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/marker.h>
20 #include <linux/errno.h>
21 #include <linux/slab.h>
23 #include <linux/pagemap.h>
24 #include <linux/jiffies.h>
25 #include <linux/crc32.h>
26 #include <linux/writeback.h>
27 #include <linux/backing-dev.h>
28 #include <linux/bio.h>
31 * Default IO end handler for temporary BJ_IO buffer_heads.
33 static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
37 set_buffer_uptodate(bh);
39 clear_buffer_uptodate(bh);
44 * When an ext4 file is truncated, it is possible that some pages are not
45 * successfully freed, because they are attached to a committing transaction.
46 * After the transaction commits, these pages are left on the LRU, with no
47 * ->mapping, and with attached buffers. These pages are trivially reclaimable
48 * by the VM, but their apparent absence upsets the VM accounting, and it makes
49 * the numbers in /proc/meminfo look odd.
51 * So here, we have a buffer which has just come off the forget list. Look to
52 * see if we can strip all buffers from the backing page.
54 * Called under lock_journal(), and possibly under journal_datalist_lock. The
55 * caller provided us with a ref against the buffer, and we drop that here.
57 static void release_buffer_page(struct buffer_head *bh)
63 if (atomic_read(&bh->b_count) != 1)
71 /* OK, it's a truncated page */
72 if (!trylock_page(page))
77 try_to_free_buffers(page);
79 page_cache_release(page);
87 * Done it all: now submit the commit record. We should have
88 * cleaned up our previous buffers by now, so if we are in abort
89 * mode we can now just skip the rest of the journal write
92 * Returns 1 if the journal needs to be aborted or 0 on success
94 static int journal_submit_commit_record(journal_t *journal,
95 transaction_t *commit_transaction,
96 struct buffer_head **cbh,
99 struct journal_head *descriptor;
100 struct commit_header *tmp;
101 struct buffer_head *bh;
103 int barrier_done = 0;
104 struct timespec now = current_kernel_time();
106 if (is_journal_aborted(journal))
109 descriptor = jbd2_journal_get_descriptor_buffer(journal);
113 bh = jh2bh(descriptor);
115 tmp = (struct commit_header *)bh->b_data;
116 tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
117 tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
118 tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
119 tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
120 tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
122 if (JBD2_HAS_COMPAT_FEATURE(journal,
123 JBD2_FEATURE_COMPAT_CHECKSUM)) {
124 tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
125 tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
126 tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
129 JBUFFER_TRACE(descriptor, "submit commit block");
131 clear_buffer_dirty(bh);
132 set_buffer_uptodate(bh);
133 bh->b_end_io = journal_end_buffer_io_sync;
135 if (journal->j_flags & JBD2_BARRIER &&
136 !JBD2_HAS_INCOMPAT_FEATURE(journal,
137 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
138 set_buffer_ordered(bh);
141 ret = submit_bh(WRITE_SYNC_PLUG, bh);
143 clear_buffer_ordered(bh);
145 /* is it possible for another commit to fail at roughly
146 * the same time as this one? If so, we don't want to
147 * trust the barrier flag in the super, but instead want
148 * to remember if we sent a barrier request
150 if (ret == -EOPNOTSUPP && barrier_done) {
152 "JBD: barrier-based sync failed on %s - "
153 "disabling barriers\n", journal->j_devname);
154 spin_lock(&journal->j_state_lock);
155 journal->j_flags &= ~JBD2_BARRIER;
156 spin_unlock(&journal->j_state_lock);
158 /* And try again, without the barrier */
160 set_buffer_uptodate(bh);
161 clear_buffer_dirty(bh);
162 ret = submit_bh(WRITE_SYNC_PLUG, bh);
169 * This function along with journal_submit_commit_record
170 * allows to write the commit record asynchronously.
