Btrfs: kill obsolete arguments in btrfs_wait_ordered_extents
[linux-2.6-block.git] / fs / btrfs / transaction.c
CommitLineData
6cbd5570
CM
1/*
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
79154b1b 19#include <linux/fs.h>
5a0e3ad6 20#include <linux/slab.h>
34088780 21#include <linux/sched.h>
d3c2fdcf 22#include <linux/writeback.h>
5f39d397 23#include <linux/pagemap.h>
5f2cc086 24#include <linux/blkdev.h>
8ea05e3a 25#include <linux/uuid.h>
79154b1b
CM
26#include "ctree.h"
27#include "disk-io.h"
28#include "transaction.h"
925baedd 29#include "locking.h"
e02119d5 30#include "tree-log.h"
581bb050 31#include "inode-map.h"
733f4fbb 32#include "volumes.h"
79154b1b 33
0f7d52f4
CM
34#define BTRFS_ROOT_TRANS_TAG 0
35
49b25e05 36void put_transaction(struct btrfs_transaction *transaction)
79154b1b 37{
13c5a93e
JB
38 WARN_ON(atomic_read(&transaction->use_count) == 0);
39 if (atomic_dec_and_test(&transaction->use_count)) {
a4abeea4 40 BUG_ON(!list_empty(&transaction->list));
00f04b88 41 WARN_ON(transaction->delayed_refs.root.rb_node);
2c90e5d6
CM
42 memset(transaction, 0, sizeof(*transaction));
43 kmem_cache_free(btrfs_transaction_cachep, transaction);
78fae27e 44 }
79154b1b
CM
45}
46
817d52f8
JB
47static noinline void switch_commit_root(struct btrfs_root *root)
48{
817d52f8
JB
49 free_extent_buffer(root->commit_root);
50 root->commit_root = btrfs_root_node(root);
817d52f8
JB
51}
52
d352ac68
CM
53/*
54 * either allocate a new transaction or hop into the existing one
55 */
a4abeea4 56static noinline int join_transaction(struct btrfs_root *root, int nofail)
79154b1b
CM
57{
58 struct btrfs_transaction *cur_trans;
19ae4e81 59 struct btrfs_fs_info *fs_info = root->fs_info;
a4abeea4 60
19ae4e81 61 spin_lock(&fs_info->trans_lock);
d43317dc 62loop:
49b25e05 63 /* The file system has been taken offline. No new transactions. */
19ae4e81
JS
64 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
65 spin_unlock(&fs_info->trans_lock);
49b25e05
JM
66 return -EROFS;
67 }
68
19ae4e81 69 if (fs_info->trans_no_join) {
a4abeea4 70 if (!nofail) {
19ae4e81 71 spin_unlock(&fs_info->trans_lock);
a4abeea4
JB
72 return -EBUSY;
73 }
74 }
75
19ae4e81 76 cur_trans = fs_info->running_transaction;
a4abeea4 77 if (cur_trans) {
871383be 78 if (cur_trans->aborted) {
19ae4e81 79 spin_unlock(&fs_info->trans_lock);
49b25e05 80 return cur_trans->aborted;
871383be 81 }
a4abeea4 82 atomic_inc(&cur_trans->use_count);
13c5a93e 83 atomic_inc(&cur_trans->num_writers);
15ee9bc7 84 cur_trans->num_joined++;
19ae4e81 85 spin_unlock(&fs_info->trans_lock);
a4abeea4 86 return 0;
79154b1b 87 }
19ae4e81 88 spin_unlock(&fs_info->trans_lock);
a4abeea4
JB
89
90 cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
91 if (!cur_trans)
92 return -ENOMEM;
d43317dc 93
19ae4e81
JS
94 spin_lock(&fs_info->trans_lock);
95 if (fs_info->running_transaction) {
d43317dc
CM
96 /*
97 * someone started a transaction after we unlocked. Make sure
98 * to redo the trans_no_join checks above
99 */
a4abeea4 100 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
19ae4e81 101 cur_trans = fs_info->running_transaction;
d43317dc 102 goto loop;
e4b50e14
DC
103 } else if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
104 spin_unlock(&fs_info->trans_lock);
7b8b92af
JB
105 kmem_cache_free(btrfs_transaction_cachep, cur_trans);
106 return -EROFS;
79154b1b 107 }
d43317dc 108
a4abeea4
JB
109 atomic_set(&cur_trans->num_writers, 1);
110 cur_trans->num_joined = 0;
111 init_waitqueue_head(&cur_trans->writer_wait);
112 init_waitqueue_head(&cur_trans->commit_wait);
113 cur_trans->in_commit = 0;
114 cur_trans->blocked = 0;
115 /*
116 * One for this trans handle, one so it will live on until we
117 * commit the transaction.
118 */
119 atomic_set(&cur_trans->use_count, 2);
120 cur_trans->commit_done = 0;
121 cur_trans->start_time = get_seconds();
122
123 cur_trans->delayed_refs.root = RB_ROOT;
124 cur_trans->delayed_refs.num_entries = 0;
125 cur_trans->delayed_refs.num_heads_ready = 0;
126 cur_trans->delayed_refs.num_heads = 0;
127 cur_trans->delayed_refs.flushing = 0;
128 cur_trans->delayed_refs.run_delayed_start = 0;
20b297d6
JS
129
130 /*
131 * although the tree mod log is per file system and not per transaction,
132 * the log must never go across transaction boundaries.
133 */
134 smp_mb();
135 if (!list_empty(&fs_info->tree_mod_seq_list)) {
136 printk(KERN_ERR "btrfs: tree_mod_seq_list not empty when "
137 "creating a fresh transaction\n");
138 WARN_ON(1);
139 }
140 if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log)) {
141 printk(KERN_ERR "btrfs: tree_mod_log rb tree not empty when "
142 "creating a fresh transaction\n");
143 WARN_ON(1);
144 }
145 atomic_set(&fs_info->tree_mod_seq, 0);
146
a4abeea4
JB
147 spin_lock_init(&cur_trans->commit_lock);
148 spin_lock_init(&cur_trans->delayed_refs.lock);
149
150 INIT_LIST_HEAD(&cur_trans->pending_snapshots);
19ae4e81 151 list_add_tail(&cur_trans->list, &fs_info->trans_list);
a4abeea4 152 extent_io_tree_init(&cur_trans->dirty_pages,
19ae4e81
JS
153 fs_info->btree_inode->i_mapping);
154 fs_info->generation++;
155 cur_trans->transid = fs_info->generation;
156 fs_info->running_transaction = cur_trans;
49b25e05 157 cur_trans->aborted = 0;
19ae4e81 158 spin_unlock(&fs_info->trans_lock);
15ee9bc7 159
79154b1b
CM
160 return 0;
161}
162
d352ac68 163/*
d397712b
CM
164 * this does all the record keeping required to make sure that a reference
165 * counted root is properly recorded in a given transaction. This is required
166 * to make sure the old root from before we joined the transaction is deleted
167 * when the transaction commits
d352ac68 168 */
7585717f 169static int record_root_in_trans(struct btrfs_trans_handle *trans,
a4abeea4 170 struct btrfs_root *root)
6702ed49 171{
5d4f98a2 172 if (root->ref_cows && root->last_trans < trans->transid) {
6702ed49 173 WARN_ON(root == root->fs_info->extent_root);
5d4f98a2
YZ
174 WARN_ON(root->commit_root != root->node);
175
7585717f
CM
176 /*
177 * see below for in_trans_setup usage rules
178 * we have the reloc mutex held now, so there
179 * is only one writer in this function
180 */
181 root->in_trans_setup = 1;
182
183 /* make sure readers find in_trans_setup before
184 * they find our root->last_trans update
185 */
186 smp_wmb();
187
a4abeea4
JB
188 spin_lock(&root->fs_info->fs_roots_radix_lock);
189 if (root->last_trans == trans->transid) {
190 spin_unlock(&root->fs_info->fs_roots_radix_lock);
191 return 0;
192 }
5d4f98a2
YZ
193 radix_tree_tag_set(&root->fs_info->fs_roots_radix,
194 (unsigned long)root->root_key.objectid,
195 BTRFS_ROOT_TRANS_TAG);
a4abeea4 196 spin_unlock(&root->fs_info->fs_roots_radix_lock);
7585717f
CM
197 root->last_trans = trans->transid;
198
199 /* this is pretty tricky. We don't want to
200 * take the relocation lock in btrfs_record_root_in_trans
201 * unless we're really doing the first setup for this root in
202 * this transaction.
203 *
204 * Normally we'd use root->last_trans as a flag to decide
205 * if we want to take the expensive mutex.
206 *
207 * But, we have to set root->last_trans before we
208 * init the relocation root, otherwise, we trip over warnings
209 * in ctree.c. The solution used here is to flag ourselves
210 * with root->in_trans_setup. When this is 1, we're still
211 * fixing up the reloc trees and everyone must wait.
