conn rcv_lock converted to spinlock, struct cor_sock created, kernel_packet skb_clone...
[cor_2_6_31.git] / fs / jbd2 / checkpoint.c
blob5d70b3e6d49bb105e3c000888c42ec835647add5
1 /*
2 * linux/fs/jbd2/checkpoint.c
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
6 * Copyright 1999 Red Hat Software --- All Rights Reserved
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.
12 * Checkpoint routines for the generic filesystem journaling code.
13 * Part of the ext2fs journaling system.
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.
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 #include <trace/events/jbd2.h>
28 * Unlink a buffer from a transaction checkpoint list.
30 * Called with j_list_lock held.
32 static inline void __buffer_unlink_first(struct journal_head *jh)
34 transaction_t *transaction = jh->b_cp_transaction;
36 jh->b_cpnext->b_cpprev = jh->b_cpprev;
37 jh->b_cpprev->b_cpnext = jh->b_cpnext;
38 if (transaction->t_checkpoint_list == jh) {
39 transaction->t_checkpoint_list = jh->b_cpnext;
40 if (transaction->t_checkpoint_list == jh)
41 transaction->t_checkpoint_list = NULL;
46 * Unlink a buffer from a transaction checkpoint(io) list.
48 * Called with j_list_lock held.
50 static inline void __buffer_unlink(struct journal_head *jh)
52 transaction_t *transaction = jh->b_cp_transaction;
54 __buffer_unlink_first(jh);
55 if (transaction->t_checkpoint_io_list == jh) {
56 transaction->t_checkpoint_io_list = jh->b_cpnext;
57 if (transaction->t_checkpoint_io_list == jh)
58 transaction->t_checkpoint_io_list = NULL;
63 * Move a buffer from the checkpoint list to the checkpoint io list
65 * Called with j_list_lock held
67 static inline void __buffer_relink_io(struct journal_head *jh)
69 transaction_t *transaction = jh->b_cp_transaction;
71 __buffer_unlink_first(jh);
73 if (!transaction->t_checkpoint_io_list) {
74 jh->b_cpnext = jh->b_cpprev = jh;
75 } else {
76 jh->b_cpnext = transaction->t_checkpoint_io_list;
77 jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev;
78 jh->b_cpprev->b_cpnext = jh;
79 jh->b_cpnext->b_cpprev = jh;
81 transaction->t_checkpoint_io_list = jh;
85 * Try to release a checkpointed buffer from its transaction.
86 * Returns 1 if we released it and 2 if we also released the
87 * whole transaction.
89 * Requires j_list_lock
90 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
92 static int __try_to_free_cp_buf(struct journal_head *jh)
94 int ret = 0;
95 struct buffer_head *bh = jh2bh(jh);
97 if (jh->b_jlist == BJ_None && !buffer_locked(bh) &&
98 !buffer_dirty(bh) && !buffer_write_io_error(bh)) {
99 JBUFFER_TRACE(jh, "remove from checkpoint list");
100 ret = __jbd2_journal_remove_checkpoint(jh) + 1;
101 jbd_unlock_bh_state(bh);
102 jbd2_journal_remove_journal_head(bh);
103 BUFFER_TRACE(bh, "release");
104 __brelse(bh);
105 } else {
106 jbd_unlock_bh_state(bh);
108 return ret;
112 * __jbd2_log_wait_for_space: wait until there is space in the journal.
114 * Called under j-state_lock *only*. It will be unlocked if we have to wait
115 * for a checkpoint to free up some space in the log.
117 void __jbd2_log_wait_for_space(journal_t *journal)
119 int nblocks, space_left;
120 assert_spin_locked(&journal->j_state_lock);
122 nblocks = jbd_space_needed(journal);
123 while (__jbd2_log_space_left(journal) < nblocks) {
124 if (journal->j_flags & JBD2_ABORT)
125 return;
126 spin_unlock(&journal->j_state_lock);
127 mutex_lock(&journal->j_checkpoint_mutex);
130 * Test again, another process may have checkpointed while we
131 * were waiting for the checkpoint lock. If there are no
132 * transactions ready to be checkpointed, try to recover
133 * journal space by calling cleanup_journal_tail(), and if
134 * that doesn't work, by waiting for the currently committing
135 * transaction to complete. If there is absolutely no way
136 * to make progress, this is either a BUG or corrupted
137 * filesystem, so abort the journal and leave a stack
138 * trace for forensic evidence.
