2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sys/vfs/hammer/hammer_flusher.c,v 1.45 2008/07/31 04:42:04 dillon Exp $
37 * HAMMER dependancy flusher thread
39 * Meta data updates create buffer dependancies which are arranged as a
45 static void hammer_flusher_master_thread(void *arg
);
46 static void hammer_flusher_slave_thread(void *arg
);
47 static void hammer_flusher_flush(hammer_mount_t hmp
);
48 static void hammer_flusher_flush_inode(hammer_inode_t ip
,
49 hammer_transaction_t trans
);
52 * Support structures for the flusher threads.
54 struct hammer_flusher_info
{
55 TAILQ_ENTRY(hammer_flusher_info
) entry
;
56 struct hammer_mount
*hmp
;
60 hammer_flush_group_t flg
;
61 hammer_inode_t work_array
[HAMMER_FLUSH_GROUP_SIZE
];
64 typedef struct hammer_flusher_info
*hammer_flusher_info_t
;
67 * Sync all inodes pending on the flusher.
69 * All flush groups will be flushed. This does not queue dirty inodes
70 * to the flush groups, it just flushes out what has already been queued!
73 hammer_flusher_sync(hammer_mount_t hmp
)
77 seq
= hammer_flusher_async(hmp
, NULL
);
78 hammer_flusher_wait(hmp
, seq
);
82 * Sync all inodes pending on the flusher - return immediately.
84 * All flush groups will be flushed.
87 hammer_flusher_async(hammer_mount_t hmp
, hammer_flush_group_t close_flg
)
89 hammer_flush_group_t flg
;
90 int seq
= hmp
->flusher
.next
;
92 TAILQ_FOREACH(flg
, &hmp
->flush_group_list
, flush_entry
) {
93 if (flg
->running
== 0)
99 if (hmp
->flusher
.td
) {
100 if (hmp
->flusher
.signal
++ == 0)
101 wakeup(&hmp
->flusher
.signal
);
103 seq
= hmp
->flusher
.done
;
109 hammer_flusher_async_one(hammer_mount_t hmp
)
113 if (hmp
->flusher
.td
) {
114 seq
= hmp
->flusher
.next
;
115 if (hmp
->flusher
.signal
++ == 0)
116 wakeup(&hmp
->flusher
.signal
);
118 seq
= hmp
->flusher
.done
;
124 * Wait for the flusher to get to the specified sequence number.
125 * Signal the flusher as often as necessary to keep it going.
128 hammer_flusher_wait(hammer_mount_t hmp
, int seq
)
130 while ((int)(seq
- hmp
->flusher
.done
) > 0) {
131 if (hmp
->flusher
.act
!= seq
) {
132 if (hmp
->flusher
.signal
++ == 0)
133 wakeup(&hmp
->flusher
.signal
);
135 tsleep(&hmp
->flusher
.done
, 0, "hmrfls", 0);
140 hammer_flusher_wait_next(hammer_mount_t hmp
)
144 seq
= hammer_flusher_async_one(hmp
);
145 hammer_flusher_wait(hmp
, seq
);
149 hammer_flusher_create(hammer_mount_t hmp
)
151 hammer_flusher_info_t info
;
154 hmp
->flusher
.signal
= 0;
155 hmp
->flusher
.act
= 0;
156 hmp
->flusher
.done
= 0;
157 hmp
->flusher
.next
= 1;
158 hammer_ref(&hmp
->flusher
.finalize_lock
);
159 TAILQ_INIT(&hmp
->flusher
.run_list
);
160 TAILQ_INIT(&hmp
->flusher
.ready_list
);
162 lwkt_create(hammer_flusher_master_thread
, hmp
,
163 &hmp
->flusher
.td
, NULL
, 0, -1, "hammer-M");
164 for (i
= 0; i
< HAMMER_MAX_FLUSHERS
; ++i
) {
165 info
= kmalloc(sizeof(*info
), hmp
->m_misc
, M_WAITOK
|M_ZERO
);
167 TAILQ_INSERT_TAIL(&hmp
->flusher
.ready_list
, info
, entry
);
168 lwkt_create(hammer_flusher_slave_thread
, info
,
169 &info
->td
, NULL
, 0, -1, "hammer-S%d", i
);
174 hammer_flusher_destroy(hammer_mount_t hmp
)
176 hammer_flusher_info_t info
;
181 hmp
->flusher
.exiting
= 1;
182 while (hmp
->flusher
.td
) {
183 ++hmp
->flusher
.signal
;
184 wakeup(&hmp
->flusher
.signal
);
185 tsleep(&hmp
->flusher
.exiting
, 0, "hmrwex", hz
);
191 while ((info
= TAILQ_FIRST(&hmp
->flusher
.ready_list
)) != NULL
) {
192 KKASSERT(info
->runstate
== 0);
193 TAILQ_REMOVE(&hmp
->flusher
.ready_list
, info
, entry
);
195 wakeup(&info
->runstate
);
197 tsleep(&info
->td
, 0, "hmrwwc", 0);
198 kfree(info
, hmp
->m_misc
);
203 * The master flusher thread manages the flusher sequence id and
204 * synchronization with the slave work threads.