212 *
213 * When this is zero, they can trust root->last_trans and fly
214 * through btrfs_record_root_in_trans without having to take the
215 * lock. smp_wmb() makes sure that all the writes above are
216 * done before we pop in the zero below
217 */
5d4f98a2 218 btrfs_init_reloc_root(trans, root);
7585717f
CM
219 smp_wmb();
220 root->in_trans_setup = 0;
5d4f98a2
YZ
221 }
222 return 0;
223}
bcc63abb 224
7585717f
CM
225
226int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
227 struct btrfs_root *root)
228{
229 if (!root->ref_cows)
230 return 0;
231
232 /*
233 * see record_root_in_trans for comments about in_trans_setup usage
234 * and barriers
235 */
236 smp_rmb();
237 if (root->last_trans == trans->transid &&
238 !root->in_trans_setup)
239 return 0;
240
241 mutex_lock(&root->fs_info->reloc_mutex);
242 record_root_in_trans(trans, root);
243 mutex_unlock(&root->fs_info->reloc_mutex);
244
245 return 0;
246}
247
d352ac68
CM
248/* wait for commit against the current transaction to become unblocked
249 * when this is done, it is safe to start a new transaction, but the current
250 * transaction might not be fully on disk.
251 */
37d1aeee 252static void wait_current_trans(struct btrfs_root *root)
79154b1b 253{
f9295749 254 struct btrfs_transaction *cur_trans;
79154b1b 255
a4abeea4 256 spin_lock(&root->fs_info->trans_lock);
f9295749 257 cur_trans = root->fs_info->running_transaction;
37d1aeee 258 if (cur_trans && cur_trans->blocked) {
13c5a93e 259 atomic_inc(&cur_trans->use_count);
a4abeea4 260 spin_unlock(&root->fs_info->trans_lock);
72d63ed6
LZ
261
262 wait_event(root->fs_info->transaction_wait,
263 !cur_trans->blocked);
f9295749 264 put_transaction(cur_trans);
a4abeea4
JB
265 } else {
266 spin_unlock(&root->fs_info->trans_lock);
f9295749 267 }
37d1aeee
CM
268}
269
249ac1e5
JB
270enum btrfs_trans_type {
271 TRANS_START,
272 TRANS_JOIN,
273 TRANS_USERSPACE,
0af3d00b 274 TRANS_JOIN_NOLOCK,
60376ce4 275 TRANS_JOIN_FREEZE,
249ac1e5
JB
276};
277
a22285a6
YZ
278static int may_wait_transaction(struct btrfs_root *root, int type)
279{
a4abeea4
JB
280 if (root->fs_info->log_root_recovering)
281 return 0;
282
283 if (type == TRANS_USERSPACE)
284 return 1;
285
286 if (type == TRANS_START &&
287 !atomic_read(&root->fs_info->open_ioctl_trans))
a22285a6 288 return 1;
a4abeea4 289
a22285a6
YZ
290 return 0;
291}
292
e02119d5 293static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
8407aa46
MX
294 u64 num_items, int type,
295 int noflush)
37d1aeee 296{
a22285a6
YZ
297 struct btrfs_trans_handle *h;
298 struct btrfs_transaction *cur_trans;
b5009945 299 u64 num_bytes = 0;
37d1aeee 300 int ret;
c5567237 301 u64 qgroup_reserved = 0;
acce952b 302
303 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
304 return ERR_PTR(-EROFS);
2a1eb461
JB
305
306 if (current->journal_info) {
307 WARN_ON(type != TRANS_JOIN && type != TRANS_JOIN_NOLOCK);
308 h = current->journal_info;
309 h->use_count++;
310 h->orig_rsv = h->block_rsv;
311 h->block_rsv = NULL;
312 goto got_it;
313 }
b5009945
JB
314
315 /*
316 * Do the reservation before we join the transaction so we can do all
317 * the appropriate flushing if need be.
318 */
319 if (num_items > 0 && root != root->fs_info->chunk_root) {
c5567237
AJ
320 if (root->fs_info->quota_enabled &&
321 is_fstree(root->root_key.objectid)) {
322 qgroup_reserved = num_items * root->leafsize;
323 ret = btrfs_qgroup_reserve(root, qgroup_reserved);
324 if (ret)
325 return ERR_PTR(ret);
326 }
327
b5009945 328 num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
8407aa46
MX
329 if (noflush)
330 ret = btrfs_block_rsv_add_noflush(root,
331 &root->fs_info->trans_block_rsv,
332 num_bytes);
333 else
334 ret = btrfs_block_rsv_add(root,
335 &root->fs_info->trans_block_rsv,
336 num_bytes);
b5009945
JB
337 if (ret)
338 return ERR_PTR(ret);
339 }
a22285a6
YZ
340again:
341 h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
342 if (!h)
343 return ERR_PTR(-ENOMEM);
37d1aeee 344
60376ce4
JB
345 if (!__sb_start_write(root->fs_info->sb, SB_FREEZE_FS, false)) {
346 if (type == TRANS_JOIN_FREEZE)
347 return ERR_PTR(-EPERM);
348 sb_start_intwrite(root->fs_info->sb);
349 }
b2b5ef5c 350
a22285a6 351 if (may_wait_transaction(root, type))
37d1aeee 352 wait_current_trans(root);
a22285a6 353
a4abeea4
JB
354 do {
355 ret = join_transaction(root, type == TRANS_JOIN_NOLOCK);
356 if (ret == -EBUSY)
357 wait_current_trans(root);
358 } while (ret == -EBUSY);
359
db5b493a 360 if (ret < 0) {
b2b5ef5c 361 sb_end_intwrite(root->fs_info->sb);
6e8df2ae 362 kmem_cache_free(btrfs_trans_handle_cachep, h);
db5b493a
TI
363 return ERR_PTR(ret);
364 }
0f7d52f4 365
a22285a6 366 cur_trans = root->fs_info->running_transaction;
a22285a6
YZ
367
368 h->transid = cur_trans->transid;
369 h->transaction = cur_trans;
79154b1b 370 h->blocks_used = 0;
a22285a6 371 h->bytes_reserved = 0;
d13603ef 372 h->root = root;
56bec294 373 h->delayed_ref_updates = 0;
2a1eb461 374 h->use_count = 1;
0e721106 375 h->adding_csums = 0;
f0486c68 376 h->block_rsv = NULL;
2a1eb461 377 h->orig_rsv = NULL;
49b25e05 378 h->aborted = 0;
c5567237 379 h->qgroup_reserved = qgroup_reserved;
bed92eae
AJ
380 h->delayed_ref_elem.seq = 0;
381 INIT_LIST_HEAD(&h->qgroup_ref_list);
ea658bad 382 INIT_LIST_HEAD(&h->new_bgs);
b7ec40d7 383
a22285a6
YZ
384 smp_mb();
385 if (cur_trans->blocked && may_wait_transaction(root, type)) {
386 btrfs_commit_transaction(h, root);
387 goto again;
388 }
389
b5009945 390 if (num_bytes) {
8c2a3ca2 391 trace_btrfs_space_reservation(root->fs_info, "transaction",
2bcc0328 392 h->transid, num_bytes, 1);
b5009945
JB
393 h->block_rsv = &root->fs_info->trans_block_rsv;
394 h->bytes_reserved = num_bytes;
a22285a6 395 }
9ed74f2d 396
2a1eb461 397got_it:
a4abeea4 398 btrfs_record_root_in_trans(h, root);
a22285a6
YZ
399
400 if (!current->journal_info && type != TRANS_USERSPACE)
401 current->journal_info = h;
79154b1b
CM
402 return h;
403}
404
f9295749 405struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
a22285a6 406 int num_items)
f9295749 407{
8407aa46 408 return start_transaction(root, num_items, TRANS_START, 0);
f9295749 409}
8407aa46
MX
410
411struct btrfs_trans_handle *btrfs_start_transaction_noflush(
412 struct btrfs_root *root, int num_items)
413{
414 return start_transaction(root, num_items, TRANS_START, 1);
415}
416
7a7eaa40 417struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
f9295749 418{
8407aa46 419 return start_transaction(root, 0, TRANS_JOIN, 0);
f9295749
CM
420}
421
7a7eaa40 422struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
0af3d00b 423{
8407aa46 424 return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
0af3d00b
JB
425}
426
7a7eaa40 427struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
9ca9ee09 428{
8407aa46 429 return start_transaction(root, 0, TRANS_USERSPACE, 0);
9ca9ee09
SW
430}
431
60376ce4
JB
432struct btrfs_trans_handle *btrfs_join_transaction_freeze(struct btrfs_root *root)
433{
434 return start_transaction(root, 0, TRANS_JOIN_FREEZE, 0);
435}
436
d352ac68 437/* wait for a transaction commit to be fully complete */
b9c8300c 438static noinline void wait_for_commit(struct btrfs_root *root,
89ce8a63
CM
439 struct btrfs_transaction *commit)
440{
72d63ed6 441 wait_event(commit->commit_wait, commit->commit_done);
89ce8a63
CM
442}
443
46204592
SW
444int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
445{
446 struct btrfs_transaction *cur_trans = NULL, *t;
447 int ret;
448
46204592
SW
449 ret = 0;
450 if (transid) {
451 if (transid <= root->fs_info->last_trans_committed)
a4abeea4 452 goto out;
46204592
SW
453
454 /* find specified transaction */
a4abeea4 455 spin_lock(&root->fs_info->trans_lock);
46204592
SW
456 list_for_each_entry(t, &root->fs_info->trans_list, list) {
