2 * linux/fs/jbd2/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>
18 #include <linux/jbd2.h>
19 #include <linux/errno.h>
20 #include <linux/slab.h>
22 #include <linux/pagemap.h>
23 #include <linux/jiffies.h>
24 #include <linux/crc32.h>
27 * Default IO end handler for temporary BJ_IO buffer_heads.
29 static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
33 set_buffer_uptodate(bh);
35 clear_buffer_uptodate(bh);
40 * When an ext3-ordered file is truncated, it is possible that many pages are
41 * not sucessfully freed, because they are attached to a committing transaction.
42 * After the transaction commits, these pages are left on the LRU, with no
43 * ->mapping, and with attached buffers. These pages are trivially reclaimable
44 * by the VM, but their apparent absence upsets the VM accounting, and it makes
45 * the numbers in /proc/meminfo look odd.
47 * So here, we have a buffer which has just come off the forget list. Look to
48 * see if we can strip all buffers from the backing page.
50 * Called under lock_journal(), and possibly under journal_datalist_lock. The
51 * caller provided us with a ref against the buffer, and we drop that here.
53 static void release_buffer_page(struct buffer_head *bh)
59 if (atomic_read(&bh->b_count) != 1)
67 /* OK, it's a truncated page */
68 if (TestSetPageLocked(page))
73 try_to_free_buffers(page);
75 page_cache_release(page);
83 * Try to acquire jbd_lock_bh_state() against the buffer, when j_list_lock is
84 * held. For ranking reasons we must trylock. If we lose, schedule away and
85 * return 0. j_list_lock is dropped in this case.
87 static int inverted_lock(journal_t *journal, struct buffer_head *bh)
89 if (!jbd_trylock_bh_state(bh)) {
90 spin_unlock(&journal->j_list_lock);
98 * Done it all: now submit the commit record. We should have
99 * cleaned up our previous buffers by now, so if we are in abort
100 * mode we can now just skip the rest of the journal write
103 * Returns 1 if the journal needs to be aborted or 0 on success
105 static int journal_submit_commit_record(journal_t *journal,
106 transaction_t *commit_transaction,
107 struct buffer_head **cbh,
110 struct journal_head *descriptor;
111 struct commit_header *tmp;
112 struct buffer_head *bh;
114 int barrier_done = 0;
116 if (is_journal_aborted(journal))
119 descriptor = jbd2_journal_get_descriptor_buffer(journal);
123 bh = jh2bh(descriptor);
125 tmp = (struct commit_header *)bh->b_data;
126 tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
127 tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
128 tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
130 if (JBD2_HAS_COMPAT_FEATURE(journal,
131 JBD2_FEATURE_COMPAT_CHECKSUM)) {
132 tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
133 tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
134 tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
137 JBUFFER_TRACE(descriptor, "submit commit block");
140 set_buffer_dirty(bh);
141 set_buffer_uptodate(bh);
142 bh->b_end_io = journal_end_buffer_io_sync;
144 if (journal->j_flags & JBD2_BARRIER &&
145 !JBD2_HAS_INCOMPAT_FEATURE(journal,
146 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
147 set_buffer_ordered(bh);
150 ret = submit_bh(WRITE, bh);
152 clear_buffer_ordered(bh);
154 /* is it possible for another commit to fail at roughly
155 * the same time as this one? If so, we don't want to
156 * trust the barrier flag in the super, but instead want
157 * to remember if we sent a barrier request
159 if (ret == -EOPNOTSUPP && barrier_done) {
160 char b[BDEVNAME_SIZE];
163 "JBD: barrier-based sync failed on %s - "
164 "disabling barriers\n",
165 bdevname(journal->j_dev, b));
166 spin_lock(&journal->j_state_lock);
167 journal->j_flags &= ~JBD2_BARRIER;
168 spin_unlock(&journal->j_state_lock);
170 /* And try again, without the barrier */
171 set_buffer_uptodate(bh);
172 set_buffer_dirty(bh);
173 ret = submit_bh(WRITE, bh);
180 * This function along with journal_submit_commit_record
181 * allows to write the commit record asynchronously.
183 static int journal_wait_on_commit_record(struct buffer_head *bh)
187 clear_buffer_dirty(bh);
190 if (unlikely(!buffer_uptodate(bh)))
192 put_bh(bh); /* One for getblk() */
193 jbd2_journal_put_journal_head(bh2jh(bh));
199 * Wait for all submitted IO to complete.
