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1/*
2 * linux/fs/jbd2/commit.c
3 *
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
5 *
6 * Copyright 1998 Red Hat corp --- All Rights Reserved
7 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * Journal commit routines for the generic filesystem journaling code;
13 * part of the ext2fs journaling system.
14 */
15
16#include <linux/time.h>
17#include <linux/fs.h>
18#include <linux/jbd2.h>
19#include <linux/errno.h>
20#include <linux/slab.h>
21#include <linux/mm.h>
22#include <linux/pagemap.h>
23#include <linux/jiffies.h>
24#include <linux/crc32.h>
25#include <linux/writeback.h>
26#include <linux/backing-dev.h>
27#include <linux/bio.h>
28#include <linux/blkdev.h>
29#include <linux/bitops.h>
30#include <trace/events/jbd2.h>
31
32/*
33 * IO end handler for temporary buffer_heads handling writes to the journal.
34 */
35static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
36{
37 struct buffer_head *orig_bh = bh->b_private;
38
39 BUFFER_TRACE(bh, "");
40 if (uptodate)
41 set_buffer_uptodate(bh);
42 else
43 clear_buffer_uptodate(bh);
44 if (orig_bh) {
45 clear_bit_unlock(BH_Shadow, &orig_bh->b_state);
46 smp_mb__after_atomic();
47 wake_up_bit(&orig_bh->b_state, BH_Shadow);
48 }
49 unlock_buffer(bh);
50}
51
52/*
53 * When an ext4 file is truncated, it is possible that some pages are not
54 * successfully freed, because they are attached to a committing transaction.
55 * After the transaction commits, these pages are left on the LRU, with no
56 * ->mapping, and with attached buffers. These pages are trivially reclaimable
57 * by the VM, but their apparent absence upsets the VM accounting, and it makes
58 * the numbers in /proc/meminfo look odd.
59 *
60 * So here, we have a buffer which has just come off the forget list. Look to
61 * see if we can strip all buffers from the backing page.
62 *
63 * Called under lock_journal(), and possibly under journal_datalist_lock. The
64 * caller provided us with a ref against the buffer, and we drop that here.
65 */
66static void release_buffer_page(struct buffer_head *bh)
67{
68 struct page *page;
69
70 if (buffer_dirty(bh))
71 goto nope;
72 if (atomic_read(&bh->b_count) != 1)
73 goto nope;
74 page = bh->b_page;
75 if (!page)
76 goto nope;
77 if (page->mapping)
78 goto nope;
79
80 /* OK, it's a truncated page */
81 if (!trylock_page(page))
82 goto nope;
83
84 get_page(page);
85 __brelse(bh);
86 try_to_free_buffers(page);
87 unlock_page(page);
88 put_page(page);
89 return;
90
91nope:
92 __brelse(bh);
93}
94
95static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
96{
97 struct commit_header *h;
98 __u32 csum;
99
100 if (!jbd2_journal_has_csum_v2or3(j))
101 return;
102
103 h = (struct commit_header *)(bh->b_data);
104 h->h_chksum_type = 0;
105 h->h_chksum_size = 0;
106 h->h_chksum[0] = 0;
107 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
108 h->h_chksum[0] = cpu_to_be32(csum);
109}
110
111/*
112 * Done it all: now submit the commit record. We should have
113 * cleaned up our previous buffers by now, so if we are in abort
114 * mode we can now just skip the rest of the journal write
115 * entirely.
116 *
117 * Returns 1 if the journal needs to be aborted or 0 on success
118 */
119static int journal_submit_commit_record(journal_t *journal,
120 transaction_t *commit_transaction,
121 struct buffer_head **cbh,
122 __u32 crc32_sum)
123{
124 struct commit_header *tmp;
125 struct buffer_head *bh;
126 int ret;
127 struct timespec now = current_kernel_time();
128
129 *cbh = NULL;
130
131 if (is_journal_aborted(journal))
132 return 0;
133
134 bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
135 JBD2_COMMIT_BLOCK);
136 if (!bh)
137 return 1;
138
139 tmp = (struct commit_header *)bh->b_data;
140 tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
141 tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
142
143 if (jbd2_has_feature_checksum(journal)) {
144 tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
145 tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
146 tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
147 }
148 jbd2_commit_block_csum_set(journal, bh);
149
150 BUFFER_TRACE(bh, "submit commit block");
151 lock_buffer(bh);
152 clear_buffer_dirty(bh);
153 set_buffer_uptodate(bh);
154 bh->b_end_io = journal_end_buffer_io_sync;
155
156 if (journal->j_flags & JBD2_BARRIER &&
157 !jbd2_has_feature_async_commit(journal))
158 ret = submit_bh(WRITE_SYNC | WRITE_FLUSH_FUA, bh);
159 else
160 ret = submit_bh(WRITE_SYNC, bh);
161
162 *cbh = bh;
163 return ret;
164}
165
166/*
167 * This function along with journal_submit_commit_record
168 * allows to write the commit record asynchronously.
169 */
170static int journal_wait_on_commit_record(journal_t *journal,
171 struct buffer_head *bh)
172{
173 int ret = 0;
174
175 clear_buffer_dirty(bh);
176 wait_on_buffer(bh);
177
178 if (unlikely(!buffer_uptodate(bh)))
179 ret = -EIO;
180 put_bh(bh); /* One for getblk() */
181
182 return ret;
183}
184
185/*
186 * write the filemap data using writepage() address_space_operations.
187 * We don't do block allocation here even for delalloc. We don't
188 * use writepages() because with dealyed allocation we may be doing
189 * block allocation in writepages().
190 */
191static int journal_submit_inode_data_buffers(struct address_space *mapping)
192{
193 int ret;
194 struct writeback_control wbc = {
195 .sync_mode = WB_SYNC_ALL,
196 .nr_to_write = mapping->nrpages * 2,
197 .range_start = 0,
198 .range_end = i_size_read(mapping->host),
199 };
200
201 ret = generic_writepages(mapping, &wbc);
202 return ret;
203}
204
205/*
206 * Submit all the data buffers of inode associated with the transaction to
207 * disk.
208 *
209 * We are in a committing transaction. Therefore no new inode can be added to
210 * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
211 * operate on from being released while we write out pages.
212 */
213static int journal_submit_data_buffers(journal_t *journal,
214 transaction_t *commit_transaction)
215{
216 struct jbd2_inode *jinode;
217 int err, ret = 0;
218 struct address_space *mapping;
219
220 spin_lock(&journal->j_list_lock);
221 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
222 mapping = jinode->i_vfs_inode->i_mapping;
223 jinode->i_flags |= JI_COMMIT_RUNNING;
224 spin_unlock(&journal->j_list_lock);
225 /*
226 * submit the inode data buffers. We use writepage
227 * instead of writepages. Because writepages can do
228 * block allocation with delalloc. We need to write
229 * only allocated blocks here.
230 */
231 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
232 err = journal_submit_inode_data_buffers(mapping);
233 if (!ret)
234 ret = err;
235 spin_lock(&journal->j_list_lock);
236 J_ASSERT(jinode->i_transaction == commit_transaction);
237 jinode->i_flags &= ~JI_COMMIT_RUNNING;
238 smp_mb();
239 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
240 }
241 spin_unlock(&journal->j_list_lock);
242 return ret;
243}
244
245/*
246 * Wait for data submitted for writeout, refile inodes to proper
247 * transaction if needed.
248 *
249 */
250static int journal_finish_inode_data_buffers(journal_t *journal,
251 transaction_t *commit_transaction)
252{
253 struct jbd2_inode *jinode, *next_i;
254 int err, ret = 0;
255
256 /* For locking, see the comment in journal_submit_data_buffers() */
257 spin_lock(&journal->j_list_lock);
258 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
259 jinode->i_flags |= JI_COMMIT_RUNNING;
260 spin_unlock(&journal->j_list_lock);
261 err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
262 if (err) {
263 /*
264 * Because AS_EIO is cleared by
265 * filemap_fdatawait_range(), set it again so
266 * that user process can get -EIO from fsync().
267 */
268 set_bit(AS_EIO,
269 &jinode->i_vfs_inode->i_mapping->flags);
270
271 if (!ret)
272 ret = err;
273 }
274 spin_lock(&journal->j_list_lock);
275 jinode->i_flags &= ~JI_COMMIT_RUNNING;
276 smp_mb();
277 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
278 }
279
280 /* Now refile inode to proper lists */
281 list_for_each_entry_safe(jinode, next_i,
282 &commit_transaction->t_inode_list, i_list) {
283 list_del(&jinode->i_list);
284 if (jinode->i_next_transaction) {
285 jinode->i_transaction = jinode->i_next_transaction;
286 jinode->i_next_transaction = NULL;
287 list_add(&jinode->i_list,
288 &jinode->i_transaction->t_inode_list);
289 } else {
290 jinode->i_transaction = NULL;
291 }
292 }
293 spin_unlock(&journal->j_list_lock);
294
295 return ret;
296}
297
298static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
299{
300 struct page *page = bh->b_page;
301 char *addr;
302 __u32 checksum;
303
304 addr = kmap_atomic(page);
305 checksum = crc32_be(crc32_sum,
306 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
307 kunmap_atomic(addr);
308
309 return checksum;
310}
311
312static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
313 unsigned long long block)
314{
315 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
316 if (jbd2_has_feature_64bit(j))
317 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
318}
319
320static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
321 struct buffer_head *bh, __u32 sequence)
322{
323 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
324 struct page *page = bh->b_page;
325 __u8 *addr;
326 __u32 csum32;
327 __be32 seq;
328
329 if (!jbd2_journal_has_csum_v2or3(j))
330 return;
331
332 seq = cpu_to_be32(sequence);
333 addr = kmap_atomic(page);
334 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
335 csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
336 bh->b_size);
337 kunmap_atomic(addr);
338
339 if (jbd2_has_feature_csum3(j))
340 tag3->t_checksum = cpu_to_be32(csum32);
341 else
342 tag->t_checksum = cpu_to_be16(csum32);
343}
344/*
345 * jbd2_journal_commit_transaction
346 *
347 * The primary function for committing a transaction to the log. This
348 * function is called by the journal thread to begin a complete commit.
