iwlagn: verify flow id in compressed BA packet
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / jbd / commit.c
blobecb44c94ba8de4251de699bd6e35a317ecee8a85
1 /*
2 * linux/fs/jbd/commit.c
4 * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
6 * Copyright 1998 Red Hat corp --- 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 * Journal commit routines for the generic filesystem journaling code;
13 * part of the ext2fs journaling system.
16 #include <linux/time.h>
17 #include <linux/fs.h>
18 #include <linux/jbd.h>
19 #include <linux/errno.h>
20 #include <linux/mm.h>
21 #include <linux/pagemap.h>
22 #include <linux/bio.h>
25 * Default IO end handler for temporary BJ_IO buffer_heads.
27 static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
29 BUFFER_TRACE(bh, "");
30 if (uptodate)
31 set_buffer_uptodate(bh);
32 else
33 clear_buffer_uptodate(bh);
34 unlock_buffer(bh);
38 * When an ext3-ordered file is truncated, it is possible that many pages are
39 * not successfully freed, because they are attached to a committing transaction.
40 * After the transaction commits, these pages are left on the LRU, with no
41 * ->mapping, and with attached buffers. These pages are trivially reclaimable
42 * by the VM, but their apparent absence upsets the VM accounting, and it makes
43 * the numbers in /proc/meminfo look odd.
45 * So here, we have a buffer which has just come off the forget list. Look to
46 * see if we can strip all buffers from the backing page.
48 * Called under journal->j_list_lock. The caller provided us with a ref
49 * against the buffer, and we drop that here.
51 static void release_buffer_page(struct buffer_head *bh)
53 struct page *page;
55 if (buffer_dirty(bh))
56 goto nope;
57 if (atomic_read(&bh->b_count) != 1)
58 goto nope;
59 page = bh->b_page;
60 if (!page)
61 goto nope;
62 if (page->mapping)
63 goto nope;
65 /* OK, it's a truncated page */
66 if (!trylock_page(page))
67 goto nope;
69 page_cache_get(page);
70 __brelse(bh);
71 try_to_free_buffers(page);
72 unlock_page(page);
73 page_cache_release(page);
74 return;
76 nope:
77 __brelse(bh);
81 * Decrement reference counter for data buffer. If it has been marked
82 * 'BH_Freed', release it and the page to which it belongs if possible.
84 static void release_data_buffer(struct buffer_head *bh)
86 if (buffer_freed(bh)) {
87 clear_buffer_freed(bh);
88 release_buffer_page(bh);
89 } else
90 put_bh(bh);
94 * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
95 * held. For ranking reasons we must trylock. If we lose, schedule away and
96 * return 0. j_list_lock is dropped in this case.
98 static int inverted_lock(journal_t *journal, struct buffer_head *bh)
100 if (!jbd_trylock_bh_state(bh)) {
101 spin_unlock(&journal->j_list_lock);
102 schedule();
103 return 0;
105 return 1;
108 /* Done it all: now write the commit record. We should have
109 * cleaned up our previous buffers by now, so if we are in abort
110 * mode we can now just skip the rest of the journal write
111 * entirely.
