof(*item) - offsetof(struct btrfs_root_item,
60 generation_v2));
61
62 uuid_le_gen(&uuid);
63 memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
64 }
65}
66
67/*
Miao Xiecb517ea2013-05-15 07:48:19 +000068 * btrfs_find_root - lookup the root by the key.
69 * root: the root of the root tree
70 * search_key: the key to search
71 * path: the path we search
72 * root_item: the root item of the tree we look for
73 * root_key: the reak key of the tree we look for
74 *
75 * If ->offset of 'seach_key' is -1ULL, it means we are not sure the offset
76 * of the search key, just lookup the root with the highest offset for a
77 * given objectid.
78 *
79 * If we find something return 0, otherwise > 0, < 0 on error.
Chris Masond352ac62008-09-29 15:18:18 -040080 */
Miao Xiecb517ea2013-05-15 07:48:19 +000081int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key,
82 struct btrfs_path *path, struct btrfs_root_item *root_item,
83 struct btrfs_key *root_key)
Chris Mason3768f362007-03-13 16:47:54 -040084{
Chris Mason5f39d392007-10-15 16:14:19 -040085 struct btrfs_key found_key;
86 struct extent_buffer *l;
Chris Mason3768f362007-03-13 16:47:54 -040087 int ret;
88 int slot;
89
Miao Xiecb517ea2013-05-15 07:48:19 +000090 ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
Chris Mason3768f362007-03-13 16:47:54 -040091 if (ret < 0)
Miao Xiecb517ea2013-05-15 07:48:19 +000092 return ret;
Chris Mason5f39d392007-10-15 16:14:19 -040093
Miao Xiecb517ea2013-05-15 07:48:19 +000094 if (search_key->offset != -1ULL) { /* the search key is exact */
95 if (ret > 0)
96 goto out;
97 } else {
98 BUG_ON(ret == 0); /* Logical error */
99 if (path->slots[0] == 0)
100 goto out;
101 path->slots[0]--;
102 ret = 0;
Chris Mason3768f362007-03-13 16:47:54 -0400103 }
Miao Xiecb517ea2013-05-15 07:48:19 +0000104
Yan, Zheng76dda932009-09-21 16:00:26 -0400105 l = path->nodes[0];
Miao Xiecb517ea2013-05-15 07:48:19 +0000106 slot = path->slots[0];
107
Yan, Zheng76dda932009-09-21 16:00:26 -0400108 btrfs_item_key_to_cpu(l, &found_key, slot);
Miao Xiecb517ea2013-05-15 07:48:19 +0000109 if (found_key.objectid != search_key->objectid ||
Yan, Zheng76dda932009-09-21 16:00:26 -0400110 found_key.type != BTRFS_ROOT_ITEM_KEY) {
111 ret = 1;
112 goto out;
113 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200114
Miao Xiecb517ea2013-05-15 07:48:19 +0000115 if (root_item)
116 btrfs_read_root_item(l, slot, root_item);
117 if (root_key)
118 memcpy(root_key, &found_key, sizeof(found_key));
Chris Mason3768f362007-03-13 16:47:54 -0400119out:
Miao Xiecb517ea2013-05-15 07:48:19 +0000120 btrfs_release_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400121 return ret;
122}
123
Mark Fashehbf5f32e2011-07-14 21:23:06 +0000124void btrfs_set_root_node(struct btrfs_root_item *item,
125 struct extent_buffer *node)
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400126{
127 btrfs_set_root_bytenr(item, node->start);
128 btrfs_set_root_level(item, btrfs_header_level(node));
129 btrfs_set_root_generation(item, btrfs_header_generation(node));
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400130}
131
Chris Masond352ac62008-09-29 15:18:18 -0400132/*
133 * copy the data in 'item' into the btree
134 */
Chris Masone089f052007-03-16 16:20:31 -0400135int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
136 *root, struct btrfs_key *key, struct btrfs_root_item
137 *item)
Chris Mason3768f362007-03-13 16:47:54 -0400138{
Chris Mason5caf2a02007-04-02 11:20:42 -0400139 struct btrfs_path *path;
