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);
511 jbd_debug(3, "JBD: commit phase 2\n");
514 * Way to go: we have now written out all of the data for a
515 * transaction! Now comes the tricky part: we need to write out
516 * metadata. Loop over the transaction's entire buffer list:
518 spin_lock(&journal->j_state_lock);
519 commit_transaction->t_state = T_COMMIT;
520 spin_unlock(&journal->j_state_lock);
522 stats.u.run.rs_logging = jiffies;
523 stats.u.run.rs_flushing = jbd2_time_diff(stats.u.run.rs_flushing,
524 stats.u.run.rs_logging);
525 stats.u.run.rs_blocks = commit_transaction->t_outstanding_credits;
526 stats.u.run.rs_blocks_logged = 0;
528 J_ASSERT(commit_transaction->t_nr_buffers <=
529 commit_transaction->t_outstanding_credits);
534 while (commit_transaction->t_buffers) {
536 /* Find the next buffer to be journaled... */
538 jh = commit_transaction->t_buffers;
540 /* If we're in abort mode, we just un-journal the buffer and
543 if (is_journal_aborted(journal)) {
544 clear_buffer_jbddirty(jh2bh(jh));
545 JBUFFER_TRACE(jh, "journal is aborting: refile");
546 jbd2_buffer_abort_trigger(jh,
548 jh->b_frozen_triggers :
550 jbd2_journal_refile_buffer(journal, jh);
551 /* If that was the last one, we need to clean up
552 * any descriptor buffers which may have been
553 * already allocated, even if we are now
555 if (!commit_transaction->t_buffers)
556 goto start_journal_io;
560 /* Make sure we have a descriptor block in which to
561 record the metadata buffer. */
564 struct buffer_head *bh;
566 J_ASSERT (bufs == 0);
568 jbd_debug(4, "JBD: get descriptor\n");
570 descriptor = jbd2_journal_get_descriptor_buffer(journal);
572 jbd2_journal_abort(journal, -EIO);
576 bh = jh2bh(descriptor);
577 jbd_debug(4, "JBD: got buffer %llu (%p)\n",
578 (unsigned long long)bh->b_blocknr, bh->b_data);
579 header = (journal_header_t *)&bh->b_data[0];
580 header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
581 header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK);
582 header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
584 tagp = &bh->b_data[sizeof(journal_header_t)];
585 space_left = bh->b_size - sizeof(journal_header_t);
587 set_buffer_jwrite(bh);
588 set_buffer_dirty(bh);
591 /* Record it so that we can wait for IO
593 BUFFER_TRACE(bh, "ph3: file as descriptor");
594 jbd2_journal_file_buffer(descriptor, commit_transaction,
598 /* Where is the buffer to be written? */
600 err = jbd2_journal_next_log_block(journal, &blocknr);
601 /* If the block mapping failed, just abandon the buffer
602 and repeat this loop: we'll fall into the
603 refile-on-abort condition above. */
605 jbd2_journal_abort(journal, err);
610 * start_this_handle() uses t_outstanding_credits to determine
611 * the free space in the log, but this counter is changed
612 * by jbd2_journal_next_log_block() also.
614 commit_transaction->t_outstanding_credits--;
616 /* Bump b_count to prevent truncate from stumbling over
617 the shadowed buffer! @@@ This can go if we ever get
618 rid of the BJ_IO/BJ_Shadow pairing of buffers. */
619 atomic_inc(&jh2bh(jh)->b_count);
621 /* Make a temporary IO buffer with which to write it out
622 (this will requeue both the metadata buffer and the
623 temporary IO buffer). new_bh goes on BJ_IO*/
625 set_bit(BH_JWrite, &jh2bh(jh)->b_state);
627 * akpm: jbd2_journal_write_metadata_buffer() sets
628 * new_bh->b_transaction to commit_transaction.