113 * Returns 1 if the journal needs to be aborted or 0 on success
115 static int journal_write_commit_record(journal_t *journal,
116 transaction_t *commit_transaction)
118 struct journal_head *descriptor;
119 struct buffer_head *bh;
120 journal_header_t *header;
121 int ret;
122 int barrier_done = 0;
124 if (is_journal_aborted(journal))
125 return 0;
127 descriptor = journal_get_descriptor_buffer(journal);
128 if (!descriptor)
129 return 1;
131 bh = jh2bh(descriptor);
133 header = (journal_header_t *)(bh->b_data);
134 header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
135 header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK);
136 header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
138 JBUFFER_TRACE(descriptor, "write commit block");
139 set_buffer_dirty(bh);
140 if (journal->j_flags & JFS_BARRIER) {
141 set_buffer_ordered(bh);
142 barrier_done = 1;
144 ret = sync_dirty_buffer(bh);
145 if (barrier_done)
146 clear_buffer_ordered(bh);
147 /* is it possible for another commit to fail at roughly
148 * the same time as this one? If so, we don't want to
149 * trust the barrier flag in the super, but instead want
150 * to remember if we sent a barrier request
152 if (ret == -EOPNOTSUPP && barrier_done) {
153 char b[BDEVNAME_SIZE];
155 printk(KERN_WARNING
156 "JBD: barrier-based sync failed on %s - "
157 "disabling barriers\n",
158 bdevname(journal->j_dev, b));
159 spin_lock(&journal->j_state_lock);
160 journal->j_flags &= ~JFS_BARRIER;
161 spin_unlock(&journal->j_state_lock);
163 /* And try again, without the barrier */
164 set_buffer_uptodate(bh);
165 set_buffer_dirty(bh);
166 ret = sync_dirty_buffer(bh);
168 put_bh(bh); /* One for getblk() */
169 journal_put_journal_head(descriptor);
171 return (ret == -EIO);
174 static void journal_do_submit_data(struct buffer_head **wbuf, int bufs,
175 int write_op)
177 int i;
179 for (i = 0; i < bufs; i++) {
180 wbuf[i]->b_end_io = end_buffer_write_sync;
181 /* We use-up our safety reference in submit_bh() */
182 submit_bh(write_op, wbuf[i]);
187 * Submit all the data buffers to disk
189 static int journal_submit_data_buffers(journal_t *journal,
190 transaction_t *commit_transaction,
191 int write_op)
193 struct journal_head *jh;
194 struct buffer_head *bh;
195 int locked;
196 int bufs = 0;
197 struct buffer_head **wbuf = journal->j_wbuf;
198 int err = 0;
201 * Whenever we unlock the journal and sleep, things can get added
202 * onto ->t_sync_datalist, so we have to keep looping back to
203 * write_out_data until we *know* that the list is empty.
205 * Cleanup any flushed data buffers from the data list. Even in
206 * abort mode, we want to flush this out as soon as possible.
208 write_out_data:
209 cond_resched();
210 spin_lock(&journal->j_list_lock);
212 while (commit_transaction->t_sync_datalist) {
213 jh = commit_transaction->t_sync_datalist;
214 bh = jh2bh(jh);
215 locked = 0;
217 /* Get reference just to make sure buffer does not disappear
218 * when we are forced to drop various locks */
219 get_bh(bh);
220 /* If the buffer is dirty, we need to submit IO and hence
221 * we need the buffer lock. We try to lock the buffer without
222 * blocking. If we fail, we need to drop j_list_lock and do
223 * blocking lock_buffer().
225 if (buffer_dirty(bh)) {
226 if (!trylock_buffer(bh)) {
227 BUFFER_TRACE(bh, "needs blocking lock");
228 spin_unlock(&journal->j_list_lock);
229 /* Write out all data to prevent deadlocks */
230 journal_do_submit_data(wbuf, bufs, write_op);
231 bufs = 0;
232 lock_buffer(bh);
233 spin_lock(&journal->j_list_lock);
235 locked = 1;
237 /* We have to get bh_state lock. Again out of order, sigh. */
238 if (!inverted_lock(journal, bh)) {
239 jbd_lock_bh_state(bh);
240 spin_lock(&journal->j_list_lock);
242 /* Someone already cleaned up the buffer? */
243 if (!buffer_jbd(bh) || bh2jh(bh) != jh
244 || jh->b_transaction != commit_transaction
245 || jh->b_jlist != BJ_SyncData) {
246 jbd_unlock_bh_state(bh);
247 if (locked)
248 unlock_buffer(bh);
249 BUFFER_TRACE(bh, "already cleaned up");
250 release_data_buffer(bh);
251 continue;
253 if (locked && test_clear_buffer_dirty(bh)) {
254 BUFFER_TRACE(bh, "needs writeout, adding to array");
255 wbuf[bufs++] = bh;
256 __journal_file_buffer(jh, commit_transaction,
257 BJ_Locked);
258 jbd_unlock_bh_state(bh);
259 if (bufs == journal->j_wbufsize) {
260 spin_unlock(&journal->j_list_lock);
261 journal_do_submit_data(wbuf, bufs, write_op);
262 bufs = 0;
263 goto write_out_data;
265 } else if (!locked && buffer_locked(bh)) {
266 __journal_file_buffer(jh, commit_transaction,
267 BJ_Locked);
268 jbd_unlock_bh_state(bh);
269 put_bh(bh);
270 } else {
271 BUFFER_TRACE(bh, "writeout complete: unfile");
272 if (unlikely(!buffer_uptodate(bh)))
273 err = -EIO;
274 __journal_unfile_buffer(jh);
275 jbd_unlock_bh_state(bh);
276 if (locked)
277 unlock_buffer(bh);
278 journal_remove_journal_head(bh);
279 /* One for our safety reference, other for
280 * journal_remove_journal_head() */
281 put_bh(bh);
282 release_data_buffer(bh);
285 if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
286 spin_unlock(&journal->j_list_lock);
287 goto write_out_data;
290 spin_unlock(&journal->j_list_lock);
291 journal_do_submit_data(wbuf, bufs, write_op);
293 return err;
297 * journal_commit_transaction
299 * The primary function for committing a transaction to the log. This
300 * function is called by the journal thread to begin a complete commit.
