Loading...
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 page *page;
66
67 if (buffer_dirty(bh))
68 goto nope;
69 if (atomic_read(&bh->b_count) != 1)
70 goto nope;
71 page = bh->b_page;
72 if (!page)
73 goto nope;
74 if (page->mapping)
75 goto nope;
76
77 /* OK, it's a truncated page */
78 if (!trylock_page(page))
79 goto nope;
80
81 get_page(page);
82 __brelse(bh);
83 try_to_free_buffers(page);
84 unlock_page(page);
85 put_page(page);
86 return;
87
88nope:
89 __brelse(bh);
90}
91
92static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
93{
94 struct commit_header *h;
95 __u32 csum;
96
97 if (!jbd2_journal_has_csum_v2or3(j))
98 return;
99
100 h = (struct commit_header *)(bh->b_data);
101 h->h_chksum_type = 0;
102 h->h_chksum_size = 0;
103 h->h_chksum[0] = 0;
104 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
105 h->h_chksum[0] = cpu_to_be32(csum);
106}
107
108/*
109 * Done it all: now submit the commit record. We should have
110 * cleaned up our previous buffers by now, so if we are in abort
111 * mode we can now just skip the rest of the journal write
112 * entirely.
113 *
114 * Returns 1 if the journal needs to be aborted or 0 on success
115 */
116static int journal_submit_commit_record(journal_t *journal,
117 transaction_t *commit_transaction,
118 struct buffer_head **cbh,
119 __u32 crc32_sum)
120{
121 struct commit_header *tmp;
122 struct buffer_head *bh;
123 int ret;
124 struct timespec64 now = current_kernel_time64();
125
126 *cbh = NULL;
127
128 if (is_journal_aborted(journal))
129 return 0;
130
131 bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
132 JBD2_COMMIT_BLOCK);
133 if (!bh)
134 return 1;
135
136 tmp = (struct commit_header *)bh->b_data;
137 tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
138 tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
139
140 if (jbd2_has_feature_checksum(journal)) {
141 tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
142 tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
143 tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
144 }
145 jbd2_commit_block_csum_set(journal, bh);
146
147 BUFFER_TRACE(bh, "submit commit block");
148 lock_buffer(bh);
149 clear_buffer_dirty(bh);
150 set_buffer_uptodate(bh);
151 bh->b_end_io = journal_end_buffer_io_sync;
152
153 if (journal->j_flags & JBD2_BARRIER &&
154 !jbd2_has_feature_async_commit(journal))
155 ret = submit_bh(REQ_OP_WRITE,
156 REQ_SYNC | REQ_PREFLUSH | REQ_FUA, bh);
157 else
158 ret = submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
159
160 *cbh = bh;
161 return ret;
162}
163
164/*
165 * This function along with journal_submit_commit_record
166 * allows to write the commit record asynchronously.
167 */
168static int journal_wait_on_commit_record(journal_t *journal,
169 struct buffer_head *bh)
170{
171 int ret = 0;
172
173 clear_buffer_dirty(bh);
174 wait_on_buffer(bh);
175
176 if (unlikely(!buffer_uptodate(bh)))
177 ret = -EIO;
178 put_bh(bh); /* One for getblk() */
179
180 return ret;
181}
182
183/*
184 * write the filemap data using writepage() address_space_operations.
185 * We don't do block allocation here even for delalloc. We don't
186 * use writepages() because with dealyed allocation we may be doing
187 * block allocation in writepages().
188 */
189static int journal_submit_inode_data_buffers(struct address_space *mapping)
190{
191 int ret;
192 struct writeback_control wbc = {
193 .sync_mode = WB_SYNC_ALL,
194 .nr_to_write = mapping->nrpages * 2,
195 .range_start = 0,
196 .range_end = i_size_read(mapping->host),
197 };
198
199 ret = generic_writepages(mapping, &wbc);
200 return ret;
201}
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 struct address_space *mapping;
217
218 spin_lock(&journal->j_list_lock);
219 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
220 if (!(jinode->i_flags & JI_WRITE_DATA))
221 continue;
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 if (!(jinode->i_flags & JI_WAIT_DATA))
260 continue;
261 jinode->i_flags |= JI_COMMIT_RUNNING;
262 spin_unlock(&journal->j_list_lock);
263 err = filemap_fdatawait_keep_errors(
264 jinode->i_vfs_inode->i_mapping);
265 if (!ret)
266 ret = err;
267 spin_lock(&journal->j_list_lock);
268 jinode->i_flags &= ~JI_COMMIT_RUNNING;
269 smp_mb();
270 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
271 }
272
273 /* Now refile inode to proper lists */
274 list_for_each_entry_safe(jinode, next_i,
275 &commit_transaction->t_inode_list, i_list) {
276 list_del(&jinode->i_list);
277 if (jinode->i_next_transaction) {
278 jinode->i_transaction = jinode->i_next_transaction;
279 jinode->i_next_transaction = NULL;
280 list_add(&jinode->i_list,
281 &jinode->i_transaction->t_inode_list);
282 } else {
283 jinode->i_transaction = NULL;
284 }
285 }
286 spin_unlock(&journal->j_list_lock);
287
288 return ret;
289}
290
291static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
292{
293 struct page *page = bh->b_page;
294 char *addr;
295 __u32 checksum;
296
297 addr = kmap_atomic(page);
298 checksum = crc32_be(crc32_sum,
299 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
300 kunmap_atomic(addr);
301
302 return checksum;
303}
304
305static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
306 unsigned long long block)
307{
308 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
309 if (jbd2_has_feature_64bit(j))
310 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
311}
312
313static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
314 struct buffer_head *bh, __u32 sequence)
315{
316 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
317 struct page *page = bh->b_page;
318 __u8 *addr;
319 __u32 csum32;
320 __be32 seq;
321
322 if (!jbd2_journal_has_csum_v2or3(j))
323 return;
324
325 seq = cpu_to_be32(sequence);
326 addr = kmap_atomic(page);
327 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
328 csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
329 bh->b_size);
330 kunmap_atomic(addr);
331
332 if (jbd2_has_feature_csum3(j))
333 tag3->t_checksum = cpu_to_be32(csum32);
334 else
335 tag->t_checksum = cpu_to_be16(csum32);
336}
337/*
338 * jbd2_journal_commit_transaction
339 *
340 * The primary function for committing a transaction to the log. This
341 * function is called by the journal thread to begin a complete commit.
342 */
343void jbd2_journal_commit_transaction(journal_t *journal)
344{
345 struct transaction_stats_s stats;
346 transaction_t *commit_transaction;
347 struct journal_head *jh;
348 struct buffer_head *descriptor;
349 struct buffer_head **wbuf = journal->j_wbuf;
350 int bufs;
351 int flags;
352 int err;
353 unsigned long long blocknr;
354 ktime_t start_time;
355 u64 commit_time;
356 char *tagp = NULL;
357 journal_block_tag_t *tag = NULL;
358 int space_left = 0;
359 int first_tag = 0;
360 int tag_flag;
361 int i;
362 int tag_bytes = journal_tag_bytes(journal);
363 struct buffer_head *cbh = NULL; /* For transactional checksums */
364 __u32 crc32_sum = ~0;
365 struct blk_plug plug;
366 /* Tail of the journal */
367 unsigned long first_block;
368 tid_t first_tid;
369 int update_tail;
370 int csum_size = 0;
371 LIST_HEAD(io_bufs);
372 LIST_HEAD(log_bufs);
373
374 if (jbd2_journal_has_csum_v2or3(journal))
375 csum_size = sizeof(struct jbd2_journal_block_tail);
376
377 /*
378 * First job: lock down the current transaction and wait for
379 * all outstanding updates to complete.
380 */
381
382 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
383 if (journal->j_flags & JBD2_FLUSHED) {
384 jbd_debug(3, "super block updated\n");
385 mutex_lock_io(&journal->j_checkpoint_mutex);
386 /*
387 * We hold j_checkpoint_mutex so tail cannot change under us.
388 * We don't need any special data guarantees for writing sb
389 * since journal is empty and it is ok for write to be
390 * flushed only with transaction commit.
