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
, 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
, 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
, 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
;
405 if (commit_transaction
->t_synchronous_commit
)
406 write_op
= WRITE_SYNC
;
407 stats
.u
.run
.rs_wait
= commit_transaction
->t_max_wait
;
408 stats
.u
.run
.rs_locked
= jiffies
;
409 stats
.u
.run
.rs_running
= jbd2_time_diff(commit_transaction
->t_start
,
410 stats
.u
.run
.rs_locked
);
412 spin_lock(&commit_transaction
->t_handle_lock
);
413 while (commit_transaction
->t_updates
) {
416 prepare_to_wait(&journal
->j_wait_updates
, &wait
,
417 TASK_UNINTERRUPTIBLE
);
418 if (commit_transaction
->t_updates
) {
419 spin_unlock(&commit_transaction
->t_handle_lock
);
420 spin_unlock(&journal
->j_state_lock
);
422 spin_lock(&journal
->j_state_lock
);
423 spin_lock(&commit_transaction
->t_handle_lock
);
425 finish_wait(&journal
->j_wait_updates
, &wait
);
427 spin_unlock(&commit_transaction
->t_handle_lock
);
429 J_ASSERT (commit_transaction
->t_outstanding_credits
<=
430 journal
->j_max_transaction_buffers
);
433 * First thing we are allowed to do is to discard any remaining
434 * BJ_Reserved buffers. Note, it is _not_ permissible to assume
435 * that there are no such buffers: if a large filesystem
436 * operation like a truncate needs to split itself over multiple
437 * transactions, then it may try to do a jbd2_journal_restart() while
438 * there are still BJ_Reserved buffers outstanding. These must
439 * be released cleanly from the current transaction.
441 * In this case, the filesystem must still reserve write access
442 * again before modifying the buffer in the new transaction, but
443 * we do not require it to remember exactly which old buffers it
444 * has reserved. This is consistent with the existing behaviour
445 * that multiple jbd2_journal_get_write_access() calls to the same
446 * buffer are perfectly permissable.
448 while (commit_transaction
->t_reserved_list
) {
449 jh
= commit_transaction
->t_reserved_list
;
450 JBUFFER_TRACE(jh
, "reserved, unused: refile");
452 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
453 * leave undo-committed data.
455 if (jh
->b_committed_data
) {
456 struct buffer_head
*bh
= jh2bh(jh
);
458 jbd_lock_bh_state(bh
);
459 jbd2_free(jh
->b_committed_data
, bh
->b_size
);
460 jh
->b_committed_data
= NULL
;
461 jbd_unlock_bh_state(bh
);
463 jbd2_journal_refile_buffer(journal
, jh
);
467 * Now try to drop any written-back buffers from the journal's
468 * checkpoint lists. We do this *before* commit because it potentially
471 spin_lock(&journal
->j_list_lock
);
472 __jbd2_journal_clean_checkpoint_list(journal
);
473 spin_unlock(&journal
->j_list_lock
);
475 jbd_debug (3, "JBD: commit phase 1\n");
478 * Switch to a new revoke table.
480 jbd2_journal_switch_revoke_table(journal
);
482 stats
.u
.run
.rs_flushing
= jiffies
;
483 stats
.u
.run
.rs_locked
= jbd2_time_diff(stats
.u
.run
.rs_locked
,
484 stats
.u
.run
.rs_flushing
);
486 commit_transaction
->t_state
= T_FLUSH
;
487 journal
->j_committing_transaction
= commit_transaction
;
488 journal
->j_running_transaction
= NULL
;
489 start_time
= ktime_get();
490 commit_transaction
->t_log_start
= journal
->j_head
;
491 wake_up(&journal
->j_wait_transaction_locked
);
492 spin_unlock(&journal
->j_state_lock
);
494 jbd_debug (3, "JBD: commit phase 2\n");
497 * Now start flushing things to disk, in the order they appear
498 * on the transaction lists. Data blocks go first.
