blob: 6914598022ce836e10a13aa8be50aab1ec3bdc74 [file] [log] [blame]
Dave Kleikamp470decc2006-10-11 01:20:57 -07001/*
Uwe Kleine-König58862692007-05-09 07:51:49 +02002 * linux/fs/jbd2/checkpoint.c
Dave Kleikamp470decc2006-10-11 01:20:57 -07003 *
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>
Mingming Caof7f4bcc2006-10-11 01:20:59 -070022#include <linux/jbd2.h>
Dave Kleikamp470decc2006-10-11 01:20:57 -070023#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 */
31static 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 */
49static 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 */
66static 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 */
91static 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");
Mingming Caof7f4bcc2006-10-11 01:20:59 -070098 ret = __jbd2_journal_remove_checkpoint(jh) + 1;
Dave Kleikamp470decc2006-10-11 01:20:57 -070099 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700100 jbd2_journal_remove_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700101 BUFFER_TRACE(bh, "release");
102 __brelse(bh);
103 } else {
104 jbd_unlock_bh_state(bh);
105 }
106 return ret;
107}
108
109/*
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700110 * __jbd2_log_wait_for_space: wait until there is space in the journal.
Dave Kleikamp470decc2006-10-11 01:20:57 -0700111 *
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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700115void __jbd2_log_wait_for_space(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700116{
117 int nblocks;
118 assert_spin_locked(&journal->j_state_lock);
119
120 nblocks = jbd_space_needed(journal);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700121 while (__jbd2_log_space_left(journal) < nblocks) {
122 if (journal->j_flags & JBD2_ABORT)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700123 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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700133 if (__jbd2_log_space_left(journal) < nblocks) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700134 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700135 jbd2_log_do_checkpoint(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700136 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 */
147static 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 */
165static 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;
173restart:
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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700201 released = __jbd2_journal_remove_checkpoint(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700202 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700203 jbd2_journal_remove_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700204 __brelse(bh);
205 }
206}
207
208#define NR_BATCH 64
209
210static 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 */
234static int __process_buffer(journal_t *journal, struct journal_head *jh,
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500235 struct buffer_head **bhs, int *batch_count,
236 transaction_t *transaction)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700237{
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
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500254 transaction->t_chp_stats.cs_forced_to_close++;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700255 spin_unlock(&journal->j_list_lock);
256 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700257 jbd2_log_start_commit(journal, tid);
258 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700259 ret = 1;
260 } else if (!buffer_dirty(bh)) {
261 J_ASSERT_JH(jh, !buffer_jbddirty(bh));
262 BUFFER_TRACE(bh, "remove from checkpoint");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700263 __jbd2_journal_remove_checkpoint(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700264 spin_unlock(&journal->j_list_lock);
265 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700266 jbd2_journal_remove_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700267 __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);
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500284 transaction->t_chp_stats.cs_written++;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700285 (*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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700302int jbd2_log_do_checkpoint(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700303{
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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700315 result = jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700316 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;
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500328 if (transaction->t_chp_stats.cs_chp_time == 0)
329 transaction->t_chp_stats.cs_chp_time = jiffies;
Dave Kleikamp470decc2006-10-11 01:20:57 -0700330 this_tid = transaction->t_tid;
331restart:
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 }
Johann Lombardi8e85fb32008-01-28 23:58:27 -0500354 retry = __process_buffer(journal, jh, bhs, &batch_count,
355 transaction);
Nick Piggin95c354f2008-01-30 13:31:20 +0100356 if (!retry && (need_resched() ||
357 spin_needbreak(&journal->j_list_lock))) {
Dave Kleikamp470decc2006-10-11 01:20:57 -0700358 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 }
382out:
383 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700384 result = jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700385 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700407int jbd2_cleanup_journal_tail(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700408{
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);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700462 if (!(journal->j_flags & JBD2_ABORT))
463 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700464 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
480static 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700528int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700529{
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);
564out:
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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700588int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700589{
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
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500612 * 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!
Dave Kleikamp470decc2006-10-11 01:20:57 -0700615 *
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500616 * The locking here around t_state is a bit sleazy.
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700617 * See the comment at the end of jbd2_journal_commit_transaction().
Dave Kleikamp470decc2006-10-11 01:20:57 -0700618 */
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500619 if (transaction->t_state != T_FINISHED) {
620 JBUFFER_TRACE(jh, "belongs to running/committing transaction");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700621 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700627 __jbd2_journal_drop_transaction(journal, transaction);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700628
629 /* Just in case anybody was waiting for more transactions to be
630 checkpointed... */
631 wake_up(&journal->j_wait_logspace);
632 ret = 1;
633out:
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 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700646void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700647 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
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700676void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700677{
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_sync_datalist == NULL);
692 J_ASSERT(transaction->t_forget == NULL);
693 J_ASSERT(transaction->t_iobuf_list == NULL);
694 J_ASSERT(transaction->t_shadow_list == NULL);
695 J_ASSERT(transaction->t_log_list == NULL);
696 J_ASSERT(transaction->t_checkpoint_list == NULL);
697 J_ASSERT(transaction->t_checkpoint_io_list == NULL);
698 J_ASSERT(transaction->t_updates == 0);
699 J_ASSERT(journal->j_committing_transaction != transaction);
700 J_ASSERT(journal->j_running_transaction != transaction);
701
702 jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
703 kfree(transaction);
704}