629 * We need to clean this up before we release new_bh
630 * (which is of type BJ_IO)
632 JBUFFER_TRACE(jh, "ph3: write metadata");
633 flags = jbd2_journal_write_metadata_buffer(commit_transaction,
634 jh, &new_jh, blocknr);
635 set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
636 wbuf[bufs++] = jh2bh(new_jh);
638 /* Record the new block's tag in the current descriptor
643 tag_flag |= JBD2_FLAG_ESCAPE;
645 tag_flag |= JBD2_FLAG_SAME_UUID;
647 tag = (journal_block_tag_t *) tagp;
648 write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
649 tag->t_flags = cpu_to_be32(tag_flag);
651 space_left -= tag_bytes;
654 memcpy (tagp, journal->j_uuid, 16);
660 /* If there's no more to do, or if the descriptor is full,
663 if (bufs == journal->j_wbufsize ||
664 commit_transaction->t_buffers == NULL ||
665 space_left < tag_bytes + 16) {
667 jbd_debug(4, "JBD: Submit %d IOs\n", bufs);
669 /* Write an end-of-descriptor marker before
670 submitting the IOs. "tag" still points to
671 the last tag we set up. */
673 tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG);
676 for (i = 0; i < bufs; i++) {
677 struct buffer_head *bh = wbuf[i];
681 if (JBD2_HAS_COMPAT_FEATURE(journal,
682 JBD2_FEATURE_COMPAT_CHECKSUM)) {
684 jbd2_checksum_data(crc32_sum, bh);
688 clear_buffer_dirty(bh);
689 set_buffer_uptodate(bh);
690 bh->b_end_io = journal_end_buffer_io_sync;
691 submit_bh(write_op, bh);
694 stats.u.run.rs_blocks_logged += bufs;
696 /* Force a new descriptor to be generated next
697 time round the loop. */
703 /* Done it all: now write the commit record asynchronously. */
705 if (JBD2_HAS_INCOMPAT_FEATURE(journal,
706 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
707 err = journal_submit_commit_record(journal, commit_transaction,
710 __jbd2_journal_abort_hard(journal);
714 * This is the right place to wait for data buffers both for ASYNC
715 * and !ASYNC commit. If commit is ASYNC, we need to wait only after
716 * the commit block went to disk (which happens above). If commit is
717 * SYNC, we need to wait for data buffers before we start writing
718 * commit block, which happens below in such setting.
720 err = journal_finish_inode_data_buffers(journal, commit_transaction);
723 "JBD2: Detected IO errors while flushing file data "
724 "on %s\n", journal->j_devname);
725 if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
726 jbd2_journal_abort(journal, err);
730 /* Lo and behold: we have just managed to send a transaction to
731 the log. Before we can commit it, wait for the IO so far to
732 complete. Control buffers being written are on the
733 transaction's t_log_list queue, and metadata buffers are on
734 the t_iobuf_list queue.
736 Wait for the buffers in reverse order. That way we are
737 less likely to be woken up until all IOs have completed, and
738 so we incur less scheduling load.
741 jbd_debug(3, "JBD: commit phase 3\n");
744 * akpm: these are BJ_IO, and j_list_lock is not needed.
745 * See __journal_try_to_free_buffer.
748 while (commit_transaction->t_iobuf_list != NULL) {
749 struct buffer_head *bh;
751 jh = commit_transaction->t_iobuf_list->b_tprev;
753 if (buffer_locked(bh)) {
760 if (unlikely(!buffer_uptodate(bh)))
763 clear_buffer_jwrite(bh);
765 JBUFFER_TRACE(jh, "ph4: unfile after journal write");
766 jbd2_journal_unfile_buffer(journal, jh);
769 * ->t_iobuf_list should contain only dummy buffer_heads
770 * which were created by jbd2_journal_write_metadata_buffer().
772 BUFFER_TRACE(bh, "dumping temporary bh");
773 jbd2_journal_put_journal_head(jh);
775 J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
776 free_buffer_head(bh);
778 /* We also have to unlock and free the corresponding
780 jh = commit_transaction->t_shadow_list->b_tprev;
782 clear_bit(BH_JWrite, &bh->b_state);
783 J_ASSERT_BH(bh, buffer_jbddirty(bh));
785 /* The metadata is now released for reuse, but we need
786 to remember it against this transaction so that when
787 we finally commit, we can do any checkpointing
789 JBUFFER_TRACE(jh, "file as BJ_Forget");
790 jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
791 /* Wake up any transactions which were waiting for this
793 wake_up_bit(&bh->b_state, BH_Unshadow);
794 JBUFFER_TRACE(jh, "brelse shadowed buffer");
798 J_ASSERT (commit_transaction->t_shadow_list == NULL);
800 jbd_debug(3, "JBD: commit phase 4\n");
802 /* Here we wait for the revoke record and descriptor record buffers */
804 while (commit_transaction->t_log_list != NULL) {
805 struct buffer_head *bh;
807 jh = commit_transaction->t_log_list->b_tprev;
809 if (buffer_locked(bh)) {
811 goto wait_for_ctlbuf;
814 goto wait_for_ctlbuf;
816 if (unlikely(!buffer_uptodate(bh)))
819 BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
820 clear_buffer_jwrite(bh);
821 jbd2_journal_unfile_buffer(journal, jh);
822 jbd2_journal_put_journal_head(jh);
823 __brelse(bh); /* One for getblk */
824 /* AKPM: bforget here */
828 jbd2_journal_abort(journal, err);
830 jbd_debug(3, "JBD: commit phase 5\n");
832 if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
833 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
834 err = journal_submit_commit_record(journal, commit_transaction,
837 __jbd2_journal_abort_hard(journal);
839 if (!err && !is_journal_aborted(journal))
840 err = journal_wait_on_commit_record(journal, cbh);
843 jbd2_journal_abort(journal, err);
845 /* End of a transaction! Finally, we can do checkpoint
846 processing: any buffers committed as a result of this
847 transaction can be removed from any checkpoint list it was on
850 jbd_debug(3, "JBD: commit phase 6\n");
852 J_ASSERT(list_empty(&commit_transaction->t_inode_list));
853 J_ASSERT(commit_transaction->t_buffers == NULL);
854 J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
855 J_ASSERT(commit_transaction->t_iobuf_list == NULL);
856 J_ASSERT(commit_transaction->t_shadow_list == NULL);
857 J_ASSERT(commit_transaction->t_log_list == NULL);
861 * As there are other places (journal_unmap_buffer()) adding buffers
862 * to this list we have to be careful and hold the j_list_lock.