140 spin_lock(&journal->j_state_lock);
141 spin_lock(&journal->j_list_lock);
142 nblocks = jbd_space_needed(journal);
143 space_left = __jbd2_log_space_left(journal);
144 if (space_left < nblocks) {
145 int chkpt = journal->j_checkpoint_transactions != NULL;
146 tid_t tid = 0;
148 if (journal->j_committing_transaction)
149 tid = journal->j_committing_transaction->t_tid;
150 spin_unlock(&journal->j_list_lock);
151 spin_unlock(&journal->j_state_lock);
152 if (chkpt) {
153 jbd2_log_do_checkpoint(journal);
154 } else if (jbd2_cleanup_journal_tail(journal) == 0) {
155 /* We were able to recover space; yay! */
157 } else if (tid) {
158 jbd2_log_wait_commit(journal, tid);
159 } else {
160 printk(KERN_ERR "%s: needed %d blocks and "
161 "only had %d space available\n",
162 __func__, nblocks, space_left);
163 printk(KERN_ERR "%s: no way to get more "
164 "journal space in %s\n", __func__,
165 journal->j_devname);
166 WARN_ON(1);
167 jbd2_journal_abort(journal, 0);
169 spin_lock(&journal->j_state_lock);
170 } else {
171 spin_unlock(&journal->j_list_lock);
173 mutex_unlock(&journal->j_checkpoint_mutex);
178 * We were unable to perform jbd_trylock_bh_state() inside j_list_lock.
179 * The caller must restart a list walk. Wait for someone else to run
180 * jbd_unlock_bh_state().
182 static void jbd_sync_bh(journal_t *journal, struct buffer_head *bh)
183 __releases(journal->j_list_lock)
185 get_bh(bh);
186 spin_unlock(&journal->j_list_lock);
187 jbd_lock_bh_state(bh);
188 jbd_unlock_bh_state(bh);
189 put_bh(bh);
193 * Clean up transaction's list of buffers submitted for io.
194 * We wait for any pending IO to complete and remove any clean
195 * buffers. Note that we take the buffers in the opposite ordering
196 * from the one in which they were submitted for IO.
198 * Return 0 on success, and return <0 if some buffers have failed
199 * to be written out.
201 * Called with j_list_lock held.
203 static int __wait_cp_io(journal_t *journal, transaction_t *transaction)
205 struct journal_head *jh;
206 struct buffer_head *bh;
207 tid_t this_tid;
208 int released = 0;
209 int ret = 0;
211 this_tid = transaction->t_tid;
212 restart:
213 /* Did somebody clean up the transaction in the meanwhile? */
214 if (journal->j_checkpoint_transactions != transaction ||
215 transaction->t_tid != this_tid)
216 return ret;
217 while (!released && transaction->t_checkpoint_io_list) {
218 jh = transaction->t_checkpoint_io_list;
219 bh = jh2bh(jh);
220 if (!jbd_trylock_bh_state(bh)) {
221 jbd_sync_bh(journal, bh);
222 spin_lock(&journal->j_list_lock);
223 goto restart;
225 if (buffer_locked(bh)) {
226 atomic_inc(&bh->b_count);
227 spin_unlock(&journal->j_list_lock);
228 jbd_unlock_bh_state(bh);
229 wait_on_buffer(bh);
230 /* the journal_head may have gone by now */
231 BUFFER_TRACE(bh, "brelse");
232 __brelse(bh);
233 spin_lock(&journal->j_list_lock);
234 goto restart;
236 if (unlikely(buffer_write_io_error(bh)))
237 ret = -EIO;
240 * Now in whatever state the buffer currently is, we know that
241 * it has been written out and so we can drop it from the list
243 released = __jbd2_journal_remove_checkpoint(jh);
244 jbd_unlock_bh_state(bh);
245 jbd2_journal_remove_journal_head(bh);
246 __brelse(bh);
249 return ret;
252 static void
253 __flush_batch(journal_t *journal, int *batch_count)
255 int i;
257 ll_rw_block(SWRITE, *batch_count, journal->j_chkpt_bhs);
258 for (i = 0; i < *batch_count; i++) {
259 struct buffer_head *bh = journal->j_chkpt_bhs[i];
260 clear_buffer_jwrite(bh);
261 BUFFER_TRACE(bh, "brelse");
262 __brelse(bh);
264 *batch_count = 0;
268 * Try to flush one buffer from the checkpoint list to disk.