349 */
350void jbd2_journal_commit_transaction(journal_t *journal)
351{
352 struct transaction_stats_s stats;
353 transaction_t *commit_transaction;
354 struct journal_head *jh;
355 struct buffer_head *descriptor;
356 struct buffer_head **wbuf = journal->j_wbuf;
357 int bufs;
358 int flags;
359 int err;
360 unsigned long long blocknr;
361 ktime_t start_time;
362 u64 commit_time;
363 char *tagp = NULL;
364 journal_block_tag_t *tag = NULL;
365 int space_left = 0;
366 int first_tag = 0;
367 int tag_flag;
368 int i;
369 int tag_bytes = journal_tag_bytes(journal);
370 struct buffer_head *cbh = NULL; /* For transactional checksums */
371 __u32 crc32_sum = ~0;
372 struct blk_plug plug;
373 /* Tail of the journal */
374 unsigned long first_block;
375 tid_t first_tid;
376 int update_tail;
377 int csum_size = 0;
378 LIST_HEAD(io_bufs);
379 LIST_HEAD(log_bufs);
380
381 if (jbd2_journal_has_csum_v2or3(journal))
382 csum_size = sizeof(struct jbd2_journal_block_tail);
383
384 /*
385 * First job: lock down the current transaction and wait for
386 * all outstanding updates to complete.
387 */
388
389 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
390 if (journal->j_flags & JBD2_FLUSHED) {
391 jbd_debug(3, "super block updated\n");
392 mutex_lock(&journal->j_checkpoint_mutex);
393 /*
394 * We hold j_checkpoint_mutex so tail cannot change under us.
395 * We don't need any special data guarantees for writing sb
396 * since journal is empty and it is ok for write to be
397 * flushed only with transaction commit.
398 */
399 jbd2_journal_update_sb_log_tail(journal,
400 journal->j_tail_sequence,
401 journal->j_tail,
402 WRITE_SYNC);
403 mutex_unlock(&journal->j_checkpoint_mutex);
404 } else {
405 jbd_debug(3, "superblock not updated\n");
406 }
407
408 J_ASSERT(journal->j_running_transaction != NULL);
409 J_ASSERT(journal->j_committing_transaction == NULL);
410
411 commit_transaction = journal->j_running_transaction;
412
413 trace_jbd2_start_commit(journal, commit_transaction);
414 jbd_debug(1, "JBD2: starting commit of transaction %d\n",
415 commit_transaction->t_tid);
416
417 write_lock(&journal->j_state_lock);
418 J_ASSERT(commit_transaction->t_state == T_RUNNING);
419 commit_transaction->t_state = T_LOCKED;
420
421 trace_jbd2_commit_locking(journal, commit_transaction);
422 stats.run.rs_wait = commit_transaction->t_max_wait;
423 stats.run.rs_request_delay = 0;
424 stats.run.rs_locked = jiffies;
425 if (commit_transaction->t_requested)
426 stats.run.rs_request_delay =
427 jbd2_time_diff(commit_transaction->t_requested,
428 stats.run.rs_locked);
429 stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
430 stats.run.rs_locked);
431
432 spin_lock(&commit_transaction->t_handle_lock);
433 while (atomic_read(&commit_transaction->t_updates)) {
434 DEFINE_WAIT(wait);
435
436 prepare_to_wait(&journal->j_wait_updates, &wait,
437 TASK_UNINTERRUPTIBLE);
438 if (atomic_read(&commit_transaction->t_updates)) {
439 spin_unlock(&commit_transaction->t_handle_lock);
440 write_unlock(&journal->j_state_lock);
441 schedule();
442 write_lock(&journal->j_state_lock);
443 spin_lock(&commit_transaction->t_handle_lock);
444 }
445 finish_wait(&journal->j_wait_updates, &wait);
446 }
447 spin_unlock(&commit_transaction->t_handle_lock);
448
449 J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
450 journal->j_max_transaction_buffers);
451
452 /*
453 * First thing we are allowed to do is to discard any remaining
454 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
455 * that there are no such buffers: if a large filesystem
456 * operation like a truncate needs to split itself over multiple
457 * transactions, then it may try to do a jbd2_journal_restart() while
458 * there are still BJ_Reserved buffers outstanding. These must
459 * be released cleanly from the current transaction.
460 *
461 * In this case, the filesystem must still reserve write access
462 * again before modifying the buffer in the new transaction, but
463 * we do not require it to remember exactly which old buffers it
464 * has reserved. This is consistent with the existing behaviour
465 * that multiple jbd2_journal_get_write_access() calls to the same
466 * buffer are perfectly permissible.
467 */
468 while (commit_transaction->t_reserved_list) {
469 jh = commit_transaction->t_reserved_list;
470 JBUFFER_TRACE(jh, "reserved, unused: refile");
471 /*
472 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
473 * leave undo-committed data.
474 */
475 if (jh->b_committed_data) {
476 struct buffer_head *bh = jh2bh(jh);
477
478 jbd_lock_bh_state(bh);
479 jbd2_free(jh->b_committed_data, bh->b_size);
480 jh->b_committed_data = NULL;
481 jbd_unlock_bh_state(bh);
482 }
483 jbd2_journal_refile_buffer(journal, jh);
484 }
485
486 /*
487 * Now try to drop any written-back buffers from the journal's
488 * checkpoint lists. We do this *before* commit because it potentially
489 * frees some memory
490 */
491 spin_lock(&journal->j_list_lock);
492 __jbd2_journal_clean_checkpoint_list(journal, false);
493 spin_unlock(&journal->j_list_lock);
494
495 jbd_debug(3, "JBD2: commit phase 1\n");
496
497 /*
498 * Clear revoked flag to reflect there is no revoked buffers
499 * in the next transaction which is going to be started.
500 */
501 jbd2_clear_buffer_revoked_flags(journal);
502
503 /*
504 * Switch to a new revoke table.
505 */
506 jbd2_journal_switch_revoke_table(journal);
507
508 /*
509 * Reserved credits cannot be claimed anymore, free them
510 */
511 atomic_sub(atomic_read(&journal->j_reserved_credits),
512 &commit_transaction->t_outstanding_credits);
513
514 trace_jbd2_commit_flushing(journal, commit_transaction);
515 stats.run.rs_flushing = jiffies;
516 stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
517 stats.run.rs_flushing);
518
519 commit_transaction->t_state = T_FLUSH;
520 journal->j_committing_transaction = commit_transaction;
521 journal->j_running_transaction = NULL;
522 start_time = ktime_get();
523 commit_transaction->t_log_start = journal->j_head;
524 wake_up(&journal->j_wait_transaction_locked);
525 write_unlock(&journal->j_state_lock);
526
527 jbd_debug(3, "JBD2: commit phase 2a\n");
528
529 /*
530 * Now start flushing things to disk, in the order they appear
531 * on the transaction lists. Data blocks go first.
532 */
533 err = journal_submit_data_buffers(journal, commit_transaction);
534 if (err)
535 jbd2_journal_abort(journal, err);
536
537 blk_start_plug(&plug);
538 jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
539
540 jbd_debug(3, "JBD2: commit phase 2b\n");
541
542 /*
543 * Way to go: we have now written out all of the data for a
544 * transaction! Now comes the tricky part: we need to write out
545 * metadata. Loop over the transaction's entire buffer list:
546 */
547 write_lock(&journal->j_state_lock);
548 commit_transaction->t_state = T_COMMIT;
549 write_unlock(&journal->j_state_lock);
550
551 trace_jbd2_commit_logging(journal, commit_transaction);
552 stats.run.rs_logging = jiffies;
553 stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
554 stats.run.rs_logging);
555 stats.run.rs_blocks =
556 atomic_read(&commit_transaction->t_outstanding_credits);
557 stats.run.rs_blocks_logged = 0;
558
559 J_ASSERT(commit_transaction->t_nr_buffers <=
560 atomic_read(&commit_transaction->t_outstanding_credits));
561
562 err = 0;
563 bufs = 0;
564 descriptor = NULL;
565 while (commit_transaction->t_buffers) {
566
567 /* Find the next buffer to be journaled... */
568
569 jh = commit_transaction->t_buffers;
570
571 /* If we're in abort mode, we just un-journal the buffer and
572 release it. */
573
574 if (is_journal_aborted(journal)) {
575 clear_buffer_jbddirty(jh2bh(jh));
576 JBUFFER_TRACE(jh, "journal is aborting: refile");
577 jbd2_buffer_abort_trigger(jh,
578 jh->b_frozen_data ?