302 void journal_commit_transaction(journal_t *journal)
304 transaction_t *commit_transaction;
305 struct journal_head *jh, *new_jh, *descriptor;
306 struct buffer_head **wbuf = journal->j_wbuf;
307 int bufs;
308 int flags;
309 int err;
310 unsigned int blocknr;
311 ktime_t start_time;
312 u64 commit_time;
313 char *tagp = NULL;
314 journal_header_t *header;
315 journal_block_tag_t *tag = NULL;
316 int space_left = 0;
317 int first_tag = 0;
318 int tag_flag;
319 int i;
320 int write_op = WRITE;
323 * First job: lock down the current transaction and wait for
324 * all outstanding updates to complete.
327 #ifdef COMMIT_STATS
328 spin_lock(&journal->j_list_lock);
329 summarise_journal_usage(journal);
330 spin_unlock(&journal->j_list_lock);
331 #endif
333 /* Do we need to erase the effects of a prior journal_flush? */
334 if (journal->j_flags & JFS_FLUSHED) {
335 jbd_debug(3, "super block updated\n");
336 journal_update_superblock(journal, 1);
337 } else {
338 jbd_debug(3, "superblock not updated\n");
341 J_ASSERT(journal->j_running_transaction != NULL);
342 J_ASSERT(journal->j_committing_transaction == NULL);
344 commit_transaction = journal->j_running_transaction;
345 J_ASSERT(commit_transaction->t_state == T_RUNNING);
347 jbd_debug(1, "JBD: starting commit of transaction %d\n",
348 commit_transaction->t_tid);
350 spin_lock(&journal->j_state_lock);
351 commit_transaction->t_state = T_LOCKED;
354 * Use plugged writes here, since we want to submit several before
355 * we unplug the device. We don't do explicit unplugging in here,
356 * instead we rely on sync_buffer() doing the unplug for us.
358 if (commit_transaction->t_synchronous_commit)
359 write_op = WRITE_SYNC_PLUG;
360 spin_lock(&commit_transaction->t_handle_lock);
361 while (commit_transaction->t_updates) {
362 DEFINE_WAIT(wait);
364 prepare_to_wait(&journal->j_wait_updates, &wait,
365 TASK_UNINTERRUPTIBLE);
366 if (commit_transaction->t_updates) {
367 spin_unlock(&commit_transaction->t_handle_lock);
368 spin_unlock(&journal->j_state_lock);
369 schedule();
370 spin_lock(&journal->j_state_lock);
371 spin_lock(&commit_transaction->t_handle_lock);
373 finish_wait(&journal->j_wait_updates, &wait);
375 spin_unlock(&commit_transaction->t_handle_lock);
377 J_ASSERT (commit_transaction->t_outstanding_credits <=
378 journal->j_max_transaction_buffers);
381 * First thing we are allowed to do is to discard any remaining
382 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
383 * that there are no such buffers: if a large filesystem
384 * operation like a truncate needs to split itself over multiple
385 * transactions, then it may try to do a journal_restart() while
386 * there are still BJ_Reserved buffers outstanding. These must
387 * be released cleanly from the current transaction.