201 static int journal_wait_on_locked_list(journal_t *journal,
202 transaction_t *commit_transaction)
205 struct journal_head *jh;
207 while (commit_transaction->t_locked_list) {
208 struct buffer_head *bh;
210 jh = commit_transaction->t_locked_list->b_tprev;
213 if (buffer_locked(bh)) {
214 spin_unlock(&journal->j_list_lock);
216 if (unlikely(!buffer_uptodate(bh)))
218 spin_lock(&journal->j_list_lock);
220 if (!inverted_lock(journal, bh)) {
222 spin_lock(&journal->j_list_lock);
225 if (buffer_jbd(bh) && jh->b_jlist == BJ_Locked) {
226 __jbd2_journal_unfile_buffer(jh);
227 jbd_unlock_bh_state(bh);
228 jbd2_journal_remove_journal_head(bh);
231 jbd_unlock_bh_state(bh);
234 cond_resched_lock(&journal->j_list_lock);
239 static void journal_do_submit_data(struct buffer_head **wbuf, int bufs)
243 for (i = 0; i < bufs; i++) {
244 wbuf[i]->b_end_io = end_buffer_write_sync;
245 /* We use-up our safety reference in submit_bh() */
246 submit_bh(WRITE, wbuf[i]);
251 * Submit all the data buffers to disk
253 static void journal_submit_data_buffers(journal_t *journal,
254 transaction_t *commit_transaction)
256 struct journal_head *jh;
257 struct buffer_head *bh;
260 struct buffer_head **wbuf = journal->j_wbuf;
263 * Whenever we unlock the journal and sleep, things can get added
264 * onto ->t_sync_datalist, so we have to keep looping back to
265 * write_out_data until we *know* that the list is empty.
267 * Cleanup any flushed data buffers from the data list. Even in
268 * abort mode, we want to flush this out as soon as possible.
272 spin_lock(&journal->j_list_lock);
274 while (commit_transaction->t_sync_datalist) {
275 jh = commit_transaction->t_sync_datalist;
279 /* Get reference just to make sure buffer does not disappear
280 * when we are forced to drop various locks */
282 /* If the buffer is dirty, we need to submit IO and hence
283 * we need the buffer lock. We try to lock the buffer without
284 * blocking. If we fail, we need to drop j_list_lock and do
285 * blocking lock_buffer().
287 if (buffer_dirty(bh)) {
288 if (test_set_buffer_locked(bh)) {
289 BUFFER_TRACE(bh, "needs blocking lock");
290 spin_unlock(&journal->j_list_lock);
291 /* Write out all data to prevent deadlocks */
292 journal_do_submit_data(wbuf, bufs);
295 spin_lock(&journal->j_list_lock);
299 /* We have to get bh_state lock. Again out of order, sigh. */
300 if (!inverted_lock(journal, bh)) {
301 jbd_lock_bh_state(bh);
302 spin_lock(&journal->j_list_lock);
304 /* Someone already cleaned up the buffer? */
306 || jh->b_transaction != commit_transaction
307 || jh->b_jlist != BJ_SyncData) {
308 jbd_unlock_bh_state(bh);
311 BUFFER_TRACE(bh, "already cleaned up");
315 if (locked && test_clear_buffer_dirty(bh)) {
316 BUFFER_TRACE(bh, "needs writeout, adding to array");
318 __jbd2_journal_file_buffer(jh, commit_transaction,
320 jbd_unlock_bh_state(bh);
321 if (bufs == journal->j_wbufsize) {
322 spin_unlock(&journal->j_list_lock);
323 journal_do_submit_data(wbuf, bufs);
327 } else if (!locked && buffer_locked(bh)) {
328 __jbd2_journal_file_buffer(jh, commit_transaction,
330 jbd_unlock_bh_state(bh);
333 BUFFER_TRACE(bh, "writeout complete: unfile");
334 __jbd2_journal_unfile_buffer(jh);
335 jbd_unlock_bh_state(bh);
338 jbd2_journal_remove_journal_head(bh);
339 /* Once for our safety reference, once for
340 * jbd2_journal_remove_journal_head() */
345 if (need_resched() || spin_needbreak(&journal->j_list_lock)) {
346 spin_unlock(&journal->j_list_lock);
350 spin_unlock(&journal->j_list_lock);
351 journal_do_submit_data(wbuf, bufs);
354 static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
356 struct page *page = bh->b_page;
360 addr = kmap_atomic(page, KM_USER0);
361 checksum = crc32_be(crc32_sum,
362 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
363 kunmap_atomic(addr, KM_USER0);
368 static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
369 unsigned long long block)
371 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
372 if (tag_bytes > JBD2_TAG_SIZE32)
373 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
377 * jbd2_journal_commit_transaction
379 * The primary function for committing a transaction to the log. This
380 * function is called by the journal thread to begin a complete commit.