207 hammer_flusher_master_thread(void *arg
)
209 hammer_flush_group_t flg
;
216 * Do at least one flush cycle. We may have to update the
217 * UNDO FIFO even if no inodes are queued.
220 while (hmp
->flusher
.group_lock
)
221 tsleep(&hmp
->flusher
.group_lock
, 0, "hmrhld", 0);
222 hmp
->flusher
.act
= hmp
->flusher
.next
;
224 hammer_flusher_clean_loose_ios(hmp
);
225 hammer_flusher_flush(hmp
);
226 hmp
->flusher
.done
= hmp
->flusher
.act
;
227 wakeup(&hmp
->flusher
.done
);
228 flg
= TAILQ_FIRST(&hmp
->flush_group_list
);
229 if (flg
== NULL
|| flg
->closed
== 0)
231 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
238 if (hmp
->flusher
.exiting
&& TAILQ_EMPTY(&hmp
->flush_group_list
))
240 while (hmp
->flusher
.signal
== 0)
241 tsleep(&hmp
->flusher
.signal
, 0, "hmrwwa", 0);
244 * Flush for each count on signal but only allow one extra
245 * flush request to build up.
247 if (--hmp
->flusher
.signal
!= 0)
248 hmp
->flusher
.signal
= 1;
254 hmp
->flusher
.td
= NULL
;
255 wakeup(&hmp
->flusher
.exiting
);
260 * Flush all inodes in the current flush group.
263 hammer_flusher_flush(hammer_mount_t hmp
)
265 hammer_flusher_info_t info
;
266 hammer_flush_group_t flg
;
267 hammer_reserve_t resv
;
269 hammer_inode_t next_ip
;
274 * Just in-case there's a flush race on mount
276 if (TAILQ_FIRST(&hmp
->flusher
.ready_list
) == NULL
)
280 * We only do one flg but we may have to loop/retry.
283 while ((flg
= TAILQ_FIRST(&hmp
->flush_group_list
)) != NULL
) {
285 if (hammer_debug_general
& 0x0001) {
286 kprintf("hammer_flush %d ttl=%d recs=%d\n",
288 flg
->total_count
, flg
->refs
);
290 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
292 hammer_start_transaction_fls(&hmp
->flusher
.trans
, hmp
);
295 * If the previous flush cycle just about exhausted our
296 * UNDO space we may have to do a dummy cycle to move the
297 * first_offset up before actually digging into a new cycle,
298 * or the new cycle will not have sufficient undo space.
300 if (hammer_flusher_undo_exhausted(&hmp
->flusher
.trans
, 3))
301 hammer_flusher_finalize(&hmp
->flusher
.trans
, 0);
304 * Ok, we are running this flush group now (this prevents new
308 if (hmp
->next_flush_group
== flg
)
309 hmp
->next_flush_group
= TAILQ_NEXT(flg
, flush_entry
);
312 * Iterate the inodes in the flg's flush_list and assign
316 info
= TAILQ_FIRST(&hmp
->flusher
.ready_list
);
317 next_ip
= TAILQ_FIRST(&flg
->flush_list
);
319 while ((ip
= next_ip
) != NULL
) {
320 next_ip
= TAILQ_NEXT(ip
, flush_entry
);
323 * Add ip to the slave's work array. The slave is
324 * not currently running.
