blob: f1c30861d062713e8feaaf5886c7bbca2596aa88 [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) {
David Sterbaf14d1042015-10-08 11:37:06 +020048 btrfs_warn(eb->fs_info,
49 "mismatching "
Alexander Block8ea05e32012-07-25 17:35:53 +020050 "generation and generation_v2 "
51 "found in root item. This root "
52 "was probably mounted with an "
53 "older kernel. Resetting all "
David Sterbaf14d1042015-10-08 11:37:06 +020054 "new fields.");
Alexander Block8ea05e32012-07-25 17:35:53 +020055 }
56 need_reset = 1;
57 }
58 if (need_reset) {
59 memset(&item->generation_v2, 0,
60 sizeof(*item) - offsetof(struct btrfs_root_item,
61 generation_v2));
62
63 uuid_le_gen(&uuid);
64 memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
65 }
66}
67
68/*
Miao Xiecb517ea2013-05-15 07:48:19 +000069 * btrfs_find_root - lookup the root by the key.
70 * root: the root of the root tree
71 * search_key: the key to search
72 * path: the path we search
73 * root_item: the root item of the tree we look for
Nicholas D Steeves01327612016-05-19 21:18:45 -040074 * root_key: the root key of the tree we look for
Miao Xiecb517ea2013-05-15 07:48:19 +000075 *
Nicholas D Steeves01327612016-05-19 21:18:45 -040076 * If ->offset of 'search_key' is -1ULL, it means we are not sure the offset
Miao Xiecb517ea2013-05-15 07:48:19 +000077 * of the search key, just lookup the root with the highest offset for a
78 * given objectid.
79 *
80 * If we find something return 0, otherwise > 0, < 0 on error.
Chris Masond352ac62008-09-29 15:18:18 -040081 */
Miao Xiecb517ea2013-05-15 07:48:19 +000082int btrfs_find_root(struct btrfs_root *root, struct btrfs_key *search_key,
83 struct btrfs_path *path, struct btrfs_root_item *root_item,
84 struct btrfs_key *root_key)
Chris Mason3768f362007-03-13 16:47:54 -040085{
Chris Mason5f39d392007-10-15 16:14:19 -040086 struct btrfs_key found_key;
87 struct extent_buffer *l;
Chris Mason3768f362007-03-13 16:47:54 -040088 int ret;
89 int slot;
90
Miao Xiecb517ea2013-05-15 07:48:19 +000091 ret = btrfs_search_slot(NULL, root, search_key, path, 0, 0);
Chris Mason3768f362007-03-13 16:47:54 -040092 if (ret < 0)
Miao Xiecb517ea2013-05-15 07:48:19 +000093 return ret;
Chris Mason5f39d392007-10-15 16:14:19 -040094
Miao Xiecb517ea2013-05-15 07:48:19 +000095 if (search_key->offset != -1ULL) { /* the search key is exact */
96 if (ret > 0)
97 goto out;
98 } else {
99 BUG_ON(ret == 0); /* Logical error */
100 if (path->slots[0] == 0)
101 goto out;
102 path->slots[0]--;
103 ret = 0;
Chris Mason3768f362007-03-13 16:47:54 -0400104 }
Miao Xiecb517ea2013-05-15 07:48:19 +0000105
Yan, Zheng76dda932009-09-21 16:00:26 -0400106 l = path->nodes[0];
Miao Xiecb517ea2013-05-15 07:48:19 +0000107 slot = path->slots[0];
108
Yan, Zheng76dda932009-09-21 16:00:26 -0400109 btrfs_item_key_to_cpu(l, &found_key, slot);
Miao Xiecb517ea2013-05-15 07:48:19 +0000110 if (found_key.objectid != search_key->objectid ||
