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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 timespec64 now = current_kernel_time64();
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(REQ_OP_WRITE,
159 REQ_SYNC | REQ_PREFLUSH | REQ_FUA, bh);
160 else
161 ret = submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
162
163 *cbh = bh;
164 return ret;
165}
166
167/*
168 * This function along with journal_submit_commit_record
169 * allows to write the commit record asynchronously.
170 */
171static int journal_wait_on_commit_record(journal_t *journal,
172 struct buffer_head *bh)
173{
174 int ret = 0;
175
176 clear_buffer_dirty(bh);
177 wait_on_buffer(bh);
178
179 if (unlikely(!buffer_uptodate(bh)))
180 ret = -EIO;
181 put_bh(bh); /* One for getblk() */
182
183 return ret;
184}
185
186/*
187 * write the filemap data using writepage() address_space_operations.
188 * We don't do block allocation here even for delalloc. We don't
189 * use writepages() because with dealyed allocation we may be doing
190 * block allocation in writepages().
191 */
192static int journal_submit_inode_data_buffers(struct address_space *mapping)
193{
194 int ret;
195 struct writeback_control wbc = {
196 .sync_mode = WB_SYNC_ALL,
197 .nr_to_write = mapping->nrpages * 2,
198 .range_start = 0,
199 .range_end = i_size_read(mapping->host),
200 };
201
202 ret = generic_writepages(mapping, &wbc);
203 return ret;
204}
205
206/*
207 * Submit all the data buffers of inode associated with the transaction to
208 * disk.
209 *
210 * We are in a committing transaction. Therefore no new inode can be added to
211 * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
212 * operate on from being released while we write out pages.
213 */
214static int journal_submit_data_buffers(journal_t *journal,
215 transaction_t *commit_transaction)
216{
217 struct jbd2_inode *jinode;
218 int err, ret = 0;
219 struct address_space *mapping;
220
221 spin_lock(&journal->j_list_lock);
222 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
223 if (!(jinode->i_flags & JI_WRITE_DATA))
224 continue;
225 mapping = jinode->i_vfs_inode->i_mapping;
226 jinode->i_flags |= JI_COMMIT_RUNNING;
227 spin_unlock(&journal->j_list_lock);
228 /*
229 * submit the inode data buffers. We use writepage
230 * instead of writepages. Because writepages can do
231 * block allocation with delalloc. We need to write
232 * only allocated blocks here.
233 */
234 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
235 err = journal_submit_inode_data_buffers(mapping);
236 if (!ret)
237 ret = err;
238 spin_lock(&journal->j_list_lock);
239 J_ASSERT(jinode->i_transaction == commit_transaction);
240 jinode->i_flags &= ~JI_COMMIT_RUNNING;
241 smp_mb();
242 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
243 }
244 spin_unlock(&journal->j_list_lock);
245 return ret;
246}
247
248/*
249 * Wait for data submitted for writeout, refile inodes to proper
250 * transaction if needed.
251 *
252 */
253static int journal_finish_inode_data_buffers(journal_t *journal,
254 transaction_t *commit_transaction)
255{
256 struct jbd2_inode *jinode, *next_i;
257 int err, ret = 0;
258
259 /* For locking, see the comment in journal_submit_data_buffers() */
260 spin_lock(&journal->j_list_lock);
261 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
262 if (!(jinode->i_flags & JI_WAIT_DATA))
263 continue;
264 jinode->i_flags |= JI_COMMIT_RUNNING;
265 spin_unlock(&journal->j_list_lock);
266 err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
267 if (err) {
268 /*
269 * Because AS_EIO is cleared by
270 * filemap_fdatawait_range(), set it again so
271 * that user process can get -EIO from fsync().
272 */
273 mapping_set_error(jinode->i_vfs_inode->i_mapping, -EIO);
274
275 if (!ret)
276 ret = err;
277 }
278 spin_lock(&journal->j_list_lock);
279 jinode->i_flags &= ~JI_COMMIT_RUNNING;
280 smp_mb();
281 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
282 }
283
284 /* Now refile inode to proper lists */
285 list_for_each_entry_safe(jinode, next_i,
286 &commit_transaction->t_inode_list, i_list) {
287 list_del(&jinode->i_list);
288 if (jinode->i_next_transaction) {
289 jinode->i_transaction = jinode->i_next_transaction;
290 jinode->i_next_transaction = NULL;
291 list_add(&jinode->i_list,
292 &jinode->i_transaction->t_inode_list);
293 } else {
294 jinode->i_transaction = NULL;
295 }
296 }
297 spin_unlock(&journal->j_list_lock);
298
299 return ret;
300}
301
302static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
303{
304 struct page *page = bh->b_page;
305 char *addr;
306 __u32 checksum;
307
308 addr = kmap_atomic(page);
309 checksum = crc32_be(crc32_sum,
310 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
311 kunmap_atomic(addr);
312
313 return checksum;
314}
315
316static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
317 unsigned long long block)
318{
319 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
320 if (jbd2_has_feature_64bit(j))
321 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
322}
323
324static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
325 struct buffer_head *bh, __u32 sequence)
326{
327 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
328 struct page *page = bh->b_page;
329 __u8 *addr;
330 __u32 csum32;
331 __be32 seq;
332
333 if (!jbd2_journal_has_csum_v2or3(j))
334 return;
335
336 seq = cpu_to_be32(sequence);
337 addr = kmap_atomic(page);
338 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
339 csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
340 bh->b_size);
341 kunmap_atomic(addr);
342
343 if (jbd2_has_feature_csum3(j))
344 tag3->t_checksum = cpu_to_be32(csum32);
345 else
346 tag->t_checksum = cpu_to_be16(csum32);
347}
348/*
349 * jbd2_journal_commit_transaction
350 *
351 * The primary function for committing a transaction to the log. This
352 * function is called by the journal thread to begin a complete commit.
353 */
354void jbd2_journal_commit_transaction(journal_t *journal)
355{
356 struct transaction_stats_s stats;
357 transaction_t *commit_transaction;
358 struct journal_head *jh;
359 struct buffer_head *descriptor;
360 struct buffer_head **wbuf = journal->j_wbuf;
361 int bufs;
362 int flags;
363 int err;
364 unsigned long long blocknr;
365 ktime_t start_time;
366 u64 commit_time;
367 char *tagp = NULL;
368 journal_block_tag_t *tag = NULL;
369 int space_left = 0;
370 int first_tag = 0;
371 int tag_flag;
372 int i;
373 int tag_bytes = journal_tag_bytes(journal);
374 struct buffer_head *cbh = NULL; /* For transactional checksums */
375 __u32 crc32_sum = ~0;
376 struct blk_plug plug;
377 /* Tail of the journal */
378 unsigned long first_block;
379 tid_t first_tid;
380 int update_tail;
381 int csum_size = 0;
382 LIST_HEAD(io_bufs);
383 LIST_HEAD(log_bufs);
384
385 if (jbd2_journal_has_csum_v2or3(journal))
386 csum_size = sizeof(struct jbd2_journal_block_tail);
387
388 /*
389 * First job: lock down the current transaction and wait for
390 * all outstanding updates to complete.