457 if (t->transid == transid) {
458 cur_trans = t;
a4abeea4 459 atomic_inc(&cur_trans->use_count);
46204592
SW
460 break;
461 }
462 if (t->transid > transid)
463 break;
464 }
a4abeea4 465 spin_unlock(&root->fs_info->trans_lock);
46204592
SW
466 ret = -EINVAL;
467 if (!cur_trans)
a4abeea4 468 goto out; /* bad transid */
46204592
SW
469 } else {
470 /* find newest transaction that is committing | committed */
a4abeea4 471 spin_lock(&root->fs_info->trans_lock);
46204592
SW
472 list_for_each_entry_reverse(t, &root->fs_info->trans_list,
473 list) {
474 if (t->in_commit) {
475 if (t->commit_done)
3473f3c0 476 break;
46204592 477 cur_trans = t;
a4abeea4 478 atomic_inc(&cur_trans->use_count);
46204592
SW
479 break;
480 }
481 }
a4abeea4 482 spin_unlock(&root->fs_info->trans_lock);
46204592 483 if (!cur_trans)
a4abeea4 484 goto out; /* nothing committing|committed */
46204592
SW
485 }
486
46204592
SW
487 wait_for_commit(root, cur_trans);
488
46204592
SW
489 put_transaction(cur_trans);
490 ret = 0;
a4abeea4 491out:
46204592
SW
492 return ret;
493}
494
37d1aeee
CM
495void btrfs_throttle(struct btrfs_root *root)
496{
a4abeea4 497 if (!atomic_read(&root->fs_info->open_ioctl_trans))
9ca9ee09 498 wait_current_trans(root);
37d1aeee
CM
499}
500
8929ecfa
YZ
501static int should_end_transaction(struct btrfs_trans_handle *trans,
502 struct btrfs_root *root)
503{
504 int ret;
36ba022a
JB
505
506 ret = btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
8929ecfa
YZ
507 return ret ? 1 : 0;
508}
509
510int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
511 struct btrfs_root *root)
512{
513 struct btrfs_transaction *cur_trans = trans->transaction;
514 int updates;
49b25e05 515 int err;
8929ecfa 516
a4abeea4 517 smp_mb();
8929ecfa
YZ
518 if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
519 return 1;
520
521 updates = trans->delayed_ref_updates;
522 trans->delayed_ref_updates = 0;
49b25e05
JM
523 if (updates) {
524 err = btrfs_run_delayed_refs(trans, root, updates);
525 if (err) /* Error code will also eval true */
526 return err;
527 }
8929ecfa
YZ
528
529 return should_end_transaction(trans, root);
530}
531
89ce8a63 532static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
0af3d00b 533 struct btrfs_root *root, int throttle, int lock)
79154b1b 534{
8929ecfa 535 struct btrfs_transaction *cur_trans = trans->transaction;
ab78c84d 536 struct btrfs_fs_info *info = root->fs_info;
c3e69d58 537 int count = 0;
4edc2ca3 538 int err = 0;
c3e69d58 539
2a1eb461
JB
540 if (--trans->use_count) {
541 trans->block_rsv = trans->orig_rsv;
542 return 0;
543 }
544
edf39272
JS
545 /*
546 * do the qgroup accounting as early as possible
547 */
548 err = btrfs_delayed_refs_qgroup_accounting(trans, info);
549
b24e03db 550 btrfs_trans_release_metadata(trans, root);
4c13d758 551 trans->block_rsv = NULL;
d13603ef
AJ
552 /*
553 * the same root has to be passed to start_transaction and
554 * end_transaction. Subvolume quota depends on this.
555 */
556 WARN_ON(trans->root != root);
c5567237
AJ
557
558 if (trans->qgroup_reserved) {
559 btrfs_qgroup_free(root, trans->qgroup_reserved);
560 trans->qgroup_reserved = 0;
561 }
562
ea658bad
JB
563 if (!list_empty(&trans->new_bgs))
564 btrfs_create_pending_block_groups(trans, root);
565
203bf287 566 while (count < 2) {
c3e69d58
CM
567 unsigned long cur = trans->delayed_ref_updates;
568 trans->delayed_ref_updates = 0;
569 if (cur &&
570 trans->transaction->delayed_refs.num_heads_ready > 64) {
571 trans->delayed_ref_updates = 0;
572 btrfs_run_delayed_refs(trans, root, cur);
573 } else {
574 break;
575 }
576 count++;
56bec294 577 }
0e721106
JB
578 btrfs_trans_release_metadata(trans, root);
579 trans->block_rsv = NULL;
56bec294 580
ea658bad
JB
581 if (!list_empty(&trans->new_bgs))
582 btrfs_create_pending_block_groups(trans, root);
583
a4abeea4
JB
584 if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
585 should_end_transaction(trans, root)) {
8929ecfa 586 trans->transaction->blocked = 1;
a4abeea4
JB
587 smp_wmb();
588 }
8929ecfa 589
0af3d00b 590 if (lock && cur_trans->blocked && !cur_trans->in_commit) {
81317fde
JB
591 if (throttle) {
592 /*
593 * We may race with somebody else here so end up having
594 * to call end_transaction on ourselves again, so inc
595 * our use_count.
596 */
597 trans->use_count++;
8929ecfa 598 return btrfs_commit_transaction(trans, root);
81317fde 599 } else {
8929ecfa 600 wake_up_process(info->transaction_kthread);
81317fde 601 }
8929ecfa
YZ
602 }
603
6df7881a
JB
604 sb_end_intwrite(root->fs_info->sb);
605
8929ecfa 606 WARN_ON(cur_trans != info->running_transaction);
13c5a93e
JB
607 WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
608 atomic_dec(&cur_trans->num_writers);
89ce8a63 609
99d16cbc 610 smp_mb();
79154b1b
CM
611 if (waitqueue_active(&cur_trans->writer_wait))
612 wake_up(&cur_trans->writer_wait);
79154b1b 613 put_transaction(cur_trans);
9ed74f2d
JB
614
615 if (current->journal_info == trans)
616 current->journal_info = NULL;
ab78c84d 617
24bbcf04
YZ
618 if (throttle)
619 btrfs_run_delayed_iputs(root);
620
49b25e05
JM
621 if (trans->aborted ||
622 root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
4edc2ca3 623 err = -EIO;
49b25e05 624 }
edf39272 625 assert_qgroups_uptodate(trans);
49b25e05 626
4edc2ca3
DJ
627 memset(trans, 0, sizeof(*trans));
628 kmem_cache_free(btrfs_trans_handle_cachep, trans);
629 return err;
79154b1b
CM
630}
631
89ce8a63
CM
632int btrfs_end_transaction(struct btrfs_trans_handle *trans,
633 struct btrfs_root *root)
634{
16cdcec7
MX
635 int ret;
636
637 ret = __btrfs_end_transaction(trans, root, 0, 1);
638 if (ret)
639 return ret;
640 return 0;
89ce8a63
CM
641}
642
643int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
644 struct btrfs_root *root)
645{
16cdcec7
MX
646 int ret;
647
648 ret = __btrfs_end_transaction(trans, root, 1, 1);
649 if (ret)
650 return ret;
651 return 0;
0af3d00b
JB
652}
653
654int btrfs_end_transaction_nolock(struct btrfs_trans_handle *trans,
655 struct btrfs_root *root)
656{
16cdcec7
MX
657 int ret;
658
659 ret = __btrfs_end_transaction(trans, root, 0, 0);
660 if (ret)
661 return ret;
662 return 0;
663}
664
665int btrfs_end_transaction_dmeta(struct btrfs_trans_handle *trans,
666 struct btrfs_root *root)
667{
668 return __btrfs_end_transaction(trans, root, 1, 1);
89ce8a63
CM
669}
670
d352ac68
CM
671/*
672 * when btree blocks are allocated, they have some corresponding bits set for
673 * them in one of two extent_io trees. This is used to make sure all of
690587d1 674 * those extents are sent to disk but does not wait on them
d352ac68 675 */
690587d1 676int btrfs_write_marked_extents(struct btrfs_root *root,
8cef4e16 677 struct extent_io_tree *dirty_pages, int mark)
79154b1b 678{
777e6bd7 679 int err = 0;
7c4452b9 680 int werr = 0;
1728366e 681 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
777e6bd7 682 u64 start = 0;
5f39d397 683 u64 end;
7c4452b9 684
1728366e
JB
685 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
686 mark)) {
687 convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT, mark,
688 GFP_NOFS);
689 err = filemap_fdatawrite_range(mapping, start, end);
690 if (err)
691 werr = err;
692 cond_resched();
693 start = end + 1;
7c4452b9 694 }
690587d1
CM
695 if (err)
696 werr = err;
697 return werr;
698}
699
700/*
701 * when btree blocks are allocated, they have some corresponding bits set for
702 * them in one of two extent_io trees. This is used to make sure all of
703 * those extents are on disk for transaction or log commit. We wait
704 * on all the pages and clear them from the dirty pages state tree
705 */
706int btrfs_wait_marked_extents(struct btrfs_root *root,
8cef4e16 707 struct extent_io_tree *dirty_pages, int mark)