391 */
392 jbd2_journal_update_sb_log_tail(journal,
393 journal->j_tail_sequence,
394 journal->j_tail,
395 REQ_SYNC);
396 mutex_unlock(&journal->j_checkpoint_mutex);
397 } else {
398 jbd_debug(3, "superblock not updated\n");
399 }
400
401 J_ASSERT(journal->j_running_transaction != NULL);
402 J_ASSERT(journal->j_committing_transaction == NULL);
403
404 commit_transaction = journal->j_running_transaction;
405
406 trace_jbd2_start_commit(journal, commit_transaction);
407 jbd_debug(1, "JBD2: starting commit of transaction %d\n",
408 commit_transaction->t_tid);
409
410 write_lock(&journal->j_state_lock);
411 J_ASSERT(commit_transaction->t_state == T_RUNNING);
412 commit_transaction->t_state = T_LOCKED;
413
414 trace_jbd2_commit_locking(journal, commit_transaction);
415 stats.run.rs_wait = commit_transaction->t_max_wait;
416 stats.run.rs_request_delay = 0;
417 stats.run.rs_locked = jiffies;
418 if (commit_transaction->t_requested)
419 stats.run.rs_request_delay =
420 jbd2_time_diff(commit_transaction->t_requested,
421 stats.run.rs_locked);
422 stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
423 stats.run.rs_locked);
424
425 spin_lock(&commit_transaction->t_handle_lock);
426 while (atomic_read(&commit_transaction->t_updates)) {
427 DEFINE_WAIT(wait);
428
429 prepare_to_wait(&journal->j_wait_updates, &wait,
430 TASK_UNINTERRUPTIBLE);
431 if (atomic_read(&commit_transaction->t_updates)) {
432 spin_unlock(&commit_transaction->t_handle_lock);
433 write_unlock(&journal->j_state_lock);
434 schedule();
435 write_lock(&journal->j_state_lock);
436 spin_lock(&commit_transaction->t_handle_lock);
437 }
438 finish_wait(&journal->j_wait_updates, &wait);
439 }
440 spin_unlock(&commit_transaction->t_handle_lock);
441
442 J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
443 journal->j_max_transaction_buffers);
444
445 /*
446 * First thing we are allowed to do is to discard any remaining
447 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
448 * that there are no such buffers: if a large filesystem
449 * operation like a truncate needs to split itself over multiple
450 * transactions, then it may try to do a jbd2_journal_restart() while
451 * there are still BJ_Reserved buffers outstanding. These must
452 * be released cleanly from the current transaction.
453 *
454 * In this case, the filesystem must still reserve write access
455 * again before modifying the buffer in the new transaction, but
456 * we do not require it to remember exactly which old buffers it
457 * has reserved. This is consistent with the existing behaviour
458 * that multiple jbd2_journal_get_write_access() calls to the same
459 * buffer are perfectly permissible.
460 */
461 while (commit_transaction->t_reserved_list) {
462 jh = commit_transaction->t_reserved_list;
463 JBUFFER_TRACE(jh, "reserved, unused: refile");
464 /*
465 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
466 * leave undo-committed data.
467 */
468 if (jh->b_committed_data) {
469 struct buffer_head *bh = jh2bh(jh);
470
471 jbd_lock_bh_state(bh);
472 jbd2_free(jh->b_committed_data, bh->b_size);
473 jh->b_committed_data = NULL;
474 jbd_unlock_bh_state(bh);
475 }
476 jbd2_journal_refile_buffer(journal, jh);
477 }
478
479 /*
480 * Now try to drop any written-back buffers from the journal's
481 * checkpoint lists. We do this *before* commit because it potentially
482 * frees some memory
483 */
484 spin_lock(&journal->j_list_lock);
485 __jbd2_journal_clean_checkpoint_list(journal, false);
486 spin_unlock(&journal->j_list_lock);
487
488 jbd_debug(3, "JBD2: commit phase 1\n");
489
490 /*
491 * Clear revoked flag to reflect there is no revoked buffers
492 * in the next transaction which is going to be started.
493 */
494 jbd2_clear_buffer_revoked_flags(journal);
495
496 /*
497 * Switch to a new revoke table.
498 */
499 jbd2_journal_switch_revoke_table(journal);
500
501 /*
502 * Reserved credits cannot be claimed anymore, free them
503 */
504 atomic_sub(atomic_read(&journal->j_reserved_credits),
505 &commit_transaction->t_outstanding_credits);
506
507 trace_jbd2_commit_flushing(journal, commit_transaction);
508 stats.run.rs_flushing = jiffies;
509 stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
510 stats.run.rs_flushing);
511
512 commit_transaction->t_state = T_FLUSH;
513 journal->j_committing_transaction = commit_transaction;
514 journal->j_running_transaction = NULL;
515 start_time = ktime_get();
516 commit_transaction->t_log_start = journal->j_head;
517 wake_up(&journal->j_wait_transaction_locked);
518 write_unlock(&journal->j_state_lock);
519
520 jbd_debug(3, "JBD2: commit phase 2a\n");
521
522 /*
523 * Now start flushing things to disk, in the order they appear
524 * on the transaction lists. Data blocks go first.
525 */
526 err = journal_submit_data_buffers(journal, commit_transaction);
527 if (err)
528 jbd2_journal_abort(journal, err);
529
530 blk_start_plug(&plug);
531 jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
532
533 jbd_debug(3, "JBD2: commit phase 2b\n");
534
535 /*
536 * Way to go: we have now written out all of the data for a
537 * transaction! Now comes the tricky part: we need to write out
538 * metadata. Loop over the transaction's entire buffer list:
539 */
540 write_lock(&journal->j_state_lock);
541 commit_transaction->t_state = T_COMMIT;
542 write_unlock(&journal->j_state_lock);
543
544 trace_jbd2_commit_logging(journal, commit_transaction);
545 stats.run.rs_logging = jiffies;
546 stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
547 stats.run.rs_logging);
548 stats.run.rs_blocks =
549 atomic_read(&commit_transaction->t_outstanding_credits);
550 stats.run.rs_blocks_logged = 0;
551
552 J_ASSERT(commit_transaction->t_nr_buffers <=
553 atomic_read(&commit_transaction->t_outstanding_credits));
554
555 err = 0;
556 bufs = 0;
557 descriptor = NULL;
558 while (commit_transaction->t_buffers) {
559
560 /* Find the next buffer to be journaled... */
561
562 jh = commit_transaction->t_buffers;
563
564 /* If we're in abort mode, we just un-journal the buffer and
565 release it. */
566
567 if (is_journal_aborted(journal)) {
568 clear_buffer_jbddirty(jh2bh(jh));
569 JBUFFER_TRACE(jh, "journal is aborting: refile");
570 jbd2_buffer_abort_trigger(jh,
571 jh->b_frozen_data ?
572 jh->b_frozen_triggers :
573 jh->b_triggers);
574 jbd2_journal_refile_buffer(journal, jh);
575 /* If that was the last one, we need to clean up
576 * any descriptor buffers which may have been
577 * already allocated, even if we are now
578 * aborting. */
579 if (!commit_transaction->t_buffers)
580 goto start_journal_io;
581 continue;
582 }
583
584 /* Make sure we have a descriptor block in which to
585 record the metadata buffer. */
586
587 if (!descriptor) {
588 J_ASSERT (bufs == 0);
589
590 jbd_debug(4, "JBD2: get descriptor\n");
591
592 descriptor = jbd2_journal_get_descriptor_buffer(
593 commit_transaction,
594 JBD2_DESCRIPTOR_BLOCK);
595 if (!descriptor) {
596 jbd2_journal_abort(journal, -EIO);
597 continue;
598 }
599
600 jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
601 (unsigned long long)descriptor->b_blocknr,
602 descriptor->b_data);
603 tagp = &descriptor->b_data[sizeof(journal_header_t)];
604 space_left = descriptor->b_size -
605 sizeof(journal_header_t);
606 first_tag = 1;
607 set_buffer_jwrite(descriptor);
608 set_buffer_dirty(descriptor);
609 wbuf[bufs++] = descriptor;
610
611 /* Record it so that we can wait for IO
612 completion later */
613 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
614 jbd2_file_log_bh(&log_bufs, descriptor);
615 }
616
617 /* Where is the buffer to be written? */
618
619 err = jbd2_journal_next_log_block(journal, &blocknr);
620 /* If the block mapping failed, just abandon the buffer
621 and repeat this loop: we'll fall into the
622 refile-on-abort condition above. */
623 if (err) {
624 jbd2_journal_abort(journal, err);
625 continue;
626 }
627
628 /*
629 * start_this_handle() uses t_outstanding_credits to determine
630 * the free space in the log, but this counter is changed
631 * by jbd2_journal_next_log_block() also.
632 */
633 atomic_dec(&commit_transaction->t_outstanding_credits);
634
635 /* Bump b_count to prevent truncate from stumbling over
636 the shadowed buffer! @@@ This can go if we ever get
637 rid of the shadow pairing of buffers. */
638 atomic_inc(&jh2bh(jh)->b_count);
639
640 /*
641 * Make a temporary IO buffer with which to write it out
642 * (this will requeue the metadata buffer to BJ_Shadow).
643 */
644 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
645 JBUFFER_TRACE(jh, "ph3: write metadata");
646 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
647 jh, &wbuf[bufs], blocknr);
648 if (flags < 0) {
649 jbd2_journal_abort(journal, flags);
650 continue;
651 }
652 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
653
654 /* Record the new block's tag in the current descriptor
655 buffer */
656
657 tag_flag = 0;
658 if (flags & 1)
659 tag_flag |= JBD2_FLAG_ESCAPE;
660 if (!first_tag)
661 tag_flag |= JBD2_FLAG_SAME_UUID;
662
663 tag = (journal_block_tag_t *) tagp;
664 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
665 tag->t_flags = cpu_to_be16(tag_flag);
666 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
667 commit_transaction->t_tid);
668 tagp += tag_bytes;
669 space_left -= tag_bytes;
670 bufs++;
671
672 if (first_tag) {
673 memcpy (tagp, journal->j_uuid, 16);
674 tagp += 16;
675 space_left -= 16;
676 first_tag = 0;
677 }
678
679 /* If there's no more to do, or if the descriptor is full,
680 let the IO rip! */
681
682 if (bufs == journal->j_wbufsize ||
683 commit_transaction->t_buffers == NULL ||
684 space_left < tag_bytes + 16 + csum_size) {
685
686 jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
687
688 /* Write an end-of-descriptor marker before
689 submitting the IOs. "tag" still points to
690 the last tag we set up. */
691
692 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
693
694 jbd2_descriptor_block_csum_set(journal, descriptor);
695start_journal_io:
696 for (i = 0; i < bufs; i++) {
697 struct buffer_head *bh = wbuf[i];
698 /*
699 * Compute checksum.