500 err
= journal_submit_data_buffers(journal
, commit_transaction
);
502 jbd2_journal_abort(journal
, err
);
504 jbd2_journal_write_revoke_records(journal
, commit_transaction
);
506 jbd_debug(3, "JBD: commit phase 2\n");
509 * Way to go: we have now written out all of the data for a
510 * transaction! Now comes the tricky part: we need to write out
511 * metadata. Loop over the transaction's entire buffer list:
513 spin_lock(&journal
->j_state_lock
);
514 commit_transaction
->t_state
= T_COMMIT
;
515 spin_unlock(&journal
->j_state_lock
);
517 stats
.u
.run
.rs_logging
= jiffies
;
518 stats
.u
.run
.rs_flushing
= jbd2_time_diff(stats
.u
.run
.rs_flushing
,
519 stats
.u
.run
.rs_logging
);
520 stats
.u
.run
.rs_blocks
= commit_transaction
->t_outstanding_credits
;
521 stats
.u
.run
.rs_blocks_logged
= 0;
523 J_ASSERT(commit_transaction
->t_nr_buffers
<=
524 commit_transaction
->t_outstanding_credits
);
529 while (commit_transaction
->t_buffers
) {
531 /* Find the next buffer to be journaled... */
533 jh
= commit_transaction
->t_buffers
;
535 /* If we're in abort mode, we just un-journal the buffer and
538 if (is_journal_aborted(journal
)) {
539 clear_buffer_jbddirty(jh2bh(jh
));
540 JBUFFER_TRACE(jh
, "journal is aborting: refile");
541 jbd2_buffer_abort_trigger(jh
,
543 jh
->b_frozen_triggers
:
545 jbd2_journal_refile_buffer(journal
, jh
);
546 /* If that was the last one, we need to clean up
547 * any descriptor buffers which may have been
548 * already allocated, even if we are now
550 if (!commit_transaction
->t_buffers
)
551 goto start_journal_io
;
555 /* Make sure we have a descriptor block in which to
556 record the metadata buffer. */
559 struct buffer_head
*bh
;
561 J_ASSERT (bufs
== 0);
563 jbd_debug(4, "JBD: get descriptor\n");
565 descriptor
= jbd2_journal_get_descriptor_buffer(journal
);
567 jbd2_journal_abort(journal
, -EIO
);
571 bh
= jh2bh(descriptor
);
572 jbd_debug(4, "JBD: got buffer %llu (%p)\n",
573 (unsigned long long)bh
->b_blocknr
, bh
->b_data
);
574 header
= (journal_header_t
*)&bh
->b_data
[0];
575 header
->h_magic
= cpu_to_be32(JBD2_MAGIC_NUMBER
);
576 header
->h_blocktype
= cpu_to_be32(JBD2_DESCRIPTOR_BLOCK
);
577 header
->h_sequence
= cpu_to_be32(commit_transaction
->t_tid
);
579 tagp
= &bh
->b_data
[sizeof(journal_header_t
)];
580 space_left
= bh
->b_size
- sizeof(journal_header_t
);
582 set_buffer_jwrite(bh
);
583 set_buffer_dirty(bh
);
586 /* Record it so that we can wait for IO
588 BUFFER_TRACE(bh
, "ph3: file as descriptor");
589 jbd2_journal_file_buffer(descriptor
, commit_transaction
,
593 /* Where is the buffer to be written? */
595 err
= jbd2_journal_next_log_block(journal
, &blocknr
);
596 /* If the block mapping failed, just abandon the buffer
597 and repeat this loop: we'll fall into the
598 refile-on-abort condition above. */
600 jbd2_journal_abort(journal
, err
);
605 * start_this_handle() uses t_outstanding_credits to determine
606 * the free space in the log, but this counter is changed
607 * by jbd2_journal_next_log_block() also.
609 commit_transaction
->t_outstanding_credits
--;
611 /* Bump b_count to prevent truncate from stumbling over
612 the shadowed buffer! @@@ This can go if we ever get
613 rid of the BJ_IO/BJ_Shadow pairing of buffers. */
614 atomic_inc(&jh2bh(jh
)->b_count
);
616 /* Make a temporary IO buffer with which to write it out
617 (this will requeue both the metadata buffer and the
618 temporary IO buffer). new_bh goes on BJ_IO*/
620 set_bit(BH_JWrite
, &jh2bh(jh
)->b_state
);
622 * akpm: jbd2_journal_write_metadata_buffer() sets
623 * new_bh->b_transaction to commit_transaction.