Yan, Zheng76dda932009-09-21 16:00:26 -0400111 found_key.type != BTRFS_ROOT_ITEM_KEY) {
112 ret = 1;
113 goto out;
114 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200115
Miao Xiecb517ea2013-05-15 07:48:19 +0000116 if (root_item)
117 btrfs_read_root_item(l, slot, root_item);
118 if (root_key)
119 memcpy(root_key, &found_key, sizeof(found_key));
Chris Mason3768f362007-03-13 16:47:54 -0400120out:
Miao Xiecb517ea2013-05-15 07:48:19 +0000121 btrfs_release_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400122 return ret;
123}
124
Mark Fashehbf5f32e2011-07-14 21:23:06 +0000125void btrfs_set_root_node(struct btrfs_root_item *item,
126 struct extent_buffer *node)
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400127{
128 btrfs_set_root_bytenr(item, node->start);
129 btrfs_set_root_level(item, btrfs_header_level(node));
130 btrfs_set_root_generation(item, btrfs_header_generation(node));
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400131}
132
Chris Masond352ac62008-09-29 15:18:18 -0400133/*
134 * copy the data in 'item' into the btree
135 */
Chris Masone089f052007-03-16 16:20:31 -0400136int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
137 *root, struct btrfs_key *key, struct btrfs_root_item
138 *item)
Chris Mason3768f362007-03-13 16:47:54 -0400139{
Chris Mason5caf2a02007-04-02 11:20:42 -0400140 struct btrfs_path *path;
Chris Mason5f39d392007-10-15 16:14:19 -0400141 struct extent_buffer *l;
Chris Mason3768f362007-03-13 16:47:54 -0400142 int ret;
143 int slot;
Chris Mason5f39d392007-10-15 16:14:19 -0400144 unsigned long ptr;
Alexandru Moise0412e582015-08-24 21:56:28 +0000145 u32 old_len;
Chris Mason3768f362007-03-13 16:47:54 -0400146
Chris Mason5caf2a02007-04-02 11:20:42 -0400147 path = btrfs_alloc_path();
Jeff Mahoneyb45a9d82011-10-03 23:22:44 -0400148 if (!path)
149 return -ENOMEM;
150
Chris Mason5caf2a02007-04-02 11:20:42 -0400151 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
David Sterba005d6422012-09-18 07:52:32 -0600152 if (ret < 0) {
153 btrfs_abort_transaction(trans, root, ret);
154 goto out;
155 }
Chris Masond6667462008-01-03 14:51:00 -0500156
157 if (ret != 0) {
158 btrfs_print_leaf(root, path->nodes[0]);
Frank Holtonefe120a2013-12-20 11:37:06 -0500159 btrfs_crit(root->fs_info, "unable to update root key %llu %u %llu",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +0200160 key->objectid, key->type, key->offset);
Chris Masond6667462008-01-03 14:51:00 -0500161 BUG_ON(1);
162 }
163
Chris Mason5f39d392007-10-15 16:14:19 -0400164 l = path->nodes[0];
Chris Mason5caf2a02007-04-02 11:20:42 -0400165 slot = path->slots[0];
Chris Mason5f39d392007-10-15 16:14:19 -0400166 ptr = btrfs_item_ptr_offset(l, slot);
Alexander Block8ea05e32012-07-25 17:35:53 +0200167 old_len = btrfs_item_size_nr(l, slot);
168
169 /*
170 * If this is the first time we update the root item which originated
171 * from an older kernel, we need to enlarge the item size to make room
172 * for the added fields.