172 static int journal_wait_on_commit_record(journal_t *journal,
173 struct buffer_head *bh)
178 clear_buffer_dirty(bh);
180 if (buffer_eopnotsupp(bh) && (journal->j_flags & JBD2_BARRIER)) {
182 "JBD2: wait_on_commit_record: sync failed on %s - "
183 "disabling barriers\n", journal->j_devname);
184 spin_lock(&journal->j_state_lock);
185 journal->j_flags &= ~JBD2_BARRIER;
186 spin_unlock(&journal->j_state_lock);
189 clear_buffer_dirty(bh);
190 set_buffer_uptodate(bh);
191 bh->b_end_io = journal_end_buffer_io_sync;
193 ret = submit_bh(WRITE_SYNC_PLUG, bh);
201 if (unlikely(!buffer_uptodate(bh)))
203 put_bh(bh); /* One for getblk() */
204 jbd2_journal_put_journal_head(bh2jh(bh));
210 * write the filemap data using writepage() address_space_operations.
211 * We don't do block allocation here even for delalloc. We don't
212 * use writepages() because with dealyed allocation we may be doing
213 * block allocation in writepages().
215 static int journal_submit_inode_data_buffers(struct address_space *mapping)
218 struct writeback_control wbc = {
219 .sync_mode = WB_SYNC_ALL,
220 .nr_to_write = mapping->nrpages * 2,
222 .range_end = i_size_read(mapping->host),
226 ret = generic_writepages(mapping, &wbc);
231 * Submit all the data buffers of inode associated with the transaction to
234 * We are in a committing transaction. Therefore no new inode can be added to
235 * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
236 * operate on from being released while we write out pages.
238 static int journal_submit_data_buffers(journal_t *journal,
239 transaction_t *commit_transaction)
241 struct jbd2_inode *jinode;
243 struct address_space *mapping;
245 spin_lock(&journal->j_list_lock);
246 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
247 mapping = jinode->i_vfs_inode->i_mapping;
248 jinode->i_flags |= JI_COMMIT_RUNNING;
249 spin_unlock(&journal->j_list_lock);
251 * submit the inode data buffers. We use writepage
252 * instead of writepages. Because writepages can do
253 * block allocation with delalloc. We need to write
254 * only allocated blocks here.
256 err = journal_submit_inode_data_buffers(mapping);
259 spin_lock(&journal->j_list_lock);
260 J_ASSERT(jinode->i_transaction == commit_transaction);
261 jinode->i_flags &= ~JI_COMMIT_RUNNING;
262 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
264 spin_unlock(&journal->j_list_lock);
269 * Wait for data submitted for writeout, refile inodes to proper
270 * transaction if needed.
273 static int journal_finish_inode_data_buffers(journal_t *journal,
274 transaction_t *commit_transaction)
276 struct jbd2_inode *jinode, *next_i;
279 /* For locking, see the comment in journal_submit_data_buffers() */
280 spin_lock(&journal->j_list_lock);
281 list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
282 jinode->i_flags |= JI_COMMIT_RUNNING;
283 spin_unlock(&journal->j_list_lock);
284 err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
287 * Because AS_EIO is cleared by
288 * wait_on_page_writeback_range(), set it again so
289 * that user process can get -EIO from fsync().
292 &jinode->i_vfs_inode->i_mapping->flags);
297 spin_lock(&journal->j_list_lock);
298 jinode->i_flags &= ~JI_COMMIT_RUNNING;
299 wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
302 /* Now refile inode to proper lists */
303 list_for_each_entry_safe(jinode, next_i,
304 &commit_transaction->t_inode_list, i_list) {
305 list_del(&jinode->i_list);
306 if (jinode->i_next_transaction) {
307 jinode->i_transaction = jinode->i_next_transaction;
308 jinode->i_next_transaction = NULL;
309 list_add(&jinode->i_list,
310 &jinode->i_transaction->t_inode_list);
312 jinode->i_transaction = NULL;
315 spin_unlock(&journal->j_list_lock);
320 static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
322 struct page *page = bh->b_page;
326 addr = kmap_atomic(page, KM_USER0);
327 checksum = crc32_be(crc32_sum,
328 (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
329 kunmap_atomic(addr, KM_USER0);
334 static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
335 unsigned long long block)
337 tag->t_blocknr = cpu_to_be32(block & (u32)~0);
338 if (tag_bytes > JBD2_TAG_SIZE32)
339 tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
343 * jbd2_journal_commit_transaction
345 * The primary function for committing a transaction to the log. This
346 * function is called by the journal thread to begin a complete commit.