624 * We need to clean this up before we release new_bh
625 * (which is of type BJ_IO)
627 JBUFFER_TRACE(jh
, "ph3: write metadata");
628 flags
= jbd2_journal_write_metadata_buffer(commit_transaction
,
629 jh
, &new_jh
, blocknr
);
630 set_bit(BH_JWrite
, &jh2bh(new_jh
)->b_state
);
631 wbuf
[bufs
++] = jh2bh(new_jh
);
633 /* Record the new block's tag in the current descriptor
638 tag_flag
|= JBD2_FLAG_ESCAPE
;
640 tag_flag
|= JBD2_FLAG_SAME_UUID
;
642 tag
= (journal_block_tag_t
*) tagp
;
643 write_tag_block(tag_bytes
, tag
, jh2bh(jh
)->b_blocknr
);
644 tag
->t_flags
= cpu_to_be32(tag_flag
);
646 space_left
-= tag_bytes
;
649 memcpy (tagp
, journal
->j_uuid
, 16);
655 /* If there's no more to do, or if the descriptor is full,
658 if (bufs
== journal
->j_wbufsize
||
659 commit_transaction
->t_buffers
== NULL
||
660 space_left
< tag_bytes
+ 16) {
662 jbd_debug(4, "JBD: Submit %d IOs\n", bufs
);
664 /* Write an end-of-descriptor marker before
665 submitting the IOs. "tag" still points to
666 the last tag we set up. */
668 tag
->t_flags
|= cpu_to_be32(JBD2_FLAG_LAST_TAG
);
671 for (i
= 0; i
< bufs
; i
++) {
672 struct buffer_head
*bh
= wbuf
[i
];
676 if (JBD2_HAS_COMPAT_FEATURE(journal
,
677 JBD2_FEATURE_COMPAT_CHECKSUM
)) {
679 jbd2_checksum_data(crc32_sum
, bh
);
683 clear_buffer_dirty(bh
);
684 set_buffer_uptodate(bh
);
685 bh
->b_end_io
= journal_end_buffer_io_sync
;
686 submit_bh(write_op
, bh
);
689 stats
.u
.run
.rs_blocks_logged
+= bufs
;
691 /* Force a new descriptor to be generated next
692 time round the loop. */
698 /* Done it all: now write the commit record asynchronously. */
700 if (JBD2_HAS_INCOMPAT_FEATURE(journal
,
701 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT
)) {
702 err
= journal_submit_commit_record(journal
, commit_transaction
,
705 __jbd2_journal_abort_hard(journal
);
709 * This is the right place to wait for data buffers both for ASYNC
710 * and !ASYNC commit. If commit is ASYNC, we need to wait only after
711 * the commit block went to disk (which happens above). If commit is
712 * SYNC, we need to wait for data buffers before we start writing
713 * commit block, which happens below in such setting.
715 err
= journal_finish_inode_data_buffers(journal
, commit_transaction
);
718 "JBD2: Detected IO errors while flushing file data "
719 "on %s\n", journal
->j_devname
);
720 if (journal
->j_flags
& JBD2_ABORT_ON_SYNCDATA_ERR
)
721 jbd2_journal_abort(journal
, err
);
725 /* Lo and behold: we have just managed to send a transaction to
726 the log. Before we can commit it, wait for the IO so far to
727 complete. Control buffers being written are on the
728 transaction's t_log_list queue, and metadata buffers are on
729 the t_iobuf_list queue.
731 Wait for the buffers in reverse order. That way we are
732 less likely to be woken up until all IOs have completed, and
733 so we incur less scheduling load.
736 jbd_debug(3, "JBD: commit phase 3\n");
739 * akpm: these are BJ_IO, and j_list_lock is not needed.
740 * See __journal_try_to_free_buffer.
743 while (commit_transaction
->t_iobuf_list
!= NULL
) {
744 struct buffer_head
*bh
;
746 jh
= commit_transaction
->t_iobuf_list
->b_tprev
;
748 if (buffer_locked(bh
)) {
755 if (unlikely(!buffer_uptodate(bh
)))
758 clear_buffer_jwrite(bh
);
760 JBUFFER_TRACE(jh
, "ph4: unfile after journal write");
761 jbd2_journal_unfile_buffer(journal
, jh
);
764 * ->t_iobuf_list should contain only dummy buffer_heads
765 * which were created by jbd2_journal_write_metadata_buffer().