579 jh->b_frozen_triggers :
580 jh->b_triggers);
581 jbd2_journal_refile_buffer(journal, jh);
582 /* If that was the last one, we need to clean up
583 * any descriptor buffers which may have been
584 * already allocated, even if we are now
585 * aborting. */
586 if (!commit_transaction->t_buffers)
587 goto start_journal_io;
588 continue;
589 }
590
591 /* Make sure we have a descriptor block in which to
592 record the metadata buffer. */
593
594 if (!descriptor) {
595 J_ASSERT (bufs == 0);
596
597 jbd_debug(4, "JBD2: get descriptor\n");
598
599 descriptor = jbd2_journal_get_descriptor_buffer(
600 commit_transaction,
601 JBD2_DESCRIPTOR_BLOCK);
602 if (!descriptor) {
603 jbd2_journal_abort(journal, -EIO);
604 continue;
605 }
606
607 jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
608 (unsigned long long)descriptor->b_blocknr,
609 descriptor->b_data);
610 tagp = &descriptor->b_data[sizeof(journal_header_t)];
611 space_left = descriptor->b_size -
612 sizeof(journal_header_t);
613 first_tag = 1;
614 set_buffer_jwrite(descriptor);
615 set_buffer_dirty(descriptor);
616 wbuf[bufs++] = descriptor;
617
618 /* Record it so that we can wait for IO
619 completion later */
620 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
621 jbd2_file_log_bh(&log_bufs, descriptor);
622 }
623
624 /* Where is the buffer to be written? */
625
626 err = jbd2_journal_next_log_block(journal, &blocknr);
627 /* If the block mapping failed, just abandon the buffer
628 and repeat this loop: we'll fall into the
629 refile-on-abort condition above. */
630 if (err) {
631 jbd2_journal_abort(journal, err);
632 continue;
633 }
634
635 /*
636 * start_this_handle() uses t_outstanding_credits to determine
637 * the free space in the log, but this counter is changed
638 * by jbd2_journal_next_log_block() also.
639 */
640 atomic_dec(&commit_transaction->t_outstanding_credits);
641
642 /* Bump b_count to prevent truncate from stumbling over
643 the shadowed buffer! @@@ This can go if we ever get
644 rid of the shadow pairing of buffers. */
645 atomic_inc(&jh2bh(jh)->b_count);
646
647 /*
648 * Make a temporary IO buffer with which to write it out
649 * (this will requeue the metadata buffer to BJ_Shadow).
650 */
651 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
652 JBUFFER_TRACE(jh, "ph3: write metadata");
653 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
654 jh, &wbuf[bufs], blocknr);
655 if (flags < 0) {
656 jbd2_journal_abort(journal, flags);
657 continue;
658 }
659 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
660
661 /* Record the new block's tag in the current descriptor
662 buffer */
663
664 tag_flag = 0;
665 if (flags & 1)
666 tag_flag |= JBD2_FLAG_ESCAPE;
667 if (!first_tag)
668 tag_flag |= JBD2_FLAG_SAME_UUID;
669
670 tag = (journal_block_tag_t *) tagp;
671 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
672 tag->t_flags = cpu_to_be16(tag_flag);
673 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
674 commit_transaction->t_tid);
675 tagp += tag_bytes;
676 space_left -= tag_bytes;
677 bufs++;
678
679 if (first_tag) {
680 memcpy (tagp, journal->j_uuid, 16);
681 tagp += 16;
682 space_left -= 16;
683 first_tag = 0;
684 }
685
686 /* If there's no more to do, or if the descriptor is full,
687 let the IO rip! */
688
689 if (bufs == journal->j_wbufsize ||
690 commit_transaction->t_buffers == NULL ||
691 space_left < tag_bytes + 16 + csum_size) {
692
693 jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
694
695 /* Write an end-of-descriptor marker before
696 submitting the IOs. "tag" still points to
697 the last tag we set up. */
698
699 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
700
701 jbd2_descriptor_block_csum_set(journal, descriptor);
702start_journal_io:
703 for (i = 0; i < bufs; i++) {
704 struct buffer_head *bh = wbuf[i];
705 /*
706 * Compute checksum.
707 */
708 if (jbd2_has_feature_checksum(journal)) {
709 crc32_sum =
710 jbd2_checksum_data(crc32_sum, bh);
711 }
712
713 lock_buffer(bh);
714 clear_buffer_dirty(bh);
715 set_buffer_uptodate(bh);
716 bh->b_end_io = journal_end_buffer_io_sync;
717 submit_bh(WRITE_SYNC, bh);
718 }
719 cond_resched();
720 stats.run.rs_blocks_logged += bufs;
721
722 /* Force a new descriptor to be generated next
723 time round the loop. */
724 descriptor = NULL;
725 bufs = 0;
726 }
727 }
728
729 err = journal_finish_inode_data_buffers(journal, commit_transaction);
730 if (err) {
731 printk(KERN_WARNING
732 "JBD2: Detected IO errors while flushing file data "
733 "on %s\n", journal->j_devname);
734 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
735 jbd2_journal_abort(journal, err);
736 err = 0;
737 }
738
739 /*
740 * Get current oldest transaction in the log before we issue flush
741 * to the filesystem device. After the flush we can be sure that
742 * blocks of all older transactions are checkpointed to persistent
743 * storage and we will be safe to update journal start in the
744 * superblock with the numbers we get here.
745 */
746 update_tail =
747 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
748
749 write_lock(&journal->j_state_lock);
750 if (update_tail) {
751 long freed = first_block - journal->j_tail;
752
753 if (first_block < journal->j_tail)
754 freed += journal->j_last - journal->j_first;
755 /* Update tail only if we free significant amount of space */
756 if (freed < journal->j_maxlen / 4)
757 update_tail = 0;
758 }
759 J_ASSERT(commit_transaction->t_state == T_COMMIT);
760 commit_transaction->t_state = T_COMMIT_DFLUSH;
761 write_unlock(&journal->j_state_lock);
762
763 /*
764 * If the journal is not located on the file system device,
765 * then we must flush the file system device before we issue
766 * the commit record
767 */
768 if (commit_transaction->t_need_data_flush &&
769 (journal->j_fs_dev != journal->j_dev) &&
770 (journal->j_flags & JBD2_BARRIER))
771 blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
772
773 /* Done it all: now write the commit record asynchronously. */
774 if (jbd2_has_feature_async_commit(journal)) {
775 err = journal_submit_commit_record(journal, commit_transaction,
776 &cbh, crc32_sum);
777 if (err)
778 __jbd2_journal_abort_hard(journal);
779 }
780
781 blk_finish_plug(&plug);
782
783 /* Lo and behold: we have just managed to send a transaction to
784 the log. Before we can commit it, wait for the IO so far to
785 complete. Control buffers being written are on the
786 transaction's t_log_list queue, and metadata buffers are on
787 the io_bufs list.
788
789 Wait for the buffers in reverse order. That way we are
790 less likely to be woken up until all IOs have completed, and
791 so we incur less scheduling load.
792 */
793
794 jbd_debug(3, "JBD2: commit phase 3\n");
795
796 while (!list_empty(&io_bufs)) {
797 struct buffer_head *bh = list_entry(io_bufs.prev,
798 struct buffer_head,
799 b_assoc_buffers);
800
801 wait_on_buffer(bh);
802 cond_resched();
803
804 if (unlikely(!buffer_uptodate(bh)))
805 err = -EIO;
806 jbd2_unfile_log_bh(bh);
807
808 /*
809 * The list contains temporary buffer heads created by
810 * jbd2_journal_write_metadata_buffer().
811 */
812 BUFFER_TRACE(bh, "dumping temporary bh");
813 __brelse(bh);
814 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
815 free_buffer_head(bh);
816
817 /* We also have to refile the corresponding shadowed buffer */
818 jh = commit_transaction->t_shadow_list->b_tprev;
819 bh = jh2bh(jh);
820 clear_buffer_jwrite(bh);
821 J_ASSERT_BH(bh, buffer_jbddirty(bh));
822 J_ASSERT_BH(bh, !buffer_shadow(bh));
823
824 /* The metadata is now released for reuse, but we need
825 to remember it against this transaction so that when
826 we finally commit, we can do any checkpointing
827 required. */
828 JBUFFER_TRACE(jh, "file as BJ_Forget");
829 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
830 JBUFFER_TRACE(jh, "brelse shadowed buffer");
831 __brelse(bh);
832 }
833
834 J_ASSERT (commit_transaction->t_shadow_list == NULL);
835
836 jbd_debug(3, "JBD2: commit phase 4\n");
837
838 /* Here we wait for the revoke record and descriptor record buffers */
839 while (!list_empty(&log_bufs)) {
840 struct buffer_head *bh;
841
842 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
843 wait_on_buffer(bh);
844 cond_resched();
845
846 if (unlikely(!buffer_uptodate(bh)))
847 err = -EIO;
848
849 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
850 clear_buffer_jwrite(bh);
851 jbd2_unfile_log_bh(bh);
852 __brelse(bh); /* One for getblk */
853 /* AKPM: bforget here */
854 }
855
856 if (err)
857 jbd2_journal_abort(journal, err);
858
859 jbd_debug(3, "JBD2: commit phase 5\n");
860 write_lock(&journal->j_state_lock);
861 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
862 commit_transaction->t_state = T_COMMIT_JFLUSH;
863 write_unlock(&journal->j_state_lock);
864
865 if (!jbd2_has_feature_async_commit(journal)) {
866 err = journal_submit_commit_record(journal, commit_transaction,
867 &cbh, crc32_sum);
868 if (err)
869 __jbd2_journal_abort_hard(journal);
870 }
871 if (cbh)
872 err = journal_wait_on_commit_record(journal, cbh);
873 if (jbd2_has_feature_async_commit(journal) &&
874 journal->j_flags & JBD2_BARRIER) {
875 blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
876 }
877
878 if (err)
879 jbd2_journal_abort(journal, err);
880
881 /*
882 * Now disk caches for filesystem device are flushed so we are safe to
883 * erase checkpointed transactions from the log by updating journal
884 * superblock.
885 */
886 if (update_tail)
887 jbd2_update_log_tail(journal, first_tid, first_block);
888
889 /* End of a transaction! Finally, we can do checkpoint
890 processing: any buffers committed as a result of this
891 transaction can be removed from any checkpoint list it was on
892 before. */
893
894 jbd_debug(3, "JBD2: commit phase 6\n");
895
896 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
897 J_ASSERT(commit_transaction->t_buffers == NULL);
898 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
899 J_ASSERT(commit_transaction->t_shadow_list == NULL);
900
901restart_loop:
902 /*
903 * As there are other places (journal_unmap_buffer()) adding buffers
904 * to this list we have to be careful and hold the j_list_lock.