391 */
392
393 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
394 if (journal->j_flags & JBD2_FLUSHED) {
395 jbd_debug(3, "super block updated\n");
396 mutex_lock(&journal->j_checkpoint_mutex);
397 /*
398 * We hold j_checkpoint_mutex so tail cannot change under us.
399 * We don't need any special data guarantees for writing sb
400 * since journal is empty and it is ok for write to be
401 * flushed only with transaction commit.
402 */
403 jbd2_journal_update_sb_log_tail(journal,
404 journal->j_tail_sequence,
405 journal->j_tail,
406 REQ_SYNC);
407 mutex_unlock(&journal->j_checkpoint_mutex);
408 } else {
409 jbd_debug(3, "superblock not updated\n");
410 }
411
412 J_ASSERT(journal->j_running_transaction != NULL);
413 J_ASSERT(journal->j_committing_transaction == NULL);
414
415 commit_transaction = journal->j_running_transaction;
416
417 trace_jbd2_start_commit(journal, commit_transaction);
418 jbd_debug(1, "JBD2: starting commit of transaction %d\n",
419 commit_transaction->t_tid);
420
421 write_lock(&journal->j_state_lock);
422 J_ASSERT(commit_transaction->t_state == T_RUNNING);
423 commit_transaction->t_state = T_LOCKED;
424
425 trace_jbd2_commit_locking(journal, commit_transaction);
426 stats.run.rs_wait = commit_transaction->t_max_wait;
427 stats.run.rs_request_delay = 0;
428 stats.run.rs_locked = jiffies;
429 if (commit_transaction->t_requested)
430 stats.run.rs_request_delay =
431 jbd2_time_diff(commit_transaction->t_requested,
432 stats.run.rs_locked);
433 stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
434 stats.run.rs_locked);
435
436 spin_lock(&commit_transaction->t_handle_lock);
437 while (atomic_read(&commit_transaction->t_updates)) {
438 DEFINE_WAIT(wait);
439
440 prepare_to_wait(&journal->j_wait_updates, &wait,
441 TASK_UNINTERRUPTIBLE);
442 if (atomic_read(&commit_transaction->t_updates)) {
443 spin_unlock(&commit_transaction->t_handle_lock);
444 write_unlock(&journal->j_state_lock);
445 schedule();
446 write_lock(&journal->j_state_lock);
447 spin_lock(&commit_transaction->t_handle_lock);
448 }
449 finish_wait(&journal->j_wait_updates, &wait);
450 }
451 spin_unlock(&commit_transaction->t_handle_lock);
452
453 J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
454 journal->j_max_transaction_buffers);
455
456 /*
457 * First thing we are allowed to do is to discard any remaining
458 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
459 * that there are no such buffers: if a large filesystem
460 * operation like a truncate needs to split itself over multiple
461 * transactions, then it may try to do a jbd2_journal_restart() while
462 * there are still BJ_Reserved buffers outstanding. These must
463 * be released cleanly from the current transaction.
464 *
465 * In this case, the filesystem must still reserve write access
466 * again before modifying the buffer in the new transaction, but
467 * we do not require it to remember exactly which old buffers it
468 * has reserved. This is consistent with the existing behaviour
469 * that multiple jbd2_journal_get_write_access() calls to the same
470 * buffer are perfectly permissible.
471 */
472 while (commit_transaction->t_reserved_list) {
473 jh = commit_transaction->t_reserved_list;
474 JBUFFER_TRACE(jh, "reserved, unused: refile");
475 /*
476 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
477 * leave undo-committed data.
478 */
479 if (jh->b_committed_data) {
480 struct buffer_head *bh = jh2bh(jh);
481
482 jbd_lock_bh_state(bh);
483 jbd2_free(jh->b_committed_data, bh->b_size);
484 jh->b_committed_data = NULL;
485 jbd_unlock_bh_state(bh);
486 }
487 jbd2_journal_refile_buffer(journal, jh);
488 }
489
490 /*
491 * Now try to drop any written-back buffers from the journal's
492 * checkpoint lists. We do this *before* commit because it potentially
493 * frees some memory
494 */
495 spin_lock(&journal->j_list_lock);
496 __jbd2_journal_clean_checkpoint_list(journal, false);
497 spin_unlock(&journal->j_list_lock);
498
499 jbd_debug(3, "JBD2: commit phase 1\n");
500
501 /*
502 * Clear revoked flag to reflect there is no revoked buffers
503 * in the next transaction which is going to be started.
504 */
505 jbd2_clear_buffer_revoked_flags(journal);
506
507 /*
508 * Switch to a new revoke table.
509 */
510 jbd2_journal_switch_revoke_table(journal);
511
512 /*
513 * Reserved credits cannot be claimed anymore, free them
514 */
515 atomic_sub(atomic_read(&journal->j_reserved_credits),
516 &commit_transaction->t_outstanding_credits);
517
518 trace_jbd2_commit_flushing(journal, commit_transaction);
519 stats.run.rs_flushing = jiffies;
520 stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
521 stats.run.rs_flushing);
522
523 commit_transaction->t_state = T_FLUSH;
524 journal->j_committing_transaction = commit_transaction;
525 journal->j_running_transaction = NULL;
526 start_time = ktime_get();
527 commit_transaction->t_log_start = journal->j_head;
528 wake_up(&journal->j_wait_transaction_locked);
529 write_unlock(&journal->j_state_lock);
530
531 jbd_debug(3, "JBD2: commit phase 2a\n");
532
533 /*
534 * Now start flushing things to disk, in the order they appear
535 * on the transaction lists. Data blocks go first.
536 */
537 err = journal_submit_data_buffers(journal, commit_transaction);
538 if (err)
539 jbd2_journal_abort(journal, err);
540
541 blk_start_plug(&plug);
542 jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
543
544 jbd_debug(3, "JBD2: commit phase 2b\n");
545
546 /*
547 * Way to go: we have now written out all of the data for a
548 * transaction! Now comes the tricky part: we need to write out
549 * metadata. Loop over the transaction's entire buffer list:
550 */
551 write_lock(&journal->j_state_lock);
552 commit_transaction->t_state = T_COMMIT;
553 write_unlock(&journal->j_state_lock);
554
555 trace_jbd2_commit_logging(journal, commit_transaction);
556 stats.run.rs_logging = jiffies;
557 stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
558 stats.run.rs_logging);
559 stats.run.rs_blocks =
560 atomic_read(&commit_transaction->t_outstanding_credits);
561 stats.run.rs_blocks_logged = 0;
562
563 J_ASSERT(commit_transaction->t_nr_buffers <=
564 atomic_read(&commit_transaction->t_outstanding_credits));
565
566 err = 0;
567 bufs = 0;
568 descriptor = NULL;
569 while (commit_transaction->t_buffers) {
570
571 /* Find the next buffer to be journaled... */
572
573 jh = commit_transaction->t_buffers;
574
575 /* If we're in abort mode, we just un-journal the buffer and
576 release it. */
577
578 if (is_journal_aborted(journal)) {
579 clear_buffer_jbddirty(jh2bh(jh));
580 JBUFFER_TRACE(jh, "journal is aborting: refile");
581 jbd2_buffer_abort_trigger(jh,
582 jh->b_frozen_data ?
