Line data Source code
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 :
19 : #include <linux/fs.h>
20 : #include <linux/slab.h>
21 : #include <linux/sched.h>
22 : #include <linux/writeback.h>
23 : #include <linux/pagemap.h>
24 : #include <linux/blkdev.h>
25 : #include <linux/uuid.h>
26 : #include "ctree.h"
27 : #include "disk-io.h"
28 : #include "transaction.h"
29 : #include "locking.h"
30 : #include "tree-log.h"
31 : #include "inode-map.h"
32 : #include "volumes.h"
33 : #include "dev-replace.h"
34 : #include "qgroup.h"
35 :
36 : #define BTRFS_ROOT_TRANS_TAG 0
37 :
38 : static unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
39 : [TRANS_STATE_RUNNING] = 0U,
40 : [TRANS_STATE_BLOCKED] = (__TRANS_USERSPACE |
41 : __TRANS_START),
42 : [TRANS_STATE_COMMIT_START] = (__TRANS_USERSPACE |
43 : __TRANS_START |
44 : __TRANS_ATTACH),
45 : [TRANS_STATE_COMMIT_DOING] = (__TRANS_USERSPACE |
46 : __TRANS_START |
47 : __TRANS_ATTACH |
48 : __TRANS_JOIN),
49 : [TRANS_STATE_UNBLOCKED] = (__TRANS_USERSPACE |
50 : __TRANS_START |
51 : __TRANS_ATTACH |
52 : __TRANS_JOIN |
53 : __TRANS_JOIN_NOLOCK),
54 : [TRANS_STATE_COMPLETED] = (__TRANS_USERSPACE |
55 : __TRANS_START |
56 : __TRANS_ATTACH |
57 : __TRANS_JOIN |
58 : __TRANS_JOIN_NOLOCK),
59 : };
60 :
61 183480 : void btrfs_put_transaction(struct btrfs_transaction *transaction)
62 : {
63 183480 : WARN_ON(atomic_read(&transaction->use_count) == 0);
64 366968 : if (atomic_dec_and_test(&transaction->use_count)) {
65 4196 : BUG_ON(!list_empty(&transaction->list));
66 2098 : WARN_ON(!RB_EMPTY_ROOT(&transaction->delayed_refs.href_root));
67 4370 : while (!list_empty(&transaction->pending_chunks)) {
68 : struct extent_map *em;
69 :
70 87 : em = list_first_entry(&transaction->pending_chunks,
71 : struct extent_map, list);
72 87 : list_del_init(&em->list);
73 87 : free_extent_map(em);
74 : }
75 2098 : kmem_cache_free(btrfs_transaction_cachep, transaction);
76 : }
77 183488 : }
78 :
79 2098 : static noinline void switch_commit_roots(struct btrfs_transaction *trans,
80 : struct btrfs_fs_info *fs_info)
81 : {
82 : struct btrfs_root *root, *tmp;
83 :
84 2098 : down_write(&fs_info->commit_root_sem);
85 13123 : list_for_each_entry_safe(root, tmp, &trans->switch_commits,
86 : dirty_list) {
87 : list_del_init(&root->dirty_list);
88 11025 : free_extent_buffer(root->commit_root);
89 11025 : root->commit_root = btrfs_root_node(root);
90 22050 : if (is_fstree(root->objectid))
91 1888 : btrfs_unpin_free_ino(root);
92 : }
93 2098 : up_write(&fs_info->commit_root_sem);
94 2098 : }
95 :
96 : static inline void extwriter_counter_inc(struct btrfs_transaction *trans,
97 : unsigned int type)
98 : {
99 178891 : if (type & TRANS_EXTWRITERS)
100 57513 : atomic_inc(&trans->num_extwriters);
101 : }
102 :
103 : static inline void extwriter_counter_dec(struct btrfs_transaction *trans,
104 : unsigned int type)
105 : {
106 180987 : if (type & TRANS_EXTWRITERS)
107 58496 : atomic_dec(&trans->num_extwriters);
108 : }
109 :
110 : static inline void extwriter_counter_init(struct btrfs_transaction *trans,
111 : unsigned int type)
112 : {
113 2098 : atomic_set(&trans->num_extwriters, ((type & TRANS_EXTWRITERS) ? 1 : 0));
114 : }
115 :
116 : static inline int extwriter_counter_read(struct btrfs_transaction *trans)
117 : {
118 : return atomic_read(&trans->num_extwriters);
119 : }
120 :
121 : /*
122 : * either allocate a new transaction or hop into the existing one
123 : */
124 182335 : static noinline int join_transaction(struct btrfs_root *root, unsigned int type)
125 : {
126 : struct btrfs_transaction *cur_trans;
127 182335 : struct btrfs_fs_info *fs_info = root->fs_info;
128 :
129 : spin_lock(&fs_info->trans_lock);
130 : loop:
131 : /* The file system has been taken offline. No new transactions. */
132 182355 : if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
133 : spin_unlock(&fs_info->trans_lock);
134 : return -EROFS;
135 : }
136 :
137 182355 : cur_trans = fs_info->running_transaction;
138 182355 : if (cur_trans) {
139 178971 : if (cur_trans->aborted) {
140 : spin_unlock(&fs_info->trans_lock);
141 0 : return cur_trans->aborted;
142 : }
143 178971 : if (btrfs_blocked_trans_types[cur_trans->state] & type) {
144 : spin_unlock(&fs_info->trans_lock);
145 : return -EBUSY;
146 : }
147 178891 : atomic_inc(&cur_trans->use_count);
148 178891 : atomic_inc(&cur_trans->num_writers);
149 : extwriter_counter_inc(cur_trans, type);
150 : spin_unlock(&fs_info->trans_lock);
151 : return 0;
152 : }
153 : spin_unlock(&fs_info->trans_lock);
154 :
155 : /*
156 : * If we are ATTACH, we just want to catch the current transaction,
157 : * and commit it. If there is no transaction, just return ENOENT.
158 : */
159 3384 : if (type == TRANS_ATTACH)
160 : return -ENOENT;
161 :
162 : /*
163 : * JOIN_NOLOCK only happens during the transaction commit, so
164 : * it is impossible that ->running_transaction is NULL
165 : */
166 2101 : BUG_ON(type == TRANS_JOIN_NOLOCK);
167 :
168 2101 : cur_trans = kmem_cache_alloc(btrfs_transaction_cachep, GFP_NOFS);
169 2101 : if (!cur_trans)
170 : return -ENOMEM;
171 :
172 : spin_lock(&fs_info->trans_lock);
173 2101 : if (fs_info->running_transaction) {
174 : /*
175 : * someone started a transaction after we unlocked. Make sure
176 : * to redo the checks above
177 : */
178 3 : kmem_cache_free(btrfs_transaction_cachep, cur_trans);
179 : goto loop;
180 2098 : } else if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
181 : spin_unlock(&fs_info->trans_lock);
182 0 : kmem_cache_free(btrfs_transaction_cachep, cur_trans);
183 : return -EROFS;
184 : }
185 :
186 : atomic_set(&cur_trans->num_writers, 1);
187 : extwriter_counter_init(cur_trans, type);
188 2098 : init_waitqueue_head(&cur_trans->writer_wait);
189 2098 : init_waitqueue_head(&cur_trans->commit_wait);
190 2098 : cur_trans->state = TRANS_STATE_RUNNING;
191 : /*
192 : * One for this trans handle, one so it will live on until we
193 : * commit the transaction.
194 : */
195 : atomic_set(&cur_trans->use_count, 2);
196 2098 : cur_trans->start_time = get_seconds();
197 :
198 2098 : cur_trans->delayed_refs.href_root = RB_ROOT;
199 : atomic_set(&cur_trans->delayed_refs.num_entries, 0);
200 2098 : cur_trans->delayed_refs.num_heads_ready = 0;
201 2098 : cur_trans->delayed_refs.num_heads = 0;
202 2098 : cur_trans->delayed_refs.flushing = 0;
203 2098 : cur_trans->delayed_refs.run_delayed_start = 0;
204 :
205 : /*
206 : * although the tree mod log is per file system and not per transaction,
207 : * the log must never go across transaction boundaries.
208 : */
209 2098 : smp_mb();
210 4196 : if (!list_empty(&fs_info->tree_mod_seq_list))
211 0 : WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
212 : "creating a fresh transaction\n");
213 2098 : if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
214 0 : WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
215 : "creating a fresh transaction\n");
216 : atomic64_set(&fs_info->tree_mod_seq, 0);
217 :
218 2098 : spin_lock_init(&cur_trans->delayed_refs.lock);
219 :
220 2098 : INIT_LIST_HEAD(&cur_trans->pending_snapshots);
221 2098 : INIT_LIST_HEAD(&cur_trans->pending_chunks);
222 2098 : INIT_LIST_HEAD(&cur_trans->switch_commits);
223 2098 : list_add_tail(&cur_trans->list, &fs_info->trans_list);
224 2098 : extent_io_tree_init(&cur_trans->dirty_pages,
225 2098 : fs_info->btree_inode->i_mapping);
226 2098 : fs_info->generation++;
227 2098 : cur_trans->transid = fs_info->generation;
228 2098 : fs_info->running_transaction = cur_trans;
229 2098 : cur_trans->aborted = 0;
230 : spin_unlock(&fs_info->trans_lock);
231 :
232 : return 0;
233 : }
234 :
235 : /*
236 : * this does all the record keeping required to make sure that a reference
237 : * counted root is properly recorded in a given transaction. This is required
238 : * to make sure the old root from before we joined the transaction is deleted
239 : * when the transaction commits
240 : */
241 2811 : static int record_root_in_trans(struct btrfs_trans_handle *trans,
242 : struct btrfs_root *root)
243 : {
244 5622 : if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
245 2811 : root->last_trans < trans->transid) {
246 2547 : WARN_ON(root == root->fs_info->extent_root);
247 2547 : WARN_ON(root->commit_root != root->node);
248 :
249 : /*
250 : * see below for IN_TRANS_SETUP usage rules
251 : * we have the reloc mutex held now, so there
252 : * is only one writer in this function
253 : */
254 : set_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
255 :
256 : /* make sure readers find IN_TRANS_SETUP before
257 : * they find our root->last_trans update
258 : */
259 2547 : smp_wmb();
260 :
261 2547 : spin_lock(&root->fs_info->fs_roots_radix_lock);
262 2547 : if (root->last_trans == trans->transid) {
263 0 : spin_unlock(&root->fs_info->fs_roots_radix_lock);
264 0 : return 0;
265 : }
266 2547 : radix_tree_tag_set(&root->fs_info->fs_roots_radix,
267 2547 : (unsigned long)root->root_key.objectid,
268 : BTRFS_ROOT_TRANS_TAG);
269 2547 : spin_unlock(&root->fs_info->fs_roots_radix_lock);
270 2547 : root->last_trans = trans->transid;
271 :
272 : /* this is pretty tricky. We don't want to
273 : * take the relocation lock in btrfs_record_root_in_trans
274 : * unless we're really doing the first setup for this root in
275 : * this transaction.
