blob: 7e958c86242f924cf3e2e89c41cbeac04cdbbb75 [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,
235 struct buffer_head **bhs, int *batch_count)
236{
237 struct buffer_head *bh = jh2bh(jh);
238 int ret = 0;
239
240 if (buffer_locked(bh)) {
241 atomic_inc(&bh->b_count);
242 spin_unlock(&journal->j_list_lock);
243 jbd_unlock_bh_state(bh);
244 wait_on_buffer(bh);
245 /* the journal_head may have gone by now */
246 BUFFER_TRACE(bh, "brelse");
247 __brelse(bh);
248 ret = 1;
249 } else if (jh->b_transaction != NULL) {
250 transaction_t *t = jh->b_transaction;
251 tid_t tid = t->t_tid;
252
253 spin_unlock(&journal->j_list_lock);
254 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700255 jbd2_log_start_commit(journal, tid);
256 jbd2_log_wait_commit(journal, tid);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700257 ret = 1;
258 } else if (!buffer_dirty(bh)) {
259 J_ASSERT_JH(jh, !buffer_jbddirty(bh));
260 BUFFER_TRACE(bh, "remove from checkpoint");
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700261 __jbd2_journal_remove_checkpoint(jh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700262 spin_unlock(&journal->j_list_lock);
263 jbd_unlock_bh_state(bh);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700264 jbd2_journal_remove_journal_head(bh);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700265 __brelse(bh);
266 ret = 1;
267 } else {
268 /*
269 * Important: we are about to write the buffer, and
270 * possibly block, while still holding the journal lock.
271 * We cannot afford to let the transaction logic start
272 * messing around with this buffer before we write it to
273 * disk, as that would break recoverability.
274 */
275 BUFFER_TRACE(bh, "queue");
276 get_bh(bh);
277 J_ASSERT_BH(bh, !buffer_jwrite(bh));
278 set_buffer_jwrite(bh);
279 bhs[*batch_count] = bh;
280 __buffer_relink_io(jh);
281 jbd_unlock_bh_state(bh);
282 (*batch_count)++;
283 if (*batch_count == NR_BATCH) {
284 spin_unlock(&journal->j_list_lock);
285 __flush_batch(journal, bhs, batch_count);
286 ret = 1;
287 }
288 }
289 return ret;
290}
291
292/*
293 * Perform an actual checkpoint. We take the first transaction on the
294 * list of transactions to be checkpointed and send all its buffers
295 * to disk. We submit larger chunks of data at once.
296 *
297 * The journal should be locked before calling this function.
298 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700299int jbd2_log_do_checkpoint(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700300{
301 transaction_t *transaction;
302 tid_t this_tid;
303 int result;
304
305 jbd_debug(1, "Start checkpoint\n");
306
307 /*
308 * First thing: if there are any transactions in the log which
309 * don't need checkpointing, just eliminate them from the
310 * journal straight away.
311 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700312 result = jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700313 jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
314 if (result <= 0)
315 return result;
316
317 /*
318 * OK, we need to start writing disk blocks. Take one transaction
319 * and write it.
320 */
321 spin_lock(&journal->j_list_lock);
322 if (!journal->j_checkpoint_transactions)
323 goto out;
324 transaction = journal->j_checkpoint_transactions;
325 this_tid = transaction->t_tid;
326restart:
327 /*
328 * If someone cleaned up this transaction while we slept, we're
329 * done (maybe it's a new transaction, but it fell at the same
330 * address).
