1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * linux/fs/jbd2/checkpoint.c
4 *
5 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
6 *
7 * Copyright 1999 Red Hat Software --- All Rights Reserved
8 *
9 * Checkpoint routines for the generic filesystem journaling code.
10 * Part of the ext2fs journaling system.
11 *
12 * Checkpointing is the process of ensuring that a section of the log is
13 * committed fully to disk, so that that portion of the log can be
14 * reused.
15 */
16
17#include <linux/time.h>
18#include <linux/fs.h>
19#include <linux/jbd2.h>
20#include <linux/errno.h>
21#include <linux/slab.h>
22#include <linux/blkdev.h>
23#include <trace/events/jbd2.h>
24
25/*
26 * Unlink a buffer from a transaction checkpoint list.
27 *
28 * Called with j_list_lock held.
29 */
30static inline void __buffer_unlink(struct journal_head *jh)
31{
32 transaction_t *transaction = jh->b_cp_transaction;
33
34 jh->b_cpnext->b_cpprev = jh->b_cpprev;
35 jh->b_cpprev->b_cpnext = jh->b_cpnext;
36 if (transaction->t_checkpoint_list == jh) {
37 transaction->t_checkpoint_list = jh->b_cpnext;
38 if (transaction->t_checkpoint_list == jh)
39 transaction->t_checkpoint_list = NULL;
40 }
41}
42
43/*
44 * __jbd2_log_wait_for_space: wait until there is space in the journal.
45 *
46 * Called under j-state_lock *only*. It will be unlocked if we have to wait
47 * for a checkpoint to free up some space in the log.
48 */
49void __jbd2_log_wait_for_space(journal_t *journal)
50__acquires(&journal->j_state_lock)
51__releases(&journal->j_state_lock)
52{
53 int nblocks, space_left;
54 /* assert_spin_locked(&journal->j_state_lock); */
55
56 nblocks = journal->j_max_transaction_buffers;
57 while (jbd2_log_space_left(journal) < nblocks) {
58 write_unlock(&journal->j_state_lock);
59 mutex_lock_io(lock: &journal->j_checkpoint_mutex);
60
61 /*
62 * Test again, another process may have checkpointed while we
63 * were waiting for the checkpoint lock. If there are no
64 * transactions ready to be checkpointed, try to recover
65 * journal space by calling cleanup_journal_tail(), and if
66 * that doesn't work, by waiting for the currently committing
67 * transaction to complete. If there is absolutely no way
68 * to make progress, this is either a BUG or corrupted
69 * filesystem, so abort the journal and leave a stack
70 * trace for forensic evidence.
71 */
72 write_lock(&journal->j_state_lock);
73 if (journal->j_flags & JBD2_ABORT) {
74 mutex_unlock(lock: &journal->j_checkpoint_mutex);
75 return;
76 }
77 spin_lock(lock: &journal->j_list_lock);
78 space_left = jbd2_log_space_left(journal);
79 if (space_left < nblocks) {
80 int chkpt = journal->j_checkpoint_transactions != NULL;
81 tid_t tid = 0;
82 bool has_transaction = false;
83
84 if (journal->j_committing_transaction) {
85 tid = journal->j_committing_transaction->t_tid;
86 has_transaction = true;
87 }
88 spin_unlock(lock: &journal->j_list_lock);
89 write_unlock(&journal->j_state_lock);
90 if (chkpt) {
91 jbd2_log_do_checkpoint(journal);
92 } else if (jbd2_cleanup_journal_tail(journal) <= 0) {
93 /*
94 * We were able to recover space or the
95 * journal was aborted due to an error.
96 */
97 ;
98 } else if (has_transaction) {
99 /*
100 * jbd2_journal_commit_transaction() may want
101 * to take the checkpoint_mutex if JBD2_FLUSHED
102 * is set. So we need to temporarily drop it.