767 BUFFER_TRACE(bh
, "dumping temporary bh");
768 jbd2_journal_put_journal_head(jh
);
770 J_ASSERT_BH(bh
, atomic_read(&bh
->b_count
) == 0);
771 free_buffer_head(bh
);
773 /* We also have to unlock and free the corresponding
775 jh
= commit_transaction
->t_shadow_list
->b_tprev
;
777 clear_bit(BH_JWrite
, &bh
->b_state
);
778 J_ASSERT_BH(bh
, buffer_jbddirty(bh
));
780 /* The metadata is now released for reuse, but we need
781 to remember it against this transaction so that when
782 we finally commit, we can do any checkpointing
784 JBUFFER_TRACE(jh
, "file as BJ_Forget");
785 jbd2_journal_file_buffer(jh
, commit_transaction
, BJ_Forget
);
786 /* Wake up any transactions which were waiting for this
788 wake_up_bit(&bh
->b_state
, BH_Unshadow
);
789 JBUFFER_TRACE(jh
, "brelse shadowed buffer");
793 J_ASSERT (commit_transaction
->t_shadow_list
== NULL
);
795 jbd_debug(3, "JBD: commit phase 4\n");
797 /* Here we wait for the revoke record and descriptor record buffers */
799 while (commit_transaction
->t_log_list
!= NULL
) {
800 struct buffer_head
*bh
;
802 jh
= commit_transaction
->t_log_list
->b_tprev
;
804 if (buffer_locked(bh
)) {
806 goto wait_for_ctlbuf
;
809 goto wait_for_ctlbuf
;
811 if (unlikely(!buffer_uptodate(bh
)))
814 BUFFER_TRACE(bh
, "ph5: control buffer writeout done: unfile");
815 clear_buffer_jwrite(bh
);
816 jbd2_journal_unfile_buffer(journal
, jh
);
817 jbd2_journal_put_journal_head(jh
);
818 __brelse(bh
); /* One for getblk */
819 /* AKPM: bforget here */
823 jbd2_journal_abort(journal
, err
);
825 jbd_debug(3, "JBD: commit phase 5\n");
827 if (!JBD2_HAS_INCOMPAT_FEATURE(journal
,
828 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT
)) {
829 err
= journal_submit_commit_record(journal
, commit_transaction
,
832 __jbd2_journal_abort_hard(journal
);
834 if (!err
&& !is_journal_aborted(journal
))
835 err
= journal_wait_on_commit_record(journal
, cbh
);
838 jbd2_journal_abort(journal
, err
);
840 /* End of a transaction! Finally, we can do checkpoint
841 processing: any buffers committed as a result of this
842 transaction can be removed from any checkpoint list it was on
845 jbd_debug(3, "JBD: commit phase 6\n");
847 J_ASSERT(list_empty(&commit_transaction
->t_inode_list
));
848 J_ASSERT(commit_transaction
->t_buffers
== NULL
);
849 J_ASSERT(commit_transaction
->t_checkpoint_list
== NULL
);
850 J_ASSERT(commit_transaction
->t_iobuf_list
== NULL
);
851 J_ASSERT(commit_transaction
->t_shadow_list
== NULL
);
852 J_ASSERT(commit_transaction
->t_log_list
== NULL
);
856 * As there are other places (journal_unmap_buffer()) adding buffers
857 * to this list we have to be careful and hold the j_list_lock.
859 spin_lock(&journal
->j_list_lock
);
860 while (commit_transaction
->t_forget
) {
861 transaction_t
*cp_transaction
;
862 struct buffer_head
*bh
;
864 jh
= commit_transaction
->t_forget
;
865 spin_unlock(&journal
->j_list_lock
);
867 jbd_lock_bh_state(bh
);
868 J_ASSERT_JH(jh
, jh
->b_transaction
== commit_transaction
||
869 jh
->b_transaction
== journal
->j_running_transaction
);
872 * If there is undo-protected committed data against
873 * this buffer, then we can remove it now. If it is a
874 * buffer needing such protection, the old frozen_data
875 * field now points to a committed version of the
876 * buffer, so rotate that field to the new committed
879 * Otherwise, we can just throw away the frozen data now.