173 */
174 if (old_len < sizeof(*item)) {
175 btrfs_release_path(path);
176 ret = btrfs_search_slot(trans, root, key, path,
177 -1, 1);
David Sterba005d6422012-09-18 07:52:32 -0600178 if (ret < 0) {
179 btrfs_abort_transaction(trans, root, ret);
180 goto out;
181 }
182
Alexander Block8ea05e32012-07-25 17:35:53 +0200183 ret = btrfs_del_item(trans, root, path);
David Sterba005d6422012-09-18 07:52:32 -0600184 if (ret < 0) {
185 btrfs_abort_transaction(trans, root, ret);
186 goto out;
187 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200188 btrfs_release_path(path);
189 ret = btrfs_insert_empty_item(trans, root, path,
190 key, sizeof(*item));
David Sterba005d6422012-09-18 07:52:32 -0600191 if (ret < 0) {
192 btrfs_abort_transaction(trans, root, ret);
193 goto out;
194 }
Alexander Block8ea05e32012-07-25 17:35:53 +0200195 l = path->nodes[0];
196 slot = path->slots[0];
197 ptr = btrfs_item_ptr_offset(l, slot);
198 }
199
200 /*
201 * Update generation_v2 so at the next mount we know the new root
202 * fields are valid.
203 */
204 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
205
Chris Mason5f39d392007-10-15 16:14:19 -0400206 write_extent_buffer(l, item, ptr, sizeof(*item));
Chris Mason5caf2a02007-04-02 11:20:42 -0400207 btrfs_mark_buffer_dirty(path->nodes[0]);
Chris Mason3768f362007-03-13 16:47:54 -0400208out:
Chris Mason5caf2a02007-04-02 11:20:42 -0400209 btrfs_free_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400210 return ret;
211}
212
Jeff Mahoneyd16cb052011-10-03 23:22:34 -0400213int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
214 struct btrfs_key *key, struct btrfs_root_item *item)
Chris Mason3768f362007-03-13 16:47:54 -0400215{
Alexander Block8ea05e32012-07-25 17:35:53 +0200216 /*
217 * Make sure generation v1 and v2 match. See update_root for details.
218 */
219 btrfs_set_root_generation_v2(item, btrfs_root_generation(item));
Jeff Mahoneyd16cb052011-10-03 23:22:34 -0400220 return btrfs_insert_item(trans, root, key, item, sizeof(*item));
Chris Mason3768f362007-03-13 16:47:54 -0400221}
222
Yan, Zheng76dda932009-09-21 16:00:26 -0400223int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
224{
225 struct extent_buffer *leaf;
226 struct btrfs_path *path;
227 struct btrfs_key key;
Yan, Zhengd68fc572010-05-16 10:49:58 -0400228 struct btrfs_key root_key;
229 struct btrfs_root *root;
Yan, Zheng76dda932009-09-21 16:00:26 -0400230 int err = 0;
231 int ret;
Josef Bacik68a73422013-06-27 11:32:16 -0400232 bool can_recover = true;
233
234 if (tree_root->fs_info->sb->s_flags & MS_RDONLY)
235 can_recover = false;
Yan, Zheng76dda932009-09-21 16:00:26 -0400236
237 path = btrfs_alloc_path();
238 if (!path)
239 return -ENOMEM;
240
241 key.objectid = BTRFS_ORPHAN_OBJECTID;
242 key.type = BTRFS_ORPHAN_ITEM_KEY;
243 key.offset = 0;
244
Yan, Zhengd68fc572010-05-16 10:49:58 -0400245 root_key.type = BTRFS_ROOT_ITEM_KEY;
246 root_key.offset = (u64)-1;
247
Yan, Zheng76dda932009-09-21 16:00:26 -0400248 while (1) {
249 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
250 if (ret < 0) {
251 err = ret;
252 break;
253 }
254
255 leaf = path->nodes[0];
256 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
257 ret = btrfs_next_leaf(tree_root, path);
258 if (ret < 0)
259 err = ret;
260 if (ret != 0)
261 break;
262 leaf = path->nodes[0];
263 }
264
265 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