270 * Return 1 if something happened which requires us to abort the current
271 * scan of the checkpoint list. Return <0 if the buffer has failed to
272 * be written out.
274 * Called with j_list_lock held and drops it if 1 is returned
275 * Called under jbd_lock_bh_state(jh2bh(jh)), and drops it
277 static int __process_buffer(journal_t *journal, struct journal_head *jh,
278 int *batch_count, transaction_t *transaction)
280 struct buffer_head *bh = jh2bh(jh);
281 int ret = 0;
283 if (buffer_locked(bh)) {
284 atomic_inc(&bh->b_count);
285 spin_unlock(&journal->j_list_lock);
286 jbd_unlock_bh_state(bh);
287 wait_on_buffer(bh);
288 /* the journal_head may have gone by now */
289 BUFFER_TRACE(bh, "brelse");
290 __brelse(bh);
291 ret = 1;
292 } else if (jh->b_transaction != NULL) {
293 transaction_t *t = jh->b_transaction;
294 tid_t tid = t->t_tid;
296 transaction->t_chp_stats.cs_forced_to_close++;
297 spin_unlock(&journal->j_list_lock);
298 jbd_unlock_bh_state(bh);
299 jbd2_log_start_commit(journal, tid);
300 jbd2_log_wait_commit(journal, tid);
301 ret = 1;
302 } else if (!buffer_dirty(bh)) {
303 ret = 1;
304 if (unlikely(buffer_write_io_error(bh)))
305 ret = -EIO;
306 J_ASSERT_JH(jh, !buffer_jbddirty(bh));
307 BUFFER_TRACE(bh, "remove from checkpoint");
308 __jbd2_journal_remove_checkpoint(jh);
309 spin_unlock(&journal->j_list_lock);
310 jbd_unlock_bh_state(bh);
311 jbd2_journal_remove_journal_head(bh);
312 __brelse(bh);
313 } else {
315 * Important: we are about to write the buffer, and
316 * possibly block, while still holding the journal lock.
317 * We cannot afford to let the transaction logic start
318 * messing around with this buffer before we write it to
319 * disk, as that would break recoverability.
321 BUFFER_TRACE(bh, "queue");
322 get_bh(bh);
323 J_ASSERT_BH(bh, !buffer_jwrite(bh));
324 set_buffer_jwrite(bh);
325 journal->j_chkpt_bhs[*batch_count] = bh;
326 __buffer_relink_io(jh);
327 jbd_unlock_bh_state(bh);
328 transaction->t_chp_stats.cs_written++;
329 (*batch_count)++;
330 if (*batch_count == JBD2_NR_BATCH) {
331 spin_unlock(&journal->j_list_lock);
332 __flush_batch(journal, batch_count);
333 ret = 1;
336 return ret;
340 * Perform an actual checkpoint. We take the first transaction on the
341 * list of transactions to be checkpointed and send all its buffers
342 * to disk. We submit larger chunks of data at once.
344 * The journal should be locked before calling this function.
345 * Called with j_checkpoint_mutex held.
347 int jbd2_log_do_checkpoint(journal_t *journal)
349 transaction_t *transaction;
350 tid_t this_tid;
351 int result;
353 jbd_debug(1, "Start checkpoint\n");
356 * First thing: if there are any transactions in the log which
357 * don't need checkpointing, just eliminate them from the
358 * journal straight away.