348 void jbd2_journal_commit_transaction(journal_t *journal)
350 struct transaction_stats_s stats;
351 transaction_t *commit_transaction;
352 struct journal_head *jh, *new_jh, *descriptor;
353 struct buffer_head **wbuf = journal->j_wbuf;
357 unsigned long long blocknr;
361 journal_header_t *header;
362 journal_block_tag_t *tag = NULL;
367 int tag_bytes = journal_tag_bytes(journal);
368 struct buffer_head *cbh = NULL; /* For transactional checksums */
369 __u32 crc32_sum = ~0;
370 int write_op = WRITE;
373 * First job: lock down the current transaction and wait for
374 * all outstanding updates to complete.
378 spin_lock(&journal->j_list_lock);
379 summarise_journal_usage(journal);
380 spin_unlock(&journal->j_list_lock);
383 /* Do we need to erase the effects of a prior jbd2_journal_flush? */
384 if (journal->j_flags & JBD2_FLUSHED) {
385 jbd_debug(3, "super block updated\n");
386 jbd2_journal_update_superblock(journal, 1);
388 jbd_debug(3, "superblock not updated\n");
391 J_ASSERT(journal->j_running_transaction != NULL);
392 J_ASSERT(journal->j_committing_transaction == NULL);
394 commit_transaction = journal->j_running_transaction;
395 J_ASSERT(commit_transaction->t_state == T_RUNNING);
397 trace_mark(jbd2_start_commit, "dev %s transaction %d",
398 journal->j_devname, commit_transaction->t_tid);
399 jbd_debug(1, "JBD: starting commit of transaction %d\n",
400 commit_transaction->t_tid);
402 spin_lock(&journal->j_state_lock);
403 commit_transaction->t_state = T_LOCKED;
406 * Use plugged writes here, since we want to submit several before
407 * we unplug the device. We don't do explicit unplugging in here,
408 * instead we rely on sync_buffer() doing the unplug for us.
410 if (commit_transaction->t_synchronous_commit)
411 write_op = WRITE_SYNC_PLUG;
412 stats.u.run.rs_wait = commit_transaction->t_max_wait;
413 stats.u.run.rs_locked = jiffies;
414 stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
415 stats.u.run.rs_locked);
417 spin_lock(&commit_transaction->t_handle_lock);
418 while (commit_transaction->t_updates) {
421 prepare_to_wait(&journal->j_wait_updates, &wait,
422 TASK_UNINTERRUPTIBLE);
423 if (commit_transaction->t_updates) {
424 spin_unlock(&commit_transaction->t_handle_lock);
425 spin_unlock(&journal->j_state_lock);
427 spin_lock(&journal->j_state_lock);
428 spin_lock(&commit_transaction->t_handle_lock);
430 finish_wait(&journal->j_wait_updates, &wait);
432 spin_unlock(&commit_transaction->t_handle_lock);
434 J_ASSERT (commit_transaction->t_outstanding_credits <=
435 journal->j_max_transaction_buffers);
438 * First thing we are allowed to do is to discard any remaining
439 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
440 * that there are no such buffers: if a large filesystem
441 * operation like a truncate needs to split itself over multiple
442 * transactions, then it may try to do a jbd2_journal_restart() while
443 * there are still BJ_Reserved buffers outstanding. These must
444 * be released cleanly from the current transaction.