700 */
701 if (jbd2_has_feature_checksum(journal)) {
702 crc32_sum =
703 jbd2_checksum_data(crc32_sum, bh);
704 }
705
706 lock_buffer(bh);
707 clear_buffer_dirty(bh);
708 set_buffer_uptodate(bh);
709 bh->b_end_io = journal_end_buffer_io_sync;
710 submit_bh(REQ_OP_WRITE, REQ_SYNC, bh);
711 }
712 cond_resched();
713 stats.run.rs_blocks_logged += bufs;
714
715 /* Force a new descriptor to be generated next
716 time round the loop. */
717 descriptor = NULL;
718 bufs = 0;
719 }
720 }
721
722 err = journal_finish_inode_data_buffers(journal, commit_transaction);
723 if (err) {
724 printk(KERN_WARNING
725 "JBD2: Detected IO errors while flushing file data "
726 "on %s\n", journal->j_devname);
727 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
728 jbd2_journal_abort(journal, err);
729 err = 0;
730 }
731
732 /*
733 * Get current oldest transaction in the log before we issue flush
734 * to the filesystem device. After the flush we can be sure that
735 * blocks of all older transactions are checkpointed to persistent
736 * storage and we will be safe to update journal start in the
737 * superblock with the numbers we get here.
738 */
739 update_tail =
740 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
741
742 write_lock(&journal->j_state_lock);
743 if (update_tail) {
744 long freed = first_block - journal->j_tail;
745
746 if (first_block < journal->j_tail)
747 freed += journal->j_last - journal->j_first;
748 /* Update tail only if we free significant amount of space */
749 if (freed < journal->j_maxlen / 4)
750 update_tail = 0;
751 }
752 J_ASSERT(commit_transaction->t_state == T_COMMIT);
753 commit_transaction->t_state = T_COMMIT_DFLUSH;
754 write_unlock(&journal->j_state_lock);
755
756 /*
757 * If the journal is not located on the file system device,
758 * then we must flush the file system device before we issue
759 * the commit record
760 */
761 if (commit_transaction->t_need_data_flush &&
762 (journal->j_fs_dev != journal->j_dev) &&
763 (journal->j_flags & JBD2_BARRIER))
764 blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
765
766 /* Done it all: now write the commit record asynchronously. */
767 if (jbd2_has_feature_async_commit(journal)) {
768 err = journal_submit_commit_record(journal, commit_transaction,
769 &cbh, crc32_sum);
770 if (err)
771 __jbd2_journal_abort_hard(journal);
772 }
773
774 blk_finish_plug(&plug);
775
776 /* Lo and behold: we have just managed to send a transaction to
777 the log. Before we can commit it, wait for the IO so far to
778 complete. Control buffers being written are on the
779 transaction's t_log_list queue, and metadata buffers are on
780 the io_bufs list.
781
782 Wait for the buffers in reverse order. That way we are
783 less likely to be woken up until all IOs have completed, and
784 so we incur less scheduling load.
785 */
786
787 jbd_debug(3, "JBD2: commit phase 3\n");
788
789 while (!list_empty(&io_bufs)) {
790 struct buffer_head *bh = list_entry(io_bufs.prev,
791 struct buffer_head,
792 b_assoc_buffers);
793
794 wait_on_buffer(bh);
795 cond_resched();
796
797 if (unlikely(!buffer_uptodate(bh)))
798 err = -EIO;
799 jbd2_unfile_log_bh(bh);
800
801 /*
802 * The list contains temporary buffer heads created by
803 * jbd2_journal_write_metadata_buffer().
804 */
805 BUFFER_TRACE(bh, "dumping temporary bh");
806 __brelse(bh);
807 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
808 free_buffer_head(bh);
809
810 /* We also have to refile the corresponding shadowed buffer */
811 jh = commit_transaction->t_shadow_list->b_tprev;
812 bh = jh2bh(jh);
813 clear_buffer_jwrite(bh);
814 J_ASSERT_BH(bh, buffer_jbddirty(bh));
815 J_ASSERT_BH(bh, !buffer_shadow(bh));
816
817 /* The metadata is now released for reuse, but we need
818 to remember it against this transaction so that when
819 we finally commit, we can do any checkpointing
820 required. */
821 JBUFFER_TRACE(jh, "file as BJ_Forget");
822 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
823 JBUFFER_TRACE(jh, "brelse shadowed buffer");
824 __brelse(bh);
825 }
826
827 J_ASSERT (commit_transaction->t_shadow_list == NULL);
828
829 jbd_debug(3, "JBD2: commit phase 4\n");
830
831 /* Here we wait for the revoke record and descriptor record buffers */
832 while (!list_empty(&log_bufs)) {
833 struct buffer_head *bh;
834
835 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
836 wait_on_buffer(bh);
837 cond_resched();
838
839 if (unlikely(!buffer_uptodate(bh)))
840 err = -EIO;
841
842 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
843 clear_buffer_jwrite(bh);
844 jbd2_unfile_log_bh(bh);
845 __brelse(bh); /* One for getblk */
846 /* AKPM: bforget here */
847 }
848
849 if (err)
850 jbd2_journal_abort(journal, err);
851
852 jbd_debug(3, "JBD2: commit phase 5\n");
853 write_lock(&journal->j_state_lock);
854 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
855 commit_transaction->t_state = T_COMMIT_JFLUSH;
856 write_unlock(&journal->j_state_lock);
857
858 if (!jbd2_has_feature_async_commit(journal)) {
859 err = journal_submit_commit_record(journal, commit_transaction,
860 &cbh, crc32_sum);
861 if (err)
862 __jbd2_journal_abort_hard(journal);
863 }
864 if (cbh)
865 err = journal_wait_on_commit_record(journal, cbh);
866 if (jbd2_has_feature_async_commit(journal) &&
867 journal->j_flags & JBD2_BARRIER) {
868 blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
869 }
870
871 if (err)
872 jbd2_journal_abort(journal, err);
873
874 /*
875 * Now disk caches for filesystem device are flushed so we are safe to
876 * erase checkpointed transactions from the log by updating journal
877 * superblock.
878 */
879 if (update_tail)
880 jbd2_update_log_tail(journal, first_tid, first_block);
881
882 /* End of a transaction! Finally, we can do checkpoint
883 processing: any buffers committed as a result of this
884 transaction can be removed from any checkpoint list it was on
885 before. */
886
887 jbd_debug(3, "JBD2: commit phase 6\n");
888
889 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
890 J_ASSERT(commit_transaction->t_buffers == NULL);
891 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
892 J_ASSERT(commit_transaction->t_shadow_list == NULL);
893
894restart_loop:
895 /*
896 * As there are other places (journal_unmap_buffer()) adding buffers
897 * to this list we have to be careful and hold the j_list_lock.
898 */
899 spin_lock(&journal->j_list_lock);
900 while (commit_transaction->t_forget) {
901 transaction_t *cp_transaction;
902 struct buffer_head *bh;
903 int try_to_free = 0;
904
905 jh = commit_transaction->t_forget;
906 spin_unlock(&journal->j_list_lock);
907 bh = jh2bh(jh);
908 /*
909 * Get a reference so that bh cannot be freed before we are
910 * done with it.
911 */
912 get_bh(bh);
913 jbd_lock_bh_state(bh);
914 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
915
916 /*
917 * If there is undo-protected committed data against
918 * this buffer, then we can remove it now. If it is a
919 * buffer needing such protection, the old frozen_data
920 * field now points to a committed version of the
921 * buffer, so rotate that field to the new committed
922 * data.
923 *
924 * Otherwise, we can just throw away the frozen data now.
925 *
926 * We also know that the frozen data has already fired
927 * its triggers if they exist, so we can clear that too.
928 */
929 if (jh->b_committed_data) {
930 jbd2_free(jh->b_committed_data, bh->b_size);
931 jh->b_committed_data = NULL;
932 if (jh->b_frozen_data) {
933 jh->b_committed_data = jh->b_frozen_data;
934 jh->b_frozen_data = NULL;
935 jh->b_frozen_triggers = NULL;
936 }
937 } else if (jh->b_frozen_data) {
938 jbd2_free(jh->b_frozen_data, bh->b_size);
939 jh->b_frozen_data = NULL;
940 jh->b_frozen_triggers = NULL;
941 }
942
943 spin_lock(&journal->j_list_lock);
944 cp_transaction = jh->b_cp_transaction;
945 if (cp_transaction) {
946 JBUFFER_TRACE(jh, "remove from old cp transaction");
947 cp_transaction->t_chp_stats.cs_dropped++;
948 __jbd2_journal_remove_checkpoint(jh);
949 }
950
951 /* Only re-checkpoint the buffer_head if it is marked
952 * dirty. If the buffer was added to the BJ_Forget list
953 * by jbd2_journal_forget, it may no longer be dirty and
954 * there's no point in keeping a checkpoint record for
955 * it. */
956
957 /*
958 * A buffer which has been freed while still being journaled by
959 * a previous transaction.