881 * We also know that the frozen data has already fired
882 * its triggers if they exist, so we can clear that too.
884 if (jh
->b_committed_data
) {
885 jbd2_free(jh
->b_committed_data
, bh
->b_size
);
886 jh
->b_committed_data
= NULL
;
887 if (jh
->b_frozen_data
) {
888 jh
->b_committed_data
= jh
->b_frozen_data
;
889 jh
->b_frozen_data
= NULL
;
890 jh
->b_frozen_triggers
= NULL
;
892 } else if (jh
->b_frozen_data
) {
893 jbd2_free(jh
->b_frozen_data
, bh
->b_size
);
894 jh
->b_frozen_data
= NULL
;
895 jh
->b_frozen_triggers
= NULL
;
898 spin_lock(&journal
->j_list_lock
);
899 cp_transaction
= jh
->b_cp_transaction
;
900 if (cp_transaction
) {
901 JBUFFER_TRACE(jh
, "remove from old cp transaction");
902 cp_transaction
->t_chp_stats
.cs_dropped
++;
903 __jbd2_journal_remove_checkpoint(jh
);
906 /* Only re-checkpoint the buffer_head if it is marked
907 * dirty. If the buffer was added to the BJ_Forget list
908 * by jbd2_journal_forget, it may no longer be dirty and
909 * there's no point in keeping a checkpoint record for
912 /* A buffer which has been freed while still being
913 * journaled by a previous transaction may end up still
914 * being dirty here, but we want to avoid writing back
915 * that buffer in the future now that the last use has
916 * been committed. That's not only a performance gain,
917 * it also stops aliasing problems if the buffer is left
918 * behind for writeback and gets reallocated for another
919 * use in a different page. */
920 if (buffer_freed(bh
)) {
921 clear_buffer_freed(bh
);
922 clear_buffer_jbddirty(bh
);
925 if (buffer_jbddirty(bh
)) {
926 JBUFFER_TRACE(jh
, "add to new checkpointing trans");
927 __jbd2_journal_insert_checkpoint(jh
, commit_transaction
);
928 if (is_journal_aborted(journal
))
929 clear_buffer_jbddirty(bh
);
930 JBUFFER_TRACE(jh
, "refile for checkpoint writeback");
931 __jbd2_journal_refile_buffer(jh
);
932 jbd_unlock_bh_state(bh
);
934 J_ASSERT_BH(bh
, !buffer_dirty(bh
));
935 /* The buffer on BJ_Forget list and not jbddirty means
936 * it has been freed by this transaction and hence it
937 * could not have been reallocated until this
938 * transaction has committed. *BUT* it could be
939 * reallocated once we have written all the data to
940 * disk and before we process the buffer on BJ_Forget
942 JBUFFER_TRACE(jh
, "refile or unfile freed buffer");
943 __jbd2_journal_refile_buffer(jh
);
944 if (!jh
->b_transaction
) {
945 jbd_unlock_bh_state(bh
);
947 jbd2_journal_remove_journal_head(bh
);
948 release_buffer_page(bh
);
950 jbd_unlock_bh_state(bh
);
952 cond_resched_lock(&journal
->j_list_lock
);
954 spin_unlock(&journal
->j_list_lock
);
956 * This is a bit sleazy. We use j_list_lock to protect transition
957 * of a transaction into T_FINISHED state and calling
958 * __jbd2_journal_drop_transaction(). Otherwise we could race with
959 * other checkpointing code processing the transaction...
961 spin_lock(&journal
->j_state_lock
);
962 spin_lock(&journal
->j_list_lock
);
964 * Now recheck if some buffers did not get attached to the transaction
965 * while the lock was dropped...