446 * In this case, the filesystem must still reserve write access
447 * again before modifying the buffer in the new transaction, but
448 * we do not require it to remember exactly which old buffers it
449 * has reserved. This is consistent with the existing behaviour
450 * that multiple jbd2_journal_get_write_access() calls to the same
451 * buffer are perfectly permissable.
453 while (commit_transaction->t_reserved_list) {
454 jh = commit_transaction->t_reserved_list;
455 JBUFFER_TRACE(jh, "reserved, unused: refile");
457 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
458 * leave undo-committed data.
460 if (jh->b_committed_data) {
461 struct buffer_head *bh = jh2bh(jh);
463 jbd_lock_bh_state(bh);
464 jbd2_free(jh->b_committed_data, bh->b_size);
465 jh->b_committed_data = NULL;
466 jbd_unlock_bh_state(bh);
468 jbd2_journal_refile_buffer(journal, jh);
472 * Now try to drop any written-back buffers from the journal's
473 * checkpoint lists. We do this *before* commit because it potentially
476 spin_lock(&journal->j_list_lock);
477 __jbd2_journal_clean_checkpoint_list(journal);
478 spin_unlock(&journal->j_list_lock);
480 jbd_debug (3, "JBD: commit phase 1\n");
483 * Switch to a new revoke table.
485 jbd2_journal_switch_revoke_table(journal);
487 stats.u.run.rs_flushing = jiffies;
488 stats.u.run.rs_locked = jbd2_time_diff(stats.u.run.rs_locked,
489 stats.u.run.rs_flushing);
491 commit_transaction->t_state = T_FLUSH;
492 journal->j_committing_transaction = commit_transaction;
493 journal->j_running_transaction = NULL;
494 start_time = ktime_get();
495 commit_transaction->t_log_start = journal->j_head;
496 wake_up(&journal->j_wait_transaction_locked);
497 spin_unlock(&journal->j_state_lock);
499 jbd_debug (3, "JBD: commit phase 2\n");
502 * Now start flushing things to disk, in the order they appear
503 * on the transaction lists. Data blocks go first.
505 err = journal_submit_data_buffers(journal, commit_transaction);
507 jbd2_journal_abort(journal, err);
509 jbd2_journal_write_revoke_records(journal, commit_transaction,
512 jbd_debug(3, "JBD: commit phase 2\n");
515 * Way to go: we have now written out all of the data for a
516 * transaction! Now comes the tricky part: we need to write out
517 * metadata. Loop over the transaction's entire buffer list:
519 spin_lock(&journal->j_state_lock);
520 commit_transaction->t_state = T_COMMIT;
521 spin_unlock(&journal->j_state_lock);
523 stats.u.run.rs_logging = jiffies;
524 stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing,
525 stats.u.run.rs_logging);
526 stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
527 stats.u.run.rs_blocks_logged = 0;
529 J_ASSERT(commit_transaction->t_nr_buffers <=
530 commit_transaction->t_outstanding_credits);
535 while (commit_transaction->t_buffers) {
537 /* Find the next buffer to be journaled... */
539 jh = commit_transaction->t_buffers;
541 /* If we're in abort mode, we just un-journal the buffer and
544 if (is_journal_aborted(journal)) {
545 clear_buffer_jbddirty(jh2bh(jh));
546 JBUFFER_TRACE(jh, "journal is aborting: refile");
547 jbd2_buffer_abort_trigger(jh,
549 jh->b_frozen_triggers :
551 jbd2_journal_refile_buffer(journal, jh);
552 /* If that was the last one, we need to clean up
553 * any descriptor buffers which may have been
554 * already allocated, even if we are now
556 if (!commit_transaction->t_buffers)
557 goto start_journal_io;
561 /* Make sure we have a descriptor block in which to
562 record the metadata buffer. */
565 struct buffer_head *bh;
567 J_ASSERT (bufs == 0);
569 jbd_debug(4, "JBD: get descriptor\n");
571 descriptor = jbd2_journal_get_descriptor_buffer(journal);
573 jbd2_journal_abort(journal, -EIO);
577 bh = jh2bh(descriptor);
578 jbd_debug(4, "JBD: got buffer %llu (%p)\n",