276 : *
277 : * Normally we'd use root->last_trans as a flag to decide
278 : * if we want to take the expensive mutex.
279 : *
280 : * But, we have to set root->last_trans before we
281 : * init the relocation root, otherwise, we trip over warnings
282 : * in ctree.c. The solution used here is to flag ourselves
283 : * with root IN_TRANS_SETUP. When this is 1, we're still
284 : * fixing up the reloc trees and everyone must wait.
285 : *
286 : * When this is zero, they can trust root->last_trans and fly
287 : * through btrfs_record_root_in_trans without having to take the
288 : * lock. smp_wmb() makes sure that all the writes above are
289 : * done before we pop in the zero below
290 : */
291 2547 : btrfs_init_reloc_root(trans, root);
292 2547 : smp_mb__before_atomic();
293 : clear_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state);
294 : }
295 : return 0;
296 : }
297 :
298 :
299 186565 : int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
300 : struct btrfs_root *root)
301 : {
302 186565 : if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
303 : return 0;
304 :
305 : /*
306 : * see record_root_in_trans for comments about IN_TRANS_SETUP usage
307 : * and barriers
308 : */
309 167863 : smp_rmb();
310 333208 : if (root->last_trans == trans->transid &&
311 : !test_bit(BTRFS_ROOT_IN_TRANS_SETUP, &root->state))
312 : return 0;
313 :
314 2520 : mutex_lock(&root->fs_info->reloc_mutex);
315 2519 : record_root_in_trans(trans, root);
316 2519 : mutex_unlock(&root->fs_info->reloc_mutex);
317 :
318 2519 : return 0;
319 : }
320 :
321 : static inline int is_transaction_blocked(struct btrfs_transaction *trans)
322 : {
323 57886 : return (trans->state >= TRANS_STATE_BLOCKED &&
324 58054 : trans->state < TRANS_STATE_UNBLOCKED &&
325 168 : !trans->aborted);
326 : }
327 :
328 : /* wait for commit against the current transaction to become unblocked
329 : * when this is done, it is safe to start a new transaction, but the current
330 : * transaction might not be fully on disk.
331 : */
332 58754 : static void wait_current_trans(struct btrfs_root *root)
333 : {
334 57838 : struct btrfs_transaction *cur_trans;
335 :
336 58754 : spin_lock(&root->fs_info->trans_lock);
337 58755 : cur_trans = root->fs_info->running_transaction;
338 116593 : if (cur_trans && is_transaction_blocked(cur_trans)) {
339 167 : atomic_inc(&cur_trans->use_count);
340 167 : spin_unlock(&root->fs_info->trans_lock);
341 :
342 334 : wait_event(root->fs_info->transaction_wait,
343 : cur_trans->state >= TRANS_STATE_UNBLOCKED ||
344 : cur_trans->aborted);
345 167 : btrfs_put_transaction(cur_trans);
346 : } else {
347 : spin_unlock(&root->fs_info->trans_lock);
348 : }
349 58755 : }
350 :
351 : static int may_wait_transaction(struct btrfs_root *root, int type)
352 : {
353 186619 : if (root->fs_info->log_root_recovering)
354 : return 0;
355 :
356 186620 : if (type == TRANS_USERSPACE)
357 : return 1;
358 :
359 244018 : if (type == TRANS_START &&
360 : !atomic_read(&root->fs_info->open_ioctl_trans))
361 : return 1;
362 :
363 : return 0;
364 : }
365 :
366 : static inline bool need_reserve_reloc_root(struct btrfs_root *root)
367 : {
368 52844 : if (!root->fs_info->reloc_ctl ||
369 1021 : !test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
370 2042 : root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
371 1021 : root->reloc_root)
372 : return false;
373 :
374 : return true;
375 : }
376 :
377 : static struct btrfs_trans_handle *
378 608160 : start_transaction(struct btrfs_root *root, u64 num_items, unsigned int type,
379 : enum btrfs_reserve_flush_enum flush)
380 : {
381 : struct btrfs_trans_handle *h;
382 : struct btrfs_transaction *cur_trans;
383 : u64 num_bytes = 0;
384 : u64 qgroup_reserved = 0;
385 : bool reloc_reserved = false;
386 : int ret;
387 :
388 : /* Send isn't supposed to start transactions. */
389 : ASSERT(current->journal_info != (void *)BTRFS_SEND_TRANS_STUB);
390 :
391 374758 : if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
392 : return ERR_PTR(-EROFS);
393 :
394 187383 : if (current->journal_info) {
395 5090 : WARN_ON(type & TRANS_EXTWRITERS);
396 5090 : h = current->journal_info;
397 5090 : h->use_count++;
398 5090 : WARN_ON(h->use_count > 2);
399 5090 : h->orig_rsv = h->block_rsv;
400 5090 : h->block_rsv = NULL;
401 5090 : goto got_it;
402 : }
403 :
404 : /*
405 : * Do the reservation before we join the transaction so we can do all
406 : * the appropriate flushing if need be.
407 : */
408 182293 : if (num_items > 0 && root != root->fs_info->chunk_root) {
409 57905 : if (root->fs_info->quota_enabled &&
410 6082 : is_fstree(root->root_key.objectid)) {
411 6082 : qgroup_reserved = num_items * root->leafsize;
412 6082 : ret = btrfs_qgroup_reserve(root, qgroup_reserved);
413 6082 : if (ret)
414 0 : return ERR_PTR(ret);
415 : }
416 :
417 51823 : num_bytes = btrfs_calc_trans_metadata_size(root, num_items);
418 : /*
419 : * Do the reservation for the relocation root creation
420 : */
421 51823 : if (unlikely(need_reserve_reloc_root(root))) {
422 2 : num_bytes += root->nodesize;
423 : reloc_reserved = true;
424 : }
425 :
426 51823 : ret = btrfs_block_rsv_add(root,
427 : &root->fs_info->trans_block_rsv,
428 : num_bytes, flush);
429 51824 : if (ret)
430 : goto reserve_fail;
431 : }
432 : again:
433 182287 : h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
434 182279 : if (!h) {
435 : ret = -ENOMEM;
436 : goto alloc_fail;
437 : }
438 :
439 : /*
440 : * If we are JOIN_NOLOCK we're already committing a transaction and
441 : * waiting on this guy, so we don't need to do the sb_start_intwrite
442 : * because we're already holding a ref. We need this because we could
443 : * have raced in and did an fsync() on a file which can kick a commit
444 : * and then we deadlock with somebody doing a freeze.
445 : *
446 : * If we are ATTACH, it means we just want to catch the current
447 : * transaction and commit it, so we needn't do sb_start_intwrite().
448 : */
449 182279 : if (type & __TRANS_FREEZABLE)
450 175806 : sb_start_intwrite(root->fs_info->sb);
451 :
452 364588 : if (may_wait_transaction(root, type))
453 57398 : wait_current_trans(root);
454 :
455 : do {
456 182339 : ret = join_transaction(root, type);
457 182349 : if (ret == -EBUSY) {
458 80 : wait_current_trans(root);
459 80 : if (unlikely(type == TRANS_ATTACH))
460 : ret = -ENOENT;
461 : }
462 182349 : } while (ret == -EBUSY);
463 :
464 182305 : if (ret < 0) {
465 : /* We must get the transaction if we are JOIN_NOLOCK. */
466 1319 : BUG_ON(type == TRANS_JOIN_NOLOCK);
467 : goto join_fail;
468 : }
469 :
470 180986 : cur_trans = root->fs_info->running_transaction;
471 :
472 180986 : h->transid = cur_trans->transid;
473 180986 : h->transaction = cur_trans;
474 180986 : h->blocks_used = 0;
475 180986 : h->bytes_reserved = 0;
476 180986 : h->root = root;
477 180986 : h->delayed_ref_updates = 0;
478 180986 : h->use_count = 1;
479 180986 : h->adding_csums = 0;
480 180986 : h->block_rsv = NULL;
481 180986 : h->orig_rsv = NULL;
482 180986 : h->aborted = 0;
483 180986 : h->qgroup_reserved = 0;
484 180986 : h->delayed_ref_elem.seq = 0;
485 180986 : h->type = type;
486 180986 : h->allocating_chunk = false;
487 180986 : h->reloc_reserved = false;
488 180986 : h->sync = false;
489 180986 : INIT_LIST_HEAD(&h->qgroup_ref_list);
490 180986 : INIT_LIST_HEAD(&h->new_bgs);
491 :
492 180986 : smp_mb();
493 185306 : if (cur_trans->state >= TRANS_STATE_BLOCKED &&
494 : may_wait_transaction(root, type)) {
495 0 : current->journal_info = h;
496 0 : btrfs_commit_transaction(h, root);
497 0 : goto again;
498 : }
499 :
500 180981 : if (num_bytes) {
501 51824 : trace_btrfs_space_reservation(root->fs_info, "transaction",
502 : h->transid, num_bytes, 1);
503 51824 : h->block_rsv = &root->fs_info->trans_block_rsv;
504 51824 : h->bytes_reserved = num_bytes;
505 51824 : h->reloc_reserved = reloc_reserved;
506 : }
507 180981 : h->qgroup_reserved = qgroup_reserved;
508 :
509 : got_it:
510 186071 : btrfs_record_root_in_trans(h, root);
511 :
512 186065 : if (!current->journal_info && type != TRANS_USERSPACE)
513 180976 : current->journal_info = h;
514 186065 : return h;
515 :
516 : join_fail:
517 1319 : if (type & __TRANS_FREEZABLE)
518 0 : sb_end_intwrite(root->fs_info->sb);
519 1319 : kmem_cache_free(btrfs_trans_handle_cachep, h);
520 : alloc_fail:
521 1312 : if (num_bytes)
522 0 : btrfs_block_rsv_release(root, &root->fs_info->trans_block_rsv,
523 : num_bytes);
524 : reserve_fail:
525 1319 : if (qgroup_reserved)
526 0 : btrfs_qgroup_free(root, qgroup_reserved);
527 2638 : return ERR_PTR(ret);
528 : }
529 :
530 57393 : struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
531 : int num_items)
532 : {
533 57397 : return start_transaction(root, num_items, TRANS_START,
534 : BTRFS_RESERVE_FLUSH_ALL);
535 : }
536 :
537 0 : struct btrfs_trans_handle *btrfs_start_transaction_lflush(
538 : struct btrfs_root *root, int num_items)
539 : {
540 0 : return start_transaction(root, num_items, TRANS_START,
541 : BTRFS_RESERVE_FLUSH_LIMIT);
542 : }
543 :
544 119455 : struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root)
545 : {
546 119455 : return start_transaction(root, 0, TRANS_JOIN, 0);
547 : }
548 :
549 8114 : struct btrfs_trans_handle *btrfs_join_transaction_nolock(struct btrfs_root *root)
550 : {
551 8114 : return start_transaction(root, 0, TRANS_JOIN_NOLOCK, 0);
552 : }
553 :
554 0 : struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *root)
555 : {
556 0 : return start_transaction(root, 0, TRANS_USERSPACE, 0);
557 : }
558 :
559 : /*
560 : * btrfs_attach_transaction() - catch the running transaction
561 : *
562 : * It is used when we want to commit the current the transaction, but
563 : * don't want to start a new one.