690587d1 708{
690587d1
CM
709 int err = 0;
710 int werr = 0;
1728366e 711 struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
690587d1
CM
712 u64 start = 0;
713 u64 end;
777e6bd7 714
1728366e
JB
715 while (!find_first_extent_bit(dirty_pages, start, &start, &end,
716 EXTENT_NEED_WAIT)) {
717 clear_extent_bits(dirty_pages, start, end, EXTENT_NEED_WAIT, GFP_NOFS);
718 err = filemap_fdatawait_range(mapping, start, end);
719 if (err)
720 werr = err;
721 cond_resched();
722 start = end + 1;
777e6bd7 723 }
7c4452b9
CM
724 if (err)
725 werr = err;
726 return werr;
79154b1b
CM
727}
728
690587d1
CM
729/*
730 * when btree blocks are allocated, they have some corresponding bits set for
731 * them in one of two extent_io trees. This is used to make sure all of
732 * those extents are on disk for transaction or log commit
733 */
734int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
8cef4e16 735 struct extent_io_tree *dirty_pages, int mark)
690587d1
CM
736{
737 int ret;
738 int ret2;
739
8cef4e16
YZ
740 ret = btrfs_write_marked_extents(root, dirty_pages, mark);
741 ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
bf0da8c1
CM
742
743 if (ret)
744 return ret;
745 if (ret2)
746 return ret2;
747 return 0;
690587d1
CM
748}
749
d0c803c4
CM
750int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
751 struct btrfs_root *root)
752{
753 if (!trans || !trans->transaction) {
754 struct inode *btree_inode;
755 btree_inode = root->fs_info->btree_inode;
756 return filemap_write_and_wait(btree_inode->i_mapping);
757 }
758 return btrfs_write_and_wait_marked_extents(root,
8cef4e16
YZ
759 &trans->transaction->dirty_pages,
760 EXTENT_DIRTY);
d0c803c4
CM
761}
762
d352ac68
CM
763/*
764 * this is used to update the root pointer in the tree of tree roots.
765 *
766 * But, in the case of the extent allocation tree, updating the root
767 * pointer may allocate blocks which may change the root of the extent
768 * allocation tree.
769 *
770 * So, this loops and repeats and makes sure the cowonly root didn't
771 * change while the root pointer was being updated in the metadata.
772 */
0b86a832
CM
773static int update_cowonly_root(struct btrfs_trans_handle *trans,
774 struct btrfs_root *root)
79154b1b
CM
775{
776 int ret;
0b86a832 777 u64 old_root_bytenr;
86b9f2ec 778 u64 old_root_used;
0b86a832 779 struct btrfs_root *tree_root = root->fs_info->tree_root;
79154b1b 780
86b9f2ec 781 old_root_used = btrfs_root_used(&root->root_item);
0b86a832 782 btrfs_write_dirty_block_groups(trans, root);
56bec294 783
d397712b 784 while (1) {
0b86a832 785 old_root_bytenr = btrfs_root_bytenr(&root->root_item);
86b9f2ec
YZ
786 if (old_root_bytenr == root->node->start &&
787 old_root_used == btrfs_root_used(&root->root_item))
79154b1b 788 break;
87ef2bb4 789
5d4f98a2 790 btrfs_set_root_node(&root->root_item, root->node);
79154b1b 791 ret = btrfs_update_root(trans, tree_root,
0b86a832
CM
792 &root->root_key,
793 &root->root_item);
49b25e05
JM
794 if (ret)
795 return ret;
56bec294 796
86b9f2ec 797 old_root_used = btrfs_root_used(&root->root_item);
4a8c9a62 798 ret = btrfs_write_dirty_block_groups(trans, root);
49b25e05
JM
799 if (ret)
800 return ret;
0b86a832 801 }
276e680d
YZ
802
803 if (root != root->fs_info->extent_root)
804 switch_commit_root(root);
805
0b86a832
CM
806 return 0;
807}
808
d352ac68
CM
809/*
810 * update all the cowonly tree roots on disk
49b25e05
JM
811 *
812 * The error handling in this function may not be obvious. Any of the
813 * failures will cause the file system to go offline. We still need
814 * to clean up the delayed refs.
d352ac68 815 */
5d4f98a2
YZ
816static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
817 struct btrfs_root *root)
0b86a832
CM
818{
819 struct btrfs_fs_info *fs_info = root->fs_info;
820 struct list_head *next;
84234f3a 821 struct extent_buffer *eb;
56bec294 822 int ret;
84234f3a 823
56bec294 824 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
49b25e05
JM
825 if (ret)
826 return ret;
87ef2bb4 827
84234f3a 828 eb = btrfs_lock_root_node(fs_info->tree_root);
49b25e05
JM
829 ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
830 0, &eb);
84234f3a
YZ
831 btrfs_tree_unlock(eb);
832 free_extent_buffer(eb);
0b86a832 833
49b25e05
JM
834 if (ret)
835 return ret;
836
56bec294 837 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
49b25e05
JM
838 if (ret)
839 return ret;
87ef2bb4 840
733f4fbb
SB
841 ret = btrfs_run_dev_stats(trans, root->fs_info);
842 BUG_ON(ret);
843
546adb0d
JS
844 ret = btrfs_run_qgroups(trans, root->fs_info);
845 BUG_ON(ret);
846
847 /* run_qgroups might have added some more refs */
848 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
849 BUG_ON(ret);
850
d397712b 851 while (!list_empty(&fs_info->dirty_cowonly_roots)) {
0b86a832
CM
852 next = fs_info->dirty_cowonly_roots.next;
853 list_del_init(next);
854 root = list_entry(next, struct btrfs_root, dirty_list);
87ef2bb4 855
49b25e05
JM
856 ret = update_cowonly_root(trans, root);
857 if (ret)
858 return ret;
79154b1b 859 }
276e680d
YZ
860
861 down_write(&fs_info->extent_commit_sem);
862 switch_commit_root(fs_info->extent_root);
863 up_write(&fs_info->extent_commit_sem);
864
79154b1b
CM
865 return 0;
866}
867
d352ac68
CM
868/*
869 * dead roots are old snapshots that need to be deleted. This allocates
870 * a dirty root struct and adds it into the list of dead roots that need to
871 * be deleted
872 */
5d4f98a2 873int btrfs_add_dead_root(struct btrfs_root *root)
5eda7b5e 874{
a4abeea4 875 spin_lock(&root->fs_info->trans_lock);
5d4f98a2 876 list_add(&root->root_list, &root->fs_info->dead_roots);
a4abeea4 877 spin_unlock(&root->fs_info->trans_lock);
5eda7b5e
CM
878 return 0;
879}
880
d352ac68 881/*
5d4f98a2 882 * update all the cowonly tree roots on disk
d352ac68 883 */
5d4f98a2
YZ
884static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
885 struct btrfs_root *root)
0f7d52f4 886{
0f7d52f4 887 struct btrfs_root *gang[8];
5d4f98a2 888 struct btrfs_fs_info *fs_info = root->fs_info;
0f7d52f4
CM
889 int i;
890 int ret;
54aa1f4d
CM
891 int err = 0;
892
a4abeea4 893 spin_lock(&fs_info->fs_roots_radix_lock);
d397712b 894 while (1) {
5d4f98a2
YZ
895 ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
896 (void **)gang, 0,
0f7d52f4
CM
897 ARRAY_SIZE(gang),
898 BTRFS_ROOT_TRANS_TAG);
899 if (ret == 0)
900 break;
901 for (i = 0; i < ret; i++) {
902 root = gang[i];
5d4f98a2
YZ
903 radix_tree_tag_clear(&fs_info->fs_roots_radix,
904 (unsigned long)root->root_key.objectid,
905 BTRFS_ROOT_TRANS_TAG);
a4abeea4 906 spin_unlock(&fs_info->fs_roots_radix_lock);
31153d81 907
e02119d5 908 btrfs_free_log(trans, root);
5d4f98a2 909 btrfs_update_reloc_root(trans, root);
d68fc57b 910 btrfs_orphan_commit_root(trans, root);
bcc63abb 911
82d5902d
LZ
912 btrfs_save_ino_cache(root, trans);
913
f1ebcc74
LB
914 /* see comments in should_cow_block() */
915 root->force_cow = 0;
916 smp_wmb();
917
978d910d 918 if (root->commit_root != root->node) {
581bb050 919 mutex_lock(&root->fs_commit_mutex);
817d52f8 920 switch_commit_root(root);
581bb050
LZ
921 btrfs_unpin_free_ino(root);
922 mutex_unlock(&root->fs_commit_mutex);
923
978d910d
YZ
924 btrfs_set_root_node(&root->root_item,
925 root->node);
926 }
5d4f98a2 927
5d4f98a2 928 err = btrfs_update_root(trans, fs_info->tree_root,
0f7d52f4
CM
929 &root->root_key,
930 &root->root_item);
a4abeea4 931 spin_lock(&fs_info->fs_roots_radix_lock);
54aa1f4d
CM
932 if (err)
933 break;
0f7d52f4
CM
934 }
935 }
a4abeea4 936 spin_unlock(&fs_info->fs_roots_radix_lock);
54aa1f4d 937 return err;
0f7d52f4
CM
938}
939
d352ac68
CM
940/*
941 * defrag a given btree. If cacheonly == 1, this won't read from the disk,
942 * otherwise every leaf in the btree is read and defragged.