579 (unsigned long long)bh->b_blocknr, bh->b_data);
580 header = (journal_header_t *)&bh->b_data[0];
581 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
582 header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK);
583 header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
585 tagp = &bh->b_data[sizeof(journal_header_t)];
586 space_left = bh->b_size - sizeof(journal_header_t);
588 set_buffer_jwrite(bh);
589 set_buffer_dirty(bh);
592 /* Record it so that we can wait for IO
594 BUFFER_TRACE(bh, "ph3: file as descriptor");
595 jbd2_journal_file_buffer(descriptor, commit_transaction,
599 /* Where is the buffer to be written? */
601 err = jbd2_journal_next_log_block(journal, &blocknr);
602 /* If the block mapping failed, just abandon the buffer
603 and repeat this loop: we'll fall into the
604 refile-on-abort condition above. */
606 jbd2_journal_abort(journal, err);
611 * start_this_handle() uses t_outstanding_credits to determine
612 * the free space in the log, but this counter is changed
613 * by jbd2_journal_next_log_block() also.
615 commit_transaction->t_outstanding_credits--;
617 /* Bump b_count to prevent truncate from stumbling over
618 the shadowed buffer! @@@ This can go if we ever get
619 rid of the BJ_IO/BJ_Shadow pairing of buffers. */
620 atomic_inc(&jh2bh(jh)->b_count);
622 /* Make a temporary IO buffer with which to write it out
623 (this will requeue both the metadata buffer and the
624 temporary IO buffer). new_bh goes on BJ_IO*/
626 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
628 * akpm: jbd2_journal_write_metadata_buffer() sets
629 * new_bh->b_transaction to commit_transaction.
630 * We need to clean this up before we release new_bh
631 * (which is of type BJ_IO)
633 JBUFFER_TRACE(jh, "ph3: write metadata");
634 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
635 jh, &new_jh, blocknr);
636 set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
637 wbuf[bufs++] = jh2bh(new_jh);
639 /* Record the new block's tag in the current descriptor
644 tag_flag |= JBD2_FLAG_ESCAPE;
646 tag_flag |= JBD2_FLAG_SAME_UUID;
648 tag = (journal_block_tag_t *) tagp;
649 write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
650 tag->t_flags = cpu_to_be32(tag_flag);
652 space_left -= tag_bytes;
655 memcpy (tagp, journal->j_uuid, 16);
661 /* If there's no more to do, or if the descriptor is full,
664 if (bufs == journal->j_wbufsize ||
665 commit_transaction->t_buffers == NULL ||
666 space_left < tag_bytes + 16) {
668 jbd_debug(4, "JBD: Submit %d IOs\n", bufs);
670 /* Write an end-of-descriptor marker before
671 submitting the IOs. "tag" still points to
672 the last tag we set up. */
674 tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG);
677 for (i = 0; i < bufs; i++) {
678 struct buffer_head *bh = wbuf[i];
682 if (JBD2_HAS_COMPAT_FEATURE(journal,
683 JBD2_FEATURE_COMPAT_CHECKSUM)) {
685 jbd2_checksum_data(crc32_sum, bh);
689 clear_buffer_dirty(bh);
690 set_buffer_uptodate(bh);
691 bh->b_end_io = journal_end_buffer_io_sync;
692 submit_bh(write_op, bh);
695 stats.u.run.rs_blocks_logged += bufs;
697 /* Force a new descriptor to be generated next
698 time round the loop. */
704 /* Done it all: now write the commit record asynchronously. */
706 if (JBD2_HAS_INCOMPAT_FEATURE(journal,
707 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
708 err = journal_submit_commit_record(journal, commit_transaction,
711 __jbd2_journal_abort_hard(journal);
715 * This is the right place to wait for data buffers both for ASYNC
716 * and !ASYNC commit. If commit is ASYNC, we need to wait only after
717 * the commit block went to disk (which happens above). If commit is
718 * SYNC, we need to wait for data buffers before we start writing
719 * commit block, which happens below in such setting.
