ext4: Add ordered mode support for delalloc
[linux-2.6] / fs / jbd2 / checkpoint.c
1 /*
2  * linux/fs/jbd2/checkpoint.c
3  *
4  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
5  *
6  * Copyright 1999 Red Hat Software --- All Rights Reserved
7  *
8  * This file is part of the Linux kernel and is made available under
9  * the terms of the GNU General Public License, version 2, or at your
10  * option, any later version, incorporated herein by reference.
11  *
12  * Checkpoint routines for the generic filesystem journaling code.
13  * Part of the ext2fs journaling system.
14  *
15  * Checkpointing is the process of ensuring that a section of the log is
16  * committed fully to disk, so that that portion of the log can be
17  * reused.
18  */
19
20 #include <linux/time.h>
21 #include <linux/fs.h>
22 #include <linux/jbd2.h>
23 #include <linux/errno.h>
24 #include <linux/slab.h>
25
26 /*
27  * Unlink a buffer from a transaction checkpoint list.
28  *
29  * Called with j_list_lock held.
30  */
31 static inline void __buffer_unlink_first(struct journal_head *jh)
32 {
33         transaction_t *transaction = jh->b_cp_transaction;
34
35         jh->b_cpnext->b_cpprev = jh->b_cpprev;
36         jh->b_cpprev->b_cpnext = jh->b_cpnext;
37         if (transaction->t_checkpoint_list == jh) {
38                 transaction->t_checkpoint_list = jh->b_cpnext;
39                 if (transaction->t_checkpoint_list == jh)
40                         transaction->t_checkpoint_list = NULL;
41         }
42 }
43
44 /*
45  * Unlink a buffer from a transaction checkpoint(io) list.
46  *
47  * Called with j_list_lock held.
48  */
49 static inline void __buffer_unlink(struct journal_head *jh)
50 {
51         transaction_t *transaction = jh->b_cp_transaction;
52
53         __buffer_unlink_first(jh);
54         if (transaction->t_checkpoint_io_list == jh) {
55                 transaction->t_checkpoint_io_list = jh->b_cpnext;
56                 if (transaction->t_checkpoint_io_list == jh)
57                         transaction->t_checkpoint_io_list = NULL;
58         }
59 }
60
61 /*
62  * Move a buffer from the checkpoint list to the checkpoint io list
63  *
64  * Called with j_list_lock held
65  */
66 static inline void __buffer_relink_io(struct journal_head *jh)
67 {
68         transaction_t *transaction = jh->b_cp_transaction;
69
70         __buffer_unlink_first(jh);
71
72         if (!transaction->t_checkpoint_io_list) {
73                 jh->b_cpnext = jh->b_cpprev = jh;
74         } else {
75                 jh->b_cpnext = transaction->t_checkpoint_io_list;
76                 jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev;
77                 jh->b_cpprev->b_cpnext = jh;
78                 jh->b_cpnext->b_cpprev = jh;
79         }
80         transaction->t_checkpoint_io_list = jh;
81 }
82
83 /*
84  * Try to release a checkpointed buffer from its transaction.
85  * Returns 1 if we released it and 2 if we also released the
86  * whole transaction.
87  *
88  * Requires j_list_lock
89  * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
90  */
91 static int __try_to_free_cp_buf(struct journal_head *jh)
92 {
93         int ret = 0;
94         struct buffer_head *bh = jh2bh(jh);
95
96         if (jh->b_jlist == BJ_None && !buffer_locked(bh) && !buffer_dirty(bh)) {
97                 JBUFFER_TRACE(jh, "remove from checkpoint list");
98                 ret = __jbd2_journal_remove_checkpoint(jh) + 1;
99                 jbd_unlock_bh_state(bh);
100                 jbd2_journal_remove_journal_head(bh);
101                 BUFFER_TRACE(bh, "release");
102                 __brelse(bh);
103         } else {
104                 jbd_unlock_bh_state(bh);
105         }
106         return ret;
107 }
108
109 /*
110  * __jbd2_log_wait_for_space: wait until there is space in the journal.
111  *
112  * Called under j-state_lock *only*.  It will be unlocked if we have to wait
113  * for a checkpoint to free up some space in the log.