103 */
104 mutex_unlock(lock: &journal->j_checkpoint_mutex);
105 jbd2_log_wait_commit(journal, tid);
106 write_lock(&journal->j_state_lock);
107 continue;
108 } else {
109 printk(KERN_ERR "%s: needed %d blocks and "
110 "only had %d space available\n",
111 __func__, nblocks, space_left);
112 printk(KERN_ERR "%s: no way to get more "
113 "journal space in %s\n", __func__,
114 journal->j_devname);
115 WARN_ON(1);
116 jbd2_journal_abort(journal, -EIO);
117 }
118 write_lock(&journal->j_state_lock);
119 } else {
120 spin_unlock(lock: &journal->j_list_lock);
121 }
122 mutex_unlock(lock: &journal->j_checkpoint_mutex);
123 }
124}
125
126static void
127__flush_batch(journal_t *journal, int *batch_count)
128{
129 int i;
130 struct blk_plug plug;
131
132 blk_start_plug(&plug);
133 for (i = 0; i < *batch_count; i++)
134 write_dirty_buffer(bh: journal->j_chkpt_bhs[i], JBD2_JOURNAL_REQ_FLAGS);
135 blk_finish_plug(&plug);
136
137 for (i = 0; i < *batch_count; i++) {
138 struct buffer_head *bh = journal->j_chkpt_bhs[i];
139 BUFFER_TRACE(bh, "brelse");
140 __brelse(bh);
141 journal->j_chkpt_bhs[i] = NULL;
142 }
143 *batch_count = 0;
144}
145
146/*
147 * Perform an actual checkpoint. We take the first transaction on the
148 * list of transactions to be checkpointed and send all its buffers
149 * to disk. We submit larger chunks of data at once.
150 *
151 * The journal should be locked before calling this function.
152 * Called with j_checkpoint_mutex held.
153 */
154int jbd2_log_do_checkpoint(journal_t *journal)
155{
156 struct journal_head *jh;
157 struct buffer_head *bh;
158 transaction_t *transaction;
159 tid_t this_tid;
160 int result, batch_count = 0;
161
162 jbd2_debug(1, "Start checkpoint\n");
163
164 /*
165 * First thing: if there are any transactions in the log which
166 * don't need checkpointing, just eliminate them from the
167 * journal straight away.
168 */
169 result = jbd2_cleanup_journal_tail(journal);
170 trace_jbd2_checkpoint(journal, result);
171 jbd2_debug(1, "cleanup_journal_tail returned %d\n", result);
172 if (result <= 0)
173 return result;
174
175 /*
176 * OK, we need to start writing disk blocks. Take one transaction
177 * and write it.
178 */
179 spin_lock(lock: &journal->j_list_lock);
180 if (!journal->j_checkpoint_transactions)
181 goto out;
182 transaction = journal->j_checkpoint_transactions;
183 if (transaction->t_chp_stats.cs_chp_time == 0)
184 transaction->t_chp_stats.cs_chp_time = jiffies;
185 this_tid = transaction->t_tid;
186restart:
187 /*
188 * If someone cleaned up this transaction while we slept, we're
189 * done (maybe it's a new transaction, but it fell at the same
190 * address).
191 */
192 if (journal->j_checkpoint_transactions != transaction ||
193 transaction->t_tid != this_tid)
194 goto out;
195
196 /* checkpoint all of the transaction's buffers */
197 while (transaction->t_checkpoint_list) {
198 jh = transaction->t_checkpoint_list;
199 bh = jh2bh(jh);
200
201 if (jh->b_transaction != NULL) {
202 transaction_t *t = jh->b_transaction;
203 tid_t tid = t->t_tid;
204
205 transaction->t_chp_stats.cs_forced_to_close++;
206 spin_unlock(lock: &journal->j_list_lock);
207 if (unlikely(journal->j_flags & JBD2_UNMOUNT))
208 /*
209 * The journal thread is dead; so
210 * starting and waiting for a commit
211 * to finish will cause us to wait for
212 * a _very_ long time.
213 */
214 printk(KERN_ERR
215 "JBD2: %s: Waiting for Godot: block %llu\n",
216 journal->j_devname, (unsigned long long) bh->b_blocknr);
217
218 if (batch_count)
219 __flush_batch(journal, batch_count: &batch_count);
220 jbd2_log_start_commit(journal, tid);
221 /*
222 * jbd2_journal_commit_transaction() may want
223 * to take the checkpoint_mutex if JBD2_FLUSHED
224 * is set, jbd2_update_log_tail() called by
225 * jbd2_journal_commit_transaction() may also take
226 * checkpoint_mutex. So we need to temporarily
227 * drop it.