583 jh->b_frozen_triggers :
584 jh->b_triggers);
585 jbd2_journal_refile_buffer(journal, jh);
586 /* If that was the last one, we need to clean up
587 * any descriptor buffers which may have been
588 * already allocated, even if we are now
589 * aborting. */
590 if (!commit_transaction->t_buffers)
591 goto start_journal_io;
592 continue;
593 }
594
595 /* Make sure we have a descriptor block in which to
596 record the metadata buffer. */
597
598 if (!descriptor) {
599 J_ASSERT (bufs == 0);
600
601 jbd_debug(4, "JBD2: get descriptor\n");
602
603 descriptor = jbd2_journal_get_descriptor_buffer(
604 commit_transaction,
605 JBD2_DESCRIPTOR_BLOCK);
606 if (!descriptor) {
607 jbd2_journal_abort(journal, -EIO);
608 continue;
609 }
610
611 jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
612 (unsigned long long)descriptor->b_blocknr,
613 descriptor->b_data);
614 tagp = &descriptor->b_data[sizeof(journal_header_t)];
615 space_left = descriptor->b_size -
616 sizeof(journal_header_t);
617 first_tag = 1;
618 set_buffer_jwrite(descriptor);
619 set_buffer_dirty(descriptor);
620 wbuf[bufs++] = descriptor;
621
622 /* Record it so that we can wait for IO
623 completion later */
624 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
625 jbd2_file_log_bh(&log_bufs, descriptor);
626 }
627
628 /* Where is the buffer to be written? */
629
630 err = jbd2_journal_next_log_block(journal, &blocknr);
631 /* If the block mapping failed, just abandon the buffer
632 and repeat this loop: we'll fall into the
633 refile-on-abort condition above. */
634 if (err) {
635 jbd2_journal_abort(journal, err);
636 continue;
637 }
638
639 /*
640 * start_this_handle() uses t_outstanding_credits to determine
641 * the free space in the log, but this counter is changed
642 * by jbd2_journal_next_log_block() also.
643 */
644 atomic_dec(&commit_transaction->t_outstanding_credits);
645
646 /* Bump b_count to prevent truncate from stumbling over
647 the shadowed buffer! @@@ This can go if we ever get
648 rid of the shadow pairing of buffers. */
649 atomic_inc(&jh2bh(jh)->b_count);
650
651 /*
652 * Make a temporary IO buffer with which to write it out
653 * (this will requeue the metadata buffer to BJ_Shadow).
654 */
655 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
656 JBUFFER_TRACE(jh, "ph3: write metadata");
657 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
658 jh, &wbuf[bufs], blocknr);
659 if (flags < 0) {
660 jbd2_journal_abort(journal, flags);
661 continue;
662 }
663 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
664
665 /* Record the new block's tag in the current descriptor
666 buffer */
667
668 tag_flag = 0;
669 if (flags & 1)
670 tag_flag |= JBD2_FLAG_ESCAPE;
671 if (!first_tag)
672 tag_flag |= JBD2_FLAG_SAME_UUID;
673
674 tag = (journal_block_tag_t *) tagp;
675 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
676 tag->t_flags = cpu_to_be16(tag_flag);
677 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
678 commit_transaction->t_tid);
679 tagp += tag_bytes;
680 space_left -= tag_bytes;
681 bufs++;
682
683 if (first_tag) {
684 memcpy (tagp, journal->j_uuid, 16);
685 tagp += 16;
686 space_left -= 16;
687 first_tag = 0;
688 }
689
690 /* If there's no more to do, or if the descriptor is full,
691 let the IO rip! */
692
693 if (bufs == journal->j_wbufsize ||
694 commit_transaction->t_buffers == NULL ||
695 space_left < tag_bytes + 16 + csum_size) {
696
697 jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
698
699 /* Write an end-of-descriptor marker before
700 submitting the IOs. "tag" still points to
701 the last tag we set up. */
702
703 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
704
705 jbd2_descriptor_block_csum_set(journal, descriptor);
706start_journal_io:
707 for (i = 0; i < bufs; i++) {
708 struct buffer_head *bh = wbuf[i];
709 /*
710 * Compute checksum.
711 */
712 if (jbd2_has_feature_checksum(journal)) {
713 crc32_sum =
714 jbd2_checksum_data(crc32_sum, bh);
715 }
716
717 lock_buffer(bh);
718 clear_buffer_dirty(bh);
719 set_buffer_uptodate(bh);
720 bh->b_end_io = journal_end_buffer_io_sync;
721 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
722 }
723 cond_resched();
724 stats.run.rs_blocks_logged += bufs;
725
726 /* Force a new descriptor to be generated next
727 time round the loop. */
728 descriptor = NULL;
729 bufs = 0;
730 }
731 }
732
733 err = journal_finish_inode_data_buffers(journal, commit_transaction);
734 if (err) {
735 printk(KERN_WARNING
736 "JBD2: Detected IO errors while flushing file data "
737 "on %s\n", journal->j_devname);
738 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
739 jbd2_journal_abort(journal, err);
740 err = 0;
741 }
742
743 /*
744 * Get current oldest transaction in the log before we issue flush
745 * to the filesystem device. After the flush we can be sure that
746 * blocks of all older transactions are checkpointed to persistent
747 * storage and we will be safe to update journal start in the
748 * superblock with the numbers we get here.
749 */
750 update_tail =
751 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
752
753 write_lock(&journal->j_state_lock);
754 if (update_tail) {
755 long freed = first_block - journal->j_tail;
756
757 if (first_block < journal->j_tail)
758 freed += journal->j_last - journal->j_first;
759 /* Update tail only if we free significant amount of space */
760 if (freed < journal->j_maxlen / 4)
761 update_tail = 0;
762 }
763 J_ASSERT(commit_transaction->t_state == T_COMMIT);
764 commit_transaction->t_state = T_COMMIT_DFLUSH;
765 write_unlock(&journal->j_state_lock);
766
767 /*
768 * If the journal is not located on the file system device,
769 * then we must flush the file system device before we issue
770 * the commit record
771 */
772 if (commit_transaction->t_need_data_flush &&
773 (journal->j_fs_dev != journal->j_dev) &&
774 (journal->j_flags & JBD2_BARRIER))
775 blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
776
777 /* Done it all: now write the commit record asynchronously. */
778 if (jbd2_has_feature_async_commit(journal)) {
779 err = journal_submit_commit_record(journal, commit_transaction,
780 &cbh, crc32_sum);
781 if (err)
782 __jbd2_journal_abort_hard(journal);
783 }
784
785 blk_finish_plug(&plug);
786
787 /* Lo and behold: we have just managed to send a transaction to
788 the log. Before we can commit it, wait for the IO so far to
789 complete. Control buffers being written are on the
790 transaction's t_log_list queue, and metadata buffers are on
791 the io_bufs list.