564 : *
565 : * Note: If this function return -ENOENT, it just means there is no
566 : * running transaction. But it is possible that the inactive transaction
567 : * is still in the memory, not fully on disk. If you hope there is no
568 : * inactive transaction in the fs when -ENOENT is returned, you should
569 : * invoke
570 : * btrfs_attach_transaction_barrier()
571 : */
572 18 : struct btrfs_trans_handle *btrfs_attach_transaction(struct btrfs_root *root)
573 : {
574 18 : return start_transaction(root, 0, TRANS_ATTACH, 0);
575 : }
576 :
577 : /*
578 : * btrfs_attach_transaction_barrier() - catch the running transaction
579 : *
580 : * It is similar to the above function, the differentia is this one
581 : * will wait for all the inactive transactions until they fully
582 : * complete.
583 : */
584 : struct btrfs_trans_handle *
585 2397 : btrfs_attach_transaction_barrier(struct btrfs_root *root)
586 : {
587 : struct btrfs_trans_handle *trans;
588 :
589 2397 : trans = start_transaction(root, 0, TRANS_ATTACH, 0);
590 3715 : if (IS_ERR(trans) && PTR_ERR(trans) == -ENOENT)
591 1317 : btrfs_wait_for_commit(root, 0);
592 :
593 2397 : return trans;
594 : }
595 :
596 : /* wait for a transaction commit to be fully complete */
597 241 : static noinline void wait_for_commit(struct btrfs_root *root,
598 : struct btrfs_transaction *commit)
599 : {
600 482 : wait_event(commit->commit_wait, commit->state == TRANS_STATE_COMPLETED);
601 241 : }
602 :
603 1315 : int btrfs_wait_for_commit(struct btrfs_root *root, u64 transid)
604 : {
605 : struct btrfs_transaction *cur_trans = NULL, *t;
606 : int ret = 0;
607 :
608 1315 : if (transid) {
609 0 : if (transid <= root->fs_info->last_trans_committed)
610 : goto out;
611 :
612 : ret = -EINVAL;
613 : /* find specified transaction */
614 : spin_lock(&root->fs_info->trans_lock);
615 0 : list_for_each_entry(t, &root->fs_info->trans_list, list) {
616 0 : if (t->transid == transid) {
617 : cur_trans = t;
618 0 : atomic_inc(&cur_trans->use_count);
619 : ret = 0;
620 0 : break;
621 : }
622 0 : if (t->transid > transid) {
623 : ret = 0;
624 : break;
625 : }
626 : }
627 0 : spin_unlock(&root->fs_info->trans_lock);
628 : /* The specified transaction doesn't exist */
629 0 : if (!cur_trans)
630 : goto out;
631 : } else {
632 : /* find newest transaction that is committing | committed */
633 1315 : spin_lock(&root->fs_info->trans_lock);
634 1322 : list_for_each_entry_reverse(t, &root->fs_info->trans_list,
635 : list) {
636 95 : if (t->state >= TRANS_STATE_COMMIT_START) {
637 90 : if (t->state == TRANS_STATE_COMPLETED)
638 : break;
639 : cur_trans = t;
640 90 : atomic_inc(&cur_trans->use_count);
641 : break;
642 : }
643 : }
644 1317 : spin_unlock(&root->fs_info->trans_lock);
645 1316 : if (!cur_trans)
646 : goto out; /* nothing committing|committed */
647 : }
648 :
649 90 : wait_for_commit(root, cur_trans);
650 90 : btrfs_put_transaction(cur_trans);
651 : out:
652 1316 : return ret;
653 : }
654 :
655 1276 : void btrfs_throttle(struct btrfs_root *root)
656 : {
657 2552 : if (!atomic_read(&root->fs_info->open_ioctl_trans))
658 1276 : wait_current_trans(root);
659 1276 : }
660 :
661 174837 : static int should_end_transaction(struct btrfs_trans_handle *trans,
662 : struct btrfs_root *root)
663 : {
664 174837 : if (root->fs_info->global_block_rsv.space_info->full &&
665 0 : btrfs_check_space_for_delayed_refs(trans, root))
666 : return 1;
667 :
668 174837 : return !!btrfs_block_rsv_check(root, &root->fs_info->global_block_rsv, 5);
669 : }
670 :
671 14 : int btrfs_should_end_transaction(struct btrfs_trans_handle *trans,
672 : struct btrfs_root *root)
673 : {
674 14 : struct btrfs_transaction *cur_trans = trans->transaction;
675 : int updates;
676 : int err;
677 :
678 14 : smp_mb();
679 28 : if (cur_trans->state >= TRANS_STATE_BLOCKED ||
680 14 : cur_trans->delayed_refs.flushing)
681 : return 1;
682 :
683 14 : updates = trans->delayed_ref_updates;
684 14 : trans->delayed_ref_updates = 0;
685 14 : if (updates) {
686 12 : err = btrfs_run_delayed_refs(trans, root, updates);
687 12 : if (err) /* Error code will also eval true */
688 : return err;
689 : }
690 :
691 14 : return should_end_transaction(trans, root);
692 : }
693 :
694 183965 : static int __btrfs_end_transaction(struct btrfs_trans_handle *trans,
695 : struct btrfs_root *root, int throttle)
696 : {
697 183965 : struct btrfs_transaction *cur_trans = trans->transaction;
698 183965 : struct btrfs_fs_info *info = root->fs_info;
699 183965 : unsigned long cur = trans->delayed_ref_updates;
700 183965 : int lock = (trans->type != TRANS_JOIN_NOLOCK);
701 : int err = 0;
702 : int must_run_delayed_refs = 0;
703 :
704 183965 : if (trans->use_count > 1) {
705 5090 : trans->use_count--;
706 5090 : trans->block_rsv = trans->orig_rsv;
707 5090 : return 0;
708 : }
709 :
710 178875 : btrfs_trans_release_metadata(trans, root);
711 178864 : trans->block_rsv = NULL;
712 :
713 357728 : if (!list_empty(&trans->new_bgs))
714 65 : btrfs_create_pending_block_groups(trans, root);
715 :
716 178868 : trans->delayed_ref_updates = 0;
717 178868 : if (!trans->sync) {
718 175224 : must_run_delayed_refs =
719 : btrfs_should_throttle_delayed_refs(trans, root);
720 175244 : cur = max_t(unsigned long, cur, 32);
721 :
722 : /*
723 : * don't make the caller wait if they are from a NOLOCK
724 : * or ATTACH transaction, it will deadlock with commit
725 : */
726 175275 : if (must_run_delayed_refs == 1 &&
727 31 : (trans->type & (__TRANS_JOIN_NOLOCK | __TRANS_ATTACH)))
728 : must_run_delayed_refs = 2;
729 : }
730 :
731 178888 : if (trans->qgroup_reserved) {
732 : /*
733 : * the same root has to be passed here between start_transaction
734 : * and end_transaction. Subvolume quota depends on this.