Chris Mason5f39d392007-10-15 16:14:19 -0400140 struct extent_buffer *l;
Chris Mason3768f362007-03-13 16:47:54 -0400141 int ret;
142 int slot;
Chris Mason5f39d392007-10-15 16:14:19 -0400143 unsigned long ptr;
Alexander Block8ea05e32012-07-25 17:35:53 +0200144 int old_len;
Chris Mason3768f362007-03-13 16:47:54 -0400145
Chris Mason5caf2a02007-04-02 11:20:42 -0400146 path = btrfs_alloc_path();
Jeff Mahoneyb45a9d82011-10-03 23:22:44 -0400147 if (!path)
148 return -ENOMEM;
149
Chris Mason5caf2a02007-04-02 11:20:42 -0400150 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
David Sterba005d6422012-09-18 07:52:32 -0600151 if (ret < 0) {
152 btrfs_abort_transaction(trans, root, ret);
153 goto out;
154 }
Chris Masond6667462008-01-03 14:51:00 -0500155
156 if (ret != 0) {
157 btrfs_print_leaf(root, path->nodes[0]);
Frank Holtonefe120a2013-12-20 11:37:06 -0500158 btrfs_crit(root->fs_info, "unable to update root key %llu %u %llu",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +0200159 key->objectid, key->type, key->offset);
Chris Masond6667462008-01-03 14:51:00 -0500160 BUG_ON(1);
161 }
162
Chris Mason5f39d392007-10-15 16:14:19 -0400163 l = path->nodes[0];
Chris Mason5caf2a02007-04-02 11:20:42 -0400164 slot = path->slots[0];
Chris Mason5f39d392007-10-15 16:14:19 -0400165 ptr = btrfs_item_ptr_offset(l, slot);
Alexander Block8ea05e32012-07-25 17:35:53 +0200166 old_len = btrfs_item_size_nr(l, slot);
167
168 /*
169 * If this is the first time we update the root item which originated
170 * from an older kernel, we need to enlarge the item size to make room
171 * for the added fields.
172 */
173 if (old_len < sizeof(*item)) {
174 btrfs_release_path(path);
175 ret = btrfs_search_slot(trans, root, key, path,
176 -1, 1);
David Sterba005d6422012-09-18 07:52:32 -0600177 if (ret < 0) {
178 btrfs_abort_transaction(trans, root, ret);
179 goto out;
180 }
181
Alexander Block8ea05e32012-07-25 17:35:53 +0200182 ret = btrfs_del_item(trans, root, path);
David Sterba005d6422012-09-18 07:52:32 -0600183 if (ret < 0) {
184 btrfs_abort_transaction(trans, root, ret);
185 goto out;
186 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200187 btrfs_release_path(path);
188 ret = btrfs_insert_empty_item(trans, root, path,
189 key, sizeof(*item));
David Sterba005d6422012-09-18 07:52:32 -0600190 if (ret < 0) {
191 btrfs_abort_transaction(trans, root, ret);
192 goto out;
193 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200194 l = path->nodes[0];
195 slot = path->slots[0];
196 ptr = btrfs_item_ptr_offset(l, slot);
197 }
198
199 /*
200 * Update generation_v2 so at the next mount we know the new root
201 * fields are valid.
202 */
203 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
204
Chris Mason5f39d392007-10-15 16:14:19 -0400205 write_extent_buffer(l, item, ptr, sizeof(*item));
Chris Mason5caf2a02007-04-02 11:20:42 -0400206 btrfs_mark_buffer_dirty(path->nodes[0]);
Chris Mason3768f362007-03-13 16:47:54 -0400207out:
Chris Mason5caf2a02007-04-02 11:20:42 -0400208 btrfs_free_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400209 return ret;
210}
211
Jeff Mahoneyd16cb052011-10-03 23:22:34 -0400212int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
213 struct btrfs_key *key, struct btrfs_root_item *item)
Chris Mason3768f362007-03-13 16:47:54 -0400214{
Alexander Block8ea05e32012-07-25 17:35:53 +0200215 /*
216 * Make sure generation v1 and v2 match. See update_root for details.