114  */
115 void __jbd2_log_wait_for_space(journal_t *journal)
116 {
117         int nblocks;
118         assert_spin_locked(&journal->j_state_lock);
119
120         nblocks = jbd_space_needed(journal);
121         while (__jbd2_log_space_left(journal) < nblocks) {
122                 if (journal->j_flags & JBD2_ABORT)
123                         return;
124                 spin_unlock(&journal->j_state_lock);
125                 mutex_lock(&journal->j_checkpoint_mutex);
126
127                 /*
128                  * Test again, another process may have checkpointed while we
129                  * were waiting for the checkpoint lock
130                  */
131                 spin_lock(&journal->j_state_lock);
132                 nblocks = jbd_space_needed(journal);
133                 if (__jbd2_log_space_left(journal) < nblocks) {
134                         spin_unlock(&journal->j_state_lock);
135                         jbd2_log_do_checkpoint(journal);
136                         spin_lock(&journal->j_state_lock);
137                 }
138                 mutex_unlock(&journal->j_checkpoint_mutex);
139         }
140 }
141
142 /*
143  * We were unable to perform jbd_trylock_bh_state() inside j_list_lock.
144  * The caller must restart a list walk.  Wait for someone else to run
145  * jbd_unlock_bh_state().
146  */
147 static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh)
148         __releases(journal->j_list_lock)
149 {
150         get_bh(bh);
151         spin_unlock(&journal->j_list_lock);
152         jbd_lock_bh_state(bh);
153         jbd_unlock_bh_state(bh);
154         put_bh(bh);
155 }
156
157 /*
158  * Clean up transaction's list of buffers submitted for io.
159  * We wait for any pending IO to complete and remove any clean
160  * buffers. Note that we take the buffers in the opposite ordering
161  * from the one in which they were submitted for IO.
162  *
163  * Called with j_list_lock held.
164  */
165 static void __wait_cp_io(journal_t *journal, transaction_t *transaction)
166 {
167         struct journal_head *jh;
168         struct buffer_head *bh;
169         tid_t this_tid;
170         int released = 0;
171
172         this_tid = transaction->t_tid;
173 restart:
174         /* Did somebody clean up the transaction in the meanwhile? */
175         if (journal->j_checkpoint_transactions != transaction ||
176                         transaction->t_tid != this_tid)
177                 return;
178         while (!released && transaction->t_checkpoint_io_list) {
179                 jh = transaction->t_checkpoint_io_list;
180                 bh = jh2bh(jh);
181                 if (!jbd_trylock_bh_state(bh)) {
182                         jbd_sync_bh(journal, bh);
183                         spin_lock(&journal->j_list_lock);
184                         goto restart;
185                 }
186                 if (buffer_locked(bh)) {
187                         atomic_inc(&bh->b_count);
188                         spin_unlock(&journal->j_list_lock);
189                         jbd_unlock_bh_state(bh);
190                         wait_on_buffer(bh);
191                         /* the journal_head may have gone by now */
192                         BUFFER_TRACE(bh, "brelse");
193                         __brelse(bh);
194                         spin_lock(&journal->j_list_lock);
195                         goto restart;
196                 }
197                 /*
198                  * Now in whatever state the buffer currently is, we know that
199                  * it has been written out and so we can drop it from the list
200                  */
201                 released = __jbd2_journal_remove_checkpoint(jh);
202                 jbd_unlock_bh_state(bh);
203                 jbd2_journal_remove_journal_head(bh);
204                 __brelse(bh);
205         }
206 }
207
208 #define NR_BATCH        64
209
210 static void
211 __flush_batch(journal_t *journal, struct buffer_head **bhs, int *batch_count)
212 {
213         int i;
214
215         ll_rw_block(SWRITE, *batch_count, bhs);
216         for (i = 0; i < *batch_count; i++) {
217                 struct buffer_head *bh = bhs[i];
218                 clear_buffer_jwrite(bh);
219                 BUFFER_TRACE(bh, "brelse");
220                 __brelse(bh);
221         }
222         *batch_count = 0;
223 }
224
225 /*
226  * Try to flush one buffer from the checkpoint list to disk.