735 : */
736 6082 : btrfs_qgroup_free(trans->root, trans->qgroup_reserved);
737 6082 : trans->qgroup_reserved = 0;
738 : }
739 :
740 178888 : btrfs_trans_release_metadata(trans, root);
741 178883 : trans->block_rsv = NULL;
742 :
743 178883 : if (!list_empty(&trans->new_bgs))
744 0 : btrfs_create_pending_block_groups(trans, root);
745 :
746 528537 : if (lock && !atomic_read(&root->fs_info->open_ioctl_trans) &&
747 174828 : should_end_transaction(trans, root) &&
748 2 : ACCESS_ONCE(cur_trans->state) == TRANS_STATE_RUNNING) {
749 : spin_lock(&info->trans_lock);
750 1 : if (cur_trans->state == TRANS_STATE_RUNNING)
751 1 : cur_trans->state = TRANS_STATE_BLOCKED;
752 : spin_unlock(&info->trans_lock);
753 : }
754 :
755 178885 : if (lock && ACCESS_ONCE(cur_trans->state) == TRANS_STATE_BLOCKED) {
756 2 : if (throttle)
757 0 : return btrfs_commit_transaction(trans, root);
758 : else
759 2 : wake_up_process(info->transaction_kthread);
760 : }
761 :
762 178885 : if (trans->type & __TRANS_FREEZABLE)
763 174749 : sb_end_intwrite(root->fs_info->sb);
764 :
765 178882 : WARN_ON(cur_trans != info->running_transaction);
766 178882 : WARN_ON(atomic_read(&cur_trans->num_writers) < 1);
767 178882 : atomic_dec(&cur_trans->num_writers);
768 178889 : extwriter_counter_dec(cur_trans, trans->type);
769 :
770 178889 : smp_mb();
771 178885 : if (waitqueue_active(&cur_trans->writer_wait))
772 82 : wake_up(&cur_trans->writer_wait);
773 178885 : btrfs_put_transaction(cur_trans);
774 :
775 178884 : if (current->journal_info == trans)
776 178882 : current->journal_info = NULL;
777 :
778 178884 : if (throttle)
779 3562 : btrfs_run_delayed_iputs(root);
780 :
781 357768 : if (trans->aborted ||
782 178884 : test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
783 0 : wake_up_process(info->transaction_kthread);
784 : err = -EIO;
785 : }
786 178884 : assert_qgroups_uptodate(trans);
787 :
788 178879 : kmem_cache_free(btrfs_trans_handle_cachep, trans);
789 178869 : if (must_run_delayed_refs) {
790 2152 : btrfs_async_run_delayed_refs(root, cur,
791 : must_run_delayed_refs == 1);
792 : }
793 178869 : return err;
794 : }
795 :
796 180401 : int btrfs_end_transaction(struct btrfs_trans_handle *trans,
797 : struct btrfs_root *root)
798 : {
799 180405 : return __btrfs_end_transaction(trans, root, 0);
800 : }
801 :
802 3562 : int btrfs_end_transaction_throttle(struct btrfs_trans_handle *trans,
803 : struct btrfs_root *root)
804 : {
805 3562 : return __btrfs_end_transaction(trans, root, 1);
806 : }
807 :
808 : /*
809 : * when btree blocks are allocated, they have some corresponding bits set for
810 : * them in one of two extent_io trees. This is used to make sure all of
811 : * those extents are sent to disk but does not wait on them
812 : */
813 5052 : int btrfs_write_marked_extents(struct btrfs_root *root,
814 : struct extent_io_tree *dirty_pages, int mark)
815 : {
816 : int err = 0;
817 : int werr = 0;
818 5052 : struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
819 5052 : struct extent_state *cached_state = NULL;
820 5052 : u64 start = 0;
821 : u64 end;
822 :
823 30139 : while (!find_first_extent_bit(dirty_pages, start, &start, &end,
824 : mark, &cached_state)) {
825 20035 : convert_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
826 : mark, &cached_state, GFP_NOFS);
827 20035 : cached_state = NULL;
828 20035 : err = filemap_fdatawrite_range(mapping, start, end);
829 20035 : if (err)
830 : werr = err;
831 20035 : cond_resched();
832 20035 : start = end + 1;
833 : }
834 5052 : if (err)
835 : werr = err;
836 5052 : return werr;
837 : }
838 :
839 : /*
840 : * when btree blocks are allocated, they have some corresponding bits set for
841 : * them in one of two extent_io trees. This is used to make sure all of
842 : * those extents are on disk for transaction or log commit. We wait
843 : * on all the pages and clear them from the dirty pages state tree
844 : */
845 5052 : int btrfs_wait_marked_extents(struct btrfs_root *root,
846 : struct extent_io_tree *dirty_pages, int mark)
847 : {
848 : int err = 0;
849 : int werr = 0;
850 5052 : struct address_space *mapping = root->fs_info->btree_inode->i_mapping;
851 5052 : struct extent_state *cached_state = NULL;
852 5052 : u64 start = 0;
853 : u64 end;
854 :
855 30139 : while (!find_first_extent_bit(dirty_pages, start, &start, &end,
856 : EXTENT_NEED_WAIT, &cached_state)) {
857 20035 : clear_extent_bit(dirty_pages, start, end, EXTENT_NEED_WAIT,
858 : 0, 0, &cached_state, GFP_NOFS);
859 20035 : err = filemap_fdatawait_range(mapping, start, end);
860 20035 : if (err)
861 : werr = err;
862 20035 : cond_resched();
863 20035 : start = end + 1;
864 : }
865 5052 : if (err)
866 : werr = err;
867 5052 : return werr;
868 : }
869 :
870 : /*
871 : * when btree blocks are allocated, they have some corresponding bits set for
872 : * them in one of two extent_io trees. This is used to make sure all of
873 : * those extents are on disk for transaction or log commit
874 : */
875 2098 : static int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
876 : struct extent_io_tree *dirty_pages, int mark)
877 : {
878 : int ret;
879 : int ret2;
880 : struct blk_plug plug;
881 :
882 2098 : blk_start_plug(&plug);
883 2098 : ret = btrfs_write_marked_extents(root, dirty_pages, mark);
884 2098 : blk_finish_plug(&plug);
885 2098 : ret2 = btrfs_wait_marked_extents(root, dirty_pages, mark);
886 :
887 2098 : if (ret)
888 : return ret;
889 2098 : if (ret2)
890 0 : return ret2;
891 : return 0;
892 : }
893 :
894 2098 : int btrfs_write_and_wait_transaction(struct btrfs_trans_handle *trans,
895 : struct btrfs_root *root)
896 : {
897 2098 : if (!trans || !trans->transaction) {
898 : struct inode *btree_inode;
899 0 : btree_inode = root->fs_info->btree_inode;
900 0 : return filemap_write_and_wait(btree_inode->i_mapping);
901 : }
902 2098 : return btrfs_write_and_wait_marked_extents(root,
903 : &trans->transaction->dirty_pages,
904 : EXTENT_DIRTY);
905 : }
906 :
907 : /*
908 : * this is used to update the root pointer in the tree of tree roots.
909 : *
910 : * But, in the case of the extent allocation tree, updating the root
911 : * pointer may allocate blocks which may change the root of the extent
912 : * allocation tree.
913 : *
914 : * So, this loops and repeats and makes sure the cowonly root didn't
915 : * change while the root pointer was being updated in the metadata.
916 : */
917 4834 : static int update_cowonly_root(struct btrfs_trans_handle *trans,
918 : struct btrfs_root *root)
919 : {
920 : int ret;
921 : u64 old_root_bytenr;
922 : u64 old_root_used;
923 4834 : struct btrfs_root *tree_root = root->fs_info->tree_root;
924 :
925 : old_root_used = btrfs_root_used(&root->root_item);
926 4834 : btrfs_write_dirty_block_groups(trans, root);
927 :
928 : while (1) {
929 : old_root_bytenr = btrfs_root_bytenr(&root->root_item);
930 14498 : if (old_root_bytenr == root->node->start &&
931 : old_root_used == btrfs_root_used(&root->root_item))
932 : break;
933 :
934 4829 : btrfs_set_root_node(&root->root_item, root->node);
935 4829 : ret = btrfs_update_root(trans, tree_root,
936 : &root->root_key,
937 : &root->root_item);
938 4829 : if (ret)
939 : return ret;
940 :
941 : old_root_used = btrfs_root_used(&root->root_item);
942 4829 : ret = btrfs_write_dirty_block_groups(trans, root);
943 4829 : if (ret)
944 : return ret;
945 : }
946 :
947 : return 0;
948 : }
949 :
950 : /*
951 : * update all the cowonly tree roots on disk
952 : *
953 : * The error handling in this function may not be obvious. Any of the
954 : * failures will cause the file system to go offline. We still need
955 : * to clean up the delayed refs.