792
793 Wait for the buffers in reverse order. That way we are
794 less likely to be woken up until all IOs have completed, and
795 so we incur less scheduling load.
796 */
797
798 jbd_debug(3, "JBD2: commit phase 3\n");
799
800 while (!list_empty(&io_bufs)) {
801 struct buffer_head *bh = list_entry(io_bufs.prev,
802 struct buffer_head,
803 b_assoc_buffers);
804
805 wait_on_buffer(bh);
806 cond_resched();
807
808 if (unlikely(!buffer_uptodate(bh)))
809 err = -EIO;
810 jbd2_unfile_log_bh(bh);
811
812 /*
813 * The list contains temporary buffer heads created by
814 * jbd2_journal_write_metadata_buffer().
815 */
816 BUFFER_TRACE(bh, "dumping temporary bh");
817 __brelse(bh);
818 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
819 free_buffer_head(bh);
820
821 /* We also have to refile the corresponding shadowed buffer */
822 jh = commit_transaction->t_shadow_list->b_tprev;
823 bh = jh2bh(jh);
824 clear_buffer_jwrite(bh);
825 J_ASSERT_BH(bh, buffer_jbddirty(bh));
826 J_ASSERT_BH(bh, !buffer_shadow(bh));
827
828 /* The metadata is now released for reuse, but we need
829 to remember it against this transaction so that when
830 we finally commit, we can do any checkpointing
831 required. */
832 JBUFFER_TRACE(jh, "file as BJ_Forget");
833 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
834 JBUFFER_TRACE(jh, "brelse shadowed buffer");
835 __brelse(bh);
836 }
837
838 J_ASSERT (commit_transaction->t_shadow_list == NULL);
839
840 jbd_debug(3, "JBD2: commit phase 4\n");
841
842 /* Here we wait for the revoke record and descriptor record buffers */
843 while (!list_empty(&log_bufs)) {
844 struct buffer_head *bh;
845
846 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
847 wait_on_buffer(bh);
848 cond_resched();
849
850 if (unlikely(!buffer_uptodate(bh)))
851 err = -EIO;
852
853 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
854 clear_buffer_jwrite(bh);
855 jbd2_unfile_log_bh(bh);
856 __brelse(bh); /* One for getblk */
857 /* AKPM: bforget here */
858 }
859
860 if (err)
861 jbd2_journal_abort(journal, err);
862
863 jbd_debug(3, "JBD2: commit phase 5\n");
864 write_lock(&journal->j_state_lock);
865 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
866 commit_transaction->t_state = T_COMMIT_JFLUSH;
867 write_unlock(&journal->j_state_lock);
868
869 if (!jbd2_has_feature_async_commit(journal)) {
870 err = journal_submit_commit_record(journal, commit_transaction,
871 &cbh, crc32_sum);
872 if (err)
873 __jbd2_journal_abort_hard(journal);
874 }
875 if (cbh)
876 err = journal_wait_on_commit_record(journal, cbh);
877 if (jbd2_has_feature_async_commit(journal) &&
878 journal->j_flags & JBD2_BARRIER) {
879 blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
880 }
881
882 if (err)
883 jbd2_journal_abort(journal, err);
884
885 /*
886 * Now disk caches for filesystem device are flushed so we are safe to
887 * erase checkpointed transactions from the log by updating journal
888 * superblock.
889 */
890 if (update_tail)
891 jbd2_update_log_tail(journal, first_tid, first_block);
892
893 /* End of a transaction! Finally, we can do checkpoint
894 processing: any buffers committed as a result of this
895 transaction can be removed from any checkpoint list it was on
896 before. */
897
898 jbd_debug(3, "JBD2: commit phase 6\n");
899
900 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
901 J_ASSERT(commit_transaction->t_buffers == NULL);
902 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
903 J_ASSERT(commit_transaction->t_shadow_list == NULL);
904
905restart_loop:
906 /*
907 * As there are other places (journal_unmap_buffer()) adding buffers
908 * to this list we have to be careful and hold the j_list_lock.
909 */
910 spin_lock(&journal->j_list_lock);
911 while (commit_transaction->t_forget) {
912 transaction_t *cp_transaction;
913 struct buffer_head *bh;
914 int try_to_free = 0;
915
916 jh = commit_transaction->t_forget;
917 spin_unlock(&journal->j_list_lock);
918 bh = jh2bh(jh);
919 /*
920 * Get a reference so that bh cannot be freed before we are
921 * done with it.
922 */
923 get_bh(bh);
924 jbd_lock_bh_state(bh);
925 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
926
927 /*
928 * If there is undo-protected committed data against
929 * this buffer, then we can remove it now. If it is a
930 * buffer needing such protection, the old frozen_data
931 * field now points to a committed version of the
932 * buffer, so rotate that field to the new committed
933 * data.
934 *
935 * Otherwise, we can just throw away the frozen data now.
936 *
937 * We also know that the frozen data has already fired
938 * its triggers if they exist, so we can clear that too.
939 */
940 if (jh->b_committed_data) {
941 jbd2_free(jh->b_committed_data, bh->b_size);
942 jh->b_committed_data = NULL;
943 if (jh->b_frozen_data) {
944 jh->b_committed_data = jh->b_frozen_data;
945 jh->b_frozen_data = NULL;
946 jh->b_frozen_triggers = NULL;
947 }
948 } else if (jh->b_frozen_data) {
949 jbd2_free(jh->b_frozen_data, bh->b_size);
950 jh->b_frozen_data = NULL;
951 jh->b_frozen_triggers = NULL;
952 }
953
954 spin_lock(&journal->j_list_lock);
955 cp_transaction = jh->b_cp_transaction;
956 if (cp_transaction) {
957 JBUFFER_TRACE(jh, "remove from old cp transaction");
958 cp_transaction->t_chp_stats.cs_dropped++;
959 __jbd2_journal_remove_checkpoint(jh);
960 }
961
962 /* Only re-checkpoint the buffer_head if it is marked
963 * dirty. If the buffer was added to the BJ_Forget list
964 * by jbd2_journal_forget, it may no longer be dirty and
965 * there's no point in keeping a checkpoint record for
966 * it. */
967
968 /*
969 * A buffer which has been freed while still being journaled by
970 * a previous transaction.
971 */
972 if (buffer_freed(bh)) {
973 /*
974 * If the running transaction is the one containing
975 * "add to orphan" operation (b_next_transaction !=
976 * NULL), we have to wait for that transaction to
977 * commit before we can really get rid of the buffer.