389 * In this case, the filesystem must still reserve write access
390 * again before modifying the buffer in the new transaction, but
391 * we do not require it to remember exactly which old buffers it
392 * has reserved. This is consistent with the existing behaviour
393 * that multiple journal_get_write_access() calls to the same
394 * buffer are perfectly permissable.
396 while (commit_transaction->t_reserved_list) {
397 jh = commit_transaction->t_reserved_list;
398 JBUFFER_TRACE(jh, "reserved, unused: refile");
400 * A journal_get_undo_access()+journal_release_buffer() may
401 * leave undo-committed data.
403 if (jh->b_committed_data) {
404 struct buffer_head *bh = jh2bh(jh);
406 jbd_lock_bh_state(bh);
407 jbd_free(jh->b_committed_data, bh->b_size);
408 jh->b_committed_data = NULL;
409 jbd_unlock_bh_state(bh);
411 journal_refile_buffer(journal, jh);
415 * Now try to drop any written-back buffers from the journal's
416 * checkpoint lists. We do this *before* commit because it potentially
417 * frees some memory
419 spin_lock(&journal->j_list_lock);
420 __journal_clean_checkpoint_list(journal);
421 spin_unlock(&journal->j_list_lock);
423 jbd_debug (3, "JBD: commit phase 1\n");
426 * Switch to a new revoke table.
428 journal_switch_revoke_table(journal);
430 commit_transaction->t_state = T_FLUSH;
431 journal->j_committing_transaction = commit_transaction;
432 journal->j_running_transaction = NULL;
433 start_time = ktime_get();
434 commit_transaction->t_log_start = journal->j_head;
435 wake_up(&journal->j_wait_transaction_locked);
436 spin_unlock(&journal->j_state_lock);
438 jbd_debug (3, "JBD: commit phase 2\n");
441 * Now start flushing things to disk, in the order they appear
442 * on the transaction lists. Data blocks go first.
444 err = journal_submit_data_buffers(journal, commit_transaction,
445 write_op);
448 * Wait for all previously submitted IO to complete.
450 spin_lock(&journal->j_list_lock);
451 while (commit_transaction->t_locked_list) {
452 struct buffer_head *bh;
454 jh = commit_transaction->t_locked_list->b_tprev;
455 bh = jh2bh(jh);
456 get_bh(bh);
457 if (buffer_locked(bh)) {
458 spin_unlock(&journal->j_list_lock);
459 wait_on_buffer(bh);
460 spin_lock(&journal->j_list_lock);
462 if (unlikely(!buffer_uptodate(bh))) {
463 if (!trylock_page(bh->b_page)) {
464 spin_unlock(&journal->j_list_lock);
465 lock_page(bh->b_page);
466 spin_lock(&journal->j_list_lock);
468 if (bh->b_page->mapping)
469 set_bit(AS_EIO, &bh->b_page->mapping->flags);
471 unlock_page(bh->b_page);
472 SetPageError(bh->b_page);
473 err = -EIO;
475 if (!inverted_lock(journal, bh)) {
476 put_bh(bh);
477 spin_lock(&journal->j_list_lock);
478 continue;
480 if (buffer_jbd(bh) && bh2jh(bh) == jh &&
481 jh->b_transaction == commit_transaction &&
482 jh->b_jlist == BJ_Locked) {
483 __journal_unfile_buffer(jh);
484 jbd_unlock_bh_state(bh);
485 journal_remove_journal_head(bh);
486 put_bh(bh);
487 } else {
488 jbd_unlock_bh_state(bh);
490 release_data_buffer(bh);
491 cond_resched_lock(&journal->j_list_lock);
493 spin_unlock(&journal->j_list_lock);
495 if (err) {
496 char b[BDEVNAME_SIZE];
498 printk(KERN_WARNING
499 "JBD: Detected IO errors while flushing file data "
500 "on %s\n", bdevname(journal->j_fs_dev, b));
501 if (journal->j_flags & JFS_ABORT_ON_SYNCDATA_ERR)
502 journal_abort(journal, err);
503 err = 0;
506 journal_write_revoke_records(journal, commit_transaction, write_op);
509 * If we found any dirty or locked buffers, then we should have
510 * looped back up to the write_out_data label. If there weren't
511 * any then journal_clean_data_list should have wiped the list
512 * clean by now, so check that it is in fact empty.