905 */
906 spin_lock(&journal->j_list_lock);
907 while (commit_transaction->t_forget) {
908 transaction_t *cp_transaction;
909 struct buffer_head *bh;
910 int try_to_free = 0;
911
912 jh = commit_transaction->t_forget;
913 spin_unlock(&journal->j_list_lock);
914 bh = jh2bh(jh);
915 /*
916 * Get a reference so that bh cannot be freed before we are
917 * done with it.
918 */
919 get_bh(bh);
920 jbd_lock_bh_state(bh);
921 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
922
923 /*
924 * If there is undo-protected committed data against
925 * this buffer, then we can remove it now. If it is a
926 * buffer needing such protection, the old frozen_data
927 * field now points to a committed version of the
928 * buffer, so rotate that field to the new committed
929 * data.
930 *
931 * Otherwise, we can just throw away the frozen data now.
932 *
933 * We also know that the frozen data has already fired
934 * its triggers if they exist, so we can clear that too.
935 */
936 if (jh->b_committed_data) {
937 jbd2_free(jh->b_committed_data, bh->b_size);
938 jh->b_committed_data = NULL;
939 if (jh->b_frozen_data) {
940 jh->b_committed_data = jh->b_frozen_data;
941 jh->b_frozen_data = NULL;
942 jh->b_frozen_triggers = NULL;
943 }
944 } else if (jh->b_frozen_data) {
945 jbd2_free(jh->b_frozen_data, bh->b_size);
946 jh->b_frozen_data = NULL;
947 jh->b_frozen_triggers = NULL;
948 }
949
950 spin_lock(&journal->j_list_lock);
951 cp_transaction = jh->b_cp_transaction;
952 if (cp_transaction) {
953 JBUFFER_TRACE(jh, "remove from old cp transaction");
954 cp_transaction->t_chp_stats.cs_dropped++;
955 __jbd2_journal_remove_checkpoint(jh);
956 }
957
958 /* Only re-checkpoint the buffer_head if it is marked
959 * dirty. If the buffer was added to the BJ_Forget list
960 * by jbd2_journal_forget, it may no longer be dirty and
961 * there's no point in keeping a checkpoint record for
962 * it. */
963
964 /*
965 * A buffer which has been freed while still being journaled by
966 * a previous transaction.
967 */
968 if (buffer_freed(bh)) {
969 /*
970 * If the running transaction is the one containing
971 * "add to orphan" operation (b_next_transaction !=
972 * NULL), we have to wait for that transaction to
973 * commit before we can really get rid of the buffer.
974 * So just clear b_modified to not confuse transaction
975 * credit accounting and refile the buffer to
976 * BJ_Forget of the running transaction. If the just
977 * committed transaction contains "add to orphan"
978 * operation, we can completely invalidate the buffer
979 * now. We are rather through in that since the
980 * buffer may be still accessible when blocksize <
981 * pagesize and it is attached to the last partial
982 * page.
983 */
984 jh->b_modified = 0;
985 if (!jh->b_next_transaction) {
986 clear_buffer_freed(bh);
987 clear_buffer_jbddirty(bh);
988 clear_buffer_mapped(bh);
989 clear_buffer_new(bh);
990 clear_buffer_req(bh);
991 bh->b_bdev = NULL;
992 }
993 }
994
995 if (buffer_jbddirty(bh)) {
996 JBUFFER_TRACE(jh, "add to new checkpointing trans");
997 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
998 if (is_journal_aborted(journal))
999 clear_buffer_jbddirty(bh);
1000 } else {
1001 J_ASSERT_BH(bh, !buffer_dirty(bh));
1002 /*
1003 * The buffer on BJ_Forget list and not jbddirty means
1004 * it has been freed by this transaction and hence it
1005 * could not have been reallocated until this
1006 * transaction has committed. *BUT* it could be
1007 * reallocated once we have written all the data to
1008 * disk and before we process the buffer on BJ_Forget
1009 * list.
1010 */
1011 if (!jh->b_next_transaction)
1012 try_to_free = 1;
1013 }
1014 JBUFFER_TRACE(jh, "refile or unfile buffer");
1015 __jbd2_journal_refile_buffer(jh);
1016 jbd_unlock_bh_state(bh);
1017 if (try_to_free)
1018 release_buffer_page(bh); /* Drops bh reference */
1019 else
1020 __brelse(bh);
1021 cond_resched_lock(&journal->j_list_lock);
1022 }
1023 spin_unlock(&journal->j_list_lock);
1024 /*
1025 * This is a bit sleazy. We use j_list_lock to protect transition
1026 * of a transaction into T_FINISHED state and calling
1027 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1028 * other checkpointing code processing the transaction...
1029 */
1030 write_lock(&journal->j_state_lock);
1031 spin_lock(&journal->j_list_lock);
1032 /*
1033 * Now recheck if some buffers did not get attached to the transaction
1034 * while the lock was dropped...
1035 */
1036 if (commit_transaction->t_forget) {
1037 spin_unlock(&journal->j_list_lock);
1038 write_unlock(&journal->j_state_lock);
1039 goto restart_loop;
1040 }
1041
1042 /* Add the transaction to the checkpoint list
1043 * __journal_remove_checkpoint() can not destroy transaction
1044 * under us because it is not marked as T_FINISHED yet */
1045 if (journal->j_checkpoint_transactions == NULL) {
1046 journal->j_checkpoint_transactions = commit_transaction;
1047 commit_transaction->t_cpnext = commit_transaction;
1048 commit_transaction->t_cpprev = commit_transaction;
1049 } else {
1050 commit_transaction->t_cpnext =
1051 journal->j_checkpoint_transactions;
1052 commit_transaction->t_cpprev =
1053 commit_transaction->t_cpnext->t_cpprev;
1054 commit_transaction->t_cpnext->t_cpprev =
1055 commit_transaction;
1056 commit_transaction->t_cpprev->t_cpnext =
1057 commit_transaction;
1058 }
1059 spin_unlock(&journal->j_list_lock);
1060
1061 /* Done with this transaction! */
1062
1063 jbd_debug(3, "JBD2: commit phase 7\n");
1064
1065 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1066
1067 commit_transaction->t_start = jiffies;
1068 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1069 commit_transaction->t_start);
1070
1071 /*
1072 * File the transaction statistics
1073 */
1074 stats.ts_tid = commit_transaction->t_tid;
1075 stats.run.rs_handle_count =
1076 atomic_read(&commit_transaction->t_handle_count);
1077 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1078 commit_transaction->t_tid, &stats.run);
1079 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1080
1081 commit_transaction->t_state = T_COMMIT_CALLBACK;
1082 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1083 journal->j_commit_sequence = commit_transaction->t_tid;
1084 journal->j_committing_transaction = NULL;
1085 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1086
1087 /*
1088 * weight the commit time higher than the average time so we don't
1089 * react too strongly to vast changes in the commit time
1090 */
1091 if (likely(journal->j_average_commit_time))
1092 journal->j_average_commit_time = (commit_time +
1093 journal->j_average_commit_time*3) / 4;
1094 else
1095 journal->j_average_commit_time = commit_time;
1096
1097 write_unlock(&journal->j_state_lock);
1098
1099 if (journal->j_commit_callback)
1100 journal->j_commit_callback(journal, commit_transaction);
1101
1102 trace_jbd2_end_commit(journal, commit_transaction);
1103 jbd_debug(1, "JBD2: commit %d complete, head %d\n",
1104 journal->j_commit_sequence, journal->j_tail_sequence);
1105
1106 write_lock(&journal->j_state_lock);
1107 spin_lock(&journal->j_list_lock);
1108 commit_transaction->t_state = T_FINISHED;
1109 /* Check if the transaction can be dropped now that we are finished */
1110 if (commit_transaction->t_checkpoint_list == NULL &&
1111 commit_transaction->t_checkpoint_io_list == NULL) {
1112 __jbd2_journal_drop_transaction(journal, commit_transaction);
1113 jbd2_journal_free_transaction(commit_transaction);
1114 }
1115 spin_unlock(&journal->j_list_lock);
1116 write_unlock(&journal->j_state_lock);
1117 wake_up(&journal->j_wait_done_commit);
1118
1119 /*
1120 * Calculate overall stats
1121 */
1122 spin_lock(&journal->j_history_lock);
1123 journal->j_stats.ts_tid++;
1124 journal->j_stats.ts_requested += stats.ts_requested;
1125 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1126 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1127 journal->j_stats.run.rs_running += stats.run.rs_running;
1128 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1129 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1130 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1131 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1132 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1133 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1134 spin_unlock(&journal->j_history_lock);
1135}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * linux/fs/jbd2/commit.c
4 *
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
6 *
7 * Copyright 1998 Red Hat corp --- All Rights Reserved
8 *
9 * Journal commit routines for the generic filesystem journaling code;
10 * part of the ext2fs journaling system.
11 */
12
13#include <linux/time.h>
14#include <linux/fs.h>
15#include <linux/jbd2.h>
16#include <linux/errno.h>
17#include <linux/slab.h>
18#include <linux/mm.h>
19#include <linux/pagemap.h>
20#include <linux/jiffies.h>
21#include <linux/crc32.h>
22#include <linux/writeback.h>
23#include <linux/backing-dev.h>
24#include <linux/bio.h>
25#include <linux/blkdev.h>
26#include <linux/bitops.h>
27#include <trace/events/jbd2.h>
28
29/*
30 * IO end handler for temporary buffer_heads handling writes to the journal.