978 * So just clear b_modified to not confuse transaction
979 * credit accounting and refile the buffer to
980 * BJ_Forget of the running transaction. If the just
981 * committed transaction contains "add to orphan"
982 * operation, we can completely invalidate the buffer
983 * now. We are rather through in that since the
984 * buffer may be still accessible when blocksize <
985 * pagesize and it is attached to the last partial
986 * page.
987 */
988 jh->b_modified = 0;
989 if (!jh->b_next_transaction) {
990 clear_buffer_freed(bh);
991 clear_buffer_jbddirty(bh);
992 clear_buffer_mapped(bh);
993 clear_buffer_new(bh);
994 clear_buffer_req(bh);
995 bh->b_bdev = NULL;
996 }
997 }
998
999 if (buffer_jbddirty(bh)) {
1000 JBUFFER_TRACE(jh, "add to new checkpointing trans");
1001 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
1002 if (is_journal_aborted(journal))
1003 clear_buffer_jbddirty(bh);
1004 } else {
1005 J_ASSERT_BH(bh, !buffer_dirty(bh));
1006 /*
1007 * The buffer on BJ_Forget list and not jbddirty means
1008 * it has been freed by this transaction and hence it
1009 * could not have been reallocated until this
1010 * transaction has committed. *BUT* it could be
1011 * reallocated once we have written all the data to
1012 * disk and before we process the buffer on BJ_Forget
1013 * list.
1014 */
1015 if (!jh->b_next_transaction)
1016 try_to_free = 1;
1017 }
1018 JBUFFER_TRACE(jh, "refile or unfile buffer");
1019 __jbd2_journal_refile_buffer(jh);
1020 jbd_unlock_bh_state(bh);
1021 if (try_to_free)
1022 release_buffer_page(bh); /* Drops bh reference */
1023 else
1024 __brelse(bh);
1025 cond_resched_lock(&journal->j_list_lock);
1026 }
1027 spin_unlock(&journal->j_list_lock);
1028 /*
1029 * This is a bit sleazy. We use j_list_lock to protect transition
1030 * of a transaction into T_FINISHED state and calling
1031 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1032 * other checkpointing code processing the transaction...
1033 */
1034 write_lock(&journal->j_state_lock);
1035 spin_lock(&journal->j_list_lock);
1036 /*
1037 * Now recheck if some buffers did not get attached to the transaction
1038 * while the lock was dropped...
1039 */
1040 if (commit_transaction->t_forget) {
1041 spin_unlock(&journal->j_list_lock);
1042 write_unlock(&journal->j_state_lock);
1043 goto restart_loop;
1044 }
1045
1046 /* Add the transaction to the checkpoint list
1047 * __journal_remove_checkpoint() can not destroy transaction
1048 * under us because it is not marked as T_FINISHED yet */
1049 if (journal->j_checkpoint_transactions == NULL) {
1050 journal->j_checkpoint_transactions = commit_transaction;
1051 commit_transaction->t_cpnext = commit_transaction;
1052 commit_transaction->t_cpprev = commit_transaction;
1053 } else {
1054 commit_transaction->t_cpnext =
1055 journal->j_checkpoint_transactions;
1056 commit_transaction->t_cpprev =
1057 commit_transaction->t_cpnext->t_cpprev;
1058 commit_transaction->t_cpnext->t_cpprev =
1059 commit_transaction;
1060 commit_transaction->t_cpprev->t_cpnext =
1061 commit_transaction;
1062 }
1063 spin_unlock(&journal->j_list_lock);
1064
1065 /* Done with this transaction! */
1066
1067 jbd_debug(3, "JBD2: commit phase 7\n");
1068
1069 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1070
1071 commit_transaction->t_start = jiffies;
1072 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1073 commit_transaction->t_start);
1074
1075 /*
1076 * File the transaction statistics
1077 */
1078 stats.ts_tid = commit_transaction->t_tid;
1079 stats.run.rs_handle_count =
1080 atomic_read(&commit_transaction->t_handle_count);
1081 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1082 commit_transaction->t_tid, &stats.run);
1083 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1084
1085 commit_transaction->t_state = T_COMMIT_CALLBACK;
1086 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1087 journal->j_commit_sequence = commit_transaction->t_tid;
1088 journal->j_committing_transaction = NULL;
1089 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1090
1091 /*
1092 * weight the commit time higher than the average time so we don't
1093 * react too strongly to vast changes in the commit time
1094 */
1095 if (likely(journal->j_average_commit_time))
1096 journal->j_average_commit_time = (commit_time +
1097 journal->j_average_commit_time*3) / 4;
1098 else
1099 journal->j_average_commit_time = commit_time;
1100
1101 write_unlock(&journal->j_state_lock);
1102
1103 if (journal->j_commit_callback)
1104 journal->j_commit_callback(journal, commit_transaction);
1105
1106 trace_jbd2_end_commit(journal, commit_transaction);
1107 jbd_debug(1, "JBD2: commit %d complete, head %d\n",
1108 journal->j_commit_sequence, journal->j_tail_sequence);
1109
1110 write_lock(&journal->j_state_lock);
1111 spin_lock(&journal->j_list_lock);
1112 commit_transaction->t_state = T_FINISHED;
1113 /* Check if the transaction can be dropped now that we are finished */
1114 if (commit_transaction->t_checkpoint_list == NULL &&
1115 commit_transaction->t_checkpoint_io_list == NULL) {
1116 __jbd2_journal_drop_transaction(journal, commit_transaction);
1117 jbd2_journal_free_transaction(commit_transaction);
1118 }
1119 spin_unlock(&journal->j_list_lock);
1120 write_unlock(&journal->j_state_lock);
1121 wake_up(&journal->j_wait_done_commit);
1122
1123 /*
1124 * Calculate overall stats
1125 */
1126 spin_lock(&journal->j_history_lock);
1127 journal->j_stats.ts_tid++;
1128 journal->j_stats.ts_requested += stats.ts_requested;
1129 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1130 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1131 journal->j_stats.run.rs_running += stats.run.rs_running;
1132 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1133 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1134 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1135 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1136 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1137 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1138 spin_unlock(&journal->j_history_lock);
1139}
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 flags;
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, false);
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 err = 0;
575 bufs = 0;
576 descriptor = NULL;
577 while (commit_transaction->t_buffers) {
578
579 /* Find the next buffer to be journaled... */
580
581 jh = commit_transaction->t_buffers;
582
583 /* If we're in abort mode, we just un-journal the buffer and
584 release it. */
585
586 if (is_journal_aborted(journal)) {
587 clear_buffer_jbddirty(jh2bh(jh));
588 JBUFFER_TRACE(jh, "journal is aborting: refile");
589 jbd2_buffer_abort_trigger(jh,
590 jh->b_frozen_data ?