David Sterbab3b4aa72011-04-21 01:20:15 +0200266 btrfs_release_path(path);
Yan, Zheng76dda932009-09-21 16:00:26 -0400267
268 if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
269 key.type != BTRFS_ORPHAN_ITEM_KEY)
270 break;
271
Yan, Zhengd68fc572010-05-16 10:49:58 -0400272 root_key.objectid = key.offset;
273 key.offset++;
274
Miao Xiecb517ea2013-05-15 07:48:19 +0000275 root = btrfs_read_fs_root(tree_root, &root_key);
Sachin Kamat886322e2014-02-17 09:13:57 +0530276 err = PTR_ERR_OR_ZERO(root);
Josef Bacik68a73422013-06-27 11:32:16 -0400277 if (err && err != -ENOENT) {
Yan, Zheng76dda932009-09-21 16:00:26 -0400278 break;
Josef Bacik68a73422013-06-27 11:32:16 -0400279 } else if (err == -ENOENT) {
280 struct btrfs_trans_handle *trans;
281
282 btrfs_release_path(path);
283
284 trans = btrfs_join_transaction(tree_root);
285 if (IS_ERR(trans)) {
286 err = PTR_ERR(trans);
Anand Jain34d97002016-03-16 16:43:06 +0800287 btrfs_handle_fs_error(tree_root->fs_info, err,
Josef Bacik68a73422013-06-27 11:32:16 -0400288 "Failed to start trans to delete "
289 "orphan item");
290 break;
291 }
292 err = btrfs_del_orphan_item(trans, tree_root,
293 root_key.objectid);
294 btrfs_end_transaction(trans, tree_root);
295 if (err) {
Anand Jain34d97002016-03-16 16:43:06 +0800296 btrfs_handle_fs_error(tree_root->fs_info, err,
Josef Bacik68a73422013-06-27 11:32:16 -0400297 "Failed to delete root orphan "
298 "item");
299 break;
300 }
301 continue;
Yan, Zheng76dda932009-09-21 16:00:26 -0400302 }
303
Miao Xiecb517ea2013-05-15 07:48:19 +0000304 err = btrfs_init_fs_root(root);
305 if (err) {
306 btrfs_free_fs_root(root);
307 break;
308 }
309
Miao Xie27cdeb72014-04-02 19:51:05 +0800310 set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state);
Miao Xiecb517ea2013-05-15 07:48:19 +0000311
312 err = btrfs_insert_fs_root(root->fs_info, root);
Filipe Manana909c3a22016-03-02 15:49:38 +0000313 /*
314 * The root might have been inserted already, as before we look
315 * for orphan roots, log replay might have happened, which
316 * triggers a transaction commit and qgroup accounting, which
317 * in turn reads and inserts fs roots while doing backref
318 * walking.
319 */
320 if (err == -EEXIST)
321 err = 0;
Miao Xiecb517ea2013-05-15 07:48:19 +0000322 if (err) {
Miao Xiecb517ea2013-05-15 07:48:19 +0000323 btrfs_free_fs_root(root);
Yan, Zhengd68fc572010-05-16 10:49:58 -0400324 break;
325 }
Miao Xie14927d92013-09-25 21:47:43 +0800326
327 if (btrfs_root_refs(&root->root_item) == 0)
328 btrfs_add_dead_root(root);
Yan, Zheng76dda932009-09-21 16:00:26 -0400329 }
330
331 btrfs_free_path(path);
332 return err;
333}
334
Chris Masond352ac62008-09-29 15:18:18 -0400335/* drop the root item for 'key' from 'root' */
Chris Masone089f052007-03-16 16:20:31 -0400336int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
337 struct btrfs_key *key)
Chris Mason3768f362007-03-13 16:47:54 -0400338{
Chris Mason5caf2a02007-04-02 11:20:42 -0400339 struct btrfs_path *path;
Chris Mason3768f362007-03-13 16:47:54 -0400340 int ret;
341
Chris Mason5caf2a02007-04-02 11:20:42 -0400342 path = btrfs_alloc_path();
Tsutomu Itohdb5b4932011-03-23 08:14:16 +0000343 if (!path)
344 return -ENOMEM;
Chris Mason5caf2a02007-04-02 11:20:42 -0400345 ret = btrfs_search_slot(trans, root, key, path, -1, 1);
Chris Mason3768f362007-03-13 16:47:54 -0400346 if (ret < 0)
347 goto out;
Chris Masonedbd8d42007-12-21 16:27:24 -0500348