514 J_ASSERT (commit_transaction->t_sync_datalist == NULL);
516 jbd_debug (3, "JBD: commit phase 3\n");
519 * Way to go: we have now written out all of the data for a
520 * transaction! Now comes the tricky part: we need to write out
521 * metadata. Loop over the transaction's entire buffer list:
523 spin_lock(&journal->j_state_lock);
524 commit_transaction->t_state = T_COMMIT;
525 spin_unlock(&journal->j_state_lock);
527 J_ASSERT(commit_transaction->t_nr_buffers <=
528 commit_transaction->t_outstanding_credits);
530 descriptor = NULL;
531 bufs = 0;
532 while (commit_transaction->t_buffers) {
534 /* Find the next buffer to be journaled... */
536 jh = commit_transaction->t_buffers;
538 /* If we're in abort mode, we just un-journal the buffer and
539 release it. */
541 if (is_journal_aborted(journal)) {
542 clear_buffer_jbddirty(jh2bh(jh));
543 JBUFFER_TRACE(jh, "journal is aborting: refile");
544 journal_refile_buffer(journal, jh);
545 /* If that was the last one, we need to clean up
546 * any descriptor buffers which may have been
547 * already allocated, even if we are now
548 * aborting. */
549 if (!commit_transaction->t_buffers)
550 goto start_journal_io;
551 continue;
554 /* Make sure we have a descriptor block in which to
555 record the metadata buffer. */
557 if (!descriptor) {
558 struct buffer_head *bh;
560 J_ASSERT (bufs == 0);
562 jbd_debug(4, "JBD: get descriptor\n");
564 descriptor = journal_get_descriptor_buffer(journal);
565 if (!descriptor) {
566 journal_abort(journal, -EIO);
567 continue;
570 bh = jh2bh(descriptor);
571 jbd_debug(4, "JBD: got buffer %llu (%p)\n",
572 (unsigned long long)bh->b_blocknr, bh->b_data);
573 header = (journal_header_t *)&bh->b_data[0];
574 header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
575 header->h_blocktype = cpu_to_be32(JFS_DESCRIPTOR_BLOCK);
576 header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
578 tagp = &bh->b_data[sizeof(journal_header_t)];
579 space_left = bh->b_size - sizeof(journal_header_t);
580 first_tag = 1;
581 set_buffer_jwrite(bh);
582 set_buffer_dirty(bh);
583 wbuf[bufs++] = bh;
585 /* Record it so that we can wait for IO
586 completion later */
587 BUFFER_TRACE(bh, "ph3: file as descriptor");
588 journal_file_buffer(descriptor, commit_transaction,
589 BJ_LogCtl);
592 /* Where is the buffer to be written? */
594 err = journal_next_log_block(journal, &blocknr);
595 /* If the block mapping failed, just abandon the buffer
596 and repeat this loop: we'll fall into the
597 refile-on-abort condition above. */
598 if (err) {
599 journal_abort(journal, err);
600 continue;
604 * start_this_handle() uses t_outstanding_credits to determine
605 * the free space in the log, but this counter is changed
606 * by journal_next_log_block() also.
608 commit_transaction->t_outstanding_credits--;
610 /* Bump b_count to prevent truncate from stumbling over
611 the shadowed buffer! @@@ This can go if we ever get
612 rid of the BJ_IO/BJ_Shadow pairing of buffers. */
613 atomic_inc(&jh2bh(jh)->b_count);
615 /* Make a temporary IO buffer with which to write it out
616 (this will requeue both the metadata buffer and the
617 temporary IO buffer). new_bh goes on BJ_IO*/
619 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
621 * akpm: journal_write_metadata_buffer() sets
622 * new_bh->b_transaction to commit_transaction.