227  *
228  * Return 1 if something happened which requires us to abort the current
229  * scan of the checkpoint list.
230  *
231  * Called with j_list_lock held and drops it if 1 is returned
232  * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
233  */
234 static int __process_buffer(journal_t *journal, struct journal_head *jh,
235                         struct buffer_head **bhs, int *batch_count,
236                         transaction_t *transaction)
237 {
238         struct buffer_head *bh = jh2bh(jh);
239         int ret = 0;
240
241         if (buffer_locked(bh)) {
242                 atomic_inc(&bh->b_count);
243                 spin_unlock(&journal->j_list_lock);
244                 jbd_unlock_bh_state(bh);
245                 wait_on_buffer(bh);
246                 /* the journal_head may have gone by now */
247                 BUFFER_TRACE(bh, "brelse");
248                 __brelse(bh);
249                 ret = 1;
250         } else if (jh->b_transaction != NULL) {
251                 transaction_t *t = jh->b_transaction;
252                 tid_t tid = t->t_tid;
253
254                 transaction->t_chp_stats.cs_forced_to_close++;
255                 spin_unlock(&journal->j_list_lock);
256                 jbd_unlock_bh_state(bh);
257                 jbd2_log_start_commit(journal, tid);
258                 jbd2_log_wait_commit(journal, tid);
259                 ret = 1;
260         } else if (!buffer_dirty(bh)) {
261                 J_ASSERT_JH(jh, !buffer_jbddirty(bh));
262                 BUFFER_TRACE(bh, "remove from checkpoint");
263                 __jbd2_journal_remove_checkpoint(jh);
264                 spin_unlock(&journal->j_list_lock);
265                 jbd_unlock_bh_state(bh);
266                 jbd2_journal_remove_journal_head(bh);
267                 __brelse(bh);
268                 ret = 1;
269         } else {
270                 /*
271                  * Important: we are about to write the buffer, and
272                  * possibly block, while still holding the journal lock.
273                  * We cannot afford to let the transaction logic start
274                  * messing around with this buffer before we write it to
275                  * disk, as that would break recoverability.
276                  */
277                 BUFFER_TRACE(bh, "queue");
278                 get_bh(bh);
279                 J_ASSERT_BH(bh, !buffer_jwrite(bh));
280                 set_buffer_jwrite(bh);
281                 bhs[*batch_count] = bh;
282                 __buffer_relink_io(jh);
283                 jbd_unlock_bh_state(bh);
284                 transaction->t_chp_stats.cs_written++;
285                 (*batch_count)++;
286                 if (*batch_count == NR_BATCH) {
287                         spin_unlock(&journal->j_list_lock);
288                         __flush_batch(journal, bhs, batch_count);
289                         ret = 1;
290                 }
291         }
292         return ret;
293 }
294
295 /*
296  * Perform an actual checkpoint. We take the first transaction on the
297  * list of transactions to be checkpointed and send all its buffers
298  * to disk. We submit larger chunks of data at once.
299  *
300  * The journal should be locked before calling this function.
301  */
302 int jbd2_log_do_checkpoint(journal_t *journal)
303 {
304         transaction_t *transaction;
305         tid_t this_tid;
306         int result;
307
308         jbd_debug(1, "Start checkpoint\n");
309
310         /*
311          * First thing: if there are any transactions in the log which
312          * don't need checkpointing, just eliminate them from the
313          * journal straight away.
314          */
315         result = jbd2_cleanup_journal_tail(journal);
316         jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
317         if (result <= 0)
318                 return result;
319
320         /*
321          * OK, we need to start writing disk blocks.  Take one transaction
322          * and write it.
323          */
324         spin_lock(&journal->j_list_lock);
325         if (!journal->j_checkpoint_transactions)
326                 goto out;
327         transaction = journal->j_checkpoint_transactions;
328         if (transaction->t_chp_stats.cs_chp_time == 0)
329                 transaction->t_chp_stats.cs_chp_time = jiffies;
330         this_tid = transaction->t_tid;
331 restart:
332         /*
333          * If someone cleaned up this transaction while we slept, we're
334          * done (maybe it's a new transaction, but it fell at the same
335          * address).