956 : */
957 2098 : static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
958 : struct btrfs_root *root)
959 : {
960 2098 : struct btrfs_fs_info *fs_info = root->fs_info;
961 : struct list_head *next;
962 : struct extent_buffer *eb;
963 : int ret;
964 :
965 2098 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
966 2098 : if (ret)
967 : return ret;
968 :
969 2098 : eb = btrfs_lock_root_node(fs_info->tree_root);
970 2098 : ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
971 : 0, &eb);
972 2098 : btrfs_tree_unlock(eb);
973 2098 : free_extent_buffer(eb);
974 :
975 2098 : if (ret)
976 : return ret;
977 :
978 2098 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
979 2098 : if (ret)
980 : return ret;
981 :
982 2098 : ret = btrfs_run_dev_stats(trans, root->fs_info);
983 2098 : if (ret)
984 : return ret;
985 2098 : ret = btrfs_run_dev_replace(trans, root->fs_info);
986 2098 : if (ret)
987 : return ret;
988 2098 : ret = btrfs_run_qgroups(trans, root->fs_info);
989 2098 : if (ret)
990 : return ret;
991 :
992 : /* run_qgroups might have added some more refs */
993 2098 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
994 2098 : if (ret)
995 : return ret;
996 :
997 13864 : while (!list_empty(&fs_info->dirty_cowonly_roots)) {
998 : next = fs_info->dirty_cowonly_roots.next;
999 : list_del_init(next);
1000 4834 : root = list_entry(next, struct btrfs_root, dirty_list);
1001 :
1002 4834 : if (root != fs_info->extent_root)
1003 2729 : list_add_tail(&root->dirty_list,
1004 2729 : &trans->transaction->switch_commits);
1005 4834 : ret = update_cowonly_root(trans, root);
1006 4834 : if (ret)
1007 : return ret;
1008 : }
1009 :
1010 2098 : list_add_tail(&fs_info->extent_root->dirty_list,
1011 2098 : &trans->transaction->switch_commits);
1012 2098 : btrfs_after_dev_replace_commit(fs_info);
1013 :
1014 2098 : return 0;
1015 : }
1016 :
1017 : /*
1018 : * dead roots are old snapshots that need to be deleted. This allocates
1019 : * a dirty root struct and adds it into the list of dead roots that need to
1020 : * be deleted
1021 : */
1022 105 : void btrfs_add_dead_root(struct btrfs_root *root)
1023 : {
1024 105 : spin_lock(&root->fs_info->trans_lock);
1025 210 : if (list_empty(&root->root_list))
1026 105 : list_add_tail(&root->root_list, &root->fs_info->dead_roots);
1027 105 : spin_unlock(&root->fs_info->trans_lock);
1028 105 : }
1029 :
1030 : /*
1031 : * update all the cowonly tree roots on disk
1032 : */
1033 2098 : static noinline int commit_fs_roots(struct btrfs_trans_handle *trans,
1034 : struct btrfs_root *root)
1035 : {
1036 : struct btrfs_root *gang[8];
1037 2098 : struct btrfs_fs_info *fs_info = root->fs_info;
1038 : int i;
1039 : int ret;
1040 : int err = 0;
1041 :
1042 : spin_lock(&fs_info->fs_roots_radix_lock);
1043 : while (1) {
1044 3707 : ret = radix_tree_gang_lookup_tag(&fs_info->fs_roots_radix,
1045 : (void **)gang, 0,
1046 : ARRAY_SIZE(gang),
1047 : BTRFS_ROOT_TRANS_TAG);
1048 3707 : if (ret == 0)
1049 : break;
1050 2548 : for (i = 0; i < ret; i++) {
1051 2548 : root = gang[i];
1052 2548 : radix_tree_tag_clear(&fs_info->fs_roots_radix,
1053 2548 : (unsigned long)root->root_key.objectid,
1054 : BTRFS_ROOT_TRANS_TAG);
1055 : spin_unlock(&fs_info->fs_roots_radix_lock);
1056 :
1057 2548 : btrfs_free_log(trans, root);
1058 2548 : btrfs_update_reloc_root(trans, root);
1059 2548 : btrfs_orphan_commit_root(trans, root);
1060 :
1061 2548 : btrfs_save_ino_cache(root, trans);
1062 :
1063 : /* see comments in should_cow_block() */
1064 : clear_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1065 2548 : smp_mb__after_atomic();
1066 :
1067 2548 : if (root->commit_root != root->node) {
1068 2002 : list_add_tail(&root->dirty_list,
1069 2002 : &trans->transaction->switch_commits);
1070 2002 : btrfs_set_root_node(&root->root_item,
1071 : root->node);
1072 : }
1073 :
1074 2548 : err = btrfs_update_root(trans, fs_info->tree_root,
1075 : &root->root_key,
1076 : &root->root_item);
1077 : spin_lock(&fs_info->fs_roots_radix_lock);
1078 2548 : if (err)
1079 : break;
1080 : }
1081 : }
1082 : spin_unlock(&fs_info->fs_roots_radix_lock);
1083 2098 : return err;
1084 : }
1085 :
1086 : /*
1087 : * defrag a given btree.
1088 : * Every leaf in the btree is read and defragged.
1089 : */
1090 4 : int btrfs_defrag_root(struct btrfs_root *root)
1091 : {
1092 4 : struct btrfs_fs_info *info = root->fs_info;
1093 : struct btrfs_trans_handle *trans;
1094 : int ret;
1095 :
1096 8 : if (test_and_set_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state))
1097 : return 0;
1098 :
1099 : while (1) {
1100 : trans = btrfs_start_transaction(root, 0);
1101 4 : if (IS_ERR(trans))
1102 0 : return PTR_ERR(trans);
1103 :
1104 4 : ret = btrfs_defrag_leaves(trans, root);
1105 :
1106 : btrfs_end_transaction(trans, root);
1107 4 : btrfs_btree_balance_dirty(info->tree_root);
1108 4 : cond_resched();
1109 :
1110 8 : if (btrfs_fs_closing(root->fs_info) || ret != -EAGAIN)
1111 : break;
1112 :
1113 0 : if (btrfs_defrag_cancelled(root->fs_info)) {
1114 0 : pr_debug("BTRFS: defrag_root cancelled\n");
1115 : ret = -EAGAIN;
1116 : break;
1117 : }
1118 : }
1119 : clear_bit(BTRFS_ROOT_DEFRAG_RUNNING, &root->state);
1120 4 : return ret;
1121 : }
1122 :
1123 : /*
1124 : * new snapshots need to be created at a very specific time in the
1125 : * transaction commit. This does the actual creation.
1126 : *
1127 : * Note:
1128 : * If the error which may affect the commitment of the current transaction
1129 : * happens, we should return the error number. If the error which just affect
1130 : * the creation of the pending snapshots, just return 0.
1131 : */
1132 146 : static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
1133 : struct btrfs_fs_info *fs_info,
1134 : struct btrfs_pending_snapshot *pending)
1135 : {
1136 : struct btrfs_key key;
1137 : struct btrfs_root_item *new_root_item;
1138 146 : struct btrfs_root *tree_root = fs_info->tree_root;
1139 146 : struct btrfs_root *root = pending->root;
1140 : struct btrfs_root *parent_root;
1141 : struct btrfs_block_rsv *rsv;
1142 : struct inode *parent_inode;
1143 : struct btrfs_path *path;
1144 : struct btrfs_dir_item *dir_item;
1145 : struct dentry *dentry;
1146 : struct extent_buffer *tmp;
1147 : struct extent_buffer *old;
1148 146 : struct timespec cur_time = CURRENT_TIME;
1149 : int ret = 0;
1150 146 : u64 to_reserve = 0;
1151 146 : u64 index = 0;
1152 : u64 objectid;
1153 : u64 root_flags;
1154 : uuid_le new_uuid;
1155 :
1156 146 : path = btrfs_alloc_path();
1157 146 : if (!path) {
1158 0 : pending->error = -ENOMEM;
1159 0 : return 0;
1160 : }
1161 :
1162 : new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
1163 146 : if (!new_root_item) {
1164 0 : pending->error = -ENOMEM;
1165 0 : goto root_item_alloc_fail;
1166 : }
1167 :
1168 146 : pending->error = btrfs_find_free_objectid(tree_root, &objectid);
1169 146 : if (pending->error)
1170 : goto no_free_objectid;
1171 :
1172 146 : btrfs_reloc_pre_snapshot(trans, pending, &to_reserve);
1173 :
1174 146 : if (to_reserve > 0) {
1175 0 : pending->error = btrfs_block_rsv_add(root,
1176 : &pending->block_rsv,
1177 : to_reserve,
1178 : BTRFS_RESERVE_NO_FLUSH);
1179 0 : if (pending->error)
1180 : goto no_free_objectid;
1181 : }
1182 :
1183 146 : key.objectid = objectid;
1184 146 : key.offset = (u64)-1;
1185 146 : key.type = BTRFS_ROOT_ITEM_KEY;
1186 :
1187 146 : rsv = trans->block_rsv;
1188 146 : trans->block_rsv = &pending->block_rsv;
1189 146 : trans->bytes_reserved = trans->block_rsv->reserved;
1190 :
1191 146 : dentry = pending->dentry;
1192 146 : parent_inode = pending->dir;
1193 146 : parent_root = BTRFS_I(parent_inode)->root;
1194 146 : record_root_in_trans(trans, parent_root);
1195 :
1196 : /*
1197 : * insert the directory item
1198 : */
1199 146 : ret = btrfs_set_inode_index(parent_inode, &index);
1200 146 : BUG_ON(ret); /* -ENOMEM */
1201 :
1202 : /* check if there is a file/dir which has the same name. */
1203 292 : dir_item = btrfs_lookup_dir_item(NULL, parent_root, path,
1204 : btrfs_ino(parent_inode),
1205 146 : dentry->d_name.name,
1206 146 : dentry->d_name.len, 0);
1207 146 : if (dir_item != NULL && !IS_ERR(dir_item)) {
1208 0 : pending->error = -EEXIST;
1209 0 : goto dir_item_existed;
1210 146 : } else if (IS_ERR(dir_item)) {
1211 0 : ret = PTR_ERR(dir_item);
1212 0 : btrfs_abort_transaction(trans, root, ret);
1213 0 : goto fail;
1214 : }
1215 146 : btrfs_release_path(path);
1216 :
1217 : /*
1218 : * pull in the delayed directory update
1219 : * and the delayed inode item
1220 : * otherwise we corrupt the FS during
1221 : * snapshot
1222 : */
1223 146 : ret = btrfs_run_delayed_items(trans, root);
1224 146 : if (ret) { /* Transaction aborted */
1225 0 : btrfs_abort_transaction(trans, root, ret);
1226 0 : goto fail;
1227 : }
1228 :
1229 146 : record_root_in_trans(trans, root);
1230 146 : btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
1231 146 : memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
1232 146 : btrfs_check_and_init_root_item(new_root_item);
1233 :
1234 : root_flags = btrfs_root_flags(new_root_item);
1235 146 : if (pending->readonly)
1236 93 : root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
1237 : else
1238 53 : root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
1239 : btrfs_set_root_flags(new_root_item, root_flags);
1240 :
1241 146 : btrfs_set_root_generation_v2(new_root_item,
1242 : trans->transid);
1243 146 : uuid_le_gen(&new_uuid);
1244 146 : memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
1245 146 : memcpy(new_root_item->parent_uuid, root->root_item.uuid,
1246 : BTRFS_UUID_SIZE);
1247 146 : if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
1248 53 : memset(new_root_item->received_uuid, 0,
1249 : sizeof(new_root_item->received_uuid));
1250 53 : memset(&new_root_item->stime, 0, sizeof(new_root_item->stime));
1251 53 : memset(&new_root_item->rtime, 0, sizeof(new_root_item->rtime));
1252 : btrfs_set_root_stransid(new_root_item, 0);
1253 : btrfs_set_root_rtransid(new_root_item, 0);
1254 : }
1255 146 : btrfs_set_stack_timespec_sec(&new_root_item->otime, cur_time.tv_sec);
1256 146 : btrfs_set_stack_timespec_nsec(&new_root_item->otime, cur_time.tv_nsec);
1257 146 : btrfs_set_root_otransid(new_root_item, trans->transid);
1258 :
1259 146 : old = btrfs_lock_root_node(root);
1260 146 : ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
1261 146 : if (ret) {
1262 0 : btrfs_tree_unlock(old);
1263 0 : free_extent_buffer(old);
1264 0 : btrfs_abort_transaction(trans, root, ret);
1265 0 : goto fail;
1266 : }
1267 :
1268 146 : btrfs_set_lock_blocking(old);
1269 :
1270 146 : ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
1271 : /* clean up in any case */
1272 146 : btrfs_tree_unlock(old);
1273 146 : free_extent_buffer(old);
1274 146 : if (ret) {
1275 0 : btrfs_abort_transaction(trans, root, ret);
1276 0 : goto fail;
1277 : }
1278 :
1279 : /*
1280 : * We need to flush delayed refs in order to make sure all of our quota
1281 : * operations have been done before we call btrfs_qgroup_inherit.