960 */
961 if (buffer_freed(bh)) {
962 /*
963 * If the running transaction is the one containing
964 * "add to orphan" operation (b_next_transaction !=
965 * NULL), we have to wait for that transaction to
966 * commit before we can really get rid of the buffer.
967 * So just clear b_modified to not confuse transaction
968 * credit accounting and refile the buffer to
969 * BJ_Forget of the running transaction. If the just
970 * committed transaction contains "add to orphan"
971 * operation, we can completely invalidate the buffer
972 * now. We are rather through in that since the
973 * buffer may be still accessible when blocksize <
974 * pagesize and it is attached to the last partial
975 * page.
976 */
977 jh->b_modified = 0;
978 if (!jh->b_next_transaction) {
979 clear_buffer_freed(bh);
980 clear_buffer_jbddirty(bh);
981 clear_buffer_mapped(bh);
982 clear_buffer_new(bh);
983 clear_buffer_req(bh);
984 bh->b_bdev = NULL;
985 }
986 }
987
988 if (buffer_jbddirty(bh)) {
989 JBUFFER_TRACE(jh, "add to new checkpointing trans");
990 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
991 if (is_journal_aborted(journal))
992 clear_buffer_jbddirty(bh);
993 } else {
994 J_ASSERT_BH(bh, !buffer_dirty(bh));
995 /*
996 * The buffer on BJ_Forget list and not jbddirty means
997 * it has been freed by this transaction and hence it
998 * could not have been reallocated until this
999 * transaction has committed. *BUT* it could be
1000 * reallocated once we have written all the data to
1001 * disk and before we process the buffer on BJ_Forget
1002 * list.
1003 */
1004 if (!jh->b_next_transaction)
1005 try_to_free = 1;
1006 }
1007 JBUFFER_TRACE(jh, "refile or unfile buffer");
1008 __jbd2_journal_refile_buffer(jh);
1009 jbd_unlock_bh_state(bh);
1010 if (try_to_free)
1011 release_buffer_page(bh); /* Drops bh reference */
1012 else
1013 __brelse(bh);
1014 cond_resched_lock(&journal->j_list_lock);
1015 }
1016 spin_unlock(&journal->j_list_lock);
1017 /*
1018 * This is a bit sleazy. We use j_list_lock to protect transition
1019 * of a transaction into T_FINISHED state and calling
1020 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1021 * other checkpointing code processing the transaction...
1022 */
1023 write_lock(&journal->j_state_lock);
1024 spin_lock(&journal->j_list_lock);
1025 /*
1026 * Now recheck if some buffers did not get attached to the transaction
1027 * while the lock was dropped...
1028 */
1029 if (commit_transaction->t_forget) {
1030 spin_unlock(&journal->j_list_lock);
1031 write_unlock(&journal->j_state_lock);
1032 goto restart_loop;
1033 }
1034
1035 /* Add the transaction to the checkpoint list
1036 * __journal_remove_checkpoint() can not destroy transaction
1037 * under us because it is not marked as T_FINISHED yet */
1038 if (journal->j_checkpoint_transactions == NULL) {
1039 journal->j_checkpoint_transactions = commit_transaction;
1040 commit_transaction->t_cpnext = commit_transaction;
1041 commit_transaction->t_cpprev = commit_transaction;
1042 } else {
1043 commit_transaction->t_cpnext =
1044 journal->j_checkpoint_transactions;
1045 commit_transaction->t_cpprev =
1046 commit_transaction->t_cpnext->t_cpprev;
1047 commit_transaction->t_cpnext->t_cpprev =
1048 commit_transaction;
1049 commit_transaction->t_cpprev->t_cpnext =
1050 commit_transaction;
1051 }
1052 spin_unlock(&journal->j_list_lock);
1053
1054 /* Done with this transaction! */
1055
1056 jbd_debug(3, "JBD2: commit phase 7\n");
1057
1058 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1059
1060 commit_transaction->t_start = jiffies;
1061 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1062 commit_transaction->t_start);
1063
1064 /*
1065 * File the transaction statistics
1066 */
1067 stats.ts_tid = commit_transaction->t_tid;
1068 stats.run.rs_handle_count =
1069 atomic_read(&commit_transaction->t_handle_count);
1070 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1071 commit_transaction->t_tid, &stats.run);
1072 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1073
1074 commit_transaction->t_state = T_COMMIT_CALLBACK;
1075 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1076 journal->j_commit_sequence = commit_transaction->t_tid;
1077 journal->j_committing_transaction = NULL;
1078 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1079
1080 /*
1081 * weight the commit time higher than the average time so we don't
1082 * react too strongly to vast changes in the commit time
1083 */
1084 if (likely(journal->j_average_commit_time))
1085 journal->j_average_commit_time = (commit_time +
1086 journal->j_average_commit_time*3) / 4;
1087 else
1088 journal->j_average_commit_time = commit_time;
1089
1090 write_unlock(&journal->j_state_lock);
1091
1092 if (journal->j_commit_callback)
1093 journal->j_commit_callback(journal, commit_transaction);
1094
1095 trace_jbd2_end_commit(journal, commit_transaction);
1096 jbd_debug(1, "JBD2: commit %d complete, head %d\n",
1097 journal->j_commit_sequence, journal->j_tail_sequence);
1098
1099 write_lock(&journal->j_state_lock);
1100 spin_lock(&journal->j_list_lock);
1101 commit_transaction->t_state = T_FINISHED;
1102 /* Check if the transaction can be dropped now that we are finished */
1103 if (commit_transaction->t_checkpoint_list == NULL &&
1104 commit_transaction->t_checkpoint_io_list == NULL) {
1105 __jbd2_journal_drop_transaction(journal, commit_transaction);
1106 jbd2_journal_free_transaction(commit_transaction);
1107 }
1108 spin_unlock(&journal->j_list_lock);
1109 write_unlock(&journal->j_state_lock);
1110 wake_up(&journal->j_wait_done_commit);
1111
1112 /*
1113 * Calculate overall stats
1114 */
1115 spin_lock(&journal->j_history_lock);
1116 journal->j_stats.ts_tid++;
1117 journal->j_stats.ts_requested += stats.ts_requested;
1118 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1119 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1120 journal->j_stats.run.rs_running += stats.run.rs_running;
1121 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1122 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1123 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1124 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1125 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1126 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1127 spin_unlock(&journal->j_history_lock);
1128}
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 struct page *page;
67
68 if (buffer_dirty(bh))
69 goto nope;
70 if (atomic_read(&bh->b_count) != 1)
71 goto nope;
72 page = bh->b_page;
73 if (!page)
74 goto nope;
75 folio = page_folio(page);
76 if (folio->mapping)
77 goto nope;
78
79 /* OK, it's a truncated page */
80 if (!folio_trylock(folio))
81 goto nope;
82
83 folio_get(folio);
84 __brelse(bh);
85 try_to_free_buffers(folio);
86 folio_unlock(folio);
87 folio_put(folio);
88 return;
89
90nope:
91 __brelse(bh);
92}
93
94static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
95{
96 struct commit_header *h;
97 __u32 csum;
98
99 if (!jbd2_journal_has_csum_v2or3(j))
100 return;
101
102 h = (struct commit_header *)(bh->b_data);
103 h->h_chksum_type = 0;
104 h->h_chksum_size = 0;
105 h->h_chksum[0] = 0;
106 csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
107 h->h_chksum[0] = cpu_to_be32(csum);
108}
109
110/*
111 * Done it all: now submit the commit record. We should have
112 * cleaned up our previous buffers by now, so if we are in abort
113 * mode we can now just skip the rest of the journal write
114 * entirely.
115 *
116 * Returns 1 if the journal needs to be aborted or 0 on success
117 */
118static int journal_submit_commit_record(journal_t *journal,
119 transaction_t *commit_transaction,
120 struct buffer_head **cbh,
121 __u32 crc32_sum)
122{
123 struct commit_header *tmp;
124 struct buffer_head *bh;
125 struct timespec64 now;
126 blk_opf_t write_flags = REQ_OP_WRITE | REQ_SYNC;
127
128 *cbh = NULL;
129
130 if (is_journal_aborted(journal))
131 return 0;
132
133 bh = jbd2_journal_get_descriptor_buffer(commit_transaction,
134 JBD2_COMMIT_BLOCK);
135 if (!bh)
136 return 1;
137
138 tmp = (struct commit_header *)bh->b_data;
139 ktime_get_coarse_real_ts64(&now);
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 write_flags |= REQ_PREFLUSH | REQ_FUA;
159
160 submit_bh(write_flags, bh);
161 *cbh = bh;
162 return 0;
163}
164
165/*
166 * This function along with journal_submit_commit_record
167 * allows to write the commit record asynchronously.