623 * We need to clean this up before we release new_bh
624 * (which is of type BJ_IO)
626 JBUFFER_TRACE(jh, "ph3: write metadata");
627 flags = journal_write_metadata_buffer(commit_transaction,
628 jh, &new_jh, blocknr);
629 set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
630 wbuf[bufs++] = jh2bh(new_jh);
632 /* Record the new block's tag in the current descriptor
633 buffer */
635 tag_flag = 0;
636 if (flags & 1)
637 tag_flag |= JFS_FLAG_ESCAPE;
638 if (!first_tag)
639 tag_flag |= JFS_FLAG_SAME_UUID;
641 tag = (journal_block_tag_t *) tagp;
642 tag->t_blocknr = cpu_to_be32(jh2bh(jh)->b_blocknr);
643 tag->t_flags = cpu_to_be32(tag_flag);
644 tagp += sizeof(journal_block_tag_t);
645 space_left -= sizeof(journal_block_tag_t);
647 if (first_tag) {
648 memcpy (tagp, journal->j_uuid, 16);
649 tagp += 16;
650 space_left -= 16;
651 first_tag = 0;
654 /* If there's no more to do, or if the descriptor is full,
655 let the IO rip! */
657 if (bufs == journal->j_wbufsize ||
658 commit_transaction->t_buffers == NULL ||
659 space_left < sizeof(journal_block_tag_t) + 16) {
661 jbd_debug(4, "JBD: Submit %d IOs\n", bufs);
663 /* Write an end-of-descriptor marker before
664 submitting the IOs. "tag" still points to
665 the last tag we set up. */
667 tag->t_flags |= cpu_to_be32(JFS_FLAG_LAST_TAG);
669 start_journal_io:
670 for (i = 0; i < bufs; i++) {
671 struct buffer_head *bh = wbuf[i];
672 lock_buffer(bh);
673 clear_buffer_dirty(bh);
674 set_buffer_uptodate(bh);
675 bh->b_end_io = journal_end_buffer_io_sync;
676 submit_bh(write_op, bh);
678 cond_resched();
680 /* Force a new descriptor to be generated next
681 time round the loop. */
682 descriptor = NULL;
683 bufs = 0;
687 /* Lo and behold: we have just managed to send a transaction to
688 the log. Before we can commit it, wait for the IO so far to
689 complete. Control buffers being written are on the
690 transaction's t_log_list queue, and metadata buffers are on
691 the t_iobuf_list queue.
693 Wait for the buffers in reverse order. That way we are
694 less likely to be woken up until all IOs have completed, and
695 so we incur less scheduling load.
698 jbd_debug(3, "JBD: commit phase 4\n");
701 * akpm: these are BJ_IO, and j_list_lock is not needed.
702 * See __journal_try_to_free_buffer.
704 wait_for_iobuf:
705 while (commit_transaction->t_iobuf_list != NULL) {
706 struct buffer_head *bh;
708 jh = commit_transaction->t_iobuf_list->b_tprev;
709 bh = jh2bh(jh);
710 if (buffer_locked(bh)) {
711 wait_on_buffer(bh);
712 goto wait_for_iobuf;
714 if (cond_resched())
715 goto wait_for_iobuf;
717 if (unlikely(!buffer_uptodate(bh)))
718 err = -EIO;
720 clear_buffer_jwrite(bh);
722 JBUFFER_TRACE(jh, "ph4: unfile after journal write");
723 journal_unfile_buffer(journal, jh);
726 * ->t_iobuf_list should contain only dummy buffer_heads
727 * which were created by journal_write_metadata_buffer().