382 void jbd2_journal_commit_transaction(journal_t *journal)
384 struct transaction_stats_s stats;
385 transaction_t *commit_transaction;
386 struct journal_head *jh, *new_jh, *descriptor;
387 struct buffer_head **wbuf = journal->j_wbuf;
391 unsigned long long blocknr;
393 journal_header_t *header;
394 journal_block_tag_t *tag = NULL;
399 int tag_bytes = journal_tag_bytes(journal);
400 struct buffer_head *cbh = NULL; /* For transactional checksums */
401 __u32 crc32_sum = ~0;
404 * First job: lock down the current transaction and wait for
405 * all outstanding updates to complete.
409 spin_lock(&journal->j_list_lock);
410 summarise_journal_usage(journal);
411 spin_unlock(&journal->j_list_lock);
414 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
415 if (journal->j_flags & JBD2_FLUSHED) {
416 jbd_debug(3, "super block updated\n");
417 jbd2_journal_update_superblock(journal, 1);
419 jbd_debug(3, "superblock not updated\n");
422 J_ASSERT(journal->j_running_transaction != NULL);
423 J_ASSERT(journal->j_committing_transaction == NULL);
425 commit_transaction = journal->j_running_transaction;
426 J_ASSERT(commit_transaction->t_state == T_RUNNING);
428 jbd_debug(1, "JBD: starting commit of transaction %d\n",
429 commit_transaction->t_tid);
431 spin_lock(&journal->j_state_lock);
432 commit_transaction->t_state = T_LOCKED;
434 stats.u.run.rs_wait = commit_transaction->t_max_wait;
435 stats.u.run.rs_locked = jiffies;
436 stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
437 stats.u.run.rs_locked);
439 spin_lock(&commit_transaction->t_handle_lock);
440 while (commit_transaction->t_updates) {
443 prepare_to_wait(&journal->j_wait_updates, &wait,
444 TASK_UNINTERRUPTIBLE);
445 if (commit_transaction->t_updates) {
446 spin_unlock(&commit_transaction->t_handle_lock);
447 spin_unlock(&journal->j_state_lock);
449 spin_lock(&journal->j_state_lock);
450 spin_lock(&commit_transaction->t_handle_lock);
452 finish_wait(&journal->j_wait_updates, &wait);
454 spin_unlock(&commit_transaction->t_handle_lock);
456 J_ASSERT (commit_transaction->t_outstanding_credits <=
457 journal->j_max_transaction_buffers);
460 * First thing we are allowed to do is to discard any remaining
461 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
462 * that there are no such buffers: if a large filesystem
463 * operation like a truncate needs to split itself over multiple
464 * transactions, then it may try to do a jbd2_journal_restart() while
465 * there are still BJ_Reserved buffers outstanding. These must
466 * be released cleanly from the current transaction.
468 * In this case, the filesystem must still reserve write access
469 * again before modifying the buffer in the new transaction, but
470 * we do not require it to remember exactly which old buffers it
471 * has reserved. This is consistent with the existing behaviour
472 * that multiple jbd2_journal_get_write_access() calls to the same
473 * buffer are perfectly permissable.
475 while (commit_transaction->t_reserved_list) {
476 jh = commit_transaction->t_reserved_list;
477 JBUFFER_TRACE(jh, "reserved, unused: refile");
479 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
480 * leave undo-committed data.
482 if (jh->b_committed_data) {
483 struct buffer_head *bh = jh2bh(jh);
485 jbd_lock_bh_state(bh);
486 jbd2_free(jh->b_committed_data, bh->b_size);
487 jh->b_committed_data = NULL;
488 jbd_unlock_bh_state(bh);
490 jbd2_journal_refile_buffer(journal, jh);
494 * Now try to drop any written-back buffers from the journal's
495 * checkpoint lists. We do this *before* commit because it potentially
498 spin_lock(&journal->j_list_lock);
499 __jbd2_journal_clean_checkpoint_list(journal);
500 spin_unlock(&journal->j_list_lock);
502 jbd_debug (3, "JBD: commit phase 1\n");
505 * Switch to a new revoke table.