217 */
218 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
Jeff Mahoneyd16cb052011-10-03 23:22:34 -0400219 return btrfs_insert_item(trans, root, key, item, sizeof(*item));
Chris Mason3768f362007-03-13 16:47:54 -0400220}
221
Yan, Zheng76dda932009-09-21 16:00:26 -0400222int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
223{
224 struct extent_buffer *leaf;
225 struct btrfs_path *path;
226 struct btrfs_key key;
Yan, Zhengd68fc572010-05-16 10:49:58 -0400227 struct btrfs_key root_key;
228 struct btrfs_root *root;
Yan, Zheng76dda932009-09-21 16:00:26 -0400229 int err = 0;
230 int ret;
Josef Bacik68a73422013-06-27 11:32:16 -0400231 bool can_recover = true;
232
233 if (tree_root->fs_info->sb->s_flags & MS_RDONLY)
234 can_recover = false;
Yan, Zheng76dda932009-09-21 16:00:26 -0400235
236 path = btrfs_alloc_path();
237 if (!path)
238 return -ENOMEM;
239
240 key.objectid = BTRFS_ORPHAN_OBJECTID;
241 key.type = BTRFS_ORPHAN_ITEM_KEY;
242 key.offset = 0;
243
Yan, Zhengd68fc572010-05-16 10:49:58 -0400244 root_key.type = BTRFS_ROOT_ITEM_KEY;
245 root_key.offset = (u64)-1;
246
Yan, Zheng76dda932009-09-21 16:00:26 -0400247 while (1) {
248 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
249 if (ret < 0) {
250 err = ret;
251 break;
252 }
253
254 leaf = path->nodes[0];
255 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
256 ret = btrfs_next_leaf(tree_root, path);
257 if (ret < 0)
258 err = ret;
259 if (ret != 0)
260 break;
261 leaf = path->nodes[0];
262 }
263
264 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
David Sterbab3b4aa72011-04-21 01:20:15 +0200265 btrfs_release_path(path);
Yan, Zheng76dda932009-09-21 16:00:26 -0400266
267 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
268 key.type != BTRFS_ORPHAN_ITEM_KEY)
269 break;
270
Yan, Zhengd68fc572010-05-16 10:49:58 -0400271 root_key.objectid = key.offset;
272 key.offset++;
273
Miao Xiecb517ea2013-05-15 07:48:19 +0000274 root = btrfs_read_fs_root(tree_root, &root_key);
Sachin Kamat886322e2014-02-17 09:13:57 +0530275 err = PTR_ERR_OR_ZERO(root);
Josef Bacik68a73422013-06-27 11:32:16 -0400276 if (err && err != -ENOENT) {
Yan, Zheng76dda932009-09-21 16:00:26 -0400277 break;
Josef Bacik68a73422013-06-27 11:32:16 -0400278 } else if (err == -ENOENT) {
279 struct btrfs_trans_handle *trans;
280
281 btrfs_release_path(path);
282
283 trans = btrfs_join_transaction(tree_root);
284 if (IS_ERR(trans)) {
285 err = PTR_ERR(trans);
286 btrfs_error(tree_root->fs_info, err,
287 "Failed to start trans to delete "
288 "orphan item");
289 break;
290 }
291 err = btrfs_del_orphan_item(trans, tree_root,
292 root_key.objectid);
293 btrfs_end_transaction(trans, tree_root);
294 if (err) {
295 btrfs_error(tree_root->fs_info, err,
296 "Failed to delete root orphan "
297 "item");
298 break;
299 }
300 continue;
Yan, Zheng76dda932009-09-21 16:00:26 -0400301 }
302
Miao Xiecb517ea2013-05-15 07:48:19 +0000303 err = btrfs_init_fs_root(root);
304 if (err) {
305 btrfs_free_fs_root(root);
306 break;
307 }
308
Miao Xie27cdeb72014-04-02 19:51:05 +0800309 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
Miao Xiecb517ea2013-05-15 07:48:19 +0000310
311 err = btrfs_insert_fs_root(root->fs_info, root);
312 if (err) {
313 BUG_ON(err == -EEXIST);
314 btrfs_free_fs_root(root);
Yan, Zhengd68fc572010-05-16 10:49:58 -0400315 break;
316 }
Miao Xie14927d92013-09-25 21:47:43 +0800317
318 if (btrfs_root_refs(&root->root_item) == 0)
319 btrfs_add_dead_root(root);
Yan, Zheng76dda932009-09-21 16:00:26 -0400320 }
321
322 btrfs_free_path(path);
323 return err;
324}
325
Chris Masond352ac62008-09-29 15:18:18 -0400326/* drop the root item for 'key' from 'root' */
Chris Masone089f052007-03-16 16:20:31 -0400327int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