Chris Mason3768f362007-03-13 16:47:54 -0400349 BUG_ON(ret != 0);
Chris Masonc5739bb2007-04-10 09:27:04 -0400350
Chris Mason5eda7b52007-06-22 14:16:25 -0400351 ret = btrfs_del_item(trans, root, path);
Chris Mason3768f362007-03-13 16:47:54 -0400352out:
Chris Mason5caf2a02007-04-02 11:20:42 -0400353 btrfs_free_path(path);
Chris Mason3768f362007-03-13 16:47:54 -0400354 return ret;
355}
Chris Mason0660b5a2008-11-17 20:37:39 -0500356
357int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
358 struct btrfs_root *tree_root,
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400359 u64 root_id, u64 ref_id, u64 dirid, u64 *sequence,
360 const char *name, int name_len)
361
Chris Mason0660b5a2008-11-17 20:37:39 -0500362{
Chris Mason0660b5a2008-11-17 20:37:39 -0500363 struct btrfs_path *path;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400364 struct btrfs_root_ref *ref;
365 struct extent_buffer *leaf;
366 struct btrfs_key key;
367 unsigned long ptr;
368 int err = 0;
369 int ret;
Chris Mason0660b5a2008-11-17 20:37:39 -0500370
371 path = btrfs_alloc_path();
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400372 if (!path)
373 return -ENOMEM;
Chris Mason0660b5a2008-11-17 20:37:39 -0500374
375 key.objectid = root_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400376 key.type = BTRFS_ROOT_BACKREF_KEY;
Chris Mason0660b5a2008-11-17 20:37:39 -0500377 key.offset = ref_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400378again:
Chris Mason0660b5a2008-11-17 20:37:39 -0500379 ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400380 BUG_ON(ret < 0);
381 if (ret == 0) {
382 leaf = path->nodes[0];
383 ref = btrfs_item_ptr(leaf, path->slots[0],
384 struct btrfs_root_ref);
Chris Mason0660b5a2008-11-17 20:37:39 -0500385
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400386 WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
387 WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
388 ptr = (unsigned long)(ref + 1);
389 WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
390 *sequence = btrfs_root_ref_sequence(leaf, ref);
391
392 ret = btrfs_del_item(trans, tree_root, path);
Tsutomu Itoh65a246c2011-05-19 04:37:44 +0000393 if (ret) {
394 err = ret;
395 goto out;
396 }
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400397 } else
398 err = -ENOENT;
399
400 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
David Sterbab3b4aa72011-04-21 01:20:15 +0200401 btrfs_release_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400402 key.objectid = ref_id;
403 key.type = BTRFS_ROOT_REF_KEY;
404 key.offset = root_id;
405 goto again;
406 }
Chris Mason0660b5a2008-11-17 20:37:39 -0500407
Tsutomu Itoh65a246c2011-05-19 04:37:44 +0000408out:
Chris Mason0660b5a2008-11-17 20:37:39 -0500409 btrfs_free_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400410 return err;
Chris Mason0660b5a2008-11-17 20:37:39 -0500411}
412
413/*
414 * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
415 * or BTRFS_ROOT_BACKREF_KEY.
416 *
417 * The dirid, sequence, name and name_len refer to the directory entry
418 * that is referencing the root.
419 *
420 * For a forward ref, the root_id is the id of the tree referencing
421 * the root and ref_id is the id of the subvol or snapshot.
422 *
423 * For a back ref the root_id is the id of the subvol or snapshot and
424 * ref_id is the id of the tree referencing it.