507 jbd2_journal_switch_revoke_table(journal);
509 stats.u.run.rs_flushing = jiffies;
510 stats.u.run.rs_locked = jbd2_time_diff(stats.u.run.rs_locked,
511 stats.u.run.rs_flushing);
513 commit_transaction->t_state = T_FLUSH;
514 journal->j_committing_transaction = commit_transaction;
515 journal->j_running_transaction = NULL;
516 commit_transaction->t_log_start = journal->j_head;
517 wake_up(&journal->j_wait_transaction_locked);
518 spin_unlock(&journal->j_state_lock);
520 jbd_debug (3, "JBD: commit phase 2\n");
523 * Now start flushing things to disk, in the order they appear
524 * on the transaction lists. Data blocks go first.
527 journal_submit_data_buffers(journal, commit_transaction);
530 * Wait for all previously submitted IO to complete if commit
531 * record is to be written synchronously.
533 spin_lock(&journal->j_list_lock);
534 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
535 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
536 err = journal_wait_on_locked_list(journal,
539 spin_unlock(&journal->j_list_lock);
542 jbd2_journal_abort(journal, err);
544 jbd2_journal_write_revoke_records(journal, commit_transaction);
546 jbd_debug(3, "JBD: commit phase 2\n");
549 * If we found any dirty or locked buffers, then we should have
550 * looped back up to the write_out_data label. If there weren't
551 * any then journal_clean_data_list should have wiped the list
552 * clean by now, so check that it is in fact empty.
554 J_ASSERT (commit_transaction->t_sync_datalist == NULL);
556 jbd_debug (3, "JBD: commit phase 3\n");
559 * Way to go: we have now written out all of the data for a
560 * transaction! Now comes the tricky part: we need to write out
561 * metadata. Loop over the transaction's entire buffer list:
563 commit_transaction->t_state = T_COMMIT;
565 stats.u.run.rs_logging = jiffies;
566 stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing,
567 stats.u.run.rs_logging);
568 stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
569 stats.u.run.rs_blocks_logged = 0;
573 while (commit_transaction->t_buffers) {
575 /* Find the next buffer to be journaled... */
577 jh = commit_transaction->t_buffers;
579 /* If we're in abort mode, we just un-journal the buffer and
580 release it for background writing. */
582 if (is_journal_aborted(journal)) {
583 JBUFFER_TRACE(jh, "journal is aborting: refile");
584 jbd2_journal_refile_buffer(journal, jh);
585 /* If that was the last one, we need to clean up
586 * any descriptor buffers which may have been
587 * already allocated, even if we are now
589 if (!commit_transaction->t_buffers)
590 goto start_journal_io;
594 /* Make sure we have a descriptor block in which to
595 record the metadata buffer. */
598 struct buffer_head *bh;
600 J_ASSERT (bufs == 0);
602 jbd_debug(4, "JBD: get descriptor\n");
604 descriptor = jbd2_journal_get_descriptor_buffer(journal);
606 jbd2_journal_abort(journal, -EIO);
610 bh = jh2bh(descriptor);
611 jbd_debug(4, "JBD: got buffer %llu (%p)\n",
612 (unsigned long long)bh->b_blocknr, bh->b_data);
613 header = (journal_header_t *)&bh->b_data[0];
614 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
615 header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK);
616 header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
618 tagp = &bh->b_data[sizeof(journal_header_t)];
619 space_left = bh->b_size - sizeof(journal_header_t);
621 set_buffer_jwrite(bh);
622 set_buffer_dirty(bh);
625 /* Record it so that we can wait for IO
627 BUFFER_TRACE(bh, "ph3: file as descriptor");
628 jbd2_journal_file_buffer(descriptor, commit_transaction,
632 /* Where is the buffer to be written? */
634 err = jbd2_journal_next_log_block(journal, &blocknr);
635 /* If the block mapping failed, just abandon the buffer
636 and repeat this loop: we'll fall into the
637 refile-on-abort condition above. */
639 jbd2_journal_abort(journal, err);
644 * start_this_handle() uses t_outstanding_credits to determine
645 * the free space in the log, but this counter is changed
646 * by jbd2_journal_next_log_block() also.