331 */
332 if (journal->j_checkpoint_transactions == transaction &&
333 transaction->t_tid == this_tid) {
334 int batch_count = 0;
335 struct buffer_head *bhs[NR_BATCH];
336 struct journal_head *jh;
337 int retry = 0;
338
339 while (!retry && transaction->t_checkpoint_list) {
340 struct buffer_head *bh;
341
342 jh = transaction->t_checkpoint_list;
343 bh = jh2bh(jh);
344 if (!jbd_trylock_bh_state(bh)) {
345 jbd_sync_bh(journal, bh);
346 retry = 1;
347 break;
348 }
349 retry = __process_buffer(journal, jh, bhs,&batch_count);
350 if (!retry && lock_need_resched(&journal->j_list_lock)){
351 spin_unlock(&journal->j_list_lock);
352 retry = 1;
353 break;
354 }
355 }
356
357 if (batch_count) {
358 if (!retry) {
359 spin_unlock(&journal->j_list_lock);
360 retry = 1;
361 }
362 __flush_batch(journal, bhs, &batch_count);
363 }
364
365 if (retry) {
366 spin_lock(&journal->j_list_lock);
367 goto restart;
368 }
369 /*
370 * Now we have cleaned up the first transaction's checkpoint
371 * list. Let's clean up the second one
372 */
373 __wait_cp_io(journal, transaction);
374 }
375out:
376 spin_unlock(&journal->j_list_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700377 result = jbd2_cleanup_journal_tail(journal);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700378 if (result < 0)
379 return result;
380 return 0;
381}
382
383/*
384 * Check the list of checkpoint transactions for the journal to see if
385 * we have already got rid of any since the last update of the log tail
386 * in the journal superblock. If so, we can instantly roll the
387 * superblock forward to remove those transactions from the log.
388 *
389 * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
390 *
391 * Called with the journal lock held.
392 *
393 * This is the only part of the journaling code which really needs to be
394 * aware of transaction aborts. Checkpointing involves writing to the
395 * main filesystem area rather than to the journal, so it can proceed
396 * even in abort state, but we must not update the journal superblock if
397 * we have an abort error outstanding.
398 */
399
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700400int jbd2_cleanup_journal_tail(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700401{
402 transaction_t * transaction;
403 tid_t first_tid;
404 unsigned long blocknr, freed;
405
406 /* OK, work out the oldest transaction remaining in the log, and
407 * the log block it starts at.
408 *
409 * If the log is now empty, we need to work out which is the
410 * next transaction ID we will write, and where it will
411 * start. */
412
413 spin_lock(&journal->j_state_lock);
414 spin_lock(&journal->j_list_lock);
415 transaction = journal->j_checkpoint_transactions;
416 if (transaction) {
417 first_tid = transaction->t_tid;
418 blocknr = transaction->t_log_start;
419 } else if ((transaction = journal->j_committing_transaction) != NULL) {
420 first_tid = transaction->t_tid;
421 blocknr = transaction->t_log_start;
422 } else if ((transaction = journal->j_running_transaction) != NULL) {
423 first_tid = transaction->t_tid;
424 blocknr = journal->j_head;
425 } else {
426 first_tid = journal->j_transaction_sequence;
427 blocknr = journal->j_head;
428 }
429 spin_unlock(&journal->j_list_lock);
430 J_ASSERT(blocknr != 0);
431
432 /* If the oldest pinned transaction is at the tail of the log
433 already then there's not much we can do right now. */
434 if (journal->j_tail_sequence == first_tid) {
435 spin_unlock(&journal->j_state_lock);
436 return 1;
437 }
438
439 /* OK, update the superblock to recover the freed space.
440 * Physical blocks come first: have we wrapped beyond the end of
441 * the log? */
442 freed = blocknr - journal->j_tail;
443 if (blocknr < journal->j_tail)
444 freed = freed + journal->j_last - journal->j_first;
445
446 jbd_debug(1,
447 "Cleaning journal tail from %d to %d (offset %lu), "
448 "freeing %lu\n",
449 journal->j_tail_sequence, first_tid, blocknr, freed);
450
451 journal->j_free += freed;
452 journal->j_tail_sequence = first_tid;
453 journal->j_tail = blocknr;
454 spin_unlock(&journal->j_state_lock);
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700455 if (!(journal->j_flags & JBD2_ABORT))
456 jbd2_journal_update_superblock(journal, 1);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700457 return 0;
458}
459
460
461/* Checkpoint list management */
462
463/*
464 * journal_clean_one_cp_list
465 *
466 * Find all the written-back checkpoint buffers in the given list and release them.