31 */
32static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
33{
34 struct buffer_head *orig_bh = bh->b_private;
35
36 BUFFER_TRACE(bh, "");
37 if (uptodate)
38 set_buffer_uptodate(bh);
39 else
40 clear_buffer_uptodate(bh);
41 if (orig_bh) {
42 clear_bit_unlock(BH_Shadow, &orig_bh->b_state);
43 smp_mb__after_atomic();
44 wake_up_bit(&orig_bh->b_state, BH_Shadow);
45 }
46 unlock_buffer(bh);
47}
48
49/*
50 * When an ext4 file is truncated, it is possible that some pages are not
51 * successfully freed, because they are attached to a committing transaction.
52 * After the transaction commits, these pages are left on the LRU, with no
53 * ->mapping, and with attached buffers. These pages are trivially reclaimable
54 * by the VM, but their apparent absence upsets the VM accounting, and it makes
55 * the numbers in /proc/meminfo look odd.
56 *
57 * So here, we have a buffer which has just come off the forget list. Look to
58 * see if we can strip all buffers from the backing page.
59 *
60 * Called under lock_journal(), and possibly under journal_datalist_lock. The
61 * caller provided us with a ref against the buffer, and we drop that here.
62 */
63static void release_buffer_page(struct buffer_head *bh)
64{
65 struct folio *folio;
66
67 if (buffer_dirty(bh))
68 goto nope;
69 if (atomic_read(&bh->b_count) != 1)
70 goto nope;
71 folio = bh->b_folio;
72 if (folio->mapping)
73 goto nope;
74
75 /* OK, it's a truncated page */
76 if (!folio_trylock(folio))
77 goto nope;
78
79 folio_get(folio);
80 __brelse(bh);
81 try_to_free_buffers(folio);
82 folio_unlock(folio);
83 folio_put(folio);
84 return;
85
86nope:
87 __brelse(bh);
88}
89
90static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
91{
92 struct commit_header *h;
93 __u32 csum;
94
95 if (!jbd2_journal_has_csum_v2or3(j))
96 return;
97
98 h = (struct commit_header *)(bh->b_data);
99 h->h_chksum_type = 0;
100 h->h_chksum_size = 0;
101 h->h_chksum[0] = 0;
102 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
103 h->h_chksum[0] = cpu_to_be32(csum);
104}
105
106/*
107 * Done it all: now submit the commit record. We should have
108 * cleaned up our previous buffers by now, so if we are in abort
109 * mode we can now just skip the rest of the journal write
110 * entirely.
111 *
112 * Returns 1 if the journal needs to be aborted or 0 on success
113 */
114static int journal_submit_commit_record(journal_t *journal,
115 transaction_t *commit_transaction,
116 struct buffer_head **cbh,
117 __u32 crc32_sum)
118{
119 struct commit_header *tmp;
120 struct buffer_head *bh;
121 struct timespec64 now;
122 blk_opf_t write_flags = REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS;
123
124 *cbh = NULL;
125
126 if (is_journal_aborted(journal))
127 return 0;
128
129 bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
130 JBD2_COMMIT_BLOCK);
131 if (!bh)
132 return 1;
133
134 tmp = (struct commit_header *)bh->b_data;
135 ktime_get_coarse_real_ts64(&now);
136 tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
137 tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
138
139 if (jbd2_has_feature_checksum(journal)) {
140 tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
141 tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
142 tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
143 }
144 jbd2_commit_block_csum_set(journal, bh);
145
146 BUFFER_TRACE(bh, "submit commit block");
147 lock_buffer(bh);
148 clear_buffer_dirty(bh);
149 set_buffer_uptodate(bh);
150 bh->b_end_io = journal_end_buffer_io_sync;
151
152 if (journal->j_flags & JBD2_BARRIER &&
153 !jbd2_has_feature_async_commit(journal))
154 write_flags |= REQ_PREFLUSH | REQ_FUA;
155
156 submit_bh(write_flags, bh);
157 *cbh = bh;
158 return 0;
159}
160
161/*
162 * This function along with journal_submit_commit_record
163 * allows to write the commit record asynchronously.
164 */
165static int journal_wait_on_commit_record(journal_t *journal,
166 struct buffer_head *bh)
167{
168 int ret = 0;
169
170 clear_buffer_dirty(bh);
171 wait_on_buffer(bh);
172
173 if (unlikely(!buffer_uptodate(bh)))
174 ret = -EIO;
175 put_bh(bh); /* One for getblk() */
176
177 return ret;
178}
179
180/* Send all the data buffers related to an inode */
181int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode)
182{
183 if (!jinode || !(jinode->i_flags & JI_WRITE_DATA))
184 return 0;
185
186 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
187 return journal->j_submit_inode_data_buffers(jinode);
188
189}
190EXPORT_SYMBOL(jbd2_submit_inode_data);
191
192int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode)
193{
194 if (!jinode || !(jinode->i_flags & JI_WAIT_DATA) ||
195 !jinode->i_vfs_inode || !jinode->i_vfs_inode->i_mapping)
196 return 0;
197 return filemap_fdatawait_range_keep_errors(
198 jinode->i_vfs_inode->i_mapping, jinode->i_dirty_start,
199 jinode->i_dirty_end);
200}
201EXPORT_SYMBOL(jbd2_wait_inode_data);
202
203/*
204 * Submit all the data buffers of inode associated with the transaction to
205 * disk.
206 *
207 * We are in a committing transaction. Therefore no new inode can be added to
208 * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
209 * operate on from being released while we write out pages.
210 */
211static int journal_submit_data_buffers(journal_t *journal,
212 transaction_t *commit_transaction)
213{
214 struct jbd2_inode *jinode;
215 int err, ret = 0;
216
217 spin_lock(&journal->j_list_lock);
218 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
219 if (!(jinode->i_flags & JI_WRITE_DATA))
220 continue;
221 jinode->i_flags |= JI_COMMIT_RUNNING;
222 spin_unlock(&journal->j_list_lock);
223 /* submit the inode data buffers. */
224 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
225 if (journal->j_submit_inode_data_buffers) {
226 err = journal->j_submit_inode_data_buffers(jinode);
227 if (!ret)
228 ret = err;
229 }
230 spin_lock(&journal->j_list_lock);
231 J_ASSERT(jinode->i_transaction == commit_transaction);
232 jinode->i_flags &= ~JI_COMMIT_RUNNING;
233 smp_mb();
234 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
235 }
236 spin_unlock(&journal->j_list_lock);
237 return ret;
238}
239
240int jbd2_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
241{
242 struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
243
244 return filemap_fdatawait_range_keep_errors(mapping,
245 jinode->i_dirty_start,
246 jinode->i_dirty_end);
247}
248
249/*
250 * Wait for data submitted for writeout, refile inodes to proper
251 * transaction if needed.
252 *
253 */
254static int journal_finish_inode_data_buffers(journal_t *journal,
255 transaction_t *commit_transaction)
256{
257 struct jbd2_inode *jinode, *next_i;
258 int err, ret = 0;
259
260 /* For locking, see the comment in journal_submit_data_buffers() */
261 spin_lock(&journal->j_list_lock);
262 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
263 if (!(jinode->i_flags & JI_WAIT_DATA))
264 continue;
265 jinode->i_flags |= JI_COMMIT_RUNNING;
266 spin_unlock(&journal->j_list_lock);
267 /* wait for the inode data buffers writeout. */
268 if (journal->j_finish_inode_data_buffers) {
269 err = journal->j_finish_inode_data_buffers(jinode);
270 if (!ret)
271 ret = err;
272 }
273 cond_resched();
274 spin_lock(&journal->j_list_lock);
275 jinode->i_flags &= ~JI_COMMIT_RUNNING;
276 smp_mb();
277 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
278 }
279
280 /* Now refile inode to proper lists */
281 list_for_each_entry_safe(jinode, next_i,
282 &commit_transaction->t_inode_list, i_list) {
283 list_del(&jinode->i_list);
284 if (jinode->i_next_transaction) {
285 jinode->i_transaction = jinode->i_next_transaction;
286 jinode->i_next_transaction = NULL;
287 list_add(&jinode->i_list,
288 &jinode->i_transaction->t_inode_list);
289 } else {
290 jinode->i_transaction = NULL;
291 jinode->i_dirty_start = 0;
292 jinode->i_dirty_end = 0;
293 }
294 }
295 spin_unlock(&journal->j_list_lock);
296
297 return ret;
298}
299
300static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
301{
302 char *addr;
303 __u32 checksum;
304
305 addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
306 checksum = crc32_be(crc32_sum, addr, bh->b_size);
307 kunmap_local(addr);
308
309 return checksum;
310}
311
312static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
313 unsigned long long block)
314{
315 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
316 if (jbd2_has_feature_64bit(j))
317 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
318}
319
320static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
321 struct buffer_head *bh, __u32 sequence)
322{
323 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
324 __u8 *addr;
325 __u32 csum32;
326 __be32 seq;
327
328 if (!jbd2_journal_has_csum_v2or3(j))
329 return;
330
331 seq = cpu_to_be32(sequence);
332 addr = kmap_local_folio(bh->b_folio, bh_offset(bh));
333 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
334 csum32 = jbd2_chksum(j, csum32, addr, bh->b_size);
335 kunmap_local(addr);
336
337 if (jbd2_has_feature_csum3(j))
338 tag3->t_checksum = cpu_to_be32(csum32);
339 else
340 tag->t_checksum = cpu_to_be16(csum32);
341}
342/*
343 * jbd2_journal_commit_transaction
344 *
345 * The primary function for committing a transaction to the log. This
346 * function is called by the journal thread to begin a complete commit.