1282 : */
1283 146 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1284 146 : if (ret) {
1285 0 : btrfs_abort_transaction(trans, root, ret);
1286 0 : goto fail;
1287 : }
1288 :
1289 146 : ret = btrfs_qgroup_inherit(trans, fs_info,
1290 : root->root_key.objectid,
1291 : objectid, pending->inherit);
1292 146 : if (ret) {
1293 0 : btrfs_abort_transaction(trans, root, ret);
1294 0 : goto fail;
1295 : }
1296 :
1297 : /* see comments in should_cow_block() */
1298 : set_bit(BTRFS_ROOT_FORCE_COW, &root->state);
1299 146 : smp_wmb();
1300 :
1301 146 : btrfs_set_root_node(new_root_item, tmp);
1302 : /* record when the snapshot was created in key.offset */
1303 146 : key.offset = trans->transid;
1304 146 : ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
1305 146 : btrfs_tree_unlock(tmp);
1306 146 : free_extent_buffer(tmp);
1307 146 : if (ret) {
1308 0 : btrfs_abort_transaction(trans, root, ret);
1309 0 : goto fail;
1310 : }
1311 :
1312 : /*
1313 : * insert root back/forward references
1314 : */
1315 438 : ret = btrfs_add_root_ref(trans, tree_root, objectid,
1316 : parent_root->root_key.objectid,
1317 : btrfs_ino(parent_inode), index,
1318 292 : dentry->d_name.name, dentry->d_name.len);
1319 146 : if (ret) {
1320 0 : btrfs_abort_transaction(trans, root, ret);
1321 0 : goto fail;
1322 : }
1323 :
1324 146 : key.offset = (u64)-1;
1325 292 : pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
1326 146 : if (IS_ERR(pending->snap)) {
1327 0 : ret = PTR_ERR(pending->snap);
1328 0 : btrfs_abort_transaction(trans, root, ret);
1329 0 : goto fail;
1330 : }
1331 :
1332 146 : ret = btrfs_reloc_post_snapshot(trans, pending);
1333 146 : if (ret) {
1334 0 : btrfs_abort_transaction(trans, root, ret);
1335 0 : goto fail;
1336 : }
1337 :
1338 146 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1339 146 : if (ret) {
1340 0 : btrfs_abort_transaction(trans, root, ret);
1341 0 : goto fail;
1342 : }
1343 :
1344 438 : ret = btrfs_insert_dir_item(trans, parent_root,
1345 292 : dentry->d_name.name, dentry->d_name.len,
1346 : parent_inode, &key,
1347 : BTRFS_FT_DIR, index);
1348 : /* We have check then name at the beginning, so it is impossible. */
1349 146 : BUG_ON(ret == -EEXIST || ret == -EOVERFLOW);
1350 146 : if (ret) {
1351 0 : btrfs_abort_transaction(trans, root, ret);
1352 0 : goto fail;
1353 : }
1354 :
1355 292 : btrfs_i_size_write(parent_inode, parent_inode->i_size +
1356 146 : dentry->d_name.len * 2);
1357 146 : parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
1358 146 : ret = btrfs_update_inode_fallback(trans, parent_root, parent_inode);
1359 146 : if (ret) {
1360 0 : btrfs_abort_transaction(trans, root, ret);
1361 0 : goto fail;
1362 : }
1363 146 : ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root, new_uuid.b,
1364 : BTRFS_UUID_KEY_SUBVOL, objectid);
1365 146 : if (ret) {
1366 0 : btrfs_abort_transaction(trans, root, ret);
1367 0 : goto fail;
1368 : }
1369 146 : if (!btrfs_is_empty_uuid(new_root_item->received_uuid)) {
1370 0 : ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
1371 : new_root_item->received_uuid,
1372 : BTRFS_UUID_KEY_RECEIVED_SUBVOL,
1373 : objectid);
1374 0 : if (ret && ret != -EEXIST) {
1375 0 : btrfs_abort_transaction(trans, root, ret);
1376 0 : goto fail;
1377 : }
1378 : }
1379 : fail:
1380 146 : pending->error = ret;
1381 : dir_item_existed:
1382 146 : trans->block_rsv = rsv;
1383 146 : trans->bytes_reserved = 0;
1384 : no_free_objectid:
1385 146 : kfree(new_root_item);
1386 : root_item_alloc_fail:
1387 146 : btrfs_free_path(path);
1388 146 : return ret;
1389 : }
1390 :
1391 : /*
1392 : * create all the snapshots we've scheduled for creation
1393 : */
1394 2098 : static noinline int create_pending_snapshots(struct btrfs_trans_handle *trans,
1395 : struct btrfs_fs_info *fs_info)
1396 : {
1397 : struct btrfs_pending_snapshot *pending, *next;
1398 2098 : struct list_head *head = &trans->transaction->pending_snapshots;
1399 : int ret = 0;
1400 :
1401 2244 : list_for_each_entry_safe(pending, next, head, list) {
1402 146 : list_del(&pending->list);
1403 146 : ret = create_pending_snapshot(trans, fs_info, pending);
1404 146 : if (ret)
1405 : break;
1406 : }
1407 2098 : return ret;
1408 : }
1409 :
1410 2098 : static void update_super_roots(struct btrfs_root *root)
1411 : {
1412 : struct btrfs_root_item *root_item;
1413 : struct btrfs_super_block *super;
1414 :
1415 2098 : super = root->fs_info->super_copy;
1416 :
1417 2098 : root_item = &root->fs_info->chunk_root->root_item;
1418 2098 : super->chunk_root = root_item->bytenr;
1419 2098 : super->chunk_root_generation = root_item->generation;
1420 2098 : super->chunk_root_level = root_item->level;
1421 :
1422 2098 : root_item = &root->fs_info->tree_root->root_item;
1423 2098 : super->root = root_item->bytenr;
1424 2098 : super->generation = root_item->generation;
1425 2098 : super->root_level = root_item->level;
1426 2098 : if (btrfs_test_opt(root, SPACE_CACHE))
1427 2098 : super->cache_generation = root_item->generation;
1428 2098 : if (root->fs_info->update_uuid_tree_gen)
1429 1650 : super->uuid_tree_generation = root_item->generation;
1430 2098 : }
1431 :
1432 154341 : int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
1433 : {
1434 : struct btrfs_transaction *trans;
1435 : int ret = 0;
1436 :
1437 : spin_lock(&info->trans_lock);
1438 154345 : trans = info->running_transaction;
1439 154345 : if (trans)
1440 144759 : ret = (trans->state >= TRANS_STATE_COMMIT_START);
1441 : spin_unlock(&info->trans_lock);
1442 154345 : return ret;
1443 : }
1444 :
1445 303 : int btrfs_transaction_blocked(struct btrfs_fs_info *info)
1446 : {
1447 48 : struct btrfs_transaction *trans;
1448 : int ret = 0;
1449 :
1450 : spin_lock(&info->trans_lock);
1451 303 : trans = info->running_transaction;
1452 303 : if (trans)
1453 : ret = is_transaction_blocked(trans);
1454 : spin_unlock(&info->trans_lock);
1455 303 : return ret;
1456 : }
1457 :
1458 : /*
1459 : * wait for the current transaction commit to start and block subsequent
1460 : * transaction joins
1461 : */
1462 0 : static void wait_current_trans_commit_start(struct btrfs_root *root,
1463 : struct btrfs_transaction *trans)
1464 : {
1465 0 : wait_event(root->fs_info->transaction_blocked_wait,
1466 : trans->state >= TRANS_STATE_COMMIT_START ||
1467 : trans->aborted);
1468 0 : }
1469 :
1470 : /*
1471 : * wait for the current transaction to start and then become unblocked.
1472 : * caller holds ref.
1473 : */
1474 0 : static void wait_current_trans_commit_start_and_unblock(struct btrfs_root *root,
1475 : struct btrfs_transaction *trans)
1476 : {
1477 0 : wait_event(root->fs_info->transaction_wait,
1478 : trans->state >= TRANS_STATE_UNBLOCKED ||
1479 : trans->aborted);
1480 0 : }
1481 :
1482 : /*
1483 : * commit transactions asynchronously. once btrfs_commit_transaction_async
1484 : * returns, any subsequent transaction will not be allowed to join.
1485 : */
1486 : struct btrfs_async_commit {
1487 : struct btrfs_trans_handle *newtrans;
1488 : struct btrfs_root *root;
1489 : struct work_struct work;
1490 : };
1491 :
1492 0 : static void do_async_commit(struct work_struct *work)
1493 : {
1494 0 : struct btrfs_async_commit *ac =
1495 : container_of(work, struct btrfs_async_commit, work);
1496 :
1497 : /*
1498 : * We've got freeze protection passed with the transaction.
1499 : * Tell lockdep about it.