967 if (commit_transaction
->t_forget
) {
968 spin_unlock(&journal
->j_list_lock
);
969 spin_unlock(&journal
->j_state_lock
);
973 /* Done with this transaction! */
975 jbd_debug(3, "JBD: commit phase 7\n");
977 J_ASSERT(commit_transaction
->t_state
== T_COMMIT
);
979 commit_transaction
->t_start
= jiffies
;
980 stats
.u
.run
.rs_logging
= jbd2_time_diff(stats
.u
.run
.rs_logging
,
981 commit_transaction
->t_start
);
984 * File the transaction for history
986 stats
.ts_type
= JBD2_STATS_RUN
;
987 stats
.ts_tid
= commit_transaction
->t_tid
;
988 stats
.u
.run
.rs_handle_count
= commit_transaction
->t_handle_count
;
989 spin_lock(&journal
->j_history_lock
);
990 memcpy(journal
->j_history
+ journal
->j_history_cur
, &stats
,
992 if (++journal
->j_history_cur
== journal
->j_history_max
)
993 journal
->j_history_cur
= 0;
996 * Calculate overall stats
998 journal
->j_stats
.ts_tid
++;
999 journal
->j_stats
.u
.run
.rs_wait
+= stats
.u
.run
.rs_wait
;
1000 journal
->j_stats
.u
.run
.rs_running
+= stats
.u
.run
.rs_running
;
1001 journal
->j_stats
.u
.run
.rs_locked
+= stats
.u
.run
.rs_locked
;
1002 journal
->j_stats
.u
.run
.rs_flushing
+= stats
.u
.run
.rs_flushing
;
1003 journal
->j_stats
.u
.run
.rs_logging
+= stats
.u
.run
.rs_logging
;
1004 journal
->j_stats
.u
.run
.rs_handle_count
+= stats
.u
.run
.rs_handle_count
;
1005 journal
->j_stats
.u
.run
.rs_blocks
+= stats
.u
.run
.rs_blocks
;
1006 journal
->j_stats
.u
.run
.rs_blocks_logged
+= stats
.u
.run
.rs_blocks_logged
;
1007 spin_unlock(&journal
->j_history_lock
);
1009 commit_transaction
->t_state
= T_FINISHED
;
1010 J_ASSERT(commit_transaction
== journal
->j_committing_transaction
);
1011 journal
->j_commit_sequence
= commit_transaction
->t_tid
;
1012 journal
->j_committing_transaction
= NULL
;
1013 commit_time
= ktime_to_ns(ktime_sub(ktime_get(), start_time
));
1016 * weight the commit time higher than the average time so we don't
1017 * react too strongly to vast changes in the commit time
1019 if (likely(journal
->j_average_commit_time
))
1020 journal
->j_average_commit_time
= (commit_time
+
1021 journal
->j_average_commit_time
*3) / 4;
1023 journal
->j_average_commit_time
= commit_time
;
1024 spin_unlock(&journal
->j_state_lock
);
1026 if (commit_transaction
->t_checkpoint_list
== NULL
&&
1027 commit_transaction
->t_checkpoint_io_list
== NULL
) {
1028 __jbd2_journal_drop_transaction(journal
, commit_transaction
);
1031 if (journal
->j_checkpoint_transactions
== NULL
) {
1032 journal
->j_checkpoint_transactions
= commit_transaction
;
1033 commit_transaction
->t_cpnext
= commit_transaction
;
1034 commit_transaction
->t_cpprev
= commit_transaction
;
1036 commit_transaction
->t_cpnext
=
1037 journal
->j_checkpoint_transactions
;
1038 commit_transaction
->t_cpprev
=
1039 commit_transaction
->t_cpnext
->t_cpprev
;
1040 commit_transaction
->t_cpnext
->t_cpprev
=
1042 commit_transaction
->t_cpprev
->t_cpnext
=
1046 spin_unlock(&journal
->j_list_lock
);
1048 if (journal
->j_commit_callback
)
1049 journal
->j_commit_callback(journal
, commit_transaction
);
1051 trace_mark(jbd2_end_commit
, "dev %s transaction %d head %d",
1052 journal
->j_devname
, commit_transaction
->t_tid
,
1053 journal
->j_tail_sequence
);
1054 jbd_debug(1, "JBD: commit %d complete, head %d\n",
1055 journal
->j_commit_sequence
, journal
->j_tail_sequence
);
1057 kfree(commit_transaction
);
1059 wake_up(&journal
->j_wait_done_commit
);