467 *
468 * Called with the journal locked.
469 * Called with j_list_lock held.
470 * Returns number of bufers reaped (for debug)
471 */
472
473static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
474{
475 struct journal_head *last_jh;
476 struct journal_head *next_jh = jh;
477 int ret, freed = 0;
478
479 *released = 0;
480 if (!jh)
481 return 0;
482
483 last_jh = jh->b_cpprev;
484 do {
485 jh = next_jh;
486 next_jh = jh->b_cpnext;
487 /* Use trylock because of the ranking */
488 if (jbd_trylock_bh_state(jh2bh(jh))) {
489 ret = __try_to_free_cp_buf(jh);
490 if (ret) {
491 freed++;
492 if (ret == 2) {
493 *released = 1;
494 return freed;
495 }
496 }
497 }
498 /*
499 * This function only frees up some memory
500 * if possible so we dont have an obligation
501 * to finish processing. Bail out if preemption
502 * requested:
503 */
504 if (need_resched())
505 return freed;
506 } while (jh != last_jh);
507
508 return freed;
509}
510
511/*
512 * journal_clean_checkpoint_list
513 *
514 * Find all the written-back checkpoint buffers in the journal and release them.
515 *
516 * Called with the journal locked.
517 * Called with j_list_lock held.
518 * Returns number of buffers reaped (for debug)
519 */
520
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700521int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700522{
523 transaction_t *transaction, *last_transaction, *next_transaction;
524 int ret = 0;
525 int released;
526
527 transaction = journal->j_checkpoint_transactions;
528 if (!transaction)
529 goto out;
530
531 last_transaction = transaction->t_cpprev;
532 next_transaction = transaction;
533 do {
534 transaction = next_transaction;
535 next_transaction = transaction->t_cpnext;
536 ret += journal_clean_one_cp_list(transaction->
537 t_checkpoint_list, &released);
538 /*
539 * This function only frees up some memory if possible so we
540 * dont have an obligation to finish processing. Bail out if
541 * preemption requested:
542 */
543 if (need_resched())
544 goto out;
545 if (released)
546 continue;
547 /*
548 * It is essential that we are as careful as in the case of
549 * t_checkpoint_list with removing the buffer from the list as
550 * we can possibly see not yet submitted buffers on io_list
551 */
552 ret += journal_clean_one_cp_list(transaction->
553 t_checkpoint_io_list, &released);
554 if (need_resched())
555 goto out;
556 } while (transaction != last_transaction);
557out:
558 return ret;
559}
560
561/*
562 * journal_remove_checkpoint: called after a buffer has been committed
563 * to disk (either by being write-back flushed to disk, or being
564 * committed to the log).
565 *
566 * We cannot safely clean a transaction out of the log until all of the
567 * buffer updates committed in that transaction have safely been stored
568 * elsewhere on disk. To achieve this, all of the buffers in a
569 * transaction need to be maintained on the transaction's checkpoint
570 * lists until they have been rewritten, at which point this function is
571 * called to remove the buffer from the existing transaction's
572 * checkpoint lists.
573 *
574 * The function returns 1 if it frees the transaction, 0 otherwise.
575 *
576 * This function is called with the journal locked.
577 * This function is called with j_list_lock held.
578 * This function is called with jbd_lock_bh_state(jh2bh(jh))
579 */
580
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700581int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700582{
583 transaction_t *transaction;
584 journal_t *journal;
585 int ret = 0;
586
587 JBUFFER_TRACE(jh, "entry");
588
589 if ((transaction = jh->b_cp_transaction) == NULL) {
590 JBUFFER_TRACE(jh, "not on transaction");
591 goto out;
592 }
593 journal = transaction->t_journal;
594
595 __buffer_unlink(jh);
596 jh->b_cp_transaction = NULL;
597
598 if (transaction->t_checkpoint_list != NULL ||
599 transaction->t_checkpoint_io_list != NULL)
600 goto out;
601 JBUFFER_TRACE(jh, "transaction has no more buffers");
602
603 /*
604 * There is one special case to worry about: if we have just pulled the
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500605 * buffer off a running or committing transaction's checkpoing list,
606 * then even if the checkpoint list is empty, the transaction obviously
607 * cannot be dropped!