943 */
e9d0b13b
CM
944int btrfs_defrag_root(struct btrfs_root *root, int cacheonly)
945{
946 struct btrfs_fs_info *info = root->fs_info;
e9d0b13b 947 struct btrfs_trans_handle *trans;
8929ecfa 948 int ret;
d3c2fdcf 949 unsigned long nr;
e9d0b13b 950
8929ecfa 951 if (xchg(&root->defrag_running, 1))
e9d0b13b 952 return 0;
8929ecfa 953
6b80053d 954 while (1) {
8929ecfa
YZ
955 trans = btrfs_start_transaction(root, 0);
956 if (IS_ERR(trans))
957 return PTR_ERR(trans);
958
e9d0b13b 959 ret = btrfs_defrag_leaves(trans, root, cacheonly);
8929ecfa 960
d3c2fdcf 961 nr = trans->blocks_used;
e9d0b13b 962 btrfs_end_transaction(trans, root);
d3c2fdcf 963 btrfs_btree_balance_dirty(info->tree_root, nr);
e9d0b13b
CM
964 cond_resched();
965
7841cb28 966 if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
e9d0b13b
CM
967 break;
968 }
969 root->defrag_running = 0;
8929ecfa 970 return ret;
e9d0b13b
CM
971}
972
d352ac68
CM
973/*
974 * new snapshots need to be created at a very specific time in the
975 * transaction commit. This does the actual creation
976 */
80b6794d 977static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
3063d29f
CM
978 struct btrfs_fs_info *fs_info,
979 struct btrfs_pending_snapshot *pending)
980{
981 struct btrfs_key key;
80b6794d 982 struct btrfs_root_item *new_root_item;
3063d29f
CM
983 struct btrfs_root *tree_root = fs_info->tree_root;
984 struct btrfs_root *root = pending->root;
6bdb72de 985 struct btrfs_root *parent_root;
98c9942a 986 struct btrfs_block_rsv *rsv;
6bdb72de 987 struct inode *parent_inode;
42874b3d
MX
988 struct btrfs_path *path;
989 struct btrfs_dir_item *dir_item;
6a912213 990 struct dentry *parent;
a22285a6 991 struct dentry *dentry;
3063d29f 992 struct extent_buffer *tmp;
925baedd 993 struct extent_buffer *old;
8ea05e3a 994 struct timespec cur_time = CURRENT_TIME;
3063d29f 995 int ret;
d68fc57b 996 u64 to_reserve = 0;
6bdb72de 997 u64 index = 0;
a22285a6 998 u64 objectid;
b83cc969 999 u64 root_flags;
8ea05e3a 1000 uuid_le new_uuid;
3063d29f 1001
42874b3d
MX
1002 path = btrfs_alloc_path();
1003 if (!path) {
1004 ret = pending->error = -ENOMEM;
1005 goto path_alloc_fail;
1006 }
1007
80b6794d
CM
1008 new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1009 if (!new_root_item) {
49b25e05 1010 ret = pending->error = -ENOMEM;
6fa9700e 1011 goto root_item_alloc_fail;
80b6794d 1012 }
a22285a6 1013
581bb050 1014 ret = btrfs_find_free_objectid(tree_root, &objectid);
a22285a6
YZ
1015 if (ret) {
1016 pending->error = ret;
6fa9700e 1017 goto no_free_objectid;
a22285a6 1018 }
3063d29f 1019
3fd0a558 1020 btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
d68fc57b
YZ
1021
1022 if (to_reserve > 0) {
62f30c54
MX
1023 ret = btrfs_block_rsv_add_noflush(root, &pending->block_rsv,
1024 to_reserve);
d68fc57b
YZ
1025 if (ret) {
1026 pending->error = ret;
6fa9700e 1027 goto no_free_objectid;
d68fc57b
YZ
1028 }
1029 }
1030
6f72c7e2
AJ
1031 ret = btrfs_qgroup_inherit(trans, fs_info, root->root_key.objectid,
1032 objectid, pending->inherit);
6f72c7e2
AJ
1033 if (ret) {
1034 pending->error = ret;
6fa9700e 1035 goto no_free_objectid;
6f72c7e2
AJ
1036 }
1037
3063d29f 1038 key.objectid = objectid;
a22285a6
YZ
1039 key.offset = (u64)-1;
1040 key.type = BTRFS_ROOT_ITEM_KEY;
3063d29f 1041
6fa9700e 1042 rsv = trans->block_rsv;
a22285a6 1043 trans->block_rsv = &pending->block_rsv;
3de4586c 1044
a22285a6 1045 dentry = pending->dentry;
6a912213
JB
1046 parent = dget_parent(dentry);
1047 parent_inode = parent->d_inode;
a22285a6 1048 parent_root = BTRFS_I(parent_inode)->root;
7585717f 1049 record_root_in_trans(trans, parent_root);
a22285a6 1050
3063d29f
CM
1051 /*
1052 * insert the directory item
1053 */
3de4586c 1054 ret = btrfs_set_inode_index(parent_inode, &index);
49b25e05 1055 BUG_ON(ret); /* -ENOMEM */
42874b3d
MX
1056
1057 /* check if there is a file/dir which has the same name. */
1058 dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1059 btrfs_ino(parent_inode),
1060 dentry->d_name.name,
1061 dentry->d_name.len, 0);
1062 if (dir_item != NULL && !IS_ERR(dir_item)) {
fe66a05a 1063 pending->error = -EEXIST;
fe66a05a 1064 goto fail;
42874b3d
MX
1065 } else if (IS_ERR(dir_item)) {
1066 ret = PTR_ERR(dir_item);
6fa9700e 1067 goto abort_trans;
79787eaa 1068 }
42874b3d 1069 btrfs_release_path(path);
52c26179 1070
e999376f
CM
1071 /*
1072 * pull in the delayed directory update
1073 * and the delayed inode item
1074 * otherwise we corrupt the FS during
1075 * snapshot
1076 */
1077 ret = btrfs_run_delayed_items(trans, root);
6fa9700e
MX
1078 if (ret) /* Transaction aborted */
1079 goto abort_trans;
e999376f 1080
7585717f 1081 record_root_in_trans(trans, root);
6bdb72de
SW
1082 btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1083 memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
08fe4db1 1084 btrfs_check_and_init_root_item(new_root_item);
6bdb72de 1085
b83cc969
LZ
1086 root_flags = btrfs_root_flags(new_root_item);
1087 if (pending->readonly)
1088 root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1089 else
1090 root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1091 btrfs_set_root_flags(new_root_item, root_flags);
1092
8ea05e3a
AB
1093 btrfs_set_root_generation_v2(new_root_item,
1094 trans->transid);
1095 uuid_le_gen(&new_uuid);
1096 memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1097 memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1098 BTRFS_UUID_SIZE);
1099 new_root_item->otime.sec = cpu_to_le64(cur_time.tv_sec);
dadd1105 1100 new_root_item->otime.nsec = cpu_to_le32(cur_time.tv_nsec);
8ea05e3a
AB
1101 btrfs_set_root_otransid(new_root_item, trans->transid);
1102 memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1103 memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1104 btrfs_set_root_stransid(new_root_item, 0);
1105 btrfs_set_root_rtransid(new_root_item, 0);
1106
6bdb72de 1107 old = btrfs_lock_root_node(root);
49b25e05 1108 ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
79787eaa
JM
1109 if (ret) {
1110 btrfs_tree_unlock(old);
1111 free_extent_buffer(old);
6fa9700e 1112 goto abort_trans;
79787eaa 1113 }
49b25e05 1114
6bdb72de
SW
1115 btrfs_set_lock_blocking(old);
1116
49b25e05 1117 ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
79787eaa 1118 /* clean up in any case */
6bdb72de
SW
1119 btrfs_tree_unlock(old);
1120 free_extent_buffer(old);
79787eaa 1121 if (ret)
6fa9700e 1122 goto abort_trans;
6bdb72de 1123
f1ebcc74
LB
1124 /* see comments in should_cow_block() */
1125 root->force_cow = 1;
1126 smp_wmb();
1127
6bdb72de 1128 btrfs_set_root_node(new_root_item, tmp);