328 struct btrfs_key *key)
Chris Mason3768f362007-03-13 16:47:54 -0400329{
Chris Mason5caf2a02007-04-02 11:20:42 -0400330 struct btrfs_path *path;
Chris Mason3768f362007-03-13 16:47:54 -0400331 int ret;
332
Chris Mason5caf2a02007-04-02 11:20:42 -0400333 path = btrfs_alloc_path();
Tsutomu Itohdb5b4932011-03-23 08:14:16 +0000334 if (!path)
335 return -ENOMEM;
Chris Mason5caf2a02007-04-02 11:20:42 -0400336 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
Chris Mason3768f362007-03-13 16:47:54 -0400337 if (ret < 0)
338 goto out;
Chris Masonedbd8d42007-12-21 16:27:24 -0500339
Chris Mason3768f362007-03-13 16:47:54 -0400340 BUG_ON(ret != 0);
Chris Masonc5739bb2007-04-10 09:27:04 -0400341
Chris Mason5eda7b52007-06-22 14:16:25 -0400342 ret = btrfs_del_item(trans, root, path);
Chris Mason3768f362007-03-13 16:47:54 -0400343out:
Chris Mason5caf2a02007-04-02 11:20:42 -0400344 btrfs_free_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400345 return ret;
346}
Chris Mason0660b5a2008-11-17 20:37:39 -0500347
348int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
349 struct btrfs_root *tree_root,
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400350 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
351 const char *name, int name_len)
352
Chris Mason0660b5a2008-11-17 20:37:39 -0500353{
Chris Mason0660b5a2008-11-17 20:37:39 -0500354 struct btrfs_path *path;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400355 struct btrfs_root_ref *ref;
356 struct extent_buffer *leaf;
357 struct btrfs_key key;
358 unsigned long ptr;
359 int err = 0;
360 int ret;
Chris Mason0660b5a2008-11-17 20:37:39 -0500361
362 path = btrfs_alloc_path();
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400363 if (!path)
364 return -ENOMEM;
Chris Mason0660b5a2008-11-17 20:37:39 -0500365
366 key.objectid = root_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400367 key.type = BTRFS_ROOT_BACKREF_KEY;
Chris Mason0660b5a2008-11-17 20:37:39 -0500368 key.offset = ref_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400369again:
Chris Mason0660b5a2008-11-17 20:37:39 -0500370 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400371 BUG_ON(ret < 0);
372 if (ret == 0) {
373 leaf = path->nodes[0];
374 ref = btrfs_item_ptr(leaf, path->slots[0],
375 struct btrfs_root_ref);
Chris Mason0660b5a2008-11-17 20:37:39 -0500376
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400377 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
378 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
379 ptr = (unsigned long)(ref + 1);
380 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
381 *sequence = btrfs_root_ref_sequence(leaf, ref);
382
383 ret = btrfs_del_item(trans, tree_root, path);
Tsutomu Itoh65a246c2011-05-19 04:37:44 +0000384 if (ret) {
385 err = ret;
386 goto out;
387 }
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400388 } else
389 err = -ENOENT;
390
391 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
David Sterbab3b4aa72011-04-21 01:20:15 +0200392 btrfs_release_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400393 key.objectid = ref_id;
394 key.type = BTRFS_ROOT_REF_KEY;
395 key.offset = root_id;
396 goto again;
397 }
Chris Mason0660b5a2008-11-17 20:37:39 -0500398
Tsutomu Itoh65a246c2011-05-19 04:37:44 +0000399out:
Chris Mason0660b5a2008-11-17 20:37:39 -0500400 btrfs_free_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400401 return err;
Chris Mason0660b5a2008-11-17 20:37:39 -0500402}
403
404/*
405 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
406 * or BTRFS_ROOT_BACKREF_KEY.
407 *
408 * The dirid, sequence, name and name_len refer to the directory entry
409 * that is referencing the root.