648 commit_transaction->t_outstanding_credits--;
650 /* Bump b_count to prevent truncate from stumbling over
651 the shadowed buffer! @@@ This can go if we ever get
652 rid of the BJ_IO/BJ_Shadow pairing of buffers. */
653 atomic_inc(&jh2bh(jh)->b_count);
655 /* Make a temporary IO buffer with which to write it out
656 (this will requeue both the metadata buffer and the
657 temporary IO buffer). new_bh goes on BJ_IO*/
659 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
661 * akpm: jbd2_journal_write_metadata_buffer() sets
662 * new_bh->b_transaction to commit_transaction.
663 * We need to clean this up before we release new_bh
664 * (which is of type BJ_IO)
666 JBUFFER_TRACE(jh, "ph3: write metadata");
667 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
668 jh, &new_jh, blocknr);
669 set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
670 wbuf[bufs++] = jh2bh(new_jh);
672 /* Record the new block's tag in the current descriptor
677 tag_flag |= JBD2_FLAG_ESCAPE;
679 tag_flag |= JBD2_FLAG_SAME_UUID;
681 tag = (journal_block_tag_t *) tagp;
682 write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
683 tag->t_flags = cpu_to_be32(tag_flag);
685 space_left -= tag_bytes;
688 memcpy (tagp, journal->j_uuid, 16);
694 /* If there's no more to do, or if the descriptor is full,
697 if (bufs == journal->j_wbufsize ||
698 commit_transaction->t_buffers == NULL ||
699 space_left < tag_bytes + 16) {
701 jbd_debug(4, "JBD: Submit %d IOs\n", bufs);
703 /* Write an end-of-descriptor marker before
704 submitting the IOs. "tag" still points to
705 the last tag we set up. */
707 tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG);
710 for (i = 0; i < bufs; i++) {
711 struct buffer_head *bh = wbuf[i];
715 if (JBD2_HAS_COMPAT_FEATURE(journal,
716 JBD2_FEATURE_COMPAT_CHECKSUM)) {
718 jbd2_checksum_data(crc32_sum, bh);
722 clear_buffer_dirty(bh);
723 set_buffer_uptodate(bh);
724 bh->b_end_io = journal_end_buffer_io_sync;
725 submit_bh(WRITE, bh);
728 stats.u.run.rs_blocks_logged += bufs;
730 /* Force a new descriptor to be generated next
731 time round the loop. */
737 /* Done it all: now write the commit record asynchronously. */
739 if (JBD2_HAS_INCOMPAT_FEATURE(journal,
740 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
741 err = journal_submit_commit_record(journal, commit_transaction,
744 __jbd2_journal_abort_hard(journal);
746 spin_lock(&journal->j_list_lock);
747 err = journal_wait_on_locked_list(journal,
749 spin_unlock(&journal->j_list_lock);
751 __jbd2_journal_abort_hard(journal);
754 /* Lo and behold: we have just managed to send a transaction to
755 the log. Before we can commit it, wait for the IO so far to
756 complete. Control buffers being written are on the
757 transaction's t_log_list queue, and metadata buffers are on
758 the t_iobuf_list queue.
760 Wait for the buffers in reverse order. That way we are
761 less likely to be woken up until all IOs have completed, and
762 so we incur less scheduling load.
765 jbd_debug(3, "JBD: commit phase 4\n");
768 * akpm: these are BJ_IO, and j_list_lock is not needed.
769 * See __journal_try_to_free_buffer.
772 while (commit_transaction->t_iobuf_list != NULL) {
773 struct buffer_head *bh;
775 jh = commit_transaction->t_iobuf_list->b_tprev;
777 if (buffer_locked(bh)) {
784 if (unlikely(!buffer_uptodate(bh)))
787 clear_buffer_jwrite(bh);
789 JBUFFER_TRACE(jh, "ph4: unfile after journal write");
790 jbd2_journal_unfile_buffer(journal, jh);
793 * ->t_iobuf_list should contain only dummy buffer_heads
794 * which were created by jbd2_journal_write_metadata_buffer().