168 */
169static int journal_wait_on_commit_record(journal_t *journal,
170 struct buffer_head *bh)
171{
172 int ret = 0;
173
174 clear_buffer_dirty(bh);
175 wait_on_buffer(bh);
176
177 if (unlikely(!buffer_uptodate(bh)))
178 ret = -EIO;
179 put_bh(bh); /* One for getblk() */
180
181 return ret;
182}
183
184/*
185 * write the filemap data using writepage() address_space_operations.
186 * We don't do block allocation here even for delalloc. We don't
187 * use writepages() because with delayed allocation we may be doing
188 * block allocation in writepages().
189 */
190int jbd2_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)
191{
192 struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
193 struct writeback_control wbc = {
194 .sync_mode = WB_SYNC_ALL,
195 .nr_to_write = mapping->nrpages * 2,
196 .range_start = jinode->i_dirty_start,
197 .range_end = jinode->i_dirty_end,
198 };
199
200 /*
201 * submit the inode data buffers. We use writepage
202 * instead of writepages. Because writepages can do
203 * block allocation with delalloc. We need to write
204 * only allocated blocks here.
205 */
206 return generic_writepages(mapping, &wbc);
207}
208
209/* Send all the data buffers related to an inode */
210int jbd2_submit_inode_data(journal_t *journal, struct jbd2_inode *jinode)
211{
212 if (!jinode || !(jinode->i_flags & JI_WRITE_DATA))
213 return 0;
214
215 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
216 return journal->j_submit_inode_data_buffers(jinode);
217
218}
219EXPORT_SYMBOL(jbd2_submit_inode_data);
220
221int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode)
222{
223 if (!jinode || !(jinode->i_flags & JI_WAIT_DATA) ||
224 !jinode->i_vfs_inode || !jinode->i_vfs_inode->i_mapping)
225 return 0;
226 return filemap_fdatawait_range_keep_errors(
227 jinode->i_vfs_inode->i_mapping, jinode->i_dirty_start,
228 jinode->i_dirty_end);
229}
230EXPORT_SYMBOL(jbd2_wait_inode_data);
231
232/*
233 * Submit all the data buffers of inode associated with the transaction to
234 * disk.
235 *
236 * We are in a committing transaction. Therefore no new inode can be added to
237 * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
238 * operate on from being released while we write out pages.
239 */
240static int journal_submit_data_buffers(journal_t *journal,
241 transaction_t *commit_transaction)
242{
243 struct jbd2_inode *jinode;
244 int err, ret = 0;
245
246 spin_lock(&journal->j_list_lock);
247 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
248 if (!(jinode->i_flags & JI_WRITE_DATA))
249 continue;
250 jinode->i_flags |= JI_COMMIT_RUNNING;
251 spin_unlock(&journal->j_list_lock);
252 /* submit the inode data buffers. */
253 trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
254 if (journal->j_submit_inode_data_buffers) {
255 err = journal->j_submit_inode_data_buffers(jinode);
256 if (!ret)
257 ret = err;
258 }
259 spin_lock(&journal->j_list_lock);
260 J_ASSERT(jinode->i_transaction == commit_transaction);
261 jinode->i_flags &= ~JI_COMMIT_RUNNING;
262 smp_mb();
263 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
264 }
265 spin_unlock(&journal->j_list_lock);
266 return ret;
267}
268
269int jbd2_journal_finish_inode_data_buffers(struct jbd2_inode *jinode)
270{
271 struct address_space *mapping = jinode->i_vfs_inode->i_mapping;
272
273 return filemap_fdatawait_range_keep_errors(mapping,
274 jinode->i_dirty_start,
275 jinode->i_dirty_end);
276}
277
278/*
279 * Wait for data submitted for writeout, refile inodes to proper
280 * transaction if needed.
281 *
282 */
283static int journal_finish_inode_data_buffers(journal_t *journal,
284 transaction_t *commit_transaction)
285{
286 struct jbd2_inode *jinode, *next_i;
287 int err, ret = 0;
288
289 /* For locking, see the comment in journal_submit_data_buffers() */
290 spin_lock(&journal->j_list_lock);
291 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
292 if (!(jinode->i_flags & JI_WAIT_DATA))
293 continue;
294 jinode->i_flags |= JI_COMMIT_RUNNING;
295 spin_unlock(&journal->j_list_lock);
296 /* wait for the inode data buffers writeout. */
297 if (journal->j_finish_inode_data_buffers) {
298 err = journal->j_finish_inode_data_buffers(jinode);
299 if (!ret)
300 ret = err;
301 }
302 spin_lock(&journal->j_list_lock);
303 jinode->i_flags &= ~JI_COMMIT_RUNNING;
304 smp_mb();
305 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
306 }
307
308 /* Now refile inode to proper lists */
309 list_for_each_entry_safe(jinode, next_i,
310 &commit_transaction->t_inode_list, i_list) {
311 list_del(&jinode->i_list);
312 if (jinode->i_next_transaction) {
313 jinode->i_transaction = jinode->i_next_transaction;
314 jinode->i_next_transaction = NULL;
315 list_add(&jinode->i_list,
316 &jinode->i_transaction->t_inode_list);
317 } else {
318 jinode->i_transaction = NULL;
319 jinode->i_dirty_start = 0;
320 jinode->i_dirty_end = 0;
321 }
322 }
323 spin_unlock(&journal->j_list_lock);
324
325 return ret;
326}
327
328static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
329{
330 struct page *page = bh->b_page;
331 char *addr;
332 __u32 checksum;
333
334 addr = kmap_atomic(page);
335 checksum = crc32_be(crc32_sum,
336 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
337 kunmap_atomic(addr);
338
339 return checksum;
340}
341
342static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
343 unsigned long long block)
344{
345 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
346 if (jbd2_has_feature_64bit(j))
347 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
348}
349
350static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
351 struct buffer_head *bh, __u32 sequence)
352{
353 journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
354 struct page *page = bh->b_page;
355 __u8 *addr;
356 __u32 csum32;
357 __be32 seq;
358
359 if (!jbd2_journal_has_csum_v2or3(j))
360 return;
361
362 seq = cpu_to_be32(sequence);
363 addr = kmap_atomic(page);
364 csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
365 csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
366 bh->b_size);
367 kunmap_atomic(addr);
368
369 if (jbd2_has_feature_csum3(j))
370 tag3->t_checksum = cpu_to_be32(csum32);
371 else
372 tag->t_checksum = cpu_to_be16(csum32);
373}
374/*
375 * jbd2_journal_commit_transaction
376 *
377 * The primary function for committing a transaction to the log. This
378 * function is called by the journal thread to begin a complete commit.
379 */
380void jbd2_journal_commit_transaction(journal_t *journal)
381{
382 struct transaction_stats_s stats;
383 transaction_t *commit_transaction;
384 struct journal_head *jh;
385 struct buffer_head *descriptor;
386 struct buffer_head **wbuf = journal->j_wbuf;
387 int bufs;
388 int flags;
389 int err;
390 unsigned long long blocknr;
391 ktime_t start_time;
392 u64 commit_time;
393 char *tagp = NULL;
394 journal_block_tag_t *tag = NULL;
395 int space_left = 0;
396 int first_tag = 0;
397 int tag_flag;
398 int i;
399 int tag_bytes = journal_tag_bytes(journal);
400 struct buffer_head *cbh = NULL; /* For transactional checksums */
401 __u32 crc32_sum = ~0;
402 struct blk_plug plug;
403 /* Tail of the journal */
404 unsigned long first_block;
405 tid_t first_tid;
406 int update_tail;
407 int csum_size = 0;
408 LIST_HEAD(io_bufs);
409 LIST_HEAD(log_bufs);
410
411 if (jbd2_journal_has_csum_v2or3(journal))
412 csum_size = sizeof(struct jbd2_journal_block_tail);
413
414 /*
415 * First job: lock down the current transaction and wait for
416 * all outstanding updates to complete.
417 */
418
419 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
420 if (journal->j_flags & JBD2_FLUSHED) {
421 jbd2_debug(3, "super block updated\n");
422 mutex_lock_io(&journal->j_checkpoint_mutex);
423 /*
424 * We hold j_checkpoint_mutex so tail cannot change under us.
425 * We don't need any special data guarantees for writing sb
426 * since journal is empty and it is ok for write to be
427 * flushed only with transaction commit.
428 */
429 jbd2_journal_update_sb_log_tail(journal,
430 journal->j_tail_sequence,
431 journal->j_tail,
432 REQ_SYNC);
433 mutex_unlock(&journal->j_checkpoint_mutex);
434 } else {
435 jbd2_debug(3, "superblock not updated\n");
436 }
437
438 J_ASSERT(journal->j_running_transaction != NULL);
439 J_ASSERT(journal->j_committing_transaction == NULL);
440
441 write_lock(&journal->j_state_lock);
442 journal->j_flags |= JBD2_FULL_COMMIT_ONGOING;
443 while (journal->j_flags & JBD2_FAST_COMMIT_ONGOING) {
444 DEFINE_WAIT(wait);
445
446 prepare_to_wait(&journal->j_fc_wait, &wait,
447 TASK_UNINTERRUPTIBLE);
448 write_unlock(&journal->j_state_lock);
449 schedule();
450 write_lock(&journal->j_state_lock);
451 finish_wait(&journal->j_fc_wait, &wait);
452 /*
453 * TODO: by blocking fast commits here, we are increasing
454 * fsync() latency slightly. Strictly speaking, we don't need
455 * to block fast commits until the transaction enters T_FLUSH
456 * state. So an optimization is possible where we block new fast
457 * commits here and wait for existing ones to complete
458 * just before we enter T_FLUSH. That way, the existing fast
459 * commits and this full commit can proceed parallely.