336          */
337         if (journal->j_checkpoint_transactions == transaction &&
338                         transaction->t_tid == this_tid) {
339                 int batch_count = 0;
340                 struct buffer_head *bhs[NR_BATCH];
341                 struct journal_head *jh;
342                 int retry = 0;
343
344                 while (!retry && transaction->t_checkpoint_list) {
345                         struct buffer_head *bh;
346
347                         jh = transaction->t_checkpoint_list;
348                         bh = jh2bh(jh);
349                         if (!jbd_trylock_bh_state(bh)) {
350                                 jbd_sync_bh(journal, bh);
351                                 retry = 1;
352                                 break;
353                         }
354                         retry = __process_buffer(journal, jh, bhs, &batch_count,
355                                                  transaction);
356                         if (!retry && (need_resched() ||
357                                 spin_needbreak(&journal->j_list_lock))) {
358                                 spin_unlock(&journal->j_list_lock);
359                                 retry = 1;
360                                 break;
361                         }
362                 }
363
364                 if (batch_count) {
365                         if (!retry) {
366                                 spin_unlock(&journal->j_list_lock);
367                                 retry = 1;
368                         }
369                         __flush_batch(journal, bhs, &batch_count);
370                 }
371
372                 if (retry) {
373                         spin_lock(&journal->j_list_lock);
374                         goto restart;
375                 }
376                 /*
377                  * Now we have cleaned up the first transaction's checkpoint
378                  * list. Let's clean up the second one
379                  */
380                 __wait_cp_io(journal, transaction);
381         }
382 out:
383         spin_unlock(&journal->j_list_lock);
384         result = jbd2_cleanup_journal_tail(journal);
385         if (result < 0)
386                 return result;
387         return 0;
388 }
389
390 /*
391  * Check the list of checkpoint transactions for the journal to see if
392  * we have already got rid of any since the last update of the log tail
393  * in the journal superblock.  If so, we can instantly roll the
394  * superblock forward to remove those transactions from the log.
395  *
396  * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
397  *
398  * Called with the journal lock held.
399  *
400  * This is the only part of the journaling code which really needs to be
401  * aware of transaction aborts.  Checkpointing involves writing to the
402  * main filesystem area rather than to the journal, so it can proceed
403  * even in abort state, but we must not update the journal superblock if
404  * we have an abort error outstanding.
405  */
406
407 int jbd2_cleanup_journal_tail(journal_t *journal)
408 {
409         transaction_t * transaction;
410         tid_t           first_tid;
411         unsigned long   blocknr, freed;
412
413         /* OK, work out the oldest transaction remaining in the log, and
414          * the log block it starts at.
415          *
416          * If the log is now empty, we need to work out which is the
417          * next transaction ID we will write, and where it will
418          * start. */
419
420         spin_lock(&journal->j_state_lock);
421         spin_lock(&journal->j_list_lock);
422         transaction = journal->j_checkpoint_transactions;
423         if (transaction) {
424                 first_tid = transaction->t_tid;
425                 blocknr = transaction->t_log_start;
426         } else if ((transaction = journal->j_committing_transaction) != NULL) {
427                 first_tid = transaction->t_tid;
428                 blocknr = transaction->t_log_start;
429         } else if ((transaction = journal->j_running_transaction) != NULL) {
430                 first_tid = transaction->t_tid;
431                 blocknr = journal->j_head;
432         } else {
433                 first_tid = journal->j_transaction_sequence;
434                 blocknr = journal->j_head;
435         }
436         spin_unlock(&journal->j_list_lock);
437         J_ASSERT(blocknr != 0);
438
439         /* If the oldest pinned transaction is at the tail of the log
440            already then there's not much we can do right now. */
441         if (journal->j_tail_sequence == first_tid) {
442                 spin_unlock(&journal->j_state_lock);
443                 return 1;
444         }
445
446         /* OK, update the superblock to recover the freed space.