591 jh->b_frozen_triggers :
592 jh->b_triggers);
593 jbd2_journal_refile_buffer(journal, jh);
594 /* If that was the last one, we need to clean up
595 * any descriptor buffers which may have been
596 * already allocated, even if we are now
597 * aborting. */
598 if (!commit_transaction->t_buffers)
599 goto start_journal_io;
600 continue;
601 }
602
603 /* Make sure we have a descriptor block in which to
604 record the metadata buffer. */
605
606 if (!descriptor) {
607 J_ASSERT (bufs == 0);
608
609 jbd2_debug(4, "JBD2: get descriptor\n");
610
611 descriptor = jbd2_journal_get_descriptor_buffer(
612 commit_transaction,
613 JBD2_DESCRIPTOR_BLOCK);
614 if (!descriptor) {
615 jbd2_journal_abort(journal, -EIO);
616 continue;
617 }
618
619 jbd2_debug(4, "JBD2: got buffer %llu (%p)\n",
620 (unsigned long long)descriptor->b_blocknr,
621 descriptor->b_data);
622 tagp = &descriptor->b_data[sizeof(journal_header_t)];
623 space_left = descriptor->b_size -
624 sizeof(journal_header_t);
625 first_tag = 1;
626 set_buffer_jwrite(descriptor);
627 set_buffer_dirty(descriptor);
628 wbuf[bufs++] = descriptor;
629
630 /* Record it so that we can wait for IO
631 completion later */
632 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
633 jbd2_file_log_bh(&log_bufs, descriptor);
634 }
635
636 /* Where is the buffer to be written? */
637
638 err = jbd2_journal_next_log_block(journal, &blocknr);
639 /* If the block mapping failed, just abandon the buffer
640 and repeat this loop: we'll fall into the
641 refile-on-abort condition above. */
642 if (err) {
643 jbd2_journal_abort(journal, err);
644 continue;
645 }
646
647 /*
648 * start_this_handle() uses t_outstanding_credits to determine
649 * the free space in the log.
650 */
651 atomic_dec(&commit_transaction->t_outstanding_credits);
652
653 /* Bump b_count to prevent truncate from stumbling over
654 the shadowed buffer! @@@ This can go if we ever get
655 rid of the shadow pairing of buffers. */
656 atomic_inc(&jh2bh(jh)->b_count);
657
658 /*
659 * Make a temporary IO buffer with which to write it out
660 * (this will requeue the metadata buffer to BJ_Shadow).
661 */
662 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
663 JBUFFER_TRACE(jh, "ph3: write metadata");
664 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
665 jh, &wbuf[bufs], blocknr);
666 if (flags < 0) {
667 jbd2_journal_abort(journal, flags);
668 continue;
669 }
670 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
671
672 /* Record the new block's tag in the current descriptor
673 buffer */
674
675 tag_flag = 0;
676 if (flags & 1)
677 tag_flag |= JBD2_FLAG_ESCAPE;
678 if (!first_tag)
679 tag_flag |= JBD2_FLAG_SAME_UUID;
680
681 tag = (journal_block_tag_t *) tagp;
682 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
683 tag->t_flags = cpu_to_be16(tag_flag);
684 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
685 commit_transaction->t_tid);
686 tagp += tag_bytes;
687 space_left -= tag_bytes;
688 bufs++;
689
690 if (first_tag) {
691 memcpy (tagp, journal->j_uuid, 16);
692 tagp += 16;
693 space_left -= 16;
694 first_tag = 0;
695 }
696
697 /* If there's no more to do, or if the descriptor is full,
698 let the IO rip! */
699
700 if (bufs == journal->j_wbufsize ||
701 commit_transaction->t_buffers == NULL ||
702 space_left < tag_bytes + 16 + csum_size) {
703
704 jbd2_debug(4, "JBD2: Submit %d IOs\n", bufs);
705
706 /* Write an end-of-descriptor marker before
707 submitting the IOs. "tag" still points to
708 the last tag we set up. */
709
710 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
711start_journal_io:
712 if (descriptor)
713 jbd2_descriptor_block_csum_set(journal,
714 descriptor);
715
716 for (i = 0; i < bufs; i++) {
717 struct buffer_head *bh = wbuf[i];
718
719 /*
720 * Compute checksum.
721 */
722 if (jbd2_has_feature_checksum(journal)) {
723 crc32_sum =
724 jbd2_checksum_data(crc32_sum, bh);
725 }
726
727 lock_buffer(bh);
728 clear_buffer_dirty(bh);
729 set_buffer_uptodate(bh);
730 bh->b_end_io = journal_end_buffer_io_sync;
731 submit_bh(REQ_OP_WRITE | JBD2_JOURNAL_REQ_FLAGS,
732 bh);
733 }
734 cond_resched();
735
736 /* Force a new descriptor to be generated next
737 time round the loop. */
738 descriptor = NULL;
739 bufs = 0;
740 }
741 }
742
743 err = journal_finish_inode_data_buffers(journal, commit_transaction);
744 if (err) {
745 printk(KERN_WARNING
746 "JBD2: Detected IO errors while flushing file data "
747 "on %s\n", journal->j_devname);
748 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
749 jbd2_journal_abort(journal, err);
750 err = 0;
751 }
752
753 /*
754 * Get current oldest transaction in the log before we issue flush
755 * to the filesystem device. After the flush we can be sure that
756 * blocks of all older transactions are checkpointed to persistent
757 * storage and we will be safe to update journal start in the
758 * superblock with the numbers we get here.
759 */
760 update_tail =
761 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
762
763 write_lock(&journal->j_state_lock);
764 if (update_tail) {
765 long freed = first_block - journal->j_tail;
766
767 if (first_block < journal->j_tail)
768 freed += journal->j_last - journal->j_first;
769 /* Update tail only if we free significant amount of space */
770 if (freed < jbd2_journal_get_max_txn_bufs(journal))
771 update_tail = 0;
772 }
773 J_ASSERT(commit_transaction->t_state == T_COMMIT);
774 commit_transaction->t_state = T_COMMIT_DFLUSH;
775 write_unlock(&journal->j_state_lock);
776
777 /*
778 * If the journal is not located on the file system device,
779 * then we must flush the file system device before we issue
780 * the commit record
781 */
782 if (commit_transaction->t_need_data_flush &&
783 (journal->j_fs_dev != journal->j_dev) &&
784 (journal->j_flags & JBD2_BARRIER))
785 blkdev_issue_flush(journal->j_fs_dev);
786
787 /* Done it all: now write the commit record asynchronously. */
788 if (jbd2_has_feature_async_commit(journal)) {
789 err = journal_submit_commit_record(journal, commit_transaction,
790 &cbh, crc32_sum);
791 if (err)
792 jbd2_journal_abort(journal, err);
793 }
794
795 blk_finish_plug(&plug);
796
797 /* Lo and behold: we have just managed to send a transaction to
798 the log. Before we can commit it, wait for the IO so far to
799 complete. Control buffers being written are on the
800 transaction's t_log_list queue, and metadata buffers are on
801 the io_bufs list.