796 BUFFER_TRACE(bh, "dumping temporary bh");
797 jbd2_journal_put_journal_head(jh);
799 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
800 free_buffer_head(bh);
802 /* We also have to unlock and free the corresponding
804 jh = commit_transaction->t_shadow_list->b_tprev;
806 clear_bit(BH_JWrite, &bh->b_state);
807 J_ASSERT_BH(bh, buffer_jbddirty(bh));
809 /* The metadata is now released for reuse, but we need
810 to remember it against this transaction so that when
811 we finally commit, we can do any checkpointing
813 JBUFFER_TRACE(jh, "file as BJ_Forget");
814 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
815 /* Wake up any transactions which were waiting for this
817 wake_up_bit(&bh->b_state, BH_Unshadow);
818 JBUFFER_TRACE(jh, "brelse shadowed buffer");
822 J_ASSERT (commit_transaction->t_shadow_list == NULL);
824 jbd_debug(3, "JBD: commit phase 5\n");
826 /* Here we wait for the revoke record and descriptor record buffers */
828 while (commit_transaction->t_log_list != NULL) {
829 struct buffer_head *bh;
831 jh = commit_transaction->t_log_list->b_tprev;
833 if (buffer_locked(bh)) {
835 goto wait_for_ctlbuf;
838 goto wait_for_ctlbuf;
840 if (unlikely(!buffer_uptodate(bh)))
843 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
844 clear_buffer_jwrite(bh);
845 jbd2_journal_unfile_buffer(journal, jh);
846 jbd2_journal_put_journal_head(jh);
847 __brelse(bh); /* One for getblk */
848 /* AKPM: bforget here */
851 jbd_debug(3, "JBD: commit phase 6\n");
853 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
854 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
855 err = journal_submit_commit_record(journal, commit_transaction,
858 __jbd2_journal_abort_hard(journal);
860 if (!err && !is_journal_aborted(journal))
861 err = journal_wait_on_commit_record(cbh);
864 jbd2_journal_abort(journal, err);
866 /* End of a transaction! Finally, we can do checkpoint
867 processing: any buffers committed as a result of this
868 transaction can be removed from any checkpoint list it was on
871 jbd_debug(3, "JBD: commit phase 7\n");
873 J_ASSERT(commit_transaction->t_sync_datalist == NULL);
874 J_ASSERT(commit_transaction->t_buffers == NULL);
875 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
876 J_ASSERT(commit_transaction->t_iobuf_list == NULL);
877 J_ASSERT(commit_transaction->t_shadow_list == NULL);
878 J_ASSERT(commit_transaction->t_log_list == NULL);
882 * As there are other places (journal_unmap_buffer()) adding buffers
883 * to this list we have to be careful and hold the j_list_lock.
885 spin_lock(&journal->j_list_lock);
886 while (commit_transaction->t_forget) {
887 transaction_t *cp_transaction;
888 struct buffer_head *bh;
890 jh = commit_transaction->t_forget;
891 spin_unlock(&journal->j_list_lock);
893 jbd_lock_bh_state(bh);
894 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction ||
895 jh->b_transaction == journal->j_running_transaction);
898 * If there is undo-protected committed data against
899 * this buffer, then we can remove it now. If it is a
900 * buffer needing such protection, the old frozen_data
901 * field now points to a committed version of the
902 * buffer, so rotate that field to the new committed
905 * Otherwise, we can just throw away the frozen data now.
907 if (jh->b_committed_data) {
908 jbd2_free(jh->b_committed_data, bh->b_size);
909 jh->b_committed_data = NULL;
910 if (jh->b_frozen_data) {
911 jh->b_committed_data = jh->b_frozen_data;
912 jh->b_frozen_data = NULL;
914 } else if (jh->b_frozen_data) {
915 jbd2_free(jh->b_frozen_data, bh->b_size);
916 jh->b_frozen_data = NULL;
919 spin_lock(&journal->j_list_lock);
920 cp_transaction = jh->b_cp_transaction;
921 if (cp_transaction) {
922 JBUFFER_TRACE(jh, "remove from old cp transaction");
923 cp_transaction->t_chp_stats.cs_dropped++;
924 __jbd2_journal_remove_checkpoint(jh);
927 /* Only re-checkpoint the buffer_head if it is marked
928 * dirty. If the buffer was added to the BJ_Forget list
929 * by jbd2_journal_forget, it may no longer be dirty and
930 * there's no point in keeping a checkpoint record for
933 /* A buffer which has been freed while still being
934 * journaled by a previous transaction may end up still
935 * being dirty here, but we want to avoid writing back
936 * that buffer in the future now that the last use has