729 BUFFER_TRACE(bh, "dumping temporary bh");
730 journal_put_journal_head(jh);
731 __brelse(bh);
732 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
733 free_buffer_head(bh);
735 /* We also have to unlock and free the corresponding
736 shadowed buffer */
737 jh = commit_transaction->t_shadow_list->b_tprev;
738 bh = jh2bh(jh);
739 clear_bit(BH_JWrite, &bh->b_state);
740 J_ASSERT_BH(bh, buffer_jbddirty(bh));
742 /* The metadata is now released for reuse, but we need
743 to remember it against this transaction so that when
744 we finally commit, we can do any checkpointing
745 required. */
746 JBUFFER_TRACE(jh, "file as BJ_Forget");
747 journal_file_buffer(jh, commit_transaction, BJ_Forget);
748 /* Wake up any transactions which were waiting for this
749 IO to complete */
750 wake_up_bit(&bh->b_state, BH_Unshadow);
751 JBUFFER_TRACE(jh, "brelse shadowed buffer");
752 __brelse(bh);
755 J_ASSERT (commit_transaction->t_shadow_list == NULL);
757 jbd_debug(3, "JBD: commit phase 5\n");
759 /* Here we wait for the revoke record and descriptor record buffers */
760 wait_for_ctlbuf:
761 while (commit_transaction->t_log_list != NULL) {
762 struct buffer_head *bh;
764 jh = commit_transaction->t_log_list->b_tprev;
765 bh = jh2bh(jh);
766 if (buffer_locked(bh)) {
767 wait_on_buffer(bh);
768 goto wait_for_ctlbuf;
770 if (cond_resched())
771 goto wait_for_ctlbuf;
773 if (unlikely(!buffer_uptodate(bh)))
774 err = -EIO;
776 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
777 clear_buffer_jwrite(bh);
778 journal_unfile_buffer(journal, jh);
779 journal_put_journal_head(jh);
780 __brelse(bh); /* One for getblk */
781 /* AKPM: bforget here */
784 if (err)
785 journal_abort(journal, err);
787 jbd_debug(3, "JBD: commit phase 6\n");
789 if (journal_write_commit_record(journal, commit_transaction))
790 err = -EIO;
792 if (err)
793 journal_abort(journal, err);
795 /* End of a transaction! Finally, we can do checkpoint
796 processing: any buffers committed as a result of this
797 transaction can be removed from any checkpoint list it was on
798 before. */
800 jbd_debug(3, "JBD: commit phase 7\n");
802 J_ASSERT(commit_transaction->t_sync_datalist == NULL);
803 J_ASSERT(commit_transaction->t_buffers == NULL);
804 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
805 J_ASSERT(commit_transaction->t_iobuf_list == NULL);
806 J_ASSERT(commit_transaction->t_shadow_list == NULL);
807 J_ASSERT(commit_transaction->t_log_list == NULL);
809 restart_loop:
811 * As there are other places (journal_unmap_buffer()) adding buffers
812 * to this list we have to be careful and hold the j_list_lock.
814 spin_lock(&journal->j_list_lock);
815 while (commit_transaction->t_forget) {
816 transaction_t *cp_transaction;
817 struct buffer_head *bh;
819 jh = commit_transaction->t_forget;
820 spin_unlock(&journal->j_list_lock);
821 bh = jh2bh(jh);
822 jbd_lock_bh_state(bh);
823 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction ||
824 jh->b_transaction == journal->j_running_transaction);
827 * If there is undo-protected committed data against
828 * this buffer, then we can remove it now. If it is a
829 * buffer needing such protection, the old frozen_data
830 * field now points to a committed version of the
831 * buffer, so rotate that field to the new committed
832 * data.
834 * Otherwise, we can just throw away the frozen data now.