802
803 Wait for the buffers in reverse order. That way we are
804 less likely to be woken up until all IOs have completed, and
805 so we incur less scheduling load.
806 */
807
808 jbd2_debug(3, "JBD2: commit phase 3\n");
809
810 while (!list_empty(&io_bufs)) {
811 struct buffer_head *bh = list_entry(io_bufs.prev,
812 struct buffer_head,
813 b_assoc_buffers);
814
815 wait_on_buffer(bh);
816 cond_resched();
817
818 if (unlikely(!buffer_uptodate(bh)))
819 err = -EIO;
820 jbd2_unfile_log_bh(bh);
821 stats.run.rs_blocks_logged++;
822
823 /*
824 * The list contains temporary buffer heads created by
825 * jbd2_journal_write_metadata_buffer().
826 */
827 BUFFER_TRACE(bh, "dumping temporary bh");
828 __brelse(bh);
829 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
830 free_buffer_head(bh);
831
832 /* We also have to refile the corresponding shadowed buffer */
833 jh = commit_transaction->t_shadow_list->b_tprev;
834 bh = jh2bh(jh);
835 clear_buffer_jwrite(bh);
836 J_ASSERT_BH(bh, buffer_jbddirty(bh));
837 J_ASSERT_BH(bh, !buffer_shadow(bh));
838
839 /* The metadata is now released for reuse, but we need
840 to remember it against this transaction so that when
841 we finally commit, we can do any checkpointing
842 required. */
843 JBUFFER_TRACE(jh, "file as BJ_Forget");
844 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
845 JBUFFER_TRACE(jh, "brelse shadowed buffer");
846 __brelse(bh);
847 }
848
849 J_ASSERT (commit_transaction->t_shadow_list == NULL);
850
851 jbd2_debug(3, "JBD2: commit phase 4\n");
852
853 /* Here we wait for the revoke record and descriptor record buffers */
854 while (!list_empty(&log_bufs)) {
855 struct buffer_head *bh;
856
857 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
858 wait_on_buffer(bh);
859 cond_resched();
860
861 if (unlikely(!buffer_uptodate(bh)))
862 err = -EIO;
863
864 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
865 clear_buffer_jwrite(bh);
866 jbd2_unfile_log_bh(bh);
867 stats.run.rs_blocks_logged++;
868 __brelse(bh); /* One for getblk */
869 /* AKPM: bforget here */
870 }
871
872 if (err)
873 jbd2_journal_abort(journal, err);
874
875 jbd2_debug(3, "JBD2: commit phase 5\n");
876 write_lock(&journal->j_state_lock);
877 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
878 commit_transaction->t_state = T_COMMIT_JFLUSH;
879 write_unlock(&journal->j_state_lock);
880
881 if (!jbd2_has_feature_async_commit(journal)) {
882 err = journal_submit_commit_record(journal, commit_transaction,
883 &cbh, crc32_sum);
884 if (err)
885 jbd2_journal_abort(journal, err);
886 }
887 if (cbh)
888 err = journal_wait_on_commit_record(journal, cbh);
889 stats.run.rs_blocks_logged++;
890 if (jbd2_has_feature_async_commit(journal) &&
891 journal->j_flags & JBD2_BARRIER) {
892 blkdev_issue_flush(journal->j_dev);
893 }
894
895 if (err)
896 jbd2_journal_abort(journal, err);
897
898 WARN_ON_ONCE(
899 atomic_read(&commit_transaction->t_outstanding_credits) < 0);
900
901 /*
902 * Now disk caches for filesystem device are flushed so we are safe to
903 * erase checkpointed transactions from the log by updating journal
904 * superblock.
905 */
906 if (update_tail)
907 jbd2_update_log_tail(journal, first_tid, first_block);
908
909 /* End of a transaction! Finally, we can do checkpoint
910 processing: any buffers committed as a result of this
911 transaction can be removed from any checkpoint list it was on
912 before. */
913
914 jbd2_debug(3, "JBD2: commit phase 6\n");
915
916 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
917 J_ASSERT(commit_transaction->t_buffers == NULL);
918 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
919 J_ASSERT(commit_transaction->t_shadow_list == NULL);
920
921restart_loop:
922 /*
923 * As there are other places (journal_unmap_buffer()) adding buffers
924 * to this list we have to be careful and hold the j_list_lock.
925 */
926 spin_lock(&journal->j_list_lock);
927 while (commit_transaction->t_forget) {
928 transaction_t *cp_transaction;
929 struct buffer_head *bh;
930 int try_to_free = 0;
931 bool drop_ref;
932
933 jh = commit_transaction->t_forget;
934 spin_unlock(&journal->j_list_lock);
935 bh = jh2bh(jh);
936 /*
937 * Get a reference so that bh cannot be freed before we are
938 * done with it.
939 */
940 get_bh(bh);
941 spin_lock(&jh->b_state_lock);
942 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
943
944 /*
945 * If there is undo-protected committed data against
946 * this buffer, then we can remove it now. If it is a
947 * buffer needing such protection, the old frozen_data
948 * field now points to a committed version of the
949 * buffer, so rotate that field to the new committed
950 * data.
951 *
952 * Otherwise, we can just throw away the frozen data now.
953 *
954 * We also know that the frozen data has already fired
955 * its triggers if they exist, so we can clear that too.
956 */
957 if (jh->b_committed_data) {
958 jbd2_free(jh->b_committed_data, bh->b_size);
959 jh->b_committed_data = NULL;
960 if (jh->b_frozen_data) {
961 jh->b_committed_data = jh->b_frozen_data;
962 jh->b_frozen_data = NULL;
963 jh->b_frozen_triggers = NULL;
964 }
965 } else if (jh->b_frozen_data) {
966 jbd2_free(jh->b_frozen_data, bh->b_size);
967 jh->b_frozen_data = NULL;
968 jh->b_frozen_triggers = NULL;
969 }
970
971 spin_lock(&journal->j_list_lock);
972 cp_transaction = jh->b_cp_transaction;
973 if (cp_transaction) {
974 JBUFFER_TRACE(jh, "remove from old cp transaction");
975 cp_transaction->t_chp_stats.cs_dropped++;
976 __jbd2_journal_remove_checkpoint(jh);
977 }
978
979 /* Only re-checkpoint the buffer_head if it is marked
980 * dirty. If the buffer was added to the BJ_Forget list
981 * by jbd2_journal_forget, it may no longer be dirty and
982 * there's no point in keeping a checkpoint record for
983 * it. */
984
985 /*
986 * A buffer which has been freed while still being journaled
987 * by a previous transaction, refile the buffer to BJ_Forget of
988 * the running transaction. If the just committed transaction
989 * contains "add to orphan" operation, we can completely
990 * invalidate the buffer now. We are rather through in that
991 * since the buffer may be still accessible when blocksize <
992 * pagesize and it is attached to the last partial page.