Jeff Mahoney79787ea2012-03-12 16:03:00 +0100425 *
426 * Will return 0, -ENOMEM, or anything from the CoW path
Chris Mason0660b5a2008-11-17 20:37:39 -0500427 */
428int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
429 struct btrfs_root *tree_root,
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400430 u64 root_id, u64 ref_id, u64 dirid, u64 sequence,
Chris Mason0660b5a2008-11-17 20:37:39 -0500431 const char *name, int name_len)
432{
433 struct btrfs_key key;
434 int ret;
435 struct btrfs_path *path;
436 struct btrfs_root_ref *ref;
437 struct extent_buffer *leaf;
438 unsigned long ptr;
439
Chris Mason0660b5a2008-11-17 20:37:39 -0500440 path = btrfs_alloc_path();
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400441 if (!path)
442 return -ENOMEM;
Chris Mason0660b5a2008-11-17 20:37:39 -0500443
444 key.objectid = root_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400445 key.type = BTRFS_ROOT_BACKREF_KEY;
Chris Mason0660b5a2008-11-17 20:37:39 -0500446 key.offset = ref_id;
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400447again:
Chris Mason0660b5a2008-11-17 20:37:39 -0500448 ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
449 sizeof(*ref) + name_len);
Jeff Mahoney79787ea2012-03-12 16:03:00 +0100450 if (ret) {
451 btrfs_abort_transaction(trans, tree_root, ret);
452 btrfs_free_path(path);
453 return ret;
454 }
Chris Mason0660b5a2008-11-17 20:37:39 -0500455
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);
464
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400465 if (key.type == BTRFS_ROOT_BACKREF_KEY) {
David Sterbab3b4aa72011-04-21 01:20:15 +0200466 btrfs_release_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400467 key.objectid = ref_id;
468 key.type = BTRFS_ROOT_REF_KEY;
469 key.offset = root_id;
470 goto again;
471 }
472
Chris Mason0660b5a2008-11-17 20:37:39 -0500473 btrfs_free_path(path);
Yan, Zheng4df27c4d2009-09-21 15:56:00 -0400474 return 0;
Chris Mason0660b5a2008-11-17 20:37:39 -0500475}
Li Zefan08fe4db2011-03-28 02:01:25 +0000476
477/*
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.
482 */
483void btrfs_check_and_init_root_item(struct btrfs_root_item *root_item)
484{
Qu Wenruo3cae2102013-07-16 11:19:18 +0800485 u64 inode_flags = btrfs_stack_inode_flags(&root_item->inode);
Li Zefan08fe4db2011-03-28 02:01:25 +0000486
487 if (!(inode_flags & BTRFS_INODE_ROOT_ITEM_INIT)) {
488 inode_flags |= BTRFS_INODE_ROOT_ITEM_INIT;
Qu Wenruo3cae2102013-07-16 11:19:18 +0800489 btrfs_set_stack_inode_flags(&root_item->inode, inode_flags);
490 btrfs_set_root_flags(root_item, 0);
491 btrfs_set_root_limit(root_item, 0);
Li Zefan08fe4db2011-03-28 02:01:25 +0000492 }
493}
Alexander Block8ea05e32012-07-25 17:35:53 +0200494
495void btrfs_update_root_times(struct btrfs_trans_handle *trans,
496 struct btrfs_root *root)
497{
498 struct btrfs_root_item *item = &root->root_item;
Deepa Dinamani04b285f2016-02-06 23:57:21 -0800499 struct timespec ct = current_fs_time(root->fs_info->sb);
Alexander Block8ea05e32012-07-25 17:35:53 +0200500
Anand Jain5f3ab902012-12-07 09:28:54 +0000501 spin_lock(&root->root_item_lock);
Qu Wenruo3cae2102013-07-16 11:19:18 +0800502 btrfs_set_root_ctransid(item, trans->transid);
503 btrfs_set_stack_timespec_sec(&item->ctime, ct.tv_sec);
504 btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
Anand Jain5f3ab902012-12-07 09:28:54 +0000505 spin_unlock(&root->root_item_lock);
Alexander Block8ea05e32012-07-25 17:35:53 +0200506}