a22285a6
YZ
1129 /* record when the snapshot was created in key.offset */
1130 key.offset = trans->transid;
1131 ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
6bdb72de
SW
1132 btrfs_tree_unlock(tmp);
1133 free_extent_buffer(tmp);
49b25e05 1134 if (ret)
6fa9700e 1135 goto abort_trans;
6bdb72de 1136
a22285a6
YZ
1137 /*
1138 * insert root back/forward references
1139 */
1140 ret = btrfs_add_root_ref(trans, tree_root, objectid,
0660b5af 1141 parent_root->root_key.objectid,
33345d01 1142 btrfs_ino(parent_inode), index,
a22285a6 1143 dentry->d_name.name, dentry->d_name.len);
49b25e05 1144 if (ret)
6fa9700e 1145 goto abort_trans;
0660b5af 1146
a22285a6
YZ
1147 key.offset = (u64)-1;
1148 pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
79787eaa
JM
1149 if (IS_ERR(pending->snap)) {
1150 ret = PTR_ERR(pending->snap);
49b25e05 1151 goto abort_trans;
79787eaa 1152 }
d68fc57b 1153
49b25e05
JM
1154 ret = btrfs_reloc_post_snapshot(trans, pending);
1155 if (ret)
1156 goto abort_trans;
361048f5
MX
1157
1158 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1159 if (ret)
1160 goto abort_trans;
42874b3d
MX
1161
1162 ret = btrfs_insert_dir_item(trans, parent_root,
1163 dentry->d_name.name, dentry->d_name.len,
1164 parent_inode, &key,
1165 BTRFS_FT_DIR, index);
1166 /* We have check then name at the beginning, so it is impossible. */
1167 BUG_ON(ret == -EEXIST);
1168 if (ret)
1169 goto abort_trans;
1170
1171 btrfs_i_size_write(parent_inode, parent_inode->i_size +
1172 dentry->d_name.len * 2);
1173 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1174 ret = btrfs_update_inode(trans, parent_root, parent_inode);
1175 if (ret)
1176 goto abort_trans;
3063d29f 1177fail:
6fa9700e 1178 dput(parent);
98c9942a 1179 trans->block_rsv = rsv;
6fa9700e
MX
1180no_free_objectid:
1181 kfree(new_root_item);
1182root_item_alloc_fail:
42874b3d
MX
1183 btrfs_free_path(path);
1184path_alloc_fail:
a22285a6 1185 btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
49b25e05
JM
1186 return ret;
1187
1188abort_trans:
1189 btrfs_abort_transaction(trans, root, ret);
1190 goto fail;
3063d29f
CM
1191}
1192
d352ac68
CM
1193/*
1194 * create all the snapshots we've scheduled for creation
1195 */
80b6794d
CM
1196static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1197 struct btrfs_fs_info *fs_info)
3de4586c
CM
1198{
1199 struct btrfs_pending_snapshot *pending;
1200 struct list_head *head = &trans->transaction->pending_snapshots;
3de4586c 1201
fe66a05a
CM
1202 list_for_each_entry(pending, head, list)
1203 create_pending_snapshot(trans, fs_info, pending);
3de4586c
CM
1204 return 0;
1205}
1206
5d4f98a2
YZ
1207static void update_super_roots(struct btrfs_root *root)
1208{
1209 struct btrfs_root_item *root_item;
1210 struct btrfs_super_block *super;
1211
6c41761f 1212 super = root->fs_info->super_copy;
5d4f98a2
YZ
1213
1214 root_item = &root->fs_info->chunk_root->root_item;
1215 super->chunk_root = root_item->bytenr;
1216 super->chunk_root_generation = root_item->generation;
1217 super->chunk_root_level = root_item->level;
1218
1219 root_item = &root->fs_info->tree_root->root_item;
1220 super->root = root_item->bytenr;
1221 super->generation = root_item->generation;
1222 super->root_level = root_item->level;
73bc1876 1223 if (btrfs_test_opt(root, SPACE_CACHE))
0af3d00b 1224 super->cache_generation = root_item->generation;
5d4f98a2
YZ
1225}
1226
f36f3042
CM
1227int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1228{
1229 int ret = 0;
a4abeea4 1230 spin_lock(&info->trans_lock);
f36f3042
CM
1231 if (info->running_transaction)
1232 ret = info->running_transaction->in_commit;
a4abeea4 1233 spin_unlock(&info->trans_lock);
f36f3042
CM
1234 return ret;
1235}
1236
8929ecfa
YZ
1237int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1238{
1239 int ret = 0;
a4abeea4 1240 spin_lock(&info->trans_lock);
8929ecfa
YZ
1241 if (info->running_transaction)
1242 ret = info->running_transaction->blocked;
a4abeea4 1243 spin_unlock(&info->trans_lock);
8929ecfa
YZ
1244 return ret;
1245}
1246
bb9c12c9
SW
1247/*
1248 * wait for the current transaction commit to start and block subsequent
1249 * transaction joins
1250 */
1251static void wait_current_trans_commit_start(struct btrfs_root *root,
1252 struct btrfs_transaction *trans)
1253{
72d63ed6 1254 wait_event(root->fs_info->transaction_blocked_wait, trans->in_commit);
bb9c12c9
SW
1255}
1256
1257/*
1258 * wait for the current transaction to start and then become unblocked.
1259 * caller holds ref.
1260 */
1261static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1262 struct btrfs_transaction *trans)
1263{
72d63ed6
LZ
1264 wait_event(root->fs_info->transaction_wait,
1265 trans->commit_done || (trans->in_commit && !trans->blocked));
bb9c12c9
SW
1266}
1267
1268/*
1269 * commit transactions asynchronously. once btrfs_commit_transaction_async
1270 * returns, any subsequent transaction will not be allowed to join.
1271 */
1272struct btrfs_async_commit {
1273 struct btrfs_trans_handle *newtrans;
1274 struct btrfs_root *root;
1275 struct delayed_work work;
1276};
1277
1278static void do_async_commit(struct work_struct *work)
1279{
1280 struct btrfs_async_commit *ac =
1281 container_of(work, struct btrfs_async_commit, work.work);
1282
6fc4e354
SW
1283 /*
1284 * We've got freeze protection passed with the transaction.
1285 * Tell lockdep about it.
1286 */
1287 rwsem_acquire_read(
1288 &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1289 0, 1, _THIS_IP_);
1290
e209db7a
SW
1291 current->journal_info = ac->newtrans;
1292
bb9c12c9
SW
1293 btrfs_commit_transaction(ac->newtrans, ac->root);
1294 kfree(ac);
1295}
1296
1297int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1298 struct btrfs_root *root,
1299 int wait_for_unblock)
1300{
1301 struct btrfs_async_commit *ac;
1302 struct btrfs_transaction *cur_trans;
1303
1304 ac = kmalloc(sizeof(*ac), GFP_NOFS);
db5b493a
TI
1305 if (!ac)
1306 return -ENOMEM;
bb9c12c9
SW
1307
1308 INIT_DELAYED_WORK(&ac->work, do_async_commit);
1309 ac->root = root;
7a7eaa40 1310 ac->newtrans = btrfs_join_transaction(root);
3612b495
TI
1311 if (IS_ERR(ac->newtrans)) {
1312 int err = PTR_ERR(ac->newtrans);
1313 kfree(ac);
1314 return err;
1315 }
bb9c12c9
SW
1316
1317 /* take transaction reference */
bb9c12c9 1318 cur_trans = trans->transaction;
13c5a93e 1319 atomic_inc(&cur_trans->use_count);
bb9c12c9
SW
1320
1321 btrfs_end_transaction(trans, root);
6fc4e354
SW
1322
1323 /*
1324 * Tell lockdep we've released the freeze rwsem, since the
1325 * async commit thread will be the one to unlock it.