347 */
348void jbd2_journal_commit_transaction(journal_t *journal)
349{
350 struct transaction_stats_s stats;
351 transaction_t *commit_transaction;
352 struct journal_head *jh;
353 struct buffer_head *descriptor;
354 struct buffer_head **wbuf = journal->j_wbuf;
355 int bufs;
356 int escape;
357 int err;
358 unsigned long long blocknr;
359 ktime_t start_time;
360 u64 commit_time;
361 char *tagp = NULL;
362 journal_block_tag_t *tag = NULL;
363 int space_left = 0;
364 int first_tag = 0;
365 int tag_flag;
366 int i;
367 int tag_bytes = journal_tag_bytes(journal);
368 struct buffer_head *cbh = NULL; /* For transactional checksums */
369 __u32 crc32_sum = ~0;
370 struct blk_plug plug;
371 /* Tail of the journal */
372 unsigned long first_block;
373 tid_t first_tid;
374 int update_tail;
375 int csum_size = 0;
376 LIST_HEAD(io_bufs);
377 LIST_HEAD(log_bufs);
378
379 if (jbd2_journal_has_csum_v2or3(journal))
380 csum_size = sizeof(struct jbd2_journal_block_tail);
381
382 /*
383 * First job: lock down the current transaction and wait for
384 * all outstanding updates to complete.
385 */
386
387 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
388 if (journal->j_flags & JBD2_FLUSHED) {
389 jbd2_debug(3, "super block updated\n");
390 mutex_lock_io(&journal->j_checkpoint_mutex);
391 /*
392 * We hold j_checkpoint_mutex so tail cannot change under us.
393 * We don't need any special data guarantees for writing sb
394 * since journal is empty and it is ok for write to be
395 * flushed only with transaction commit.
396 */
397 jbd2_journal_update_sb_log_tail(journal,
398 journal->j_tail_sequence,
399 journal->j_tail, 0);
400 mutex_unlock(&journal->j_checkpoint_mutex);
401 } else {
402 jbd2_debug(3, "superblock not updated\n");
403 }
404
405 J_ASSERT(journal->j_running_transaction != NULL);
406 J_ASSERT(journal->j_committing_transaction == NULL);
407
408 write_lock(&journal->j_state_lock);
409 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
410 while (journal->j_flags & JBD2_FAST_COMMIT_ONGOING) {
411 DEFINE_WAIT(wait);
412
413 prepare_to_wait(&journal->j_fc_wait, &wait,
414 TASK_UNINTERRUPTIBLE);
415 write_unlock(&journal->j_state_lock);
416 schedule();
417 write_lock(&journal->j_state_lock);
418 finish_wait(&journal->j_fc_wait, &wait);
419 /*
420 * TODO: by blocking fast commits here, we are increasing
421 * fsync() latency slightly. Strictly speaking, we don't need
422 * to block fast commits until the transaction enters T_FLUSH
423 * state. So an optimization is possible where we block new fast
424 * commits here and wait for existing ones to complete
425 * just before we enter T_FLUSH. That way, the existing fast
426 * commits and this full commit can proceed parallely.
427 */
428 }
429 write_unlock(&journal->j_state_lock);
430
431 commit_transaction = journal->j_running_transaction;
432
433 trace_jbd2_start_commit(journal, commit_transaction);
434 jbd2_debug(1, "JBD2: starting commit of transaction %d\n",
435 commit_transaction->t_tid);
436
437 write_lock(&journal->j_state_lock);
438 journal->j_fc_off = 0;
439 J_ASSERT(commit_transaction->t_state == T_RUNNING);
440 commit_transaction->t_state = T_LOCKED;
441
442 trace_jbd2_commit_locking(journal, commit_transaction);
443 stats.run.rs_wait = commit_transaction->t_max_wait;
444 stats.run.rs_request_delay = 0;
445 stats.run.rs_locked = jiffies;
446 if (commit_transaction->t_requested)
447 stats.run.rs_request_delay =
448 jbd2_time_diff(commit_transaction->t_requested,
449 stats.run.rs_locked);
450 stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
451 stats.run.rs_locked);
452
453 // waits for any t_updates to finish
454 jbd2_journal_wait_updates(journal);
455
456 commit_transaction->t_state = T_SWITCH;
457
458 J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
459 journal->j_max_transaction_buffers);
460
461 /*
462 * First thing we are allowed to do is to discard any remaining
463 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
464 * that there are no such buffers: if a large filesystem
465 * operation like a truncate needs to split itself over multiple
466 * transactions, then it may try to do a jbd2_journal_restart() while
467 * there are still BJ_Reserved buffers outstanding. These must
468 * be released cleanly from the current transaction.
469 *
470 * In this case, the filesystem must still reserve write access
471 * again before modifying the buffer in the new transaction, but
472 * we do not require it to remember exactly which old buffers it
473 * has reserved. This is consistent with the existing behaviour
474 * that multiple jbd2_journal_get_write_access() calls to the same
475 * buffer are perfectly permissible.
476 * We use journal->j_state_lock here to serialize processing of
477 * t_reserved_list with eviction of buffers from journal_unmap_buffer().
478 */
479 while (commit_transaction->t_reserved_list) {
480 jh = commit_transaction->t_reserved_list;
481 JBUFFER_TRACE(jh, "reserved, unused: refile");
482 /*
483 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
484 * leave undo-committed data.
485 */
486 if (jh->b_committed_data) {
487 struct buffer_head *bh = jh2bh(jh);
488
489 spin_lock(&jh->b_state_lock);
490 jbd2_free(jh->b_committed_data, bh->b_size);
491 jh->b_committed_data = NULL;
492 spin_unlock(&jh->b_state_lock);
493 }
494 jbd2_journal_refile_buffer(journal, jh);
495 }
496
497 write_unlock(&journal->j_state_lock);
498 /*
499 * Now try to drop any written-back buffers from the journal's
500 * checkpoint lists. We do this *before* commit because it potentially
501 * frees some memory
502 */
503 spin_lock(&journal->j_list_lock);
504 __jbd2_journal_clean_checkpoint_list(journal, JBD2_SHRINK_BUSY_STOP);
505 spin_unlock(&journal->j_list_lock);
506
507 jbd2_debug(3, "JBD2: commit phase 1\n");
508
509 /*
510 * Clear revoked flag to reflect there is no revoked buffers
511 * in the next transaction which is going to be started.
512 */
513 jbd2_clear_buffer_revoked_flags(journal);
514
515 /*
516 * Switch to a new revoke table.
517 */
518 jbd2_journal_switch_revoke_table(journal);
519
520 write_lock(&journal->j_state_lock);
521 /*
522 * Reserved credits cannot be claimed anymore, free them
523 */
524 atomic_sub(atomic_read(&journal->j_reserved_credits),
525 &commit_transaction->t_outstanding_credits);
526
527 trace_jbd2_commit_flushing(journal, commit_transaction);
528 stats.run.rs_flushing = jiffies;
529 stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
530 stats.run.rs_flushing);
531
532 commit_transaction->t_state = T_FLUSH;
533 journal->j_committing_transaction = commit_transaction;
534 journal->j_running_transaction = NULL;
535 start_time = ktime_get();
536 commit_transaction->t_log_start = journal->j_head;
537 wake_up_all(&journal->j_wait_transaction_locked);
538 write_unlock(&journal->j_state_lock);
539
540 jbd2_debug(3, "JBD2: commit phase 2a\n");
541
542 /*
543 * Now start flushing things to disk, in the order they appear
544 * on the transaction lists. Data blocks go first.
545 */
546 err = journal_submit_data_buffers(journal, commit_transaction);
547 if (err)
548 jbd2_journal_abort(journal, err);
549
550 blk_start_plug(&plug);
551 jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
552
553 jbd2_debug(3, "JBD2: commit phase 2b\n");
554
555 /*
556 * Way to go: we have now written out all of the data for a
557 * transaction! Now comes the tricky part: we need to write out
558 * metadata. Loop over the transaction's entire buffer list:
559 */
560 write_lock(&journal->j_state_lock);
561 commit_transaction->t_state = T_COMMIT;
562 write_unlock(&journal->j_state_lock);
563
564 trace_jbd2_commit_logging(journal, commit_transaction);
565 stats.run.rs_logging = jiffies;
566 stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
567 stats.run.rs_logging);
568 stats.run.rs_blocks = commit_transaction->t_nr_buffers;
569 stats.run.rs_blocks_logged = 0;
570
571 J_ASSERT(commit_transaction->t_nr_buffers <=
572 atomic_read(&commit_transaction->t_outstanding_credits));
573
574 bufs = 0;
575 descriptor = NULL;
576 while (commit_transaction->t_buffers) {
577
578 /* Find the next buffer to be journaled... */
579
580 jh = commit_transaction->t_buffers;
581
582 /* If we're in abort mode, we just un-journal the buffer and
583 release it. */
584
585 if (is_journal_aborted(journal)) {
586 clear_buffer_jbddirty(jh2bh(jh));
587 JBUFFER_TRACE(jh, "journal is aborting: refile");
588 jbd2_buffer_abort_trigger(jh,
589 jh->b_frozen_data ?