447          * Physical blocks come first: have we wrapped beyond the end of
448          * the log?  */
449         freed = blocknr - journal->j_tail;
450         if (blocknr < journal->j_tail)
451                 freed = freed + journal->j_last - journal->j_first;
452
453         jbd_debug(1,
454                   "Cleaning journal tail from %d to %d (offset %lu), "
455                   "freeing %lu\n",
456                   journal->j_tail_sequence, first_tid, blocknr, freed);
457
458         journal->j_free += freed;
459         journal->j_tail_sequence = first_tid;
460         journal->j_tail = blocknr;
461         spin_unlock(&journal->j_state_lock);
462         if (!(journal->j_flags & JBD2_ABORT))
463                 jbd2_journal_update_superblock(journal, 1);
464         return 0;
465 }
466
467
468 /* Checkpoint list management */
469
470 /*
471  * journal_clean_one_cp_list
472  *
473  * Find all the written-back checkpoint buffers in the given list and release them.
474  *
475  * Called with the journal locked.
476  * Called with j_list_lock held.
477  * Returns number of bufers reaped (for debug)
478  */
479
480 static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
481 {
482         struct journal_head *last_jh;
483         struct journal_head *next_jh = jh;
484         int ret, freed = 0;
485
486         *released = 0;
487         if (!jh)
488                 return 0;
489
490         last_jh = jh->b_cpprev;
491         do {
492                 jh = next_jh;
493                 next_jh = jh->b_cpnext;
494                 /* Use trylock because of the ranking */
495                 if (jbd_trylock_bh_state(jh2bh(jh))) {
496                         ret = __try_to_free_cp_buf(jh);
497                         if (ret) {
498                                 freed++;
499                                 if (ret == 2) {
500                                         *released = 1;
501                                         return freed;
502                                 }
503                         }
504                 }
505                 /*
506                  * This function only frees up some memory
507                  * if possible so we dont have an obligation
508                  * to finish processing. Bail out if preemption
509                  * requested:
510                  */
511                 if (need_resched())
512                         return freed;
513         } while (jh != last_jh);
514
515         return freed;
516 }
517
518 /*
519  * journal_clean_checkpoint_list
520  *
521  * Find all the written-back checkpoint buffers in the journal and release them.
522  *
523  * Called with the journal locked.
524  * Called with j_list_lock held.
525  * Returns number of buffers reaped (for debug)
526  */
527
528 int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
529 {
530         transaction_t *transaction, *last_transaction, *next_transaction;
531         int ret = 0;
532         int released;
533
534         transaction = journal->j_checkpoint_transactions;
535         if (!transaction)
536                 goto out;
537
538         last_transaction = transaction->t_cpprev;
539         next_transaction = transaction;
540         do {
541                 transaction = next_transaction;
542                 next_transaction = transaction->t_cpnext;
543                 ret += journal_clean_one_cp_list(transaction->
544                                 t_checkpoint_list, &released);
545                 /*
546                  * This function only frees up some memory if possible so we
547                  * dont have an obligation to finish processing. Bail out if
548                  * preemption requested:
549                  */
550                 if (need_resched())
551                         goto out;
552                 if (released)
553                         continue;
554                 /*
555                  * It is essential that we are as careful as in the case of
556                  * t_checkpoint_list with removing the buffer from the list as
557                  * we can possibly see not yet submitted buffers on io_list
558                  */
559                 ret += journal_clean_one_cp_list(transaction->
560                                 t_checkpoint_io_list, &released);
561                 if (need_resched())
562                         goto out;
563         } while (transaction != last_transaction);
564 out:
565         return ret;
566 }
567
568 /*
569  * journal_remove_checkpoint: called after a buffer has been committed
570  * to disk (either by being write-back flushed to disk, or being
571  * committed to the log).
572  *
573  * We cannot safely clean a transaction out of the log until all of the
574  * buffer updates committed in that transaction have safely been stored
575  * elsewhere on disk.  To achieve this, all of the buffers in a
576  * transaction need to be maintained on the transaction's checkpoint
577  * lists until they have been rewritten, at which point this function is
578  * called to remove the buffer from the existing transaction's
579  * checkpoint lists.
580  *
581  * The function returns 1 if it frees the transaction, 0 otherwise.
582  *
583  * This function is called with the journal locked.