1326 */
1327 rwsem_release(&root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1328 1, _THIS_IP_);
1329
bb9c12c9
SW
1330 schedule_delayed_work(&ac->work, 0);
1331
1332 /* wait for transaction to start and unblock */
bb9c12c9
SW
1333 if (wait_for_unblock)
1334 wait_current_trans_commit_start_and_unblock(root, cur_trans);
1335 else
1336 wait_current_trans_commit_start(root, cur_trans);
bb9c12c9 1337
38e88054
SW
1338 if (current->journal_info == trans)
1339 current->journal_info = NULL;
1340
1341 put_transaction(cur_trans);
bb9c12c9
SW
1342 return 0;
1343}
1344
49b25e05
JM
1345
1346static void cleanup_transaction(struct btrfs_trans_handle *trans,
7b8b92af 1347 struct btrfs_root *root, int err)
49b25e05
JM
1348{
1349 struct btrfs_transaction *cur_trans = trans->transaction;
1350
1351 WARN_ON(trans->use_count > 1);
1352
7b8b92af
JB
1353 btrfs_abort_transaction(trans, root, err);
1354
49b25e05
JM
1355 spin_lock(&root->fs_info->trans_lock);
1356 list_del_init(&cur_trans->list);
d7096fc3
JB
1357 if (cur_trans == root->fs_info->running_transaction) {
1358 root->fs_info->running_transaction = NULL;
1359 root->fs_info->trans_no_join = 0;
1360 }
49b25e05
JM
1361 spin_unlock(&root->fs_info->trans_lock);
1362
1363 btrfs_cleanup_one_transaction(trans->transaction, root);
1364
1365 put_transaction(cur_trans);
1366 put_transaction(cur_trans);
1367
1368 trace_btrfs_transaction_commit(root);
1369
1370 btrfs_scrub_continue(root);
1371
1372 if (current->journal_info == trans)
1373 current->journal_info = NULL;
1374
1375 kmem_cache_free(btrfs_trans_handle_cachep, trans);
1376}
1377
bb9c12c9
SW
1378/*
1379 * btrfs_transaction state sequence:
1380 * in_commit = 0, blocked = 0 (initial)
1381 * in_commit = 1, blocked = 1
1382 * blocked = 0
1383 * commit_done = 1
1384 */
79154b1b
CM
1385int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1386 struct btrfs_root *root)
1387{
15ee9bc7 1388 unsigned long joined = 0;
49b25e05 1389 struct btrfs_transaction *cur_trans = trans->transaction;
8fd17795 1390 struct btrfs_transaction *prev_trans = NULL;
79154b1b 1391 DEFINE_WAIT(wait);
49b25e05 1392 int ret = -EIO;
89573b9c
CM
1393 int should_grow = 0;
1394 unsigned long now = get_seconds();
dccae999 1395 int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
79154b1b 1396
5a3f23d5
CM
1397 btrfs_run_ordered_operations(root, 0);
1398
49b25e05
JM
1399 if (cur_trans->aborted)
1400 goto cleanup_transaction;
1401
56bec294
CM
1402 /* make a pass through all the delayed refs we have so far
1403 * any runnings procs may add more while we are here
1404 */
1405 ret = btrfs_run_delayed_refs(trans, root, 0);
49b25e05
JM
1406 if (ret)
1407 goto cleanup_transaction;
56bec294 1408
0e721106
JB
1409 btrfs_trans_release_metadata(trans, root);
1410 trans->block_rsv = NULL;
1411
b7ec40d7 1412 cur_trans = trans->transaction;
49b25e05 1413
56bec294
CM
1414 /*
1415 * set the flushing flag so procs in this transaction have to
1416 * start sending their work down.
1417 */
b7ec40d7 1418 cur_trans->delayed_refs.flushing = 1;
56bec294 1419
ea658bad
JB
1420 if (!list_empty(&trans->new_bgs))
1421 btrfs_create_pending_block_groups(trans, root);
1422
c3e69d58 1423 ret = btrfs_run_delayed_refs(trans, root, 0);
49b25e05
JM
1424 if (ret)
1425 goto cleanup_transaction;
56bec294 1426
a4abeea4 1427 spin_lock(&cur_trans->commit_lock);
b7ec40d7 1428 if (cur_trans->in_commit) {
a4abeea4 1429 spin_unlock(&cur_trans->commit_lock);
13c5a93e 1430 atomic_inc(&cur_trans->use_count);
49b25e05 1431 ret = btrfs_end_transaction(trans, root);
ccd467d6 1432
b9c8300c 1433 wait_for_commit(root, cur_trans);
15ee9bc7 1434
79154b1b 1435 put_transaction(cur_trans);
15ee9bc7 1436
49b25e05 1437 return ret;
79154b1b 1438 }
4313b399 1439
2c90e5d6 1440 trans->transaction->in_commit = 1;
f9295749 1441 trans->transaction->blocked = 1;
a4abeea4 1442 spin_unlock(&cur_trans->commit_lock);
bb9c12c9
SW
1443 wake_up(&root->fs_info->transaction_blocked_wait);
1444
a4abeea4 1445 spin_lock(&root->fs_info->trans_lock);
ccd467d6
CM
1446 if (cur_trans->list.prev != &root->fs_info->trans_list) {
1447 prev_trans = list_entry(cur_trans->list.prev,
1448 struct btrfs_transaction, list);
1449 if (!prev_trans->commit_done) {
13c5a93e 1450 atomic_inc(&prev_trans->use_count);
a4abeea4 1451 spin_unlock(&root->fs_info->trans_lock);
ccd467d6
CM
1452
1453 wait_for_commit(root, prev_trans);
ccd467d6 1454
15ee9bc7 1455 put_transaction(prev_trans);
a4abeea4
JB
1456 } else {
1457 spin_unlock(&root->fs_info->trans_lock);
ccd467d6 1458 }
a4abeea4
JB
1459 } else {
1460 spin_unlock(&root->fs_info->trans_lock);
ccd467d6 1461 }
15ee9bc7 1462
e39e64ac
CM
1463 if (!btrfs_test_opt(root, SSD) &&
1464 (now < cur_trans->start_time || now - cur_trans->start_time < 1))
89573b9c
CM
1465 should_grow = 1;
1466
15ee9bc7 1467 do {
7ea394f1 1468 int snap_pending = 0;
a4abeea4 1469
15ee9bc7 1470 joined = cur_trans->num_joined;
7ea394f1
YZ
1471 if (!list_empty(&trans->transaction->pending_snapshots))
1472 snap_pending = 1;
1473
2c90e5d6 1474 WARN_ON(cur_trans != trans->transaction);
15ee9bc7 1475
0bdb1db2 1476 if (flush_on_commit || snap_pending) {
24bbcf04 1477 btrfs_start_delalloc_inodes(root, 1);
6bbe3a9c 1478 btrfs_wait_ordered_extents(root, 1);
7ea394f1
YZ
1479 }
1480
16cdcec7 1481 ret = btrfs_run_delayed_items(trans, root);
49b25e05
JM
1482 if (ret)
1483 goto cleanup_transaction;
16cdcec7 1484
edf39272
JS
1485 /*
1486 * running the delayed items may have added new refs. account
1487 * them now so that they hinder processing of more delayed refs
1488 * as little as possible.
1489 */
1490 btrfs_delayed_refs_qgroup_accounting(trans, root->fs_info);
1491
5a3f23d5
CM
1492 /*
1493 * rename don't use btrfs_join_transaction, so, once we
1494 * set the transaction to blocked above, we aren't going
1495 * to get any new ordered operations. We can safely run
1496 * it here and no for sure that nothing new will be added
1497 * to the list
1498 */
1499 btrfs_run_ordered_operations(root, 1);
1500
ed3b3d31
CM
1501 prepare_to_wait(&cur_trans->writer_wait, &wait,
1502 TASK_UNINTERRUPTIBLE);
1503
13c5a93e 1504 if (atomic_read(&cur_trans->num_writers) > 1)
99d16cbc
SW
1505 schedule_timeout(MAX_SCHEDULE_TIMEOUT);
1506 else if (should_grow)
1507 schedule_timeout(1);
15ee9bc7 1508
15ee9bc7 1509 finish_wait(&cur_trans->writer_wait, &wait);
13c5a93e 1510 } while (atomic_read(&cur_trans->num_writers) > 1 ||
89573b9c 1511 (should_grow && cur_trans->num_joined != joined));
15ee9bc7 1512
ed0ca140
JB
1513 /*
1514 * Ok now we need to make sure to block out any other joins while we
1515 * commit the transaction. We could have started a join before setting
1516 * no_join so make sure to wait for num_writers to == 1 again.
1517 */
1518 spin_lock(&root->fs_info->trans_lock);
1519 root->fs_info->trans_no_join = 1;
1520 spin_unlock(&root->fs_info->trans_lock);
1521 wait_event(cur_trans->writer_wait,
1522 atomic_read(&cur_trans->num_writers) == 1);
1523
7585717f
CM
1524 /*
1525 * the reloc mutex makes sure that we stop
1526 * the balancing code from coming in and moving
1527 * extents around in the middle of the commit
1528 */
1529 mutex_lock(&root->fs_info->reloc_mutex);
1530
42874b3d
MX
1531 /*
1532 * We needn't worry about the delayed items because we will
1533 * deal with them in create_pending_snapshot(), which is the
1534 * core function of the snapshot creation.