326 info
->work_array
[info
->count
++] = ip
;
327 if (info
->count
!= HAMMER_FLUSH_GROUP_SIZE
)
331 * Get the slave running
333 TAILQ_REMOVE(&hmp
->flusher
.ready_list
, info
, entry
);
334 TAILQ_INSERT_TAIL(&hmp
->flusher
.run_list
, info
, entry
);
337 wakeup(&info
->runstate
);
340 * Get a new slave. We may have to wait for one to
343 while ((info
= TAILQ_FIRST(&hmp
->flusher
.ready_list
)) == NULL
) {
344 tsleep(&hmp
->flusher
.ready_list
, 0, "hmrfcc", 0);
349 * Run the current slave if necessary
352 TAILQ_REMOVE(&hmp
->flusher
.ready_list
, info
, entry
);
353 TAILQ_INSERT_TAIL(&hmp
->flusher
.run_list
, info
, entry
);
356 wakeup(&info
->runstate
);
360 * Wait for all slaves to finish running
362 while (TAILQ_FIRST(&hmp
->flusher
.run_list
) != NULL
)
363 tsleep(&hmp
->flusher
.ready_list
, 0, "hmrfcc", 0);
366 * Do the final finalization, clean up
368 hammer_flusher_finalize(&hmp
->flusher
.trans
, 1);
369 hmp
->flusher
.tid
= hmp
->flusher
.trans
.tid
;
371 hammer_done_transaction(&hmp
->flusher
.trans
);
374 * Loop up on the same flg. If the flg is done clean it up
375 * and break out. We only flush one flg.
377 if (TAILQ_FIRST(&flg
->flush_list
) == NULL
) {
378 KKASSERT(TAILQ_EMPTY(&flg
->flush_list
));
379 KKASSERT(flg
->refs
== 0);
380 TAILQ_REMOVE(&hmp
->flush_group_list
, flg
, flush_entry
);
381 kfree(flg
, hmp
->m_misc
);
387 * We may have pure meta-data to flush, or we may have to finish
388 * cycling the UNDO FIFO, even if there were no flush groups.
390 if (count
== 0 && hammer_flusher_haswork(hmp
)) {
391 hammer_start_transaction_fls(&hmp
->flusher
.trans
, hmp
);
392 hammer_flusher_finalize(&hmp
->flusher
.trans
, 1);
393 hammer_done_transaction(&hmp
->flusher
.trans
);
397 * Clean up any freed big-blocks (typically zone-2).
398 * resv->flush_group is typically set several flush groups ahead
399 * of the free to ensure that the freed block is not reused until
400 * it can no longer be reused.
402 while ((resv
= TAILQ_FIRST(&hmp
->delay_list
)) != NULL
) {
403 if (resv
->flush_group
!= hmp
->flusher
.act
)
405 hammer_reserve_clrdelay(hmp
, resv
);
411 * The slave flusher thread pulls work off the master flush_list until no
415 hammer_flusher_slave_thread(void *arg
)
417 hammer_flush_group_t flg
;
418 hammer_flusher_info_t info
;
427 while (info
->runstate
== 0)
428 tsleep(&info
->runstate
, 0, "hmrssw", 0);
429 if (info
->runstate
< 0)
433 for (i
= 0; i
< info
->count
; ++i
) {
434 ip
= info
->work_array
[i
];
435 hammer_flusher_flush_inode(ip
, &hmp
->flusher
.trans
);
436 ++hammer_stats_inode_flushes
;
440 TAILQ_REMOVE(&hmp
->flusher
.run_list
, info
, entry
);
441 TAILQ_INSERT_TAIL(&hmp
->flusher
.ready_list
, info
, entry
);
442 wakeup(&hmp
->flusher
.ready_list
);
450 hammer_flusher_clean_loose_ios(hammer_mount_t hmp
)
452 hammer_buffer_t buffer
;
456 * loose ends - buffers without bp's aren't tracked by the kernel
457 * and can build up, so clean them out. This can occur when an
458 * IO completes on a buffer with no references left.