584  * This function is called with j_list_lock held.
585  * This function is called with jbd_lock_bh_state(jh2bh(jh))
586  */
587
588 int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
589 {
590         transaction_t *transaction;
591         journal_t *journal;
592         int ret = 0;
593
594         JBUFFER_TRACE(jh, "entry");
595
596         if ((transaction = jh->b_cp_transaction) == NULL) {
597                 JBUFFER_TRACE(jh, "not on transaction");
598                 goto out;
599         }
600         journal = transaction->t_journal;
601
602         __buffer_unlink(jh);
603         jh->b_cp_transaction = NULL;
604
605         if (transaction->t_checkpoint_list != NULL ||
606             transaction->t_checkpoint_io_list != NULL)
607                 goto out;
608         JBUFFER_TRACE(jh, "transaction has no more buffers");
609
610         /*
611          * There is one special case to worry about: if we have just pulled the
612          * buffer off a running or committing transaction's checkpoing list,
613          * then even if the checkpoint list is empty, the transaction obviously
614          * cannot be dropped!
615          *
616          * The locking here around t_state is a bit sleazy.
617          * See the comment at the end of jbd2_journal_commit_transaction().
618          */
619         if (transaction->t_state != T_FINISHED) {
620                 JBUFFER_TRACE(jh, "belongs to running/committing transaction");
621                 goto out;
622         }
623
624         /* OK, that was the last buffer for the transaction: we can now
625            safely remove this transaction from the log */
626
627         __jbd2_journal_drop_transaction(journal, transaction);
628
629         /* Just in case anybody was waiting for more transactions to be
630            checkpointed... */
631         wake_up(&journal->j_wait_logspace);
632         ret = 1;
633 out:
634         JBUFFER_TRACE(jh, "exit");
635         return ret;
636 }
637
638 /*
639  * journal_insert_checkpoint: put a committed buffer onto a checkpoint
640  * list so that we know when it is safe to clean the transaction out of
641  * the log.
642  *
643  * Called with the journal locked.
644  * Called with j_list_lock held.
645  */
646 void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
647                                transaction_t *transaction)
648 {
649         JBUFFER_TRACE(jh, "entry");
650         J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
651         J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
652
653         jh->b_cp_transaction = transaction;
654
655         if (!transaction->t_checkpoint_list) {
656                 jh->b_cpnext = jh->b_cpprev = jh;
657         } else {
658                 jh->b_cpnext = transaction->t_checkpoint_list;
659                 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
660                 jh->b_cpprev->b_cpnext = jh;
661                 jh->b_cpnext->b_cpprev = jh;
662         }
663         transaction->t_checkpoint_list = jh;
664 }
665
666 /*
667  * We've finished with this transaction structure: adios...
668  *
669  * The transaction must have no links except for the checkpoint by this
670  * point.
671  *
672  * Called with the journal locked.
673  * Called with j_list_lock held.
674  */
675
676 void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
677 {
678         assert_spin_locked(&journal->j_list_lock);
679         if (transaction->t_cpnext) {
680                 transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
681                 transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
682                 if (journal->j_checkpoint_transactions == transaction)
683                         journal->j_checkpoint_transactions =
684                                 transaction->t_cpnext;
685                 if (journal->j_checkpoint_transactions == transaction)
686                         journal->j_checkpoint_transactions = NULL;
687         }
688
689         J_ASSERT(transaction->t_state == T_FINISHED);
690         J_ASSERT(transaction->t_buffers == NULL);
691         J_ASSERT(transaction->t_forget == NULL);
692         J_ASSERT(transaction->t_iobuf_list == NULL);
693         J_ASSERT(transaction->t_shadow_list == NULL);
694         J_ASSERT(transaction->t_log_list == NULL);
695         J_ASSERT(transaction->t_checkpoint_list == NULL);
696         J_ASSERT(transaction->t_checkpoint_io_list == NULL);
697         J_ASSERT(transaction->t_updates == 0);
698         J_ASSERT(journal->j_committing_transaction != transaction);
699         J_ASSERT(journal->j_running_transaction != transaction);
700
701         jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
702         kfree(transaction);
703 }