1500 : */
1501 : if (ac->newtrans->type & __TRANS_FREEZABLE)
1502 : rwsem_acquire_read(
1503 : &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1504 : 0, 1, _THIS_IP_);
1505 :
1506 0 : current->journal_info = ac->newtrans;
1507 :
1508 0 : btrfs_commit_transaction(ac->newtrans, ac->root);
1509 0 : kfree(ac);
1510 0 : }
1511 :
1512 0 : int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
1513 : struct btrfs_root *root,
1514 : int wait_for_unblock)
1515 : {
1516 : struct btrfs_async_commit *ac;
1517 : struct btrfs_transaction *cur_trans;
1518 :
1519 : ac = kmalloc(sizeof(*ac), GFP_NOFS);
1520 0 : if (!ac)
1521 : return -ENOMEM;
1522 :
1523 0 : INIT_WORK(&ac->work, do_async_commit);
1524 0 : ac->root = root;
1525 0 : ac->newtrans = btrfs_join_transaction(root);
1526 0 : if (IS_ERR(ac->newtrans)) {
1527 0 : int err = PTR_ERR(ac->newtrans);
1528 0 : kfree(ac);
1529 0 : return err;
1530 : }
1531 :
1532 : /* take transaction reference */
1533 0 : cur_trans = trans->transaction;
1534 0 : atomic_inc(&cur_trans->use_count);
1535 :
1536 : btrfs_end_transaction(trans, root);
1537 :
1538 : /*
1539 : * Tell lockdep we've released the freeze rwsem, since the
1540 : * async commit thread will be the one to unlock it.
1541 : */
1542 : if (ac->newtrans->type & __TRANS_FREEZABLE)
1543 : rwsem_release(
1544 : &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
1545 : 1, _THIS_IP_);
1546 :
1547 0 : schedule_work(&ac->work);
1548 :
1549 : /* wait for transaction to start and unblock */
1550 0 : if (wait_for_unblock)
1551 0 : wait_current_trans_commit_start_and_unblock(root, cur_trans);
1552 : else
1553 0 : wait_current_trans_commit_start(root, cur_trans);
1554 :
1555 0 : if (current->journal_info == trans)
1556 0 : current->journal_info = NULL;
1557 :
1558 0 : btrfs_put_transaction(cur_trans);
1559 0 : return 0;
1560 : }
1561 :
1562 :
1563 0 : static void cleanup_transaction(struct btrfs_trans_handle *trans,
1564 : struct btrfs_root *root, int err)
1565 : {
1566 0 : struct btrfs_transaction *cur_trans = trans->transaction;
1567 0 : DEFINE_WAIT(wait);
1568 :
1569 0 : WARN_ON(trans->use_count > 1);
1570 :
1571 0 : btrfs_abort_transaction(trans, root, err);
1572 :
1573 0 : spin_lock(&root->fs_info->trans_lock);
1574 :
1575 : /*
1576 : * If the transaction is removed from the list, it means this
1577 : * transaction has been committed successfully, so it is impossible
1578 : * to call the cleanup function.
1579 : */
1580 0 : BUG_ON(list_empty(&cur_trans->list));
1581 :
1582 : list_del_init(&cur_trans->list);
1583 0 : if (cur_trans == root->fs_info->running_transaction) {
1584 0 : cur_trans->state = TRANS_STATE_COMMIT_DOING;
1585 0 : spin_unlock(&root->fs_info->trans_lock);
1586 0 : wait_event(cur_trans->writer_wait,
1587 : atomic_read(&cur_trans->num_writers) == 1);
1588 :
1589 0 : spin_lock(&root->fs_info->trans_lock);
1590 : }
1591 0 : spin_unlock(&root->fs_info->trans_lock);
1592 :
1593 0 : btrfs_cleanup_one_transaction(trans->transaction, root);
1594 :
1595 0 : spin_lock(&root->fs_info->trans_lock);
1596 0 : if (cur_trans == root->fs_info->running_transaction)
1597 0 : root->fs_info->running_transaction = NULL;
1598 0 : spin_unlock(&root->fs_info->trans_lock);
1599 :
1600 0 : if (trans->type & __TRANS_FREEZABLE)
1601 0 : sb_end_intwrite(root->fs_info->sb);
1602 0 : btrfs_put_transaction(cur_trans);
1603 0 : btrfs_put_transaction(cur_trans);
1604 :
1605 0 : trace_btrfs_transaction_commit(root);
1606 :
1607 0 : if (current->journal_info == trans)
1608 0 : current->journal_info = NULL;
1609 0 : btrfs_scrub_cancel(root->fs_info);
1610 :
1611 0 : kmem_cache_free(btrfs_trans_handle_cachep, trans);
1612 0 : }
1613 :
1614 2098 : static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info)
1615 : {
1616 2098 : if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1617 3 : return btrfs_start_delalloc_roots(fs_info, 1, -1);
1618 : return 0;
1619 : }
1620 :
1621 2098 : static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info)
1622 : {
1623 2098 : if (btrfs_test_opt(fs_info->tree_root, FLUSHONCOMMIT))
1624 3 : btrfs_wait_ordered_roots(fs_info, -1);
1625 2098 : }
1626 :
1627 2190 : int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
1628 2098 : struct btrfs_root *root)
1629 : {
1630 2190 : struct btrfs_transaction *cur_trans = trans->transaction;
1631 : struct btrfs_transaction *prev_trans = NULL;
1632 : int ret;
1633 :
1634 : /* Stop the commit early if ->aborted is set */
1635 2190 : if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1636 0 : ret = cur_trans->aborted;
1637 0 : btrfs_end_transaction(trans, root);
1638 0 : return ret;
1639 : }
1640 :
1641 : /* make a pass through all the delayed refs we have so far
1642 : * any runnings procs may add more while we are here
1643 : */
1644 2190 : ret = btrfs_run_delayed_refs(trans, root, 0);
1645 2190 : if (ret) {
1646 0 : btrfs_end_transaction(trans, root);
1647 0 : return ret;
1648 : }
1649 :
1650 2190 : btrfs_trans_release_metadata(trans, root);
1651 2190 : trans->block_rsv = NULL;
1652 2190 : if (trans->qgroup_reserved) {
1653 0 : btrfs_qgroup_free(root, trans->qgroup_reserved);
1654 0 : trans->qgroup_reserved = 0;
1655 : }
1656 :
1657 2190 : cur_trans = trans->transaction;
1658 :
1659 : /*
1660 : * set the flushing flag so procs in this transaction have to
1661 : * start sending their work down.
1662 : */
1663 2190 : cur_trans->delayed_refs.flushing = 1;
1664 2190 : smp_wmb();
1665 :
1666 4378 : if (!list_empty(&trans->new_bgs))
1667 0 : btrfs_create_pending_block_groups(trans, root);
1668 :
1669 2189 : ret = btrfs_run_delayed_refs(trans, root, 0);
1670 2190 : if (ret) {
1671 0 : btrfs_end_transaction(trans, root);
1672 0 : return ret;
1673 : }
1674 :
1675 2190 : spin_lock(&root->fs_info->trans_lock);
1676 2190 : if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
1677 92 : spin_unlock(&root->fs_info->trans_lock);
1678 92 : atomic_inc(&cur_trans->use_count);
1679 92 : ret = btrfs_end_transaction(trans, root);
1680 :
1681 92 : wait_for_commit(root, cur_trans);
1682 :
1683 91 : btrfs_put_transaction(cur_trans);
1684 :
1685 92 : return ret;
1686 : }
1687 :
1688 2098 : cur_trans->state = TRANS_STATE_COMMIT_START;
1689 2098 : wake_up(&root->fs_info->transaction_blocked_wait);
1690 :
1691 2098 : if (cur_trans->list.prev != &root->fs_info->trans_list) {
1692 59 : prev_trans = list_entry(cur_trans->list.prev,
1693 : struct btrfs_transaction, list);
1694 59 : if (prev_trans->state != TRANS_STATE_COMPLETED) {
1695 59 : atomic_inc(&prev_trans->use_count);
1696 59 : spin_unlock(&root->fs_info->trans_lock);
1697 :
1698 59 : wait_for_commit(root, prev_trans);
1699 :
1700 59 : btrfs_put_transaction(prev_trans);
1701 : } else {
1702 : spin_unlock(&root->fs_info->trans_lock);
1703 : }
1704 : } else {
1705 : spin_unlock(&root->fs_info->trans_lock);
1706 : }
1707 :
1708 2098 : extwriter_counter_dec(cur_trans, trans->type);
1709 :
1710 2098 : ret = btrfs_start_delalloc_flush(root->fs_info);
1711 2098 : if (ret)
1712 : goto cleanup_transaction;
1713 :
1714 2098 : ret = btrfs_run_delayed_items(trans, root);
1715 2098 : if (ret)
1716 : goto cleanup_transaction;
1717 :
1718 2251 : wait_event(cur_trans->writer_wait,
1719 : extwriter_counter_read(cur_trans) == 0);
1720 :
1721 : /* some pending stuffs might be added after the previous flush. */
1722 2098 : ret = btrfs_run_delayed_items(trans, root);
1723 2098 : if (ret)
1724 : goto cleanup_transaction;
1725 :
1726 2098 : btrfs_wait_delalloc_flush(root->fs_info);
1727 :
1728 2098 : btrfs_scrub_pause(root);
1729 : /*
1730 : * Ok now we need to make sure to block out any other joins while we
1731 : * commit the transaction. We could have started a join before setting
1732 : * COMMIT_DOING so make sure to wait for num_writers to == 1 again.
1733 : */
1734 2098 : spin_lock(&root->fs_info->trans_lock);
1735 2098 : cur_trans->state = TRANS_STATE_COMMIT_DOING;
1736 2098 : spin_unlock(&root->fs_info->trans_lock);
1737 2131 : wait_event(cur_trans->writer_wait,
1738 : atomic_read(&cur_trans->num_writers) == 1);
1739 :
1740 : /* ->aborted might be set after the previous check, so check it */
1741 2098 : if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1742 0 : ret = cur_trans->aborted;
1743 0 : goto scrub_continue;
1744 : }
1745 : /*
1746 : * the reloc mutex makes sure that we stop
1747 : * the balancing code from coming in and moving
1748 : * extents around in the middle of the commit
1749 : */
1750 2098 : mutex_lock(&root->fs_info->reloc_mutex);
1751 :
1752 : /*
1753 : * We needn't worry about the delayed items because we will
1754 : * deal with them in create_pending_snapshot(), which is the
1755 : * core function of the snapshot creation.