937 * been committed. That's not only a performance gain,
938 * it also stops aliasing problems if the buffer is left
939 * behind for writeback and gets reallocated for another
940 * use in a different page. */
941 if (buffer_freed(bh)) {
942 clear_buffer_freed(bh);
943 clear_buffer_jbddirty(bh);
946 if (buffer_jbddirty(bh)) {
947 JBUFFER_TRACE(jh, "add to new checkpointing trans");
948 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
949 JBUFFER_TRACE(jh, "refile for checkpoint writeback");
950 __jbd2_journal_refile_buffer(jh);
951 jbd_unlock_bh_state(bh);
953 J_ASSERT_BH(bh, !buffer_dirty(bh));
954 /* The buffer on BJ_Forget list and not jbddirty means
955 * it has been freed by this transaction and hence it
956 * could not have been reallocated until this
957 * transaction has committed. *BUT* it could be
958 * reallocated once we have written all the data to
959 * disk and before we process the buffer on BJ_Forget
961 JBUFFER_TRACE(jh, "refile or unfile freed buffer");
962 __jbd2_journal_refile_buffer(jh);
963 if (!jh->b_transaction) {
964 jbd_unlock_bh_state(bh);
966 jbd2_journal_remove_journal_head(bh);
967 release_buffer_page(bh);
969 jbd_unlock_bh_state(bh);
971 cond_resched_lock(&journal->j_list_lock);
973 spin_unlock(&journal->j_list_lock);
975 * This is a bit sleazy. We use j_list_lock to protect transition
976 * of a transaction into T_FINISHED state and calling
977 * __jbd2_journal_drop_transaction(). Otherwise we could race with
978 * other checkpointing code processing the transaction...
980 spin_lock(&journal->j_state_lock);
981 spin_lock(&journal->j_list_lock);
983 * Now recheck if some buffers did not get attached to the transaction
984 * while the lock was dropped...
986 if (commit_transaction->t_forget) {
987 spin_unlock(&journal->j_list_lock);
988 spin_unlock(&journal->j_state_lock);
992 /* Done with this transaction! */
994 jbd_debug(3, "JBD: commit phase 8\n");
996 J_ASSERT(commit_transaction->t_state == T_COMMIT);
998 commit_transaction->t_start = jiffies;
999 stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging,
1000 commit_transaction->t_start);
1003 * File the transaction for history
1005 stats.ts_type = JBD2_STATS_RUN;
1006 stats.ts_tid = commit_transaction->t_tid;
1007 stats.u.run.rs_handle_count = commit_transaction->t_handle_count;
1008 spin_lock(&journal->j_history_lock);
1009 memcpy(journal->j_history + journal->j_history_cur, &stats,
1011 if (++journal->j_history_cur == journal->j_history_max)
1012 journal->j_history_cur = 0;
1015 * Calculate overall stats
1017 journal->j_stats.ts_tid++;
1018 journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait;
1019 journal->j_stats.u.run.rs_running += stats.u.run.rs_running;
1020 journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked;
1021 journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing;
1022 journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging;
1023 journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count;
1024 journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks;
1025 journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged;
1026 spin_unlock(&journal->j_history_lock);
1028 commit_transaction->t_state = T_FINISHED;
1029 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1030 journal->j_commit_sequence = commit_transaction->t_tid;
1031 journal->j_committing_transaction = NULL;
1032 spin_unlock(&journal->j_state_lock);
1034 if (commit_transaction->t_checkpoint_list == NULL &&
1035 commit_transaction->t_checkpoint_io_list == NULL) {
1036 __jbd2_journal_drop_transaction(journal, commit_transaction);
1038 if (journal->j_checkpoint_transactions == NULL) {
1039 journal->j_checkpoint_transactions = commit_transaction;
1040 commit_transaction->t_cpnext = commit_transaction;
1041 commit_transaction->t_cpprev = commit_transaction;
1043 commit_transaction->t_cpnext =
1044 journal->j_checkpoint_transactions;
1045 commit_transaction->t_cpprev =
1046 commit_transaction->t_cpnext->t_cpprev;
1047 commit_transaction->t_cpnext->t_cpprev =
1049 commit_transaction->t_cpprev->t_cpnext =
1053 spin_unlock(&journal->j_list_lock);
1055 jbd_debug(1, "JBD: commit %d complete, head %d\n",
1056 journal->j_commit_sequence, journal->j_tail_sequence);
1058 wake_up(&journal->j_wait_done_commit);