590 jh->b_frozen_triggers :
591 jh->b_triggers);
592 jbd2_journal_refile_buffer(journal, jh);
593 /* If that was the last one, we need to clean up
594 * any descriptor buffers which may have been
595 * already allocated, even if we are now
596 * aborting. */
597 if (!commit_transaction->t_buffers)
598 goto start_journal_io;
599 continue;
600 }
601
602 /* Make sure we have a descriptor block in which to
603 record the metadata buffer. */
604
605 if (!descriptor) {
606 J_ASSERT (bufs == 0);
607
608 jbd2_debug(4, "JBD2: get descriptor\n");
609
610 descriptor = jbd2_journal_get_descriptor_buffer(
611 commit_transaction,
612 JBD2_DESCRIPTOR_BLOCK);
613 if (!descriptor) {
614 jbd2_journal_abort(journal, -EIO);
615 continue;
616 }
617
618 jbd2_debug(4, "JBD2: got buffer %llu (%p)\n",
619 (unsigned long long)descriptor->b_blocknr,
620 descriptor->b_data);
621 tagp = &descriptor->b_data[sizeof(journal_header_t)];
622 space_left = descriptor->b_size -
623 sizeof(journal_header_t);
624 first_tag = 1;
625 set_buffer_jwrite(descriptor);
626 set_buffer_dirty(descriptor);
627 wbuf[bufs++] = descriptor;
628
629 /* Record it so that we can wait for IO
630 completion later */
631 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
632 jbd2_file_log_bh(&log_bufs, descriptor);
633 }
634
635 /* Where is the buffer to be written? */
636
637 err = jbd2_journal_next_log_block(journal, &blocknr);
638 /* If the block mapping failed, just abandon the buffer
639 and repeat this loop: we'll fall into the
640 refile-on-abort condition above. */
641 if (err) {
642 jbd2_journal_abort(journal, err);
643 continue;
644 }
645
646 /*
647 * start_this_handle() uses t_outstanding_credits to determine
648 * the free space in the log.
649 */
650 atomic_dec(&commit_transaction->t_outstanding_credits);
651
652 /* Bump b_count to prevent truncate from stumbling over
653 the shadowed buffer! @@@ This can go if we ever get
654 rid of the shadow pairing of buffers. */
655 atomic_inc(&jh2bh(jh)->b_count);
656
657 /*
658 * Make a temporary IO buffer with which to write it out
659 * (this will requeue the metadata buffer to BJ_Shadow).
660 */
661 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
662 JBUFFER_TRACE(jh, "ph3: write metadata");
663 escape = jbd2_journal_write_metadata_buffer(commit_transaction,
664 jh, &wbuf[bufs], blocknr);
665 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
666
667 /* Record the new block's tag in the current descriptor
668 buffer */
669
670 tag_flag = 0;
671 if (escape)
672 tag_flag |= JBD2_FLAG_ESCAPE;
673 if (!first_tag)
674 tag_flag |= JBD2_FLAG_SAME_UUID;
675
676 tag = (journal_block_tag_t *) tagp;
677 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
678 tag->t_flags = cpu_to_be16(tag_flag);
679 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
680 commit_transaction->t_tid);
681 tagp += tag_bytes;
682 space_left -= tag_bytes;
683 bufs++;
684
685 if (first_tag) {
686 memcpy (tagp, journal->j_uuid, 16);
687 tagp += 16;
688 space_left -= 16;
689 first_tag = 0;
690 }
691
692 /* If there's no more to do, or if the descriptor is full,
693 let the IO rip! */
694
695 if (bufs == journal->j_wbufsize ||
696 commit_transaction->t_buffers == NULL ||
697 space_left < tag_bytes + 16 + csum_size) {
698
699 jbd2_debug(4, "JBD2: Submit %d IOs\n", bufs);
700
701 /* Write an end-of-descriptor marker before
702 submitting the IOs. "tag" still points to
703 the last tag we set up. */
704
705 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
706start_journal_io:
707 if (descriptor)
708 jbd2_descriptor_block_csum_set(journal,
709 descriptor);
710
711 for (i = 0; i < bufs; i++) {
712 struct buffer_head *bh = wbuf[i];
713
714 /*
715 * Compute checksum.
716 */
717 if (jbd2_has_feature_checksum(journal)) {
718 crc32_sum =
719 jbd2_checksum_data(crc32_sum, bh);
720 }
721
722 lock_buffer(bh);
723 clear_buffer_dirty(bh);
724 set_buffer_uptodate(bh);
725 bh->b_end_io = journal_end_buffer_io_sync;
726 submit_bh(REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS,
727 bh);
728 }
729 cond_resched();
730
731 /* Force a new descriptor to be generated next
732 time round the loop. */
733 descriptor = NULL;
734 bufs = 0;
735 }
736 }
737
738 err = journal_finish_inode_data_buffers(journal, commit_transaction);
739 if (err) {
740 printk(KERN_WARNING
741 "JBD2: Detected IO errors while flushing file data "
742 "on %s\n", journal->j_devname);
743 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
744 jbd2_journal_abort(journal, err);
745 err = 0;
746 }
747
748 /*
749 * Get current oldest transaction in the log before we issue flush
750 * to the filesystem device. After the flush we can be sure that
751 * blocks of all older transactions are checkpointed to persistent
752 * storage and we will be safe to update journal start in the
753 * superblock with the numbers we get here.
754 */
755 update_tail =
756 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
757
758 write_lock(&journal->j_state_lock);
759 if (update_tail) {
760 long freed = first_block - journal->j_tail;
761
762 if (first_block < journal->j_tail)
763 freed += journal->j_last - journal->j_first;
764 /* Update tail only if we free significant amount of space */
765 if (freed < journal->j_max_transaction_buffers)
766 update_tail = 0;
767 }
768 J_ASSERT(commit_transaction->t_state == T_COMMIT);
769 commit_transaction->t_state = T_COMMIT_DFLUSH;
770 write_unlock(&journal->j_state_lock);
771
772 /*
773 * If the journal is not located on the file system device,
774 * then we must flush the file system device before we issue
775 * the commit record and update the journal tail sequence.
776 */
777 if ((commit_transaction->t_need_data_flush || update_tail) &&
778 (journal->j_fs_dev != journal->j_dev) &&
779 (journal->j_flags & JBD2_BARRIER))
780 blkdev_issue_flush(journal->j_fs_dev);
781
782 /* Done it all: now write the commit record asynchronously. */
783 if (jbd2_has_feature_async_commit(journal)) {
784 err = journal_submit_commit_record(journal, commit_transaction,
785 &cbh, crc32_sum);
786 if (err)
787 jbd2_journal_abort(journal, err);
788 }
789
790 blk_finish_plug(&plug);
791
792 /* Lo and behold: we have just managed to send a transaction to
793 the log. Before we can commit it, wait for the IO so far to
794 complete. Control buffers being written are on the
795 transaction's t_log_list queue, and metadata buffers are on
796 the io_bufs list.
797
798 Wait for the buffers in reverse order. That way we are
799 less likely to be woken up until all IOs have completed, and
800 so we incur less scheduling load.
801 */
802
803 jbd2_debug(3, "JBD2: commit phase 3\n");
804
805 while (!list_empty(&io_bufs)) {
806 struct buffer_head *bh = list_entry(io_bufs.prev,
807 struct buffer_head,
808 b_assoc_buffers);
809
810 wait_on_buffer(bh);
811 cond_resched();
812
813 if (unlikely(!buffer_uptodate(bh)))
814 err = -EIO;
815 jbd2_unfile_log_bh(bh);
816 stats.run.rs_blocks_logged++;
817
818 /*
819 * The list contains temporary buffer heads created by
820 * jbd2_journal_write_metadata_buffer().
821 */
822 BUFFER_TRACE(bh, "dumping temporary bh");
823 __brelse(bh);
824 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
825 free_buffer_head(bh);
826
827 /* We also have to refile the corresponding shadowed buffer */
828 jh = commit_transaction->t_shadow_list->b_tprev;
829 bh = jh2bh(jh);
830 clear_buffer_jwrite(bh);
831 J_ASSERT_BH(bh, buffer_jbddirty(bh));
832 J_ASSERT_BH(bh, !buffer_shadow(bh));
833
834 /* The metadata is now released for reuse, but we need
835 to remember it against this transaction so that when
836 we finally commit, we can do any checkpointing
837 required. */
838 JBUFFER_TRACE(jh, "file as BJ_Forget");
839 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
840 JBUFFER_TRACE(jh, "brelse shadowed buffer");
841 __brelse(bh);
842 }
843
844 J_ASSERT (commit_transaction->t_shadow_list == NULL);
845
846 jbd2_debug(3, "JBD2: commit phase 4\n");
847
848 /* Here we wait for the revoke record and descriptor record buffers */
849 while (!list_empty(&log_bufs)) {
850 struct buffer_head *bh;
851
852 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
853 wait_on_buffer(bh);
854 cond_resched();
855
856 if (unlikely(!buffer_uptodate(bh)))
857 err = -EIO;
858
859 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
860 clear_buffer_jwrite(bh);
861 jbd2_unfile_log_bh(bh);
862 stats.run.rs_blocks_logged++;
863 __brelse(bh); /* One for getblk */
864 /* AKPM: bforget here */
865 }
866
867 if (err)
868 jbd2_journal_abort(journal, err);
869
870 jbd2_debug(3, "JBD2: commit phase 5\n");
871 write_lock(&journal->j_state_lock);
872 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
873 commit_transaction->t_state = T_COMMIT_JFLUSH;
874 write_unlock(&journal->j_state_lock);
875
876 if (!jbd2_has_feature_async_commit(journal)) {
877 err = journal_submit_commit_record(journal, commit_transaction,
878 &cbh, crc32_sum);
879 if (err)
880 jbd2_journal_abort(journal, err);
881 }
882 if (cbh)
883 err = journal_wait_on_commit_record(journal, cbh);
884 stats.run.rs_blocks_logged++;
885 if (jbd2_has_feature_async_commit(journal) &&
886 journal->j_flags & JBD2_BARRIER) {
887 blkdev_issue_flush(journal->j_dev);
888 }
889
890 if (err)
891 jbd2_journal_abort(journal, err);
892
893 WARN_ON_ONCE(
894 atomic_read(&commit_transaction->t_outstanding_credits) < 0);
895
896 /*
897 * Now disk caches for filesystem device are flushed so we are safe to
898 * erase checkpointed transactions from the log by updating journal
899 * superblock.