1756 : */
1757 2098 : ret = create_pending_snapshots(trans, root->fs_info);
1758 2098 : if (ret) {
1759 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1760 0 : goto scrub_continue;
1761 : }
1762 :
1763 : /*
1764 : * We insert the dir indexes of the snapshots and update the inode
1765 : * of the snapshots' parents after the snapshot creation, so there
1766 : * are some delayed items which are not dealt with. Now deal with
1767 : * them.
1768 : *
1769 : * We needn't worry that this operation will corrupt the snapshots,
1770 : * because all the tree which are snapshoted will be forced to COW
1771 : * the nodes and leaves.
1772 : */
1773 2098 : ret = btrfs_run_delayed_items(trans, root);
1774 2098 : if (ret) {
1775 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1776 0 : goto scrub_continue;
1777 : }
1778 :
1779 2098 : ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
1780 2098 : if (ret) {
1781 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1782 0 : goto scrub_continue;
1783 : }
1784 :
1785 : /*
1786 : * make sure none of the code above managed to slip in a
1787 : * delayed item
1788 : */
1789 2098 : btrfs_assert_delayed_root_empty(root);
1790 :
1791 2098 : WARN_ON(cur_trans != trans->transaction);
1792 :
1793 : /* btrfs_commit_tree_roots is responsible for getting the
1794 : * various roots consistent with each other. Every pointer
1795 : * in the tree of tree roots has to point to the most up to date
1796 : * root for every subvolume and other tree. So, we have to keep
1797 : * the tree logging code from jumping in and changing any
1798 : * of the trees.
1799 : *
1800 : * At this point in the commit, there can't be any tree-log
1801 : * writers, but a little lower down we drop the trans mutex
1802 : * and let new people in. By holding the tree_log_mutex
1803 : * from now until after the super is written, we avoid races
1804 : * with the tree-log code.
1805 : */
1806 2098 : mutex_lock(&root->fs_info->tree_log_mutex);
1807 :
1808 2098 : ret = commit_fs_roots(trans, root);
1809 2098 : if (ret) {
1810 0 : mutex_unlock(&root->fs_info->tree_log_mutex);
1811 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1812 0 : goto scrub_continue;
1813 : }
1814 :
1815 : /*
1816 : * Since the transaction is done, we should set the inode map cache flag
1817 : * before any other comming transaction.
1818 : */
1819 2098 : if (btrfs_test_opt(root, CHANGE_INODE_CACHE))
1820 0 : btrfs_set_opt(root->fs_info->mount_opt, INODE_MAP_CACHE);
1821 : else
1822 2098 : btrfs_clear_opt(root->fs_info->mount_opt, INODE_MAP_CACHE);
1823 :
1824 : /* commit_fs_roots gets rid of all the tree log roots, it is now
1825 : * safe to free the root of tree log roots
1826 : */
1827 2098 : btrfs_free_log_root_tree(trans, root->fs_info);
1828 :
1829 2098 : ret = commit_cowonly_roots(trans, root);
1830 2098 : if (ret) {
1831 0 : mutex_unlock(&root->fs_info->tree_log_mutex);
1832 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1833 0 : goto scrub_continue;
1834 : }
1835 :
1836 : /*
1837 : * The tasks which save the space cache and inode cache may also
1838 : * update ->aborted, check it.
1839 : */
1840 2098 : if (unlikely(ACCESS_ONCE(cur_trans->aborted))) {
1841 0 : ret = cur_trans->aborted;
1842 0 : mutex_unlock(&root->fs_info->tree_log_mutex);
1843 0 : mutex_unlock(&root->fs_info->reloc_mutex);
1844 0 : goto scrub_continue;
1845 : }
1846 :
1847 2098 : btrfs_prepare_extent_commit(trans, root);
1848 :
1849 2098 : cur_trans = root->fs_info->running_transaction;
1850 :
1851 2098 : btrfs_set_root_node(&root->fs_info->tree_root->root_item,
1852 2098 : root->fs_info->tree_root->node);
1853 2098 : list_add_tail(&root->fs_info->tree_root->dirty_list,
1854 : &cur_trans->switch_commits);
1855 :
1856 2098 : btrfs_set_root_node(&root->fs_info->chunk_root->root_item,
1857 2098 : root->fs_info->chunk_root->node);
1858 2098 : list_add_tail(&root->fs_info->chunk_root->dirty_list,
1859 : &cur_trans->switch_commits);
1860 :
1861 2098 : switch_commit_roots(cur_trans, root->fs_info);
1862 :
1863 2098 : assert_qgroups_uptodate(trans);
1864 2098 : update_super_roots(root);
1865 :
1866 2098 : btrfs_set_super_log_root(root->fs_info->super_copy, 0);
1867 2098 : btrfs_set_super_log_root_level(root->fs_info->super_copy, 0);
1868 2098 : memcpy(root->fs_info->super_for_commit, root->fs_info->super_copy,
1869 : sizeof(*root->fs_info->super_copy));
1870 :
1871 2098 : spin_lock(&root->fs_info->trans_lock);
1872 2098 : cur_trans->state = TRANS_STATE_UNBLOCKED;
1873 2098 : root->fs_info->running_transaction = NULL;
1874 2098 : spin_unlock(&root->fs_info->trans_lock);
1875 2098 : mutex_unlock(&root->fs_info->reloc_mutex);
1876 :
1877 2098 : wake_up(&root->fs_info->transaction_wait);
1878 :
1879 2098 : ret = btrfs_write_and_wait_transaction(trans, root);
1880 2098 : if (ret) {
1881 0 : btrfs_error(root->fs_info, ret,
1882 : "Error while writing out transaction");
1883 0 : mutex_unlock(&root->fs_info->tree_log_mutex);
1884 0 : goto scrub_continue;
1885 : }
1886 :
1887 2098 : ret = write_ctree_super(trans, root, 0);
1888 2098 : if (ret) {
1889 0 : mutex_unlock(&root->fs_info->tree_log_mutex);
1890 0 : goto scrub_continue;
1891 : }
1892 :
1893 : /*
1894 : * the super is written, we can safely allow the tree-loggers
1895 : * to go about their business
1896 : */
1897 2098 : mutex_unlock(&root->fs_info->tree_log_mutex);
1898 :
1899 2098 : btrfs_finish_extent_commit(trans, root);
1900 :
1901 2098 : root->fs_info->last_trans_committed = cur_trans->transid;
1902 : /*
1903 : * We needn't acquire the lock here because there is no other task
1904 : * which can change it.
1905 : */
1906 2098 : cur_trans->state = TRANS_STATE_COMPLETED;
1907 2098 : wake_up(&cur_trans->commit_wait);
1908 :
1909 2098 : spin_lock(&root->fs_info->trans_lock);
1910 2098 : list_del_init(&cur_trans->list);
1911 2098 : spin_unlock(&root->fs_info->trans_lock);
1912 :
1913 2098 : btrfs_put_transaction(cur_trans);
1914 2098 : btrfs_put_transaction(cur_trans);
1915 :
1916 2098 : if (trans->type & __TRANS_FREEZABLE)
1917 1081 : sb_end_intwrite(root->fs_info->sb);
1918 :
1919 2098 : trace_btrfs_transaction_commit(root);
1920 :
1921 2098 : btrfs_scrub_continue(root);
1922 :
1923 2098 : if (current->journal_info == trans)
1924 2098 : current->journal_info = NULL;
1925 :
1926 2098 : kmem_cache_free(btrfs_trans_handle_cachep, trans);
1927 :
1928 2098 : if (current != root->fs_info->transaction_kthread)
1929 2082 : btrfs_run_delayed_iputs(root);
1930 :
1931 2098 : return ret;
1932 :
1933 : scrub_continue:
1934 0 : btrfs_scrub_continue(root);
1935 : cleanup_transaction:
1936 0 : btrfs_trans_release_metadata(trans, root);
1937 0 : trans->block_rsv = NULL;
1938 0 : if (trans->qgroup_reserved) {
1939 0 : btrfs_qgroup_free(root, trans->qgroup_reserved);
1940 0 : trans->qgroup_reserved = 0;
1941 : }
1942 0 : btrfs_warn(root->fs_info, "Skipping commit of aborted transaction.");
1943 0 : if (current->journal_info == trans)
1944 0 : current->journal_info = NULL;
1945 0 : cleanup_transaction(trans, root, ret);
1946 :
1947 0 : return ret;
1948 : }
1949 :
1950 : /*
1951 : * return < 0 if error
1952 : * 0 if there are no more dead_roots at the time of call
1953 : * 1 there are more to be processed, call me again
1954 : *
1955 : * The return value indicates there are certainly more snapshots to delete, but
1956 : * if there comes a new one during processing, it may return 0. We don't mind,
1957 : * because btrfs_commit_super will poke cleaner thread and it will process it a
1958 : * few seconds later.
1959 : */
1960 295 : int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
1961 : {
1962 : int ret;
1963 295 : struct btrfs_fs_info *fs_info = root->fs_info;
1964 :
1965 : spin_lock(&fs_info->trans_lock);
1966 590 : if (list_empty(&fs_info->dead_roots)) {
1967 : spin_unlock(&fs_info->trans_lock);
1968 284 : return 0;
1969 : }
1970 11 : root = list_first_entry(&fs_info->dead_roots,
1971 : struct btrfs_root, root_list);
1972 11 : list_del_init(&root->root_list);
1973 : spin_unlock(&fs_info->trans_lock);
1974 :
1975 11 : pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
1976 :
1977 11 : btrfs_kill_all_delayed_nodes(root);
1978 :
1979 22 : if (btrfs_header_backref_rev(root->node) <
1980 : BTRFS_MIXED_BACKREF_REV)
1981 0 : ret = btrfs_drop_snapshot(root, NULL, 0, 0);
1982 : else
1983 11 : ret = btrfs_drop_snapshot(root, NULL, 1, 0);
1984 : /*
1985 : * If we encounter a transaction abort during snapshot cleaning, we
1986 : * don't want to crash here
1987 : */
1988 11 : return (ret < 0) ? 0 : 1;
1989 : }
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