228 */
229 mutex_unlock(lock: &journal->j_checkpoint_mutex);
230 jbd2_log_wait_commit(journal, tid);
231 mutex_lock_io(lock: &journal->j_checkpoint_mutex);
232 spin_lock(lock: &journal->j_list_lock);
233 goto restart;
234 }
235 if (!trylock_buffer(bh)) {
236 /*
237 * The buffer is locked, it may be writing back, or
238 * flushing out in the last couple of cycles, or
239 * re-adding into a new transaction, need to check
240 * it again until it's unlocked.
241 */
242 get_bh(bh);
243 spin_unlock(lock: &journal->j_list_lock);
244 wait_on_buffer(bh);
245 /* the journal_head may have gone by now */
246 BUFFER_TRACE(bh, "brelse");
247 __brelse(bh);
248 goto retry;
249 } else if (!buffer_dirty(bh)) {
250 unlock_buffer(bh);
251 BUFFER_TRACE(bh, "remove from checkpoint");
252 /*
253 * If the transaction was released or the checkpoint
254 * list was empty, we're done.
255 */
256 if (__jbd2_journal_remove_checkpoint(jh) ||
257 !transaction->t_checkpoint_list)
258 goto out;
259 } else {
260 unlock_buffer(bh);
261 /*
262 * We are about to write the buffer, it could be
263 * raced by some other transaction shrink or buffer
264 * re-log logic once we release the j_list_lock,
265 * leave it on the checkpoint list and check status
266 * again to make sure it's clean.
267 */
268 BUFFER_TRACE(bh, "queue");
269 get_bh(bh);
270 J_ASSERT_BH(bh, !buffer_jwrite(bh));
271 journal->j_chkpt_bhs[batch_count++] = bh;
272 transaction->t_chp_stats.cs_written++;
273 transaction->t_checkpoint_list = jh->b_cpnext;
274 }
275
276 if ((batch_count == JBD2_NR_BATCH) ||
277 need_resched() || spin_needbreak(lock: &journal->j_list_lock) ||
278 jh2bh(jh: transaction->t_checkpoint_list) == journal->j_chkpt_bhs[0])
279 goto unlock_and_flush;
280 }
281
282 if (batch_count) {
283 unlock_and_flush:
284 spin_unlock(lock: &journal->j_list_lock);
285 retry:
286 if (batch_count)
287 __flush_batch(journal, batch_count: &batch_count);
288 cond_resched();
289 spin_lock(lock: &journal->j_list_lock);
290 goto restart;
291 }
292
293out:
294 spin_unlock(lock: &journal->j_list_lock);
295 result = jbd2_cleanup_journal_tail(journal);
296
297 return (result < 0) ? result : 0;
298}
299
300/*
301 * Check the list of checkpoint transactions for the journal to see if
302 * we have already got rid of any since the last update of the log tail
303 * in the journal superblock. If so, we can instantly roll the
304 * superblock forward to remove those transactions from the log.
305 *
306 * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
307 *
308 * Called with the journal lock held.
309 *
310 * This is the only part of the journaling code which really needs to be
311 * aware of transaction aborts. Checkpointing involves writing to the
312 * main filesystem area rather than to the journal, so it can proceed
313 * even in abort state, but we must not update the super block if
314 * checkpointing may have failed. Otherwise, we would lose some metadata
315 * buffers which should be written-back to the filesystem.
316 */
317
318int jbd2_cleanup_journal_tail(journal_t *journal)
319{
320 tid_t first_tid;
321 unsigned long blocknr;
322
323 if (is_journal_aborted(journal))
324 return -EIO;
325
326 if (!jbd2_journal_get_log_tail(journal, tid: &first_tid, block: &blocknr))
327 return 1;
328 J_ASSERT(blocknr != 0);
329
330 /*
331 * We need to make sure that any blocks that were recently written out
332 * --- perhaps by jbd2_log_do_checkpoint() --- are flushed out before
333 * we drop the transactions from the journal. It's unlikely this will
334 * be necessary, especially with an appropriately sized journal, but we
335 * need this to guarantee correctness. Fortunately
336 * jbd2_cleanup_journal_tail() doesn't get called all that often.