360 result = jbd2_cleanup_journal_tail(journal);
361 trace_jbd2_checkpoint(journal, result);
362 jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
363 if (result <= 0)
364 return result;
367 * OK, we need to start writing disk blocks. Take one transaction
368 * and write it.
370 result = 0;
371 spin_lock(&journal->j_list_lock);
372 if (!journal->j_checkpoint_transactions)
373 goto out;
374 transaction = journal->j_checkpoint_transactions;
375 if (transaction->t_chp_stats.cs_chp_time == 0)
376 transaction->t_chp_stats.cs_chp_time = jiffies;
377 this_tid = transaction->t_tid;
378 restart:
380 * If someone cleaned up this transaction while we slept, we're
381 * done (maybe it's a new transaction, but it fell at the same
382 * address).
384 if (journal->j_checkpoint_transactions == transaction &&
385 transaction->t_tid == this_tid) {
386 int batch_count = 0;
387 struct journal_head *jh;
388 int retry = 0, err;
390 while (!retry && transaction->t_checkpoint_list) {
391 struct buffer_head *bh;
393 jh = transaction->t_checkpoint_list;
394 bh = jh2bh(jh);
395 if (!jbd_trylock_bh_state(bh)) {
396 jbd_sync_bh(journal, bh);
397 retry = 1;
398 break;
400 retry = __process_buffer(journal, jh, &batch_count,
401 transaction);
402 if (retry < 0 && !result)
403 result = retry;
404 if (!retry && (need_resched() ||
405 spin_needbreak(&journal->j_list_lock))) {
406 spin_unlock(&journal->j_list_lock);
407 retry = 1;
408 break;
412 if (batch_count) {
413 if (!retry) {
414 spin_unlock(&journal->j_list_lock);
415 retry = 1;
417 __flush_batch(journal, &batch_count);
420 if (retry) {
421 spin_lock(&journal->j_list_lock);
422 goto restart;
425 * Now we have cleaned up the first transaction's checkpoint
426 * list. Let's clean up the second one
428 err = __wait_cp_io(journal, transaction);
429 if (!result)
430 result = err;
432 out:
433 spin_unlock(&journal->j_list_lock);
434 if (result < 0)
435 jbd2_journal_abort(journal, result);
436 else
437 result = jbd2_cleanup_journal_tail(journal);
439 return (result < 0) ? result : 0;
443 * Check the list of checkpoint transactions for the journal to see if
444 * we have already got rid of any since the last update of the log tail
445 * in the journal superblock. If so, we can instantly roll the
446 * superblock forward to remove those transactions from the log.
448 * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
450 * Called with the journal lock held.
452 * This is the only part of the journaling code which really needs to be
453 * aware of transaction aborts. Checkpointing involves writing to the
454 * main filesystem area rather than to the journal, so it can proceed
455 * even in abort state, but we must not update the super block if
456 * checkpointing may have failed. Otherwise, we would lose some metadata
457 * buffers which should be written-back to the filesystem.
460 int jbd2_cleanup_journal_tail(journal_t *journal)
462 transaction_t * transaction;
463 tid_t first_tid;
464 unsigned long blocknr, freed;
466 if (is_journal_aborted(journal))
467 return 1;
469 /* OK, work out the oldest transaction remaining in the log, and
470 * the log block it starts at.
472 * If the log is now empty, we need to work out which is the
473 * next transaction ID we will write, and where it will
474 * start. */
476 spin_lock(&journal->j_state_lock);
477 spin_lock(&journal->j_list_lock);
478 transaction = journal->j_checkpoint_transactions;
479 if (transaction) {
480 first_tid = transaction->t_tid;
481 blocknr = transaction->t_log_start;
482 } else if ((transaction = journal->j_committing_transaction) != NULL) {
483 first_tid = transaction->t_tid;
484 blocknr = transaction->t_log_start;
485 } else if ((transaction = journal->j_running_transaction) != NULL) {
486 first_tid = transaction->t_tid;
487 blocknr = journal->j_head;
488 } else {
489 first_tid = journal->j_transaction_sequence;
490 blocknr = journal->j_head;
492 spin_unlock(&journal->j_list_lock);
493 J_ASSERT(blocknr != 0);
495 /* If the oldest pinned transaction is at the tail of the log
496 already then there's not much we can do right now. */
497 if (journal->j_tail_sequence == first_tid) {
498 spin_unlock(&journal->j_state_lock);
499 return 1;
502 /* OK, update the superblock to recover the freed space.