864 spin_lock(&journal->j_list_lock);
865 while (commit_transaction->t_forget) {
866 transaction_t *cp_transaction;
867 struct buffer_head *bh;
869 jh = commit_transaction->t_forget;
870 spin_unlock(&journal->j_list_lock);
872 jbd_lock_bh_state(bh);
873 J_ASSERT_JH(jh, jh->b_transaction == commit_transaction ||
874 jh->b_transaction == journal->j_running_transaction);
877 * If there is undo-protected committed data against
878 * this buffer, then we can remove it now. If it is a
879 * buffer needing such protection, the old frozen_data
880 * field now points to a committed version of the
881 * buffer, so rotate that field to the new committed
884 * Otherwise, we can just throw away the frozen data now.
886 * We also know that the frozen data has already fired
887 * its triggers if they exist, so we can clear that too.
889 if (jh->b_committed_data) {
890 jbd2_free(jh->b_committed_data, bh->b_size);
891 jh->b_committed_data = NULL;
892 if (jh->b_frozen_data) {
893 jh->b_committed_data = jh->b_frozen_data;
894 jh->b_frozen_data = NULL;
895 jh->b_frozen_triggers = NULL;
897 } else if (jh->b_frozen_data) {
898 jbd2_free(jh->b_frozen_data, bh->b_size);
899 jh->b_frozen_data = NULL;
900 jh->b_frozen_triggers = NULL;
903 spin_lock(&journal->j_list_lock);
904 cp_transaction = jh->b_cp_transaction;
905 if (cp_transaction) {
906 JBUFFER_TRACE(jh, "remove from old cp transaction");
907 cp_transaction->t_chp_stats.cs_dropped++;
908 __jbd2_journal_remove_checkpoint(jh);
911 /* Only re-checkpoint the buffer_head if it is marked
912 * dirty. If the buffer was added to the BJ_Forget list
913 * by jbd2_journal_forget, it may no longer be dirty and
914 * there's no point in keeping a checkpoint record for
917 /* A buffer which has been freed while still being
918 * journaled by a previous transaction may end up still
919 * being dirty here, but we want to avoid writing back
920 * that buffer in the future now that the last use has
921 * been committed. That's not only a performance gain,
922 * it also stops aliasing problems if the buffer is left
923 * behind for writeback and gets reallocated for another
924 * use in a different page. */
925 if (buffer_freed(bh)) {
926 clear_buffer_freed(bh);
927 clear_buffer_jbddirty(bh);
930 if (buffer_jbddirty(bh)) {
931 JBUFFER_TRACE(jh, "add to new checkpointing trans");
932 __jbd2_journal_insert_checkpoint(jh, commit_transaction);
933 if (is_journal_aborted(journal))
934 clear_buffer_jbddirty(bh);
935 JBUFFER_TRACE(jh, "refile for checkpoint writeback");
936 __jbd2_journal_refile_buffer(jh);
937 jbd_unlock_bh_state(bh);
939 J_ASSERT_BH(bh, !buffer_dirty(bh));
940 /* The buffer on BJ_Forget list and not jbddirty means
941 * it has been freed by this transaction and hence it
942 * could not have been reallocated until this
943 * transaction has committed. *BUT* it could be
944 * reallocated once we have written all the data to
945 * disk and before we process the buffer on BJ_Forget
947 JBUFFER_TRACE(jh, "refile or unfile freed buffer");
948 __jbd2_journal_refile_buffer(jh);
949 if (!jh->b_transaction) {
950 jbd_unlock_bh_state(bh);
952 jbd2_journal_remove_journal_head(bh);
953 release_buffer_page(bh);
955 jbd_unlock_bh_state(bh);
957 cond_resched_lock(&journal->j_list_lock);
959 spin_unlock(&journal->j_list_lock);
961 * This is a bit sleazy. We use j_list_lock to protect transition
962 * of a transaction into T_FINISHED state and calling
963 * __jbd2_journal_drop_transaction(). Otherwise we could race with
964 * other checkpointing code processing the transaction...