836 if (jh->b_committed_data) {
837 jbd_free(jh->b_committed_data, bh->b_size);
838 jh->b_committed_data = NULL;
839 if (jh->b_frozen_data) {
840 jh->b_committed_data = jh->b_frozen_data;
841 jh->b_frozen_data = NULL;
843 } else if (jh->b_frozen_data) {
844 jbd_free(jh->b_frozen_data, bh->b_size);
845 jh->b_frozen_data = NULL;
848 spin_lock(&journal->j_list_lock);
849 cp_transaction = jh->b_cp_transaction;
850 if (cp_transaction) {
851 JBUFFER_TRACE(jh, "remove from old cp transaction");
852 __journal_remove_checkpoint(jh);
855 /* Only re-checkpoint the buffer_head if it is marked
856 * dirty. If the buffer was added to the BJ_Forget list
857 * by journal_forget, it may no longer be dirty and
858 * there's no point in keeping a checkpoint record for
859 * it. */
861 /* A buffer which has been freed while still being
862 * journaled by a previous transaction may end up still
863 * being dirty here, but we want to avoid writing back
864 * that buffer in the future after the "add to orphan"
865 * operation been committed, That's not only a performance
866 * gain, it also stops aliasing problems if the buffer is
867 * left behind for writeback and gets reallocated for another
868 * use in a different page. */
869 if (buffer_freed(bh) && !jh->b_next_transaction) {
870 clear_buffer_freed(bh);
871 clear_buffer_jbddirty(bh);
874 if (buffer_jbddirty(bh)) {
875 JBUFFER_TRACE(jh, "add to new checkpointing trans");
876 __journal_insert_checkpoint(jh, commit_transaction);
877 if (is_journal_aborted(journal))
878 clear_buffer_jbddirty(bh);
879 JBUFFER_TRACE(jh, "refile for checkpoint writeback");
880 __journal_refile_buffer(jh);
881 jbd_unlock_bh_state(bh);
882 } else {
883 J_ASSERT_BH(bh, !buffer_dirty(bh));
884 /* The buffer on BJ_Forget list and not jbddirty means
885 * it has been freed by this transaction and hence it
886 * could not have been reallocated until this
887 * transaction has committed. *BUT* it could be
888 * reallocated once we have written all the data to
889 * disk and before we process the buffer on BJ_Forget
890 * list. */
891 JBUFFER_TRACE(jh, "refile or unfile freed buffer");
892 __journal_refile_buffer(jh);
893 if (!jh->b_transaction) {
894 jbd_unlock_bh_state(bh);
895 /* needs a brelse */
896 journal_remove_journal_head(bh);
897 release_buffer_page(bh);
898 } else
899 jbd_unlock_bh_state(bh);
901 cond_resched_lock(&journal->j_list_lock);
903 spin_unlock(&journal->j_list_lock);
905 * This is a bit sleazy. We use j_list_lock to protect transition
906 * of a transaction into T_FINISHED state and calling
907 * __journal_drop_transaction(). Otherwise we could race with
908 * other checkpointing code processing the transaction...
910 spin_lock(&journal->j_state_lock);
911 spin_lock(&journal->j_list_lock);
913 * Now recheck if some buffers did not get attached to the transaction
914 * while the lock was dropped...
916 if (commit_transaction->t_forget) {
917 spin_unlock(&journal->j_list_lock);
918 spin_unlock(&journal->j_state_lock);
919 goto restart_loop;
922 /* Done with this transaction! */
924 jbd_debug(3, "JBD: commit phase 8\n");
926 J_ASSERT(commit_transaction->t_state == T_COMMIT);
928 commit_transaction->t_state = T_FINISHED;
929 J_ASSERT(commit_transaction == journal->j_committing_transaction);
930 journal->j_commit_sequence = commit_transaction->t_tid;
931 journal->j_committing_transaction = NULL;
932 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
935 * weight the commit time higher than the average time so we don't
936 * react too strongly to vast changes in commit time
938 if (likely(journal->j_average_commit_time))
939 journal->j_average_commit_time = (commit_time*3 +
940 journal->j_average_commit_time) / 4;
941 else
942 journal->j_average_commit_time = commit_time;
944 spin_unlock(&journal->j_state_lock);
946 if (commit_transaction->t_checkpoint_list == NULL &&
947 commit_transaction->t_checkpoint_io_list == NULL) {
948 __journal_drop_transaction(journal, commit_transaction);
949 } else {
950 if (journal->j_checkpoint_transactions == NULL) {
951 journal->j_checkpoint_transactions = commit_transaction;
952 commit_transaction->t_cpnext = commit_transaction;
953 commit_transaction->t_cpprev = commit_transaction;
954 } else {
955 commit_transaction->t_cpnext =
956 journal->j_checkpoint_transactions;
957 commit_transaction->t_cpprev =
958 commit_transaction->t_cpnext->t_cpprev;
959 commit_transaction->t_cpnext->t_cpprev =
960 commit_transaction;
961 commit_transaction->t_cpprev->t_cpnext =
962 commit_transaction;
965 spin_unlock(&journal->j_list_lock);
967 jbd_debug(1, "JBD: commit %d complete, head %d\n",
968 journal->j_commit_sequence, journal->j_tail_sequence);
970 wake_up(&journal->j_wait_done_commit);