503 * Physical blocks come first: have we wrapped beyond the end of
504 * the log? */
505 freed = blocknr - journal->j_tail;
506 if (blocknr < journal->j_tail)
507 freed = freed + journal->j_last - journal->j_first;
509 jbd_debug(1,
510 "Cleaning journal tail from %d to %d (offset %lu), "
511 "freeing %lu\n",
512 journal->j_tail_sequence, first_tid, blocknr, freed);
514 journal->j_free += freed;
515 journal->j_tail_sequence = first_tid;
516 journal->j_tail = blocknr;
517 spin_unlock(&journal->j_state_lock);
518 if (!(journal->j_flags & JBD2_ABORT))
519 jbd2_journal_update_superblock(journal, 1);
520 return 0;
524 /* Checkpoint list management */
527 * journal_clean_one_cp_list
529 * Find all the written-back checkpoint buffers in the given list and release them.
531 * Called with the journal locked.
532 * Called with j_list_lock held.
533 * Returns number of bufers reaped (for debug)
536 static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
538 struct journal_head *last_jh;
539 struct journal_head *next_jh = jh;
540 int ret, freed = 0;
542 *released = 0;
543 if (!jh)
544 return 0;
546 last_jh = jh->b_cpprev;
547 do {
548 jh = next_jh;
549 next_jh = jh->b_cpnext;
550 /* Use trylock because of the ranking */
551 if (jbd_trylock_bh_state(jh2bh(jh))) {
552 ret = __try_to_free_cp_buf(jh);
553 if (ret) {
554 freed++;
555 if (ret == 2) {
556 *released = 1;
557 return freed;
562 * This function only frees up some memory
563 * if possible so we dont have an obligation
564 * to finish processing. Bail out if preemption
565 * requested:
567 if (need_resched())
568 return freed;
569 } while (jh != last_jh);
571 return freed;
575 * journal_clean_checkpoint_list
577 * Find all the written-back checkpoint buffers in the journal and release them.
579 * Called with the journal locked.
580 * Called with j_list_lock held.
581 * Returns number of buffers reaped (for debug)
584 int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
586 transaction_t *transaction, *last_transaction, *next_transaction;
587 int ret = 0;
588 int released;
590 transaction = journal->j_checkpoint_transactions;
591 if (!transaction)
592 goto out;
594 last_transaction = transaction->t_cpprev;
595 next_transaction = transaction;
596 do {
597 transaction = next_transaction;
598 next_transaction = transaction->t_cpnext;
599 ret += journal_clean_one_cp_list(transaction->
600 t_checkpoint_list, &released);
602 * This function only frees up some memory if possible so we
603 * dont have an obligation to finish processing. Bail out if
604 * preemption requested:
606 if (need_resched())
607 goto out;
608 if (released)
609 continue;
611 * It is essential that we are as careful as in the case of
612 * t_checkpoint_list with removing the buffer from the list as
613 * we can possibly see not yet submitted buffers on io_list
615 ret += journal_clean_one_cp_list(transaction->
616 t_checkpoint_io_list, &released);
617 if (need_resched())
618 goto out;
619 } while (transaction != last_transaction);
620 out:
621 return ret;
625 * journal_remove_checkpoint: called after a buffer has been committed
626 * to disk (either by being write-back flushed to disk, or being
627 * committed to the log).
629 * We cannot safely clean a transaction out of the log until all of the
630 * buffer updates committed in that transaction have safely been stored
631 * elsewhere on disk. To achieve this, all of the buffers in a
632 * transaction need to be maintained on the transaction's checkpoint
633 * lists until they have been rewritten, at which point this function is
634 * called to remove the buffer from the existing transaction's
635 * checkpoint lists.