721 err = journal_finish_inode_data_buffers(journal, commit_transaction);
724 "JBD2: Detected IO errors while flushing file data "
725 "on %s\n", journal->j_devname);
726 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
727 jbd2_journal_abort(journal, err);
731 /* Lo and behold: we have just managed to send a transaction to
732 the log. Before we can commit it, wait for the IO so far to
733 complete. Control buffers being written are on the
734 transaction's t_log_list queue, and metadata buffers are on
735 the t_iobuf_list queue.
737 Wait for the buffers in reverse order. That way we are
738 less likely to be woken up until all IOs have completed, and
739 so we incur less scheduling load.
742 jbd_debug(3, "JBD: commit phase 3\n");
745 * akpm: these are BJ_IO, and j_list_lock is not needed.
746 * See __journal_try_to_free_buffer.
749 while (commit_transaction->t_iobuf_list != NULL) {
750 struct buffer_head *bh;
752 jh = commit_transaction->t_iobuf_list->b_tprev;
754 if (buffer_locked(bh)) {
761 if (unlikely(!buffer_uptodate(bh)))
764 clear_buffer_jwrite(bh);
766 JBUFFER_TRACE(jh, "ph4: unfile after journal write");
767 jbd2_journal_unfile_buffer(journal, jh);
770 * ->t_iobuf_list should contain only dummy buffer_heads
771 * which were created by jbd2_journal_write_metadata_buffer().
773 BUFFER_TRACE(bh, "dumping temporary bh");
774 jbd2_journal_put_journal_head(jh);
776 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
777 free_buffer_head(bh);
779 /* We also have to unlock and free the corresponding
781 jh = commit_transaction->t_shadow_list->b_tprev;
783 clear_bit(BH_JWrite, &bh->b_state);
784 J_ASSERT_BH(bh, buffer_jbddirty(bh));
786 /* The metadata is now released for reuse, but we need
787 to remember it against this transaction so that when
788 we finally commit, we can do any checkpointing
790 JBUFFER_TRACE(jh, "file as BJ_Forget");
791 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
792 /* Wake up any transactions which were waiting for this
794 wake_up_bit(&bh->b_state, BH_Unshadow);
795 JBUFFER_TRACE(jh, "brelse shadowed buffer");
799 J_ASSERT (commit_transaction->t_shadow_list == NULL);
801 jbd_debug(3, "JBD: commit phase 4\n");
803 /* Here we wait for the revoke record and descriptor record buffers */
805 while (commit_transaction->t_log_list != NULL) {
806 struct buffer_head *bh;
808 jh = commit_transaction->t_log_list->b_tprev;
810 if (buffer_locked(bh)) {
812 goto wait_for_ctlbuf;
815 goto wait_for_ctlbuf;
817 if (unlikely(!buffer_uptodate(bh)))
820 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
821 clear_buffer_jwrite(bh);
822 jbd2_journal_unfile_buffer(journal, jh);
823 jbd2_journal_put_journal_head(jh);
824 __brelse(bh); /* One for getblk */
825 /* AKPM: bforget here */
829 jbd2_journal_abort(journal, err);
831 jbd_debug(3, "JBD: commit phase 5\n");
833 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
834 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
835 err = journal_submit_commit_record(journal, commit_transaction,
838 __jbd2_journal_abort_hard(journal);
840 if (!err && !is_journal_aborted(journal))
841 err = journal_wait_on_commit_record(journal, cbh);
844 jbd2_journal_abort(journal, err);
846 /* End of a transaction! Finally, we can do checkpoint
847 processing: any buffers committed as a result of this
848 transaction can be removed from any checkpoint list it was on
851 jbd_debug(3, "JBD: commit phase 6\n");
853 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
854 J_ASSERT(commit_transaction->t_buffers == NULL);
855 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
856 J_ASSERT(commit_transaction->t_iobuf_list == NULL);
857 J_ASSERT(commit_transaction->t_shadow_list == NULL);
858 J_ASSERT(commit_transaction->t_log_list == NULL);
862 * As there are other places (journal_unmap_buffer()) adding buffers
863 * to this list we have to be careful and hold the j_list_lock.