460 */
461 }
462 write_unlock(&journal->j_state_lock);
463
464 commit_transaction = journal->j_running_transaction;
465
466 trace_jbd2_start_commit(journal, commit_transaction);
467 jbd2_debug(1, "JBD2: starting commit of transaction %d\n",
468 commit_transaction->t_tid);
469
470 write_lock(&journal->j_state_lock);
471 journal->j_fc_off = 0;
472 J_ASSERT(commit_transaction->t_state == T_RUNNING);
473 commit_transaction->t_state = T_LOCKED;
474
475 trace_jbd2_commit_locking(journal, commit_transaction);
476 stats.run.rs_wait = commit_transaction->t_max_wait;
477 stats.run.rs_request_delay = 0;
478 stats.run.rs_locked = jiffies;
479 if (commit_transaction->t_requested)
480 stats.run.rs_request_delay =
481 jbd2_time_diff(commit_transaction->t_requested,
482 stats.run.rs_locked);
483 stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
484 stats.run.rs_locked);
485
486 // waits for any t_updates to finish
487 jbd2_journal_wait_updates(journal);
488
489 commit_transaction->t_state = T_SWITCH;
490
491 J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
492 journal->j_max_transaction_buffers);
493
494 /*
495 * First thing we are allowed to do is to discard any remaining
496 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
497 * that there are no such buffers: if a large filesystem
498 * operation like a truncate needs to split itself over multiple
499 * transactions, then it may try to do a jbd2_journal_restart() while
500 * there are still BJ_Reserved buffers outstanding. These must
501 * be released cleanly from the current transaction.
502 *
503 * In this case, the filesystem must still reserve write access
504 * again before modifying the buffer in the new transaction, but
505 * we do not require it to remember exactly which old buffers it
506 * has reserved. This is consistent with the existing behaviour
507 * that multiple jbd2_journal_get_write_access() calls to the same
508 * buffer are perfectly permissible.
509 * We use journal->j_state_lock here to serialize processing of
510 * t_reserved_list with eviction of buffers from journal_unmap_buffer().
511 */
512 while (commit_transaction->t_reserved_list) {
513 jh = commit_transaction->t_reserved_list;
514 JBUFFER_TRACE(jh, "reserved, unused: refile");
515 /*
516 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
517 * leave undo-committed data.
518 */
519 if (jh->b_committed_data) {
520 struct buffer_head *bh = jh2bh(jh);
521
522 spin_lock(&jh->b_state_lock);
523 jbd2_free(jh->b_committed_data, bh->b_size);
524 jh->b_committed_data = NULL;
525 spin_unlock(&jh->b_state_lock);
526 }
527 jbd2_journal_refile_buffer(journal, jh);
528 }
529
530 write_unlock(&journal->j_state_lock);
531 /*
532 * Now try to drop any written-back buffers from the journal's
533 * checkpoint lists. We do this *before* commit because it potentially
534 * frees some memory
535 */
536 spin_lock(&journal->j_list_lock);
537 __jbd2_journal_clean_checkpoint_list(journal, false);
538 spin_unlock(&journal->j_list_lock);
539
540 jbd2_debug(3, "JBD2: commit phase 1\n");
541
542 /*
543 * Clear revoked flag to reflect there is no revoked buffers
544 * in the next transaction which is going to be started.
545 */
546 jbd2_clear_buffer_revoked_flags(journal);
547
548 /*
549 * Switch to a new revoke table.
550 */
551 jbd2_journal_switch_revoke_table(journal);
552
553 write_lock(&journal->j_state_lock);
554 /*
555 * Reserved credits cannot be claimed anymore, free them
556 */
557 atomic_sub(atomic_read(&journal->j_reserved_credits),
558 &commit_transaction->t_outstanding_credits);
559
560 trace_jbd2_commit_flushing(journal, commit_transaction);
561 stats.run.rs_flushing = jiffies;
562 stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
563 stats.run.rs_flushing);
564
565 commit_transaction->t_state = T_FLUSH;
566 journal->j_committing_transaction = commit_transaction;
567 journal->j_running_transaction = NULL;
568 start_time = ktime_get();
569 commit_transaction->t_log_start = journal->j_head;
570 wake_up_all(&journal->j_wait_transaction_locked);
571 write_unlock(&journal->j_state_lock);
572
573 jbd2_debug(3, "JBD2: commit phase 2a\n");
574
575 /*
576 * Now start flushing things to disk, in the order they appear
577 * on the transaction lists. Data blocks go first.
578 */
579 err = journal_submit_data_buffers(journal, commit_transaction);
580 if (err)
581 jbd2_journal_abort(journal, err);
582
583 blk_start_plug(&plug);
584 jbd2_journal_write_revoke_records(commit_transaction, &log_bufs);
585
586 jbd2_debug(3, "JBD2: commit phase 2b\n");
587
588 /*
589 * Way to go: we have now written out all of the data for a
590 * transaction! Now comes the tricky part: we need to write out
591 * metadata. Loop over the transaction's entire buffer list:
592 */
593 write_lock(&journal->j_state_lock);
594 commit_transaction->t_state = T_COMMIT;
595 write_unlock(&journal->j_state_lock);
596
597 trace_jbd2_commit_logging(journal, commit_transaction);
598 stats.run.rs_logging = jiffies;
599 stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
600 stats.run.rs_logging);
601 stats.run.rs_blocks = commit_transaction->t_nr_buffers;
602 stats.run.rs_blocks_logged = 0;
603
604 J_ASSERT(commit_transaction->t_nr_buffers <=
605 atomic_read(&commit_transaction->t_outstanding_credits));
606
607 err = 0;
608 bufs = 0;
609 descriptor = NULL;
610 while (commit_transaction->t_buffers) {
611
612 /* Find the next buffer to be journaled... */
613
614 jh = commit_transaction->t_buffers;
615
616 /* If we're in abort mode, we just un-journal the buffer and
617 release it. */
618
619 if (is_journal_aborted(journal)) {
620 clear_buffer_jbddirty(jh2bh(jh));
621 JBUFFER_TRACE(jh, "journal is aborting: refile");
622 jbd2_buffer_abort_trigger(jh,
623 jh->b_frozen_data ?
624 jh->b_frozen_triggers :
625 jh->b_triggers);
626 jbd2_journal_refile_buffer(journal, jh);
627 /* If that was the last one, we need to clean up
628 * any descriptor buffers which may have been
629 * already allocated, even if we are now
630 * aborting. */
631 if (!commit_transaction->t_buffers)
632 goto start_journal_io;
633 continue;
634 }
635
636 /* Make sure we have a descriptor block in which to
637 record the metadata buffer. */
638
639 if (!descriptor) {
640 J_ASSERT (bufs == 0);
641
642 jbd2_debug(4, "JBD2: get descriptor\n");
643
644 descriptor = jbd2_journal_get_descriptor_buffer(
645 commit_transaction,
646 JBD2_DESCRIPTOR_BLOCK);
647 if (!descriptor) {
648 jbd2_journal_abort(journal, -EIO);
649 continue;
650 }
651
652 jbd2_debug(4, "JBD2: got buffer %llu (%p)\n",
653 (unsigned long long)descriptor->b_blocknr,
654 descriptor->b_data);
655 tagp = &descriptor->b_data[sizeof(journal_header_t)];
656 space_left = descriptor->b_size -
657 sizeof(journal_header_t);
658 first_tag = 1;
659 set_buffer_jwrite(descriptor);
660 set_buffer_dirty(descriptor);
661 wbuf[bufs++] = descriptor;
662
663 /* Record it so that we can wait for IO
664 completion later */
665 BUFFER_TRACE(descriptor, "ph3: file as descriptor");
666 jbd2_file_log_bh(&log_bufs, descriptor);
667 }
668
669 /* Where is the buffer to be written? */
670
671 err = jbd2_journal_next_log_block(journal, &blocknr);
672 /* If the block mapping failed, just abandon the buffer
673 and repeat this loop: we'll fall into the
674 refile-on-abort condition above. */
675 if (err) {
676 jbd2_journal_abort(journal, err);
677 continue;
678 }
679
680 /*
681 * start_this_handle() uses t_outstanding_credits to determine
682 * the free space in the log.
683 */
684 atomic_dec(&commit_transaction->t_outstanding_credits);
685
686 /* Bump b_count to prevent truncate from stumbling over
687 the shadowed buffer! @@@ This can go if we ever get
688 rid of the shadow pairing of buffers. */
689 atomic_inc(&jh2bh(jh)->b_count);
690
691 /*
692 * Make a temporary IO buffer with which to write it out
693 * (this will requeue the metadata buffer to BJ_Shadow).