637 * The function returns 1 if it frees the transaction, 0 otherwise.
639 * This function is called with the journal locked.
640 * This function is called with j_list_lock held.
641 * This function is called with jbd_lock_bh_state(jh2bh(jh))
644 int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
646 transaction_t *transaction;
647 journal_t *journal;
648 int ret = 0;
650 JBUFFER_TRACE(jh, "entry");
652 if ((transaction = jh->b_cp_transaction) == NULL) {
653 JBUFFER_TRACE(jh, "not on transaction");
654 goto out;
656 journal = transaction->t_journal;
658 __buffer_unlink(jh);
659 jh->b_cp_transaction = NULL;
661 if (transaction->t_checkpoint_list != NULL ||
662 transaction->t_checkpoint_io_list != NULL)
663 goto out;
664 JBUFFER_TRACE(jh, "transaction has no more buffers");
667 * There is one special case to worry about: if we have just pulled the
668 * buffer off a running or committing transaction's checkpoing list,
669 * then even if the checkpoint list is empty, the transaction obviously
670 * cannot be dropped!
672 * The locking here around t_state is a bit sleazy.
673 * See the comment at the end of jbd2_journal_commit_transaction().
675 if (transaction->t_state != T_FINISHED) {
676 JBUFFER_TRACE(jh, "belongs to running/committing transaction");
677 goto out;
680 /* OK, that was the last buffer for the transaction: we can now
681 safely remove this transaction from the log */
683 __jbd2_journal_drop_transaction(journal, transaction);
684 kfree(transaction);
686 /* Just in case anybody was waiting for more transactions to be
687 checkpointed... */
688 wake_up(&journal->j_wait_logspace);
689 ret = 1;
690 out:
691 JBUFFER_TRACE(jh, "exit");
692 return ret;
696 * journal_insert_checkpoint: put a committed buffer onto a checkpoint
697 * list so that we know when it is safe to clean the transaction out of
698 * the log.
700 * Called with the journal locked.
701 * Called with j_list_lock held.
703 void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
704 transaction_t *transaction)
706 JBUFFER_TRACE(jh, "entry");
707 J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
708 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
710 jh->b_cp_transaction = transaction;
712 if (!transaction->t_checkpoint_list) {
713 jh->b_cpnext = jh->b_cpprev = jh;
714 } else {
715 jh->b_cpnext = transaction->t_checkpoint_list;
716 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
717 jh->b_cpprev->b_cpnext = jh;
718 jh->b_cpnext->b_cpprev = jh;
720 transaction->t_checkpoint_list = jh;
724 * We've finished with this transaction structure: adios...
726 * The transaction must have no links except for the checkpoint by this
727 * point.
729 * Called with the journal locked.
730 * Called with j_list_lock held.
733 void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
735 assert_spin_locked(&journal->j_list_lock);
736 if (transaction->t_cpnext) {
737 transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
738 transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
739 if (journal->j_checkpoint_transactions == transaction)
740 journal->j_checkpoint_transactions =
741 transaction->t_cpnext;
742 if (journal->j_checkpoint_transactions == transaction)
743 journal->j_checkpoint_transactions = NULL;
746 J_ASSERT(transaction->t_state == T_FINISHED);
747 J_ASSERT(transaction->t_buffers == NULL);
748 J_ASSERT(transaction->t_forget == NULL);
749 J_ASSERT(transaction->t_iobuf_list == NULL);
750 J_ASSERT(transaction->t_shadow_list == NULL);
751 J_ASSERT(transaction->t_log_list == NULL);
752 J_ASSERT(transaction->t_checkpoint_list == NULL);
753 J_ASSERT(transaction->t_checkpoint_io_list == NULL);
754 J_ASSERT(transaction->t_updates == 0);
755 J_ASSERT(journal->j_committing_transaction != transaction);
756 J_ASSERT(journal->j_running_transaction != transaction);
758 jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);