900 */
901 if (update_tail)
902 jbd2_update_log_tail(journal, first_tid, first_block);
903
904 /* End of a transaction! Finally, we can do checkpoint
905 processing: any buffers committed as a result of this
906 transaction can be removed from any checkpoint list it was on
907 before. */
908
909 jbd2_debug(3, "JBD2: commit phase 6\n");
910
911 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
912 J_ASSERT(commit_transaction->t_buffers == NULL);
913 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
914 J_ASSERT(commit_transaction->t_shadow_list == NULL);
915
916restart_loop:
917 /*
918 * As there are other places (journal_unmap_buffer()) adding buffers
919 * to this list we have to be careful and hold the j_list_lock.
920 */
921 spin_lock(&journal->j_list_lock);
922 while (commit_transaction->t_forget) {
923 transaction_t *cp_transaction;
924 struct buffer_head *bh;
925 int try_to_free = 0;
926 bool drop_ref;
927
928 jh = commit_transaction->t_forget;
929 spin_unlock(&journal->j_list_lock);
930 bh = jh2bh(jh);
931 /*
932 * Get a reference so that bh cannot be freed before we are
933 * done with it.
934 */
935 get_bh(bh);
936 spin_lock(&jh->b_state_lock);
937 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
938
939 /*
940 * If there is undo-protected committed data against
941 * this buffer, then we can remove it now. If it is a
942 * buffer needing such protection, the old frozen_data
943 * field now points to a committed version of the
944 * buffer, so rotate that field to the new committed
945 * data.
946 *
947 * Otherwise, we can just throw away the frozen data now.
948 *
949 * We also know that the frozen data has already fired
950 * its triggers if they exist, so we can clear that too.
951 */
952 if (jh->b_committed_data) {
953 jbd2_free(jh->b_committed_data, bh->b_size);
954 jh->b_committed_data = NULL;
955 if (jh->b_frozen_data) {
956 jh->b_committed_data = jh->b_frozen_data;
957 jh->b_frozen_data = NULL;
958 jh->b_frozen_triggers = NULL;
959 }
960 } else if (jh->b_frozen_data) {
961 jbd2_free(jh->b_frozen_data, bh->b_size);
962 jh->b_frozen_data = NULL;
963 jh->b_frozen_triggers = NULL;
964 }
965
966 spin_lock(&journal->j_list_lock);
967 cp_transaction = jh->b_cp_transaction;
968 if (cp_transaction) {
969 JBUFFER_TRACE(jh, "remove from old cp transaction");
970 cp_transaction->t_chp_stats.cs_dropped++;
971 __jbd2_journal_remove_checkpoint(jh);
972 }
973
974 /* Only re-checkpoint the buffer_head if it is marked
975 * dirty. If the buffer was added to the BJ_Forget list
976 * by jbd2_journal_forget, it may no longer be dirty and
977 * there's no point in keeping a checkpoint record for
978 * it. */
979
980 /*
981 * A buffer which has been freed while still being journaled
982 * by a previous transaction, refile the buffer to BJ_Forget of
983 * the running transaction. If the just committed transaction
984 * contains "add to orphan" operation, we can completely
985 * invalidate the buffer now. We are rather through in that
986 * since the buffer may be still accessible when blocksize <
987 * pagesize and it is attached to the last partial page.
988 */
989 if (buffer_freed(bh) && !jh->b_next_transaction) {
990 struct address_space *mapping;
991
992 clear_buffer_freed(bh);
993 clear_buffer_jbddirty(bh);
994
995 /*
996 * Block device buffers need to stay mapped all the
997 * time, so it is enough to clear buffer_jbddirty and
998 * buffer_freed bits. For the file mapping buffers (i.e.
999 * journalled data) we need to unmap buffer and clear
1000 * more bits. We also need to be careful about the check
1001 * because the data page mapping can get cleared under
1002 * our hands. Note that if mapping == NULL, we don't
1003 * need to make buffer unmapped because the page is
1004 * already detached from the mapping and buffers cannot
1005 * get reused.
1006 */
1007 mapping = READ_ONCE(bh->b_folio->mapping);
1008 if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
1009 clear_buffer_mapped(bh);
1010 clear_buffer_new(bh);
1011 clear_buffer_req(bh);
1012 bh->b_bdev = NULL;
1013 }
1014 }
1015
1016 if (buffer_jbddirty(bh)) {
1017 JBUFFER_TRACE(jh, "add to new checkpointing trans");
1018 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
1019 if (is_journal_aborted(journal))
1020 clear_buffer_jbddirty(bh);
1021 } else {
1022 J_ASSERT_BH(bh, !buffer_dirty(bh));
1023 /*
1024 * The buffer on BJ_Forget list and not jbddirty means
1025 * it has been freed by this transaction and hence it
1026 * could not have been reallocated until this
1027 * transaction has committed. *BUT* it could be
1028 * reallocated once we have written all the data to
1029 * disk and before we process the buffer on BJ_Forget
1030 * list.
1031 */
1032 if (!jh->b_next_transaction)
1033 try_to_free = 1;
1034 }
1035 JBUFFER_TRACE(jh, "refile or unfile buffer");
1036 drop_ref = __jbd2_journal_refile_buffer(jh);
1037 spin_unlock(&jh->b_state_lock);
1038 if (drop_ref)
1039 jbd2_journal_put_journal_head(jh);
1040 if (try_to_free)
1041 release_buffer_page(bh); /* Drops bh reference */
1042 else
1043 __brelse(bh);
1044 cond_resched_lock(&journal->j_list_lock);
1045 }
1046 spin_unlock(&journal->j_list_lock);
1047 /*
1048 * This is a bit sleazy. We use j_list_lock to protect transition
1049 * of a transaction into T_FINISHED state and calling
1050 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1051 * other checkpointing code processing the transaction...
1052 */
1053 write_lock(&journal->j_state_lock);
1054 spin_lock(&journal->j_list_lock);
1055 /*
1056 * Now recheck if some buffers did not get attached to the transaction
1057 * while the lock was dropped...
1058 */
1059 if (commit_transaction->t_forget) {
1060 spin_unlock(&journal->j_list_lock);
1061 write_unlock(&journal->j_state_lock);
1062 goto restart_loop;
1063 }
1064
1065 /* Add the transaction to the checkpoint list
1066 * __journal_remove_checkpoint() can not destroy transaction
1067 * under us because it is not marked as T_FINISHED yet */
1068 if (journal->j_checkpoint_transactions == NULL) {
1069 journal->j_checkpoint_transactions = commit_transaction;
1070 commit_transaction->t_cpnext = commit_transaction;
1071 commit_transaction->t_cpprev = commit_transaction;
1072 } else {
1073 commit_transaction->t_cpnext =
1074 journal->j_checkpoint_transactions;
1075 commit_transaction->t_cpprev =
1076 commit_transaction->t_cpnext->t_cpprev;
1077 commit_transaction->t_cpnext->t_cpprev =
1078 commit_transaction;
1079 commit_transaction->t_cpprev->t_cpnext =
1080 commit_transaction;
1081 }
1082 spin_unlock(&journal->j_list_lock);
1083
1084 /* Done with this transaction! */
1085
1086 jbd2_debug(3, "JBD2: commit phase 7\n");
1087
1088 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1089
1090 commit_transaction->t_start = jiffies;
1091 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1092 commit_transaction->t_start);
1093
1094 /*
1095 * File the transaction statistics
1096 */
1097 stats.ts_tid = commit_transaction->t_tid;
1098 stats.run.rs_handle_count =
1099 atomic_read(&commit_transaction->t_handle_count);
1100 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1101 commit_transaction->t_tid, &stats.run);
1102 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1103
1104 commit_transaction->t_state = T_COMMIT_CALLBACK;
1105 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1106 WRITE_ONCE(journal->j_commit_sequence, commit_transaction->t_tid);
1107 journal->j_committing_transaction = NULL;
1108 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1109
1110 /*
1111 * weight the commit time higher than the average time so we don't
1112 * react too strongly to vast changes in the commit time
1113 */
1114 if (likely(journal->j_average_commit_time))
1115 journal->j_average_commit_time = (commit_time +
1116 journal->j_average_commit_time*3) / 4;
1117 else
1118 journal->j_average_commit_time = commit_time;
1119
1120 write_unlock(&journal->j_state_lock);
1121
1122 if (journal->j_commit_callback)
1123 journal->j_commit_callback(journal, commit_transaction);
1124 if (journal->j_fc_cleanup_callback)
1125 journal->j_fc_cleanup_callback(journal, 1, commit_transaction->t_tid);
1126
1127 trace_jbd2_end_commit(journal, commit_transaction);
1128 jbd2_debug(1, "JBD2: commit %d complete, head %d\n",
1129 journal->j_commit_sequence, journal->j_tail_sequence);
1130
1131 write_lock(&journal->j_state_lock);
1132 journal->j_flags &= ~JBD2_FULL_COMMIT_ONGOING;
1133 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
1134 spin_lock(&journal->j_list_lock);
1135 commit_transaction->t_state = T_FINISHED;
1136 /* Check if the transaction can be dropped now that we are finished */
1137 if (commit_transaction->t_checkpoint_list == NULL) {
1138 __jbd2_journal_drop_transaction(journal, commit_transaction);
1139 jbd2_journal_free_transaction(commit_transaction);
1140 }
1141 spin_unlock(&journal->j_list_lock);
1142 write_unlock(&journal->j_state_lock);
1143 wake_up(&journal->j_wait_done_commit);
1144 wake_up(&journal->j_fc_wait);
1145
1146 /*
1147 * Calculate overall stats
1148 */
1149 spin_lock(&journal->j_history_lock);
1150 journal->j_stats.ts_tid++;
1151 journal->j_stats.ts_requested += stats.ts_requested;
1152 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1153 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1154 journal->j_stats.run.rs_running += stats.run.rs_running;
1155 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1156 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1157 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1158 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1159 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1160 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1161 spin_unlock(&journal->j_history_lock);
1162}