865 spin_lock(&journal->j_list_lock);
866 while (commit_transaction->t_forget) {
867 transaction_t *cp_transaction;
868 struct buffer_head *bh;
870 jh = commit_transaction->t_forget;
871 spin_unlock(&journal->j_list_lock);
873 jbd_lock_bh_state(bh);
874 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction ||
875 jh->b_transaction == journal->j_running_transaction);
878 * If there is undo-protected committed data against
879 * this buffer, then we can remove it now. If it is a
880 * buffer needing such protection, the old frozen_data
881 * field now points to a committed version of the
882 * buffer, so rotate that field to the new committed
885 * Otherwise, we can just throw away the frozen data now.
887 * We also know that the frozen data has already fired
888 * its triggers if they exist, so we can clear that too.
890 if (jh->b_committed_data) {
891 jbd2_free(jh->b_committed_data, bh->b_size);
892 jh->b_committed_data = NULL;
893 if (jh->b_frozen_data) {
894 jh->b_committed_data = jh->b_frozen_data;
895 jh->b_frozen_data = NULL;
896 jh->b_frozen_triggers = NULL;
898 } else if (jh->b_frozen_data) {
899 jbd2_free(jh->b_frozen_data, bh->b_size);
900 jh->b_frozen_data = NULL;
901 jh->b_frozen_triggers = NULL;
904 spin_lock(&journal->j_list_lock);
905 cp_transaction = jh->b_cp_transaction;
906 if (cp_transaction) {
907 JBUFFER_TRACE(jh, "remove from old cp transaction");
908 cp_transaction->t_chp_stats.cs_dropped++;
909 __jbd2_journal_remove_checkpoint(jh);
912 /* Only re-checkpoint the buffer_head if it is marked
913 * dirty. If the buffer was added to the BJ_Forget list
914 * by jbd2_journal_forget, it may no longer be dirty and
915 * there's no point in keeping a checkpoint record for
918 /* A buffer which has been freed while still being
919 * journaled by a previous transaction may end up still
920 * being dirty here, but we want to avoid writing back
921 * that buffer in the future now that the last use has
922 * been committed. That's not only a performance gain,
923 * it also stops aliasing problems if the buffer is left
924 * behind for writeback and gets reallocated for another
925 * use in a different page. */
926 if (buffer_freed(bh)) {
927 clear_buffer_freed(bh);
928 clear_buffer_jbddirty(bh);
931 if (buffer_jbddirty(bh)) {
932 JBUFFER_TRACE(jh, "add to new checkpointing trans");
933 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
934 if (is_journal_aborted(journal))
935 clear_buffer_jbddirty(bh);
936 JBUFFER_TRACE(jh, "refile for checkpoint writeback");
937 __jbd2_journal_refile_buffer(jh);
938 jbd_unlock_bh_state(bh);
940 J_ASSERT_BH(bh, !buffer_dirty(bh));
941 /* The buffer on BJ_Forget list and not jbddirty means
942 * it has been freed by this transaction and hence it
943 * could not have been reallocated until this
944 * transaction has committed. *BUT* it could be
945 * reallocated once we have written all the data to
946 * disk and before we process the buffer on BJ_Forget
948 JBUFFER_TRACE(jh, "refile or unfile freed buffer");
949 __jbd2_journal_refile_buffer(jh);
950 if (!jh->b_transaction) {
951 jbd_unlock_bh_state(bh);
953 jbd2_journal_remove_journal_head(bh);
954 release_buffer_page(bh);
956 jbd_unlock_bh_state(bh);
958 cond_resched_lock(&journal->j_list_lock);
960 spin_unlock(&journal->j_list_lock);
962 * This is a bit sleazy. We use j_list_lock to protect transition
963 * of a transaction into T_FINISHED state and calling
964 * __jbd2_journal_drop_transaction(). Otherwise we could race with
965 * other checkpointing code processing the transaction...