694 */
695 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
696 JBUFFER_TRACE(jh, "ph3: write metadata");
697 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
698 jh, &wbuf[bufs], blocknr);
699 if (flags < 0) {
700 jbd2_journal_abort(journal, flags);
701 continue;
702 }
703 jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
704
705 /* Record the new block's tag in the current descriptor
706 buffer */
707
708 tag_flag = 0;
709 if (flags & 1)
710 tag_flag |= JBD2_FLAG_ESCAPE;
711 if (!first_tag)
712 tag_flag |= JBD2_FLAG_SAME_UUID;
713
714 tag = (journal_block_tag_t *) tagp;
715 write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
716 tag->t_flags = cpu_to_be16(tag_flag);
717 jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
718 commit_transaction->t_tid);
719 tagp += tag_bytes;
720 space_left -= tag_bytes;
721 bufs++;
722
723 if (first_tag) {
724 memcpy (tagp, journal->j_uuid, 16);
725 tagp += 16;
726 space_left -= 16;
727 first_tag = 0;
728 }
729
730 /* If there's no more to do, or if the descriptor is full,
731 let the IO rip! */
732
733 if (bufs == journal->j_wbufsize ||
734 commit_transaction->t_buffers == NULL ||
735 space_left < tag_bytes + 16 + csum_size) {
736
737 jbd2_debug(4, "JBD2: Submit %d IOs\n", bufs);
738
739 /* Write an end-of-descriptor marker before
740 submitting the IOs. "tag" still points to
741 the last tag we set up. */
742
743 tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG);
744start_journal_io:
745 if (descriptor)
746 jbd2_descriptor_block_csum_set(journal,
747 descriptor);
748
749 for (i = 0; i < bufs; i++) {
750 struct buffer_head *bh = wbuf[i];
751 /*
752 * Compute checksum.
753 */
754 if (jbd2_has_feature_checksum(journal)) {
755 crc32_sum =
756 jbd2_checksum_data(crc32_sum, bh);
757 }
758
759 lock_buffer(bh);
760 clear_buffer_dirty(bh);
761 set_buffer_uptodate(bh);
762 bh->b_end_io = journal_end_buffer_io_sync;
763 submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
764 }
765 cond_resched();
766
767 /* Force a new descriptor to be generated next
768 time round the loop. */
769 descriptor = NULL;
770 bufs = 0;
771 }
772 }
773
774 err = journal_finish_inode_data_buffers(journal, commit_transaction);
775 if (err) {
776 printk(KERN_WARNING
777 "JBD2: Detected IO errors while flushing file data "
778 "on %s\n", journal->j_devname);
779 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
780 jbd2_journal_abort(journal, err);
781 err = 0;
782 }
783
784 /*
785 * Get current oldest transaction in the log before we issue flush
786 * to the filesystem device. After the flush we can be sure that
787 * blocks of all older transactions are checkpointed to persistent
788 * storage and we will be safe to update journal start in the
789 * superblock with the numbers we get here.
790 */
791 update_tail =
792 jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
793
794 write_lock(&journal->j_state_lock);
795 if (update_tail) {
796 long freed = first_block - journal->j_tail;
797
798 if (first_block < journal->j_tail)
799 freed += journal->j_last - journal->j_first;
800 /* Update tail only if we free significant amount of space */
801 if (freed < jbd2_journal_get_max_txn_bufs(journal))
802 update_tail = 0;
803 }
804 J_ASSERT(commit_transaction->t_state == T_COMMIT);
805 commit_transaction->t_state = T_COMMIT_DFLUSH;
806 write_unlock(&journal->j_state_lock);
807
808 /*
809 * If the journal is not located on the file system device,
810 * then we must flush the file system device before we issue
811 * the commit record
812 */
813 if (commit_transaction->t_need_data_flush &&
814 (journal->j_fs_dev != journal->j_dev) &&
815 (journal->j_flags & JBD2_BARRIER))
816 blkdev_issue_flush(journal->j_fs_dev);
817
818 /* Done it all: now write the commit record asynchronously. */
819 if (jbd2_has_feature_async_commit(journal)) {
820 err = journal_submit_commit_record(journal, commit_transaction,
821 &cbh, crc32_sum);
822 if (err)
823 jbd2_journal_abort(journal, err);
824 }
825
826 blk_finish_plug(&plug);
827
828 /* Lo and behold: we have just managed to send a transaction to
829 the log. Before we can commit it, wait for the IO so far to
830 complete. Control buffers being written are on the
831 transaction's t_log_list queue, and metadata buffers are on
832 the io_bufs list.
833
834 Wait for the buffers in reverse order. That way we are
835 less likely to be woken up until all IOs have completed, and
836 so we incur less scheduling load.
837 */
838
839 jbd2_debug(3, "JBD2: commit phase 3\n");
840
841 while (!list_empty(&io_bufs)) {
842 struct buffer_head *bh = list_entry(io_bufs.prev,
843 struct buffer_head,
844 b_assoc_buffers);
845
846 wait_on_buffer(bh);
847 cond_resched();
848
849 if (unlikely(!buffer_uptodate(bh)))
850 err = -EIO;
851 jbd2_unfile_log_bh(bh);
852 stats.run.rs_blocks_logged++;
853
854 /*
855 * The list contains temporary buffer heads created by
856 * jbd2_journal_write_metadata_buffer().
857 */
858 BUFFER_TRACE(bh, "dumping temporary bh");
859 __brelse(bh);
860 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
861 free_buffer_head(bh);
862
863 /* We also have to refile the corresponding shadowed buffer */
864 jh = commit_transaction->t_shadow_list->b_tprev;
865 bh = jh2bh(jh);
866 clear_buffer_jwrite(bh);
867 J_ASSERT_BH(bh, buffer_jbddirty(bh));
868 J_ASSERT_BH(bh, !buffer_shadow(bh));
869
870 /* The metadata is now released for reuse, but we need
871 to remember it against this transaction so that when
872 we finally commit, we can do any checkpointing
873 required. */
874 JBUFFER_TRACE(jh, "file as BJ_Forget");
875 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
876 JBUFFER_TRACE(jh, "brelse shadowed buffer");
877 __brelse(bh);
878 }
879
880 J_ASSERT (commit_transaction->t_shadow_list == NULL);
881
882 jbd2_debug(3, "JBD2: commit phase 4\n");
883
884 /* Here we wait for the revoke record and descriptor record buffers */
885 while (!list_empty(&log_bufs)) {
886 struct buffer_head *bh;
887
888 bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
889 wait_on_buffer(bh);
890 cond_resched();
891
892 if (unlikely(!buffer_uptodate(bh)))
893 err = -EIO;
894
895 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
896 clear_buffer_jwrite(bh);
897 jbd2_unfile_log_bh(bh);
898 stats.run.rs_blocks_logged++;
899 __brelse(bh); /* One for getblk */
900 /* AKPM: bforget here */
901 }
902
903 if (err)
904 jbd2_journal_abort(journal, err);
905
906 jbd2_debug(3, "JBD2: commit phase 5\n");
907 write_lock(&journal->j_state_lock);
908 J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
909 commit_transaction->t_state = T_COMMIT_JFLUSH;
910 write_unlock(&journal->j_state_lock);
911
912 if (!jbd2_has_feature_async_commit(journal)) {
913 err = journal_submit_commit_record(journal, commit_transaction,
914 &cbh, crc32_sum);
915 if (err)
916 jbd2_journal_abort(journal, err);
917 }
918 if (cbh)
919 err = journal_wait_on_commit_record(journal, cbh);
920 stats.run.rs_blocks_logged++;
921 if (jbd2_has_feature_async_commit(journal) &&
922 journal->j_flags & JBD2_BARRIER) {
923 blkdev_issue_flush(journal->j_dev);
924 }
925
926 if (err)
927 jbd2_journal_abort(journal, err);
928
929 WARN_ON_ONCE(
930 atomic_read(&commit_transaction->t_outstanding_credits) < 0);
931
932 /*
933 * Now disk caches for filesystem device are flushed so we are safe to
934 * erase checkpointed transactions from the log by updating journal
935 * superblock.
936 */
937 if (update_tail)
938 jbd2_update_log_tail(journal, first_tid, first_block);
939
940 /* End of a transaction! Finally, we can do checkpoint
941 processing: any buffers committed as a result of this
942 transaction can be removed from any checkpoint list it was on
943 before. */
944
945 jbd2_debug(3, "JBD2: commit phase 6\n");
946
947 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
948 J_ASSERT(commit_transaction->t_buffers == NULL);
949 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
950 J_ASSERT(commit_transaction->t_shadow_list == NULL);
951
952restart_loop:
953 /*
954 * As there are other places (journal_unmap_buffer()) adding buffers
955 * to this list we have to be careful and hold the j_list_lock.
956 */
957 spin_lock(&journal->j_list_lock);
958 while (commit_transaction->t_forget) {
959 transaction_t *cp_transaction;
960 struct buffer_head *bh;
961 int try_to_free = 0;
962 bool drop_ref;
963
964 jh = commit_transaction->t_forget;
965 spin_unlock(&journal->j_list_lock);
966 bh = jh2bh(jh);
967 /*
968 * Get a reference so that bh cannot be freed before we are
969 * done with it.
970 */
971 get_bh(bh);
972 spin_lock(&jh->b_state_lock);
973 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction);
974
975 /*
976 * If there is undo-protected committed data against
977 * this buffer, then we can remove it now. If it is a
978 * buffer needing such protection, the old frozen_data
979 * field now points to a committed version of the
980 * buffer, so rotate that field to the new committed
981 * data.