410 *
411 * For a forward ref, the root_id is the id of the tree referencing
412 * the root and ref_id is the id of the subvol or snapshot.
413 *
414 * For a back ref the root_id is the id of the subvol or snapshot and
415 * ref_id is the id of the tree referencing it.
Jeff Mahoney79787ea2012-03-12 16:03:00 +0100416 *
417 * Will return 0, -ENOMEM, or anything from the CoW path
Chris Mason0660b5a2008-11-17 20:37:39 -0500418 */
419int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
420 struct btrfs_root *tree_root,
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400421 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
Chris Mason0660b5a2008-11-17 20:37:39 -0500422 const char *name, int name_len)
423{
424 struct btrfs_key key;
425 int ret;
426 struct btrfs_path *path;
427 struct btrfs_root_ref *ref;
428 struct extent_buffer *leaf;
429 unsigned long ptr;
430
Chris Mason0660b5a2008-11-17 20:37:39 -0500431 path = btrfs_alloc_path();
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400432 if (!path)
433 return -ENOMEM;
Chris Mason0660b5a2008-11-17 20:37:39 -0500434
435 key.objectid = root_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400436 key.type = BTRFS_ROOT_BACKREF_KEY;
Chris Mason0660b5a2008-11-17 20:37:39 -0500437 key.offset = ref_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400438again:
Chris Mason0660b5a2008-11-17 20:37:39 -0500439 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
440 sizeof(*ref) + name_len);
Jeff Mahoney79787ea2012-03-12 16:03:00 +0100441 if (ret) {
442 btrfs_abort_transaction(trans, tree_root, ret);
443 btrfs_free_path(path);
444 return ret;
445 }
Chris Mason0660b5a2008-11-17 20:37:39 -0500446
447 leaf = path->nodes[0];
448 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
449 btrfs_set_root_ref_dirid(leaf, ref, dirid);
450 btrfs_set_root_ref_sequence(leaf, ref, sequence);
451 btrfs_set_root_ref_name_len(leaf, ref, name_len);
452 ptr = (unsigned long)(ref + 1);
453 write_extent_buffer(leaf, name, ptr, name_len);
454 btrfs_mark_buffer_dirty(leaf);
455
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400456 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
David Sterbab3b4aa72011-04-21 01:20:15 +0200457 btrfs_release_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400458 key.objectid = ref_id;
459 key.type = BTRFS_ROOT_REF_KEY;
460 key.offset = root_id;
461 goto again;
462 }
463
Chris Mason0660b5a2008-11-17 20:37:39 -0500464 btrfs_free_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400465 return 0;
Chris Mason0660b5a2008-11-17 20:37:39 -0500466}
Li Zefan08fe4db2011-03-28 02:01:25 +0000467
468/*
469 * Old btrfs forgets to init root_item->flags and root_item->byte_limit
470 * for subvolumes. To work around this problem, we steal a bit from
471 * root_item->inode_item->flags, and use it to indicate if those fields
472 * have been properly initialized.
473 */
474void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
475{
Qu Wenruo3cae2102013-07-16 11:19:18 +0800476 u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
Li Zefan08fe4db2011-03-28 02:01:25 +0000477
478 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
479 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
Qu Wenruo3cae2102013-07-16 11:19:18 +0800480 btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
481 btrfs_set_root_flags(root_item, 0);
482 btrfs_set_root_limit(root_item, 0);
Li Zefan08fe4db2011-03-28 02:01:25 +0000483 }
484}
Alexander Block8ea05e32012-07-25 17:35:53 +0200485
486void btrfs_update_root_times(struct btrfs_trans_handle *trans,
487 struct btrfs_root *root)
488{
489 struct btrfs_root_item *item = &root->root_item;
490 struct timespec ct = CURRENT_TIME;
491
Anand Jain5f3ab902012-12-07 09:28:54 +0000492 spin_lock(&root->root_item_lock);
Qu Wenruo3cae2102013-07-16 11:19:18 +0800493 btrfs_set_root_ctransid(item, trans->transid);
494 btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
495 btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
Anand Jain5f3ab902012-12-07 09:28:54 +0000496 spin_unlock(&root->root_item_lock);
Alexander Block8ea05e32012-07-25 17:35:53 +0200497}