1535 */
1536 ret = create_pending_snapshots(trans, root->fs_info);
49b25e05
JM
1537 if (ret) {
1538 mutex_unlock(&root->fs_info->reloc_mutex);
1539 goto cleanup_transaction;
1540 }
3063d29f 1541
42874b3d
MX
1542 /*
1543 * We insert the dir indexes of the snapshots and update the inode
1544 * of the snapshots' parents after the snapshot creation, so there
1545 * are some delayed items which are not dealt with. Now deal with
1546 * them.
1547 *
1548 * We needn't worry that this operation will corrupt the snapshots,
1549 * because all the tree which are snapshoted will be forced to COW
1550 * the nodes and leaves.
1551 */
1552 ret = btrfs_run_delayed_items(trans, root);
49b25e05
JM
1553 if (ret) {
1554 mutex_unlock(&root->fs_info->reloc_mutex);
1555 goto cleanup_transaction;
1556 }
16cdcec7 1557
56bec294 1558 ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
49b25e05
JM
1559 if (ret) {
1560 mutex_unlock(&root->fs_info->reloc_mutex);
1561 goto cleanup_transaction;
1562 }
56bec294 1563
e999376f
CM
1564 /*
1565 * make sure none of the code above managed to slip in a
1566 * delayed item
1567 */
1568 btrfs_assert_delayed_root_empty(root);
1569
2c90e5d6 1570 WARN_ON(cur_trans != trans->transaction);
dc17ff8f 1571
a2de733c 1572 btrfs_scrub_pause(root);
e02119d5
CM
1573 /* btrfs_commit_tree_roots is responsible for getting the
1574 * various roots consistent with each other. Every pointer
1575 * in the tree of tree roots has to point to the most up to date
1576 * root for every subvolume and other tree. So, we have to keep
1577 * the tree logging code from jumping in and changing any
1578 * of the trees.
1579 *
1580 * At this point in the commit, there can't be any tree-log
1581 * writers, but a little lower down we drop the trans mutex
1582 * and let new people in. By holding the tree_log_mutex
1583 * from now until after the super is written, we avoid races
1584 * with the tree-log code.
1585 */
1586 mutex_lock(&root->fs_info->tree_log_mutex);
1587
5d4f98a2 1588 ret = commit_fs_roots(trans, root);
49b25e05
JM
1589 if (ret) {
1590 mutex_unlock(&root->fs_info->tree_log_mutex);
871383be 1591 mutex_unlock(&root->fs_info->reloc_mutex);
49b25e05
JM
1592 goto cleanup_transaction;
1593 }
54aa1f4d 1594
5d4f98a2 1595 /* commit_fs_roots gets rid of all the tree log roots, it is now
e02119d5
CM
1596 * safe to free the root of tree log roots
1597 */
1598 btrfs_free_log_root_tree(trans, root->fs_info);
1599
5d4f98a2 1600 ret = commit_cowonly_roots(trans, root);
49b25e05
JM
1601 if (ret) {
1602 mutex_unlock(&root->fs_info->tree_log_mutex);
871383be 1603 mutex_unlock(&root->fs_info->reloc_mutex);
49b25e05
JM
1604 goto cleanup_transaction;
1605 }
54aa1f4d 1606
11833d66
YZ
1607 btrfs_prepare_extent_commit(trans, root);
1608
78fae27e 1609 cur_trans = root->fs_info->running_transaction;
5d4f98a2
YZ
1610
1611 btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1612 root->fs_info->tree_root->node);
817d52f8 1613 switch_commit_root(root->fs_info->tree_root);
5d4f98a2
YZ
1614
1615 btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1616 root->fs_info->chunk_root->node);
817d52f8 1617 switch_commit_root(root->fs_info->chunk_root);
5d4f98a2 1618
edf39272 1619 assert_qgroups_uptodate(trans);
5d4f98a2 1620 update_super_roots(root);
e02119d5
CM
1621
1622 if (!root->fs_info->log_root_recovering) {
6c41761f
DS
1623 btrfs_set_super_log_root(root->fs_info->super_copy, 0);
1624 btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
e02119d5
CM
1625 }
1626
6c41761f
DS
1627 memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
1628 sizeof(*root->fs_info->super_copy));
ccd467d6 1629
f9295749 1630 trans->transaction->blocked = 0;
a4abeea4
JB
1631 spin_lock(&root->fs_info->trans_lock);
1632 root->fs_info->running_transaction = NULL;
1633 root->fs_info->trans_no_join = 0;
1634 spin_unlock(&root->fs_info->trans_lock);
7585717f 1635 mutex_unlock(&root->fs_info->reloc_mutex);
b7ec40d7 1636
f9295749 1637 wake_up(&root->fs_info->transaction_wait);
e6dcd2dc 1638
79154b1b 1639 ret = btrfs_write_and_wait_transaction(trans, root);
49b25e05
JM
1640 if (ret) {
1641 btrfs_error(root->fs_info, ret,
1642 "Error while writing out transaction.");
1643 mutex_unlock(&root->fs_info->tree_log_mutex);
1644 goto cleanup_transaction;
1645 }
1646
1647 ret = write_ctree_super(trans, root, 0);
1648 if (ret) {
1649 mutex_unlock(&root->fs_info->tree_log_mutex);
1650 goto cleanup_transaction;
1651 }
4313b399 1652
e02119d5
CM
1653 /*
1654 * the super is written, we can safely allow the tree-loggers
1655 * to go about their business
1656 */
1657 mutex_unlock(&root->fs_info->tree_log_mutex);
1658
11833d66 1659 btrfs_finish_extent_commit(trans, root);
4313b399 1660
2c90e5d6 1661 cur_trans->commit_done = 1;
b7ec40d7 1662
15ee9bc7 1663 root->fs_info->last_trans_committed = cur_trans->transid;
817d52f8 1664
2c90e5d6 1665 wake_up(&cur_trans->commit_wait);
3de4586c 1666
a4abeea4 1667 spin_lock(&root->fs_info->trans_lock);
13c5a93e 1668 list_del_init(&cur_trans->list);
a4abeea4
JB
1669 spin_unlock(&root->fs_info->trans_lock);
1670
78fae27e 1671 put_transaction(cur_trans);
79154b1b 1672 put_transaction(cur_trans);
58176a96 1673
b2b5ef5c
JK
1674 sb_end_intwrite(root->fs_info->sb);
1675
1abe9b8a 1676 trace_btrfs_transaction_commit(root);
1677
a2de733c
AJ
1678 btrfs_scrub_continue(root);
1679
9ed74f2d
JB
1680 if (current->journal_info == trans)
1681 current->journal_info = NULL;
1682
2c90e5d6 1683 kmem_cache_free(btrfs_trans_handle_cachep, trans);
24bbcf04
YZ
1684
1685 if (current != root->fs_info->transaction_kthread)
1686 btrfs_run_delayed_iputs(root);
1687
79154b1b 1688 return ret;
49b25e05
JM
1689
1690cleanup_transaction:
0e721106
JB
1691 btrfs_trans_release_metadata(trans, root);
1692 trans->block_rsv = NULL;
49b25e05
JM
1693 btrfs_printk(root->fs_info, "Skipping commit of aborted transaction.\n");
1694// WARN_ON(1);
1695 if (current->journal_info == trans)
1696 current->journal_info = NULL;
7b8b92af 1697 cleanup_transaction(trans, root, ret);
49b25e05
JM
1698
1699 return ret;
79154b1b
CM
1700}
1701
d352ac68
CM
1702/*
1703 * interface function to delete all the snapshots we have scheduled for deletion
1704 */
e9d0b13b
CM
1705int btrfs_clean_old_snapshots(struct btrfs_root *root)
1706{
5d4f98a2
YZ
1707 LIST_HEAD(list);
1708 struct btrfs_fs_info *fs_info = root->fs_info;
1709
a4abeea4 1710 spin_lock(&fs_info->trans_lock);
5d4f98a2 1711 list_splice_init(&fs_info->dead_roots, &list);
a4abeea4 1712 spin_unlock(&fs_info->trans_lock);
e9d0b13b 1713
5d4f98a2 1714 while (!list_empty(&list)) {
2c536799
JM
1715 int ret;
1716
5d4f98a2 1717 root = list_entry(list.next, struct btrfs_root, root_list);
76dda93c
YZ
1718 list_del(&root->root_list);
1719
16cdcec7
MX
1720 btrfs_kill_all_delayed_nodes(root);
1721
76dda93c
YZ
1722 if (btrfs_header_backref_rev(root->node) <
1723 BTRFS_MIXED_BACKREF_REV)
2c536799 1724 ret = btrfs_drop_snapshot(root, NULL, 0, 0);
76dda93c 1725 else
2c536799
JM
1726 ret =btrfs_drop_snapshot(root, NULL, 1, 0);
1727 BUG_ON(ret < 0);
e9d0b13b
CM
1728 }
1729 return 0;
1730}