982 *
983 * Otherwise, we can just throw away the frozen data now.
984 *
985 * We also know that the frozen data has already fired
986 * its triggers if they exist, so we can clear that too.
987 */
988 if (jh->b_committed_data) {
989 jbd2_free(jh->b_committed_data, bh->b_size);
990 jh->b_committed_data = NULL;
991 if (jh->b_frozen_data) {
992 jh->b_committed_data = jh->b_frozen_data;
993 jh->b_frozen_data = NULL;
994 jh->b_frozen_triggers = NULL;
995 }
996 } else if (jh->b_frozen_data) {
997 jbd2_free(jh->b_frozen_data, bh->b_size);
998 jh->b_frozen_data = NULL;
999 jh->b_frozen_triggers = NULL;
1000 }
1001
1002 spin_lock(&journal->j_list_lock);
1003 cp_transaction = jh->b_cp_transaction;
1004 if (cp_transaction) {
1005 JBUFFER_TRACE(jh, "remove from old cp transaction");
1006 cp_transaction->t_chp_stats.cs_dropped++;
1007 __jbd2_journal_remove_checkpoint(jh);
1008 }
1009
1010 /* Only re-checkpoint the buffer_head if it is marked
1011 * dirty. If the buffer was added to the BJ_Forget list
1012 * by jbd2_journal_forget, it may no longer be dirty and
1013 * there's no point in keeping a checkpoint record for
1014 * it. */
1015
1016 /*
1017 * A buffer which has been freed while still being journaled
1018 * by a previous transaction, refile the buffer to BJ_Forget of
1019 * the running transaction. If the just committed transaction
1020 * contains "add to orphan" operation, we can completely
1021 * invalidate the buffer now. We are rather through in that
1022 * since the buffer may be still accessible when blocksize <
1023 * pagesize and it is attached to the last partial page.
1024 */
1025 if (buffer_freed(bh) && !jh->b_next_transaction) {
1026 struct address_space *mapping;
1027
1028 clear_buffer_freed(bh);
1029 clear_buffer_jbddirty(bh);
1030
1031 /*
1032 * Block device buffers need to stay mapped all the
1033 * time, so it is enough to clear buffer_jbddirty and
1034 * buffer_freed bits. For the file mapping buffers (i.e.
1035 * journalled data) we need to unmap buffer and clear
1036 * more bits. We also need to be careful about the check
1037 * because the data page mapping can get cleared under
1038 * our hands. Note that if mapping == NULL, we don't
1039 * need to make buffer unmapped because the page is
1040 * already detached from the mapping and buffers cannot
1041 * get reused.
1042 */
1043 mapping = READ_ONCE(bh->b_page->mapping);
1044 if (mapping && !sb_is_blkdev_sb(mapping->host->i_sb)) {
1045 clear_buffer_mapped(bh);
1046 clear_buffer_new(bh);
1047 clear_buffer_req(bh);
1048 bh->b_bdev = NULL;
1049 }
1050 }
1051
1052 if (buffer_jbddirty(bh)) {
1053 JBUFFER_TRACE(jh, "add to new checkpointing trans");
1054 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
1055 if (is_journal_aborted(journal))
1056 clear_buffer_jbddirty(bh);
1057 } else {
1058 J_ASSERT_BH(bh, !buffer_dirty(bh));
1059 /*
1060 * The buffer on BJ_Forget list and not jbddirty means
1061 * it has been freed by this transaction and hence it
1062 * could not have been reallocated until this
1063 * transaction has committed. *BUT* it could be
1064 * reallocated once we have written all the data to
1065 * disk and before we process the buffer on BJ_Forget
1066 * list.
1067 */
1068 if (!jh->b_next_transaction)
1069 try_to_free = 1;
1070 }
1071 JBUFFER_TRACE(jh, "refile or unfile buffer");
1072 drop_ref = __jbd2_journal_refile_buffer(jh);
1073 spin_unlock(&jh->b_state_lock);
1074 if (drop_ref)
1075 jbd2_journal_put_journal_head(jh);
1076 if (try_to_free)
1077 release_buffer_page(bh); /* Drops bh reference */
1078 else
1079 __brelse(bh);
1080 cond_resched_lock(&journal->j_list_lock);
1081 }
1082 spin_unlock(&journal->j_list_lock);
1083 /*
1084 * This is a bit sleazy. We use j_list_lock to protect transition
1085 * of a transaction into T_FINISHED state and calling
1086 * __jbd2_journal_drop_transaction(). Otherwise we could race with
1087 * other checkpointing code processing the transaction...
1088 */
1089 write_lock(&journal->j_state_lock);
1090 spin_lock(&journal->j_list_lock);
1091 /*
1092 * Now recheck if some buffers did not get attached to the transaction
1093 * while the lock was dropped...
1094 */
1095 if (commit_transaction->t_forget) {
1096 spin_unlock(&journal->j_list_lock);
1097 write_unlock(&journal->j_state_lock);
1098 goto restart_loop;
1099 }
1100
1101 /* Add the transaction to the checkpoint list
1102 * __journal_remove_checkpoint() can not destroy transaction
1103 * under us because it is not marked as T_FINISHED yet */
1104 if (journal->j_checkpoint_transactions == NULL) {
1105 journal->j_checkpoint_transactions = commit_transaction;
1106 commit_transaction->t_cpnext = commit_transaction;
1107 commit_transaction->t_cpprev = commit_transaction;
1108 } else {
1109 commit_transaction->t_cpnext =
1110 journal->j_checkpoint_transactions;
1111 commit_transaction->t_cpprev =
1112 commit_transaction->t_cpnext->t_cpprev;
1113 commit_transaction->t_cpnext->t_cpprev =
1114 commit_transaction;
1115 commit_transaction->t_cpprev->t_cpnext =
1116 commit_transaction;
1117 }
1118 spin_unlock(&journal->j_list_lock);
1119
1120 /* Done with this transaction! */
1121
1122 jbd2_debug(3, "JBD2: commit phase 7\n");
1123
1124 J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
1125
1126 commit_transaction->t_start = jiffies;
1127 stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
1128 commit_transaction->t_start);
1129
1130 /*
1131 * File the transaction statistics
1132 */
1133 stats.ts_tid = commit_transaction->t_tid;
1134 stats.run.rs_handle_count =
1135 atomic_read(&commit_transaction->t_handle_count);
1136 trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
1137 commit_transaction->t_tid, &stats.run);
1138 stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
1139
1140 commit_transaction->t_state = T_COMMIT_CALLBACK;
1141 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1142 journal->j_commit_sequence = commit_transaction->t_tid;
1143 journal->j_committing_transaction = NULL;
1144 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1145
1146 /*
1147 * weight the commit time higher than the average time so we don't
1148 * react too strongly to vast changes in the commit time
1149 */
1150 if (likely(journal->j_average_commit_time))
1151 journal->j_average_commit_time = (commit_time +
1152 journal->j_average_commit_time*3) / 4;
1153 else
1154 journal->j_average_commit_time = commit_time;
1155
1156 write_unlock(&journal->j_state_lock);
1157
1158 if (journal->j_commit_callback)
1159 journal->j_commit_callback(journal, commit_transaction);
1160 if (journal->j_fc_cleanup_callback)
1161 journal->j_fc_cleanup_callback(journal, 1, commit_transaction->t_tid);
1162
1163 trace_jbd2_end_commit(journal, commit_transaction);
1164 jbd2_debug(1, "JBD2: commit %d complete, head %d\n",
1165 journal->j_commit_sequence, journal->j_tail_sequence);
1166
1167 write_lock(&journal->j_state_lock);
1168 journal->j_flags &= ~JBD2_FULL_COMMIT_ONGOING;
1169 journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING;
1170 spin_lock(&journal->j_list_lock);
1171 commit_transaction->t_state = T_FINISHED;
1172 /* Check if the transaction can be dropped now that we are finished */
1173 if (commit_transaction->t_checkpoint_list == NULL &&
1174 commit_transaction->t_checkpoint_io_list == NULL) {
1175 __jbd2_journal_drop_transaction(journal, commit_transaction);
1176 jbd2_journal_free_transaction(commit_transaction);
1177 }
1178 spin_unlock(&journal->j_list_lock);
1179 write_unlock(&journal->j_state_lock);
1180 wake_up(&journal->j_wait_done_commit);
1181 wake_up(&journal->j_fc_wait);
1182
1183 /*
1184 * Calculate overall stats
1185 */
1186 spin_lock(&journal->j_history_lock);
1187 journal->j_stats.ts_tid++;
1188 journal->j_stats.ts_requested += stats.ts_requested;
1189 journal->j_stats.run.rs_wait += stats.run.rs_wait;
1190 journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
1191 journal->j_stats.run.rs_running += stats.run.rs_running;
1192 journal->j_stats.run.rs_locked += stats.run.rs_locked;
1193 journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
1194 journal->j_stats.run.rs_logging += stats.run.rs_logging;
1195 journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
1196 journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
1197 journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
1198 spin_unlock(&journal->j_history_lock);
1199}