967 spin_lock(&journal->j_state_lock);
968 spin_lock(&journal->j_list_lock);
970 * Now recheck if some buffers did not get attached to the transaction
971 * while the lock was dropped...
973 if (commit_transaction->t_forget) {
974 spin_unlock(&journal->j_list_lock);
975 spin_unlock(&journal->j_state_lock);
979 /* Done with this transaction! */
981 jbd_debug(3, "JBD: commit phase 7\n");
983 J_ASSERT(commit_transaction->t_state == T_COMMIT);
985 commit_transaction->t_start = jiffies;
986 stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging,
987 commit_transaction->t_start);
990 * File the transaction for history
992 stats.ts_type = JBD2_STATS_RUN;
993 stats.ts_tid = commit_transaction->t_tid;
994 stats.u.run.rs_handle_count = commit_transaction->t_handle_count;
995 spin_lock(&journal->j_history_lock);
996 memcpy(journal->j_history + journal->j_history_cur, &stats,
998 if (++journal->j_history_cur == journal->j_history_max)
999 journal->j_history_cur = 0;
1002 * Calculate overall stats
1004 journal->j_stats.ts_tid++;
1005 journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait;
1006 journal->j_stats.u.run.rs_running += stats.u.run.rs_running;
1007 journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked;
1008 journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing;
1009 journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging;
1010 journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count;
1011 journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks;
1012 journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged;
1013 spin_unlock(&journal->j_history_lock);
1015 commit_transaction->t_state = T_FINISHED;
1016 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1017 journal->j_commit_sequence = commit_transaction->t_tid;
1018 journal->j_committing_transaction = NULL;
1019 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1022 * weight the commit time higher than the average time so we don't
1023 * react too strongly to vast changes in the commit time
1025 if (likely(journal->j_average_commit_time))
1026 journal->j_average_commit_time = (commit_time +
1027 journal->j_average_commit_time*3) / 4;
1029 journal->j_average_commit_time = commit_time;
1030 spin_unlock(&journal->j_state_lock);
1032 if (commit_transaction->t_checkpoint_list == NULL &&
1033 commit_transaction->t_checkpoint_io_list == NULL) {
1034 __jbd2_journal_drop_transaction(journal, commit_transaction);
1037 if (journal->j_checkpoint_transactions == NULL) {
1038 journal->j_checkpoint_transactions = commit_transaction;
1039 commit_transaction->t_cpnext = commit_transaction;
1040 commit_transaction->t_cpprev = commit_transaction;
1042 commit_transaction->t_cpnext =
1043 journal->j_checkpoint_transactions;
1044 commit_transaction->t_cpprev =
1045 commit_transaction->t_cpnext->t_cpprev;
1046 commit_transaction->t_cpnext->t_cpprev =
1048 commit_transaction->t_cpprev->t_cpnext =
1052 spin_unlock(&journal->j_list_lock);
1054 if (journal->j_commit_callback)
1055 journal->j_commit_callback(journal, commit_transaction);
1057 trace_mark(jbd2_end_commit, "dev %s transaction %d head %d",
1058 journal->j_devname, commit_transaction->t_tid,
1059 journal->j_tail_sequence);
1060 jbd_debug(1, "JBD: commit %d complete, head %d\n",
1061 journal->j_commit_sequence, journal->j_tail_sequence);
1063 kfree(commit_transaction);
1065 wake_up(&journal->j_wait_done_commit);