966 spin_lock(&journal->j_state_lock);
967 spin_lock(&journal->j_list_lock);
969 * Now recheck if some buffers did not get attached to the transaction
970 * while the lock was dropped...
972 if (commit_transaction->t_forget) {
973 spin_unlock(&journal->j_list_lock);
974 spin_unlock(&journal->j_state_lock);
978 /* Done with this transaction! */
980 jbd_debug(3, "JBD: commit phase 7\n");
982 J_ASSERT(commit_transaction->t_state == T_COMMIT);
984 commit_transaction->t_start = jiffies;
985 stats.u.run.rs_logging = jbd2_time_diff(stats.u.run.rs_logging,
986 commit_transaction->t_start);
989 * File the transaction for history
991 stats.ts_type = JBD2_STATS_RUN;
992 stats.ts_tid = commit_transaction->t_tid;
993 stats.u.run.rs_handle_count = commit_transaction->t_handle_count;
994 spin_lock(&journal->j_history_lock);
995 memcpy(journal->j_history + journal->j_history_cur, &stats,
997 if (++journal->j_history_cur == journal->j_history_max)
998 journal->j_history_cur = 0;
1001 * Calculate overall stats
1003 journal->j_stats.ts_tid++;
1004 journal->j_stats.u.run.rs_wait += stats.u.run.rs_wait;
1005 journal->j_stats.u.run.rs_running += stats.u.run.rs_running;
1006 journal->j_stats.u.run.rs_locked += stats.u.run.rs_locked;
1007 journal->j_stats.u.run.rs_flushing += stats.u.run.rs_flushing;
1008 journal->j_stats.u.run.rs_logging += stats.u.run.rs_logging;
1009 journal->j_stats.u.run.rs_handle_count += stats.u.run.rs_handle_count;
1010 journal->j_stats.u.run.rs_blocks += stats.u.run.rs_blocks;
1011 journal->j_stats.u.run.rs_blocks_logged += stats.u.run.rs_blocks_logged;
1012 spin_unlock(&journal->j_history_lock);
1014 commit_transaction->t_state = T_FINISHED;
1015 J_ASSERT(commit_transaction == journal->j_committing_transaction);
1016 journal->j_commit_sequence = commit_transaction->t_tid;
1017 journal->j_committing_transaction = NULL;
1018 commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
1021 * weight the commit time higher than the average time so we don't
1022 * react too strongly to vast changes in the commit time
1024 if (likely(journal->j_average_commit_time))
1025 journal->j_average_commit_time = (commit_time +
1026 journal->j_average_commit_time*3) / 4;
1028 journal->j_average_commit_time = commit_time;
1029 spin_unlock(&journal->j_state_lock);
1031 if (commit_transaction->t_checkpoint_list == NULL &&
1032 commit_transaction->t_checkpoint_io_list == NULL) {
1033 __jbd2_journal_drop_transaction(journal, commit_transaction);
1036 if (journal->j_checkpoint_transactions == NULL) {
1037 journal->j_checkpoint_transactions = commit_transaction;
1038 commit_transaction->t_cpnext = commit_transaction;
1039 commit_transaction->t_cpprev = commit_transaction;
1041 commit_transaction->t_cpnext =
1042 journal->j_checkpoint_transactions;
1043 commit_transaction->t_cpprev =
1044 commit_transaction->t_cpnext->t_cpprev;
1045 commit_transaction->t_cpnext->t_cpprev =
1047 commit_transaction->t_cpprev->t_cpnext =
1051 spin_unlock(&journal->j_list_lock);
1053 if (journal->j_commit_callback)
1054 journal->j_commit_callback(journal, commit_transaction);
1056 trace_mark(jbd2_end_commit, "dev %s transaction %d head %d",
1057 journal->j_devname, commit_transaction->t_tid,
1058 journal->j_tail_sequence);
1059 jbd_debug(1, "JBD: commit %d complete, head %d\n",
1060 journal->j_commit_sequence, journal->j_tail_sequence);
1062 kfree(commit_transaction);
1064 wake_up(&journal->j_wait_done_commit);