337 */
338 if (journal->j_flags & JBD2_BARRIER)
339 blkdev_issue_flush(bdev: journal->j_fs_dev);
340
341 return __jbd2_update_log_tail(journal, tid: first_tid, block: blocknr);
342}
343
344
345/* Checkpoint list management */
346
347/*
348 * journal_shrink_one_cp_list
349 *
350 * Find all the written-back checkpoint buffers in the given list
351 * and try to release them. If the whole transaction is released, set
352 * the 'released' parameter. Return the number of released checkpointed
353 * buffers.
354 *
355 * Called with j_list_lock held.
356 */
357static unsigned long journal_shrink_one_cp_list(struct journal_head *jh,
358 enum jbd2_shrink_type type,
359 bool *released)
360{
361 struct journal_head *last_jh;
362 struct journal_head *next_jh = jh;
363 unsigned long nr_freed = 0;
364 int ret;
365
366 *released = false;
367 if (!jh)
368 return 0;
369
370 last_jh = jh->b_cpprev;
371 do {
372 jh = next_jh;
373 next_jh = jh->b_cpnext;
374
375 if (type == JBD2_SHRINK_DESTROY) {
376 ret = __jbd2_journal_remove_checkpoint(jh);
377 } else {
378 ret = jbd2_journal_try_remove_checkpoint(jh);
379 if (ret < 0) {
380 if (type == JBD2_SHRINK_BUSY_SKIP)
381 continue;
382 break;
383 }
384 }
385
386 nr_freed++;
387 if (ret) {
388 *released = true;
389 break;
390 }
391
392 if (need_resched())
393 break;
394 } while (jh != last_jh);
395
396 return nr_freed;
397}
398
399/*
400 * jbd2_journal_shrink_checkpoint_list
401 *
402 * Find 'nr_to_scan' written-back checkpoint buffers in the journal
403 * and try to release them. Return the number of released checkpointed
404 * buffers.
405 *
406 * Called with j_list_lock held.
407 */
408unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal,
409 unsigned long *nr_to_scan)
410{
411 transaction_t *transaction, *last_transaction, *next_transaction;
412 bool __maybe_unused released;
413 tid_t first_tid = 0, last_tid = 0, next_tid = 0;
414 tid_t tid = 0;
415 unsigned long nr_freed = 0;
416 unsigned long freed;
417 bool first_set = false;
418
419again:
420 spin_lock(lock: &journal->j_list_lock);
421 if (!journal->j_checkpoint_transactions) {
422 spin_unlock(lock: &journal->j_list_lock);
423 goto out;
424 }
425
426 /*
427 * Get next shrink transaction, resume previous scan or start
428 * over again. If some others do checkpoint and drop transaction
429 * from the checkpoint list, we ignore saved j_shrink_transaction
430 * and start over unconditionally.
431 */
432 if (journal->j_shrink_transaction)
433 transaction = journal->j_shrink_transaction;
434 else
435 transaction = journal->j_checkpoint_transactions;
436
437 if (!first_set) {
438 first_tid = transaction->t_tid;
439 first_set = true;
440 }
441 last_transaction = journal->j_checkpoint_transactions->t_cpprev;
442 next_transaction = transaction;
443 last_tid = last_transaction->t_tid;
444 do {
445 transaction = next_transaction;
446 next_transaction = transaction->t_cpnext;
447 tid = transaction->t_tid;
448
449 freed = journal_shrink_one_cp_list(jh: transaction->t_checkpoint_list,
450 type: JBD2_SHRINK_BUSY_SKIP, released: &released);
451 nr_freed += freed;
452 (*nr_to_scan) -= min(*nr_to_scan, freed);
453 if (*nr_to_scan == 0)
454 break;
455 if (need_resched() || spin_needbreak(lock: &journal->j_list_lock))
456 break;
457 } while (transaction != last_transaction);
458
459 if (transaction != last_transaction) {
460 journal->j_shrink_transaction = next_transaction;
461 next_tid = next_transaction->t_tid;
462 } else {
463 journal->j_shrink_transaction = NULL;
464 next_tid = 0;
465 }
466
467 spin_unlock(lock: &journal->j_list_lock);
468 cond_resched();
469
470 if (*nr_to_scan && journal->j_shrink_transaction)
471 goto again;
472out:
473 trace_jbd2_shrink_checkpoint_list(journal, first_tid, tid, last_tid,
474 nr_freed, next_tid);
475
476 return nr_freed;
477}
478
479/*
480 * journal_clean_checkpoint_list
481 *
482 * Find all the written-back checkpoint buffers in the journal and release them.