993 */
994 if (buffer_freed(bh) && !jh->b_next_transaction) {
995 struct address_space *mapping;
996
997 clear_buffer_freed(bh);
998 clear_buffer_jbddirty(bh);
999
1000 /*
1001 * Block device buffers need to stay mapped all the
1002 * time, so it is enough to clear buffer_jbddirty and
1003 * buffer_freed bits. For the file mapping buffers (i.e.
1004 * journalled data) we need to unmap buffer and clear
1005 * more bits. We also need to be careful about the check
1006 * because the data page mapping can get cleared under
1007 * our hands. Note that if mapping == NULL, we don't
1008 * need to make buffer unmapped because the page is
1009 * already detached from the mapping and buffers cannot
1010 * get reused.
1011 */
1012 mapping = READ_ONCE(bh->b_folio->mapping);
1013 if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
1014 clear_buffer_mapped(bh);
1015 clear_buffer_new(bh);
1016 clear_buffer_req(bh);
1017 bh->b_bdev = NULL;
1018 }
1019 }
1020
1021 if (buffer_jbddirty(bh)) {
1022 JBUFFER_TRACE(jh, "add to new checkpointing trans");
1023 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
1024 if (is_journal_aborted(journal))
1025 clear_buffer_jbddirty(bh);
1026 } else {
1027 J_ASSERT_BH(bh, !buffer_dirty(bh));
1028 /*
1029 * The buffer on BJ_Forget list and not jbddirty means
1030 * it has been freed by this transaction and hence it
1031 * could not have been reallocated until this
1032 * transaction has committed. *BUT* it could be
1033 * reallocated once we have written all the data to
1034 * disk and before we process the buffer on BJ_Forget
1035 * list.
1036 */
1037 if (!jh->b_next_transaction)
1038 try_to_free = 1;
1039 }
1040 JBUFFER_TRACE(jh, "refile or unfile buffer");
1041 drop_ref = __jbd2_journal_refile_buffer(jh);
1042 spin_unlock(&jh->b_state_lock);
1043 if (drop_ref)
1044 jbd2_journal_put_journal_head(jh);
1045 if (try_to_free)
1046 release_buffer_page(bh); /* Drops bh reference */
1047 else
1048 __brelse(bh);
1049 cond_resched_lock(&journal->j_list_lock);
1050 }
1051 spin_unlock(&journal->j_list_lock);
1052 /*
1053 * This is a bit sleazy. We use j_list_lock to protect transition
1054 * of a transaction into T_FINISHED state and calling
1055 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1056 * other checkpointing code processing the transaction...
1057 */
1058 write_lock(&journal->j_state_lock);
1059 spin_lock(&journal->j_list_lock);
1060 /*
1061 * Now recheck if some buffers did not get attached to the transaction
1062 * while the lock was dropped...
1063 */
1064 if (commit_transaction->t_forget) {
1065 spin_unlock(&journal->j_list_lock);
1066 write_unlock(&journal->j_state_lock);
1067 goto restart_loop;
1068 }
1069
1070 /* Add the transaction to the checkpoint list
1071 * __journal_remove_checkpoint() can not destroy transaction
1072 * under us because it is not marked as T_FINISHED yet */
1073 if (journal->j_checkpoint_transactions == NULL) {
1074 journal->j_checkpoint_transactions = commit_transaction;
1075 commit_transaction->t_cpnext = commit_transaction;
1076 commit_transaction->t_cpprev = commit_transaction;
1077 } else {
1078 commit_transaction->t_cpnext =
1079 journal->j_checkpoint_transactions;
1080 commit_transaction->t_cpprev =
1081 commit_transaction->t_cpnext->t_cpprev;
1082 commit_transaction->t_cpnext->t_cpprev =
1083 commit_transaction;
1084 commit_transaction->t_cpprev->t_cpnext =
1085 commit_transaction;
1086 }
1087 spin_unlock(&journal->j_list_lock);
1088
1089 /* Done with this transaction! */
1090
1091 jbd2_debug(3, "JBD2: commit phase 7\n");
1092
1093 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1094
1095 commit_transaction->t_start = jiffies;
1096 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1097 commit_transaction->t_start);
1098
1099 /*
1100 * File the transaction statistics
1101 */
1102 stats.ts_tid = commit_transaction->t_tid;
1103 stats.run.rs_handle_count =
1104 atomic_read(&commit_transaction->t_handle_count);
1105 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1106 commit_transaction->t_tid, &stats.run);
1107 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1108
1109 commit_transaction->t_state = T_COMMIT_CALLBACK;
1110 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1111 journal->j_commit_sequence = commit_transaction->t_tid;
1112 journal->j_committing_transaction = NULL;
1113 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1114
1115 /*
1116 * weight the commit time higher than the average time so we don't
1117 * react too strongly to vast changes in the commit time
1118 */
1119 if (likely(journal->j_average_commit_time))
1120 journal->j_average_commit_time = (commit_time +
1121 journal->j_average_commit_time*3) / 4;
1122 else
1123 journal->j_average_commit_time = commit_time;
1124
1125 write_unlock(&journal->j_state_lock);
1126
1127 if (journal->j_commit_callback)
1128 journal->j_commit_callback(journal, commit_transaction);
1129 if (journal->j_fc_cleanup_callback)
1130 journal->j_fc_cleanup_callback(journal, 1, commit_transaction->t_tid);
1131
1132 trace_jbd2_end_commit(journal, commit_transaction);
1133 jbd2_debug(1, "JBD2: commit %d complete, head %d\n",
1134 journal->j_commit_sequence, journal->j_tail_sequence);
1135
1136 write_lock(&journal->j_state_lock);
1137 journal->j_flags &= ~JBD2_FULL_COMMIT_ONGOING;
1138 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
1139 spin_lock(&journal->j_list_lock);
1140 commit_transaction->t_state = T_FINISHED;
1141 /* Check if the transaction can be dropped now that we are finished */
1142 if (commit_transaction->t_checkpoint_list == NULL) {
1143 __jbd2_journal_drop_transaction(journal, commit_transaction);
1144 jbd2_journal_free_transaction(commit_transaction);
1145 }
1146 spin_unlock(&journal->j_list_lock);
1147 write_unlock(&journal->j_state_lock);
1148 wake_up(&journal->j_wait_done_commit);
1149 wake_up(&journal->j_fc_wait);
1150
1151 /*
1152 * Calculate overall stats
1153 */
1154 spin_lock(&journal->j_history_lock);
1155 journal->j_stats.ts_tid++;
1156 journal->j_stats.ts_requested += stats.ts_requested;
1157 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1158 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1159 journal->j_stats.run.rs_running += stats.run.rs_running;
1160 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1161 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1162 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1163 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1164 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1165 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1166 spin_unlock(&journal->j_history_lock);
1167}