Dave Kleikamp470decc2006-10-11 01:20:57 -0700608 *
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500609 * The locking here around t_state is a bit sleazy.
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700610 * See the comment at the end of jbd2_journal_commit_transaction().
Dave Kleikamp470decc2006-10-11 01:20:57 -0700611 */
Jan Karaf5a7a6b2008-01-28 23:58:27 -0500612 if (transaction->t_state != T_FINISHED) {
613 JBUFFER_TRACE(jh, "belongs to running/committing transaction");
Dave Kleikamp470decc2006-10-11 01:20:57 -0700614 goto out;
615 }
616
617 /* OK, that was the last buffer for the transaction: we can now
618 safely remove this transaction from the log */
619
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700620 __jbd2_journal_drop_transaction(journal, transaction);
Dave Kleikamp470decc2006-10-11 01:20:57 -0700621
622 /* Just in case anybody was waiting for more transactions to be
623 checkpointed... */
624 wake_up(&journal->j_wait_logspace);
625 ret = 1;
626out:
627 JBUFFER_TRACE(jh, "exit");
628 return ret;
629}
630
631/*
632 * journal_insert_checkpoint: put a committed buffer onto a checkpoint
633 * list so that we know when it is safe to clean the transaction out of
634 * the log.
635 *
636 * Called with the journal locked.
637 * Called with j_list_lock held.
638 */
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700639void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
Dave Kleikamp470decc2006-10-11 01:20:57 -0700640 transaction_t *transaction)
641{
642 JBUFFER_TRACE(jh, "entry");
643 J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
644 J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
645
646 jh->b_cp_transaction = transaction;
647
648 if (!transaction->t_checkpoint_list) {
649 jh->b_cpnext = jh->b_cpprev = jh;
650 } else {
651 jh->b_cpnext = transaction->t_checkpoint_list;
652 jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
653 jh->b_cpprev->b_cpnext = jh;
654 jh->b_cpnext->b_cpprev = jh;
655 }
656 transaction->t_checkpoint_list = jh;
657}
658
659/*
660 * We've finished with this transaction structure: adios...
661 *
662 * The transaction must have no links except for the checkpoint by this
663 * point.
664 *
665 * Called with the journal locked.
666 * Called with j_list_lock held.
667 */
668
Mingming Caof7f4bcc2006-10-11 01:20:59 -0700669void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
Dave Kleikamp470decc2006-10-11 01:20:57 -0700670{
671 assert_spin_locked(&journal->j_list_lock);
672 if (transaction->t_cpnext) {
673 transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
674 transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
675 if (journal->j_checkpoint_transactions == transaction)
676 journal->j_checkpoint_transactions =
677 transaction->t_cpnext;
678 if (journal->j_checkpoint_transactions == transaction)
679 journal->j_checkpoint_transactions = NULL;
680 }
681
682 J_ASSERT(transaction->t_state == T_FINISHED);
683 J_ASSERT(transaction->t_buffers == NULL);
684 J_ASSERT(transaction->t_sync_datalist == NULL);
685 J_ASSERT(transaction->t_forget == NULL);
686 J_ASSERT(transaction->t_iobuf_list == NULL);
687 J_ASSERT(transaction->t_shadow_list == NULL);
688 J_ASSERT(transaction->t_log_list == NULL);
689 J_ASSERT(transaction->t_checkpoint_list == NULL);
690 J_ASSERT(transaction->t_checkpoint_io_list == NULL);
691 J_ASSERT(transaction->t_updates == 0);
692 J_ASSERT(journal->j_committing_transaction != transaction);
693 J_ASSERT(journal->j_running_transaction != transaction);
694
695 jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
696 kfree(transaction);
697}