483 * If 'type' is JBD2_SHRINK_DESTROY, release all buffers unconditionally. If
484 * 'type' is JBD2_SHRINK_BUSY_STOP, will stop release buffers if encounters a
485 * busy buffer. To avoid wasting CPU cycles scanning the buffer list in some
486 * cases, don't pass JBD2_SHRINK_BUSY_SKIP 'type' for this function.
487 *
488 * Called with j_list_lock held.
489 */
490void __jbd2_journal_clean_checkpoint_list(journal_t *journal,
491 enum jbd2_shrink_type type)
492{
493 transaction_t *transaction, *last_transaction, *next_transaction;
494 bool released;
495
496 WARN_ON_ONCE(type == JBD2_SHRINK_BUSY_SKIP);
497
498 transaction = journal->j_checkpoint_transactions;
499 if (!transaction)
500 return;
501
502 last_transaction = transaction->t_cpprev;
503 next_transaction = transaction;
504 do {
505 transaction = next_transaction;
506 next_transaction = transaction->t_cpnext;
507 journal_shrink_one_cp_list(jh: transaction->t_checkpoint_list,
508 type, released: &released);
509 /*
510 * This function only frees up some memory if possible so we
511 * dont have an obligation to finish processing. Bail out if
512 * preemption requested:
513 */
514 if (need_resched())
515 return;
516 /*
517 * Stop scanning if we couldn't free the transaction. This
518 * avoids pointless scanning of transactions which still
519 * weren't checkpointed.
520 */
521 if (!released)
522 return;
523 } while (transaction != last_transaction);
524}
525
526/*
527 * Remove buffers from all checkpoint lists as journal is aborted and we just
528 * need to free memory
529 */
530void jbd2_journal_destroy_checkpoint(journal_t *journal)
531{
532 /*
533 * We loop because __jbd2_journal_clean_checkpoint_list() may abort
534 * early due to a need of rescheduling.
535 */
536 while (1) {
537 spin_lock(lock: &journal->j_list_lock);
538 if (!journal->j_checkpoint_transactions) {
539 spin_unlock(lock: &journal->j_list_lock);
540 break;
541 }
542 __jbd2_journal_clean_checkpoint_list(journal, type: JBD2_SHRINK_DESTROY);
543 spin_unlock(lock: &journal->j_list_lock);
544 cond_resched();
545 }
546}
547
548/*
549 * journal_remove_checkpoint: called after a buffer has been committed
550 * to disk (either by being write-back flushed to disk, or being
551 * committed to the log).
552 *
553 * We cannot safely clean a transaction out of the log until all of the
554 * buffer updates committed in that transaction have safely been stored
555 * elsewhere on disk. To achieve this, all of the buffers in a
556 * transaction need to be maintained on the transaction's checkpoint
557 * lists until they have been rewritten, at which point this function is
558 * called to remove the buffer from the existing transaction's
559 * checkpoint lists.
560 *
561 * The function returns 1 if it frees the transaction, 0 otherwise.
562 * The function can free jh and bh.
563 *
564 * This function is called with j_list_lock held.
565 */
566int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
567{
568 struct transaction_chp_stats_s *stats;
569 transaction_t *transaction;
570 journal_t *journal;
571
572 JBUFFER_TRACE(jh, "entry");
573
574 transaction = jh->b_cp_transaction;
575 if (!transaction) {
576 JBUFFER_TRACE(jh, "not on transaction");
577 return 0;
578 }
579 journal = transaction->t_journal;
580
581 JBUFFER_TRACE(jh, "removing from transaction");
582
583 __buffer_unlink(jh);
584 jh->b_cp_transaction = NULL;
585 percpu_counter_dec(fbc: &journal->j_checkpoint_jh_count);
586 jbd2_journal_put_journal_head(jh);
587
588 /* Is this transaction empty? */
589 if (transaction->t_checkpoint_list)
590 return 0;
591
592 /*
593 * There is one special case to worry about: if we have just pulled the
594 * buffer off a running or committing transaction's checkpoing list,
595 * then even if the checkpoint list is empty, the transaction obviously
596 * cannot be dropped!
597 *
598 * The locking here around t_state is a bit sleazy.
599 * See the comment at the end of jbd2_journal_commit_transaction().
600 */
601 if (transaction->t_state != T_FINISHED)
602 return 0;
603
604 /*
605 * OK, that was the last buffer for the transaction, we can now
606 * safely remove this transaction from the log.
607 */
608 stats = &transaction->t_chp_stats;
609 if (stats->cs_chp_time)
610 stats->cs_chp_time = jbd2_time_diff(start: stats->cs_chp_time,
611 end: jiffies);
612 trace_jbd2_checkpoint_stats(dev: journal->j_fs_dev->bd_dev,
613 tid: transaction->t_tid, stats);
614
615 __jbd2_journal_drop_transaction(journal, transaction);
616 jbd2_journal_free_transaction(transaction);
617 return 1;
618}
619
620/*
621 * Check the checkpoint buffer and try to remove it from the checkpoint
622 * list if it's clean. Returns -EBUSY if it is not clean, returns 1 if
623 * it frees the transaction, 0 otherwise.
624 *
625 * This function is called with j_list_lock held.
626 */
627int jbd2_journal_try_remove_checkpoint(struct journal_head *jh)
628{
629 struct buffer_head *bh = jh2bh(jh);
630
631 if (jh->b_transaction)
632 return -EBUSY;
633 if (!trylock_buffer(bh))
634 return -EBUSY;
635 if (buffer_dirty(bh)) {
636 unlock_buffer(bh);
637 return -EBUSY;
638 }
639 unlock_buffer(bh);
640
641 /*
642 * Buffer is clean and the IO has finished (we held the buffer
643 * lock) so the checkpoint is done. We can safely remove the
644 * buffer from this transaction.
645 */
646 JBUFFER_TRACE(jh, "remove from checkpoint list");
647 return __jbd2_journal_remove_checkpoint(jh);
648}
649
650/*
651 * journal_insert_checkpoint: put a committed buffer onto a checkpoint
652 * list so that we know when it is safe to clean the transaction out of
653 * the log.
654 *
655 * Called with the journal locked.
656 * Called with j_list_lock held.
657 */
658void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
659 transaction_t *transaction)
660{
661 JBUFFER_TRACE(jh, "entry");
662 J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
663 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
664
665 /* Get reference for checkpointing transaction */
666 jbd2_journal_grab_journal_head(bh: jh2bh(jh));
667 jh->b_cp_transaction = transaction;
668
669 if (!transaction->t_checkpoint_list) {
670 jh->b_cpnext = jh->b_cpprev = jh;
671 } else {
672 jh->b_cpnext = transaction->t_checkpoint_list;
673 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
674 jh->b_cpprev->b_cpnext = jh;
675 jh->b_cpnext->b_cpprev = jh;
676 }
677 transaction->t_checkpoint_list = jh;
678 percpu_counter_inc(fbc: &transaction->t_journal->j_checkpoint_jh_count);
679}
680
681/*
682 * We've finished with this transaction structure: adios...
683 *
684 * The transaction must have no links except for the checkpoint by this
685 * point.
686 *
687 * Called with the journal locked.
688 * Called with j_list_lock held.
689 */
690
691void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
692{
693 assert_spin_locked(&journal->j_list_lock);
694
695 journal->j_shrink_transaction = NULL;
696 if (transaction->t_cpnext) {
697 transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
698 transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
699 if (journal->j_checkpoint_transactions == transaction)
700 journal->j_checkpoint_transactions =
701 transaction->t_cpnext;
702 if (journal->j_checkpoint_transactions == transaction)
703 journal->j_checkpoint_transactions = NULL;
704 }
705
706 J_ASSERT(transaction->t_state == T_FINISHED);
707 J_ASSERT(transaction->t_buffers == NULL);
708 J_ASSERT(transaction->t_forget == NULL);
709 J_ASSERT(transaction->t_shadow_list == NULL);
710 J_ASSERT(transaction->t_checkpoint_list == NULL);
711 J_ASSERT(atomic_read(&transaction->t_updates) == 0);
712 J_ASSERT(journal->j_committing_transaction != transaction);
713 J_ASSERT(journal->j_running_transaction != transaction);
714
715 trace_jbd2_drop_transaction(journal, commit_transaction: transaction);
716
717 jbd2_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
718}
719