460 if ((io
= TAILQ_FIRST(&hmp
->lose_list
)) != NULL
) {
461 crit_enter(); /* biodone() race */
462 while ((io
= TAILQ_FIRST(&hmp
->lose_list
)) != NULL
) {
463 KKASSERT(io
->mod_list
== &hmp
->lose_list
);
464 TAILQ_REMOVE(&hmp
->lose_list
, io
, mod_entry
);
466 if (io
->lock
.refs
== 0)
467 ++hammer_count_refedbufs
;
468 hammer_ref(&io
->lock
);
470 hammer_rel_buffer(buffer
, 0);
477 * Flush a single inode that is part of a flush group.
479 * Flusher errors are extremely serious, even ENOSPC shouldn't occur because
480 * the front-end should have reserved sufficient space on the media. Any
481 * error other then EWOULDBLOCK will force the mount to be read-only.
485 hammer_flusher_flush_inode(hammer_inode_t ip
, hammer_transaction_t trans
)
487 hammer_mount_t hmp
= ip
->hmp
;
490 hammer_flusher_clean_loose_ios(hmp
);
491 error
= hammer_sync_inode(trans
, ip
);
494 * EWOULDBLOCK can happen under normal operation, all other errors
495 * are considered extremely serious. We must set WOULDBLOCK
496 * mechanics to deal with the mess left over from the abort of the
500 ip
->flags
|= HAMMER_INODE_WOULDBLOCK
;
501 if (error
== EWOULDBLOCK
)
504 hammer_flush_inode_done(ip
, error
);
505 while (hmp
->flusher
.finalize_want
)
506 tsleep(&hmp
->flusher
.finalize_want
, 0, "hmrsxx", 0);
507 if (hammer_flusher_undo_exhausted(trans
, 1)) {
508 kprintf("HAMMER: Warning: UNDO area too small!\n");
509 hammer_flusher_finalize(trans
, 1);
510 } else if (hammer_flusher_meta_limit(trans
->hmp
)) {
511 hammer_flusher_finalize(trans
, 0);
516 * Return non-zero if the UNDO area has less then (QUARTER / 4) of its
519 * 1/4 - Emergency free undo space level. Below this point the flusher
520 * will finalize even if directory dependancies have not been resolved.
522 * 2/4 - Used by the pruning and reblocking code. These functions may be
523 * running in parallel with a flush and cannot be allowed to drop
524 * available undo space to emergency levels.
526 * 3/4 - Used at the beginning of a flush to force-sync the volume header
527 * to give the flush plenty of runway to work in.
530 hammer_flusher_undo_exhausted(hammer_transaction_t trans
, int quarter
)
532 if (hammer_undo_space(trans
) <
533 hammer_undo_max(trans
->hmp
) * quarter
/ 4) {
541 * Flush all pending UNDOs, wait for write completion, update the volume
542 * header with the new UNDO end position, and flush it. Then
543 * asynchronously flush the meta-data.
545 * If this is the last finalization in a flush group we also synchronize
546 * our cached blockmap and set hmp->flusher_undo_start and our cached undo
547 * fifo first_offset so the next flush resets the FIFO pointers.
549 * If this is not final it is being called because too many dirty meta-data
550 * buffers have built up and must be flushed with UNDO synchronization to
551 * avoid a buffer cache deadlock.
554 hammer_flusher_finalize(hammer_transaction_t trans
, int final
)
556 hammer_volume_t root_volume
;
557 hammer_blockmap_t cundomap
, dundomap
;
564 root_volume
= trans
->rootvol
;
567 * Exclusively lock the flusher. This guarantees that all dirty
568 * buffers will be idled (have a mod-count of 0).
570 ++hmp
->flusher
.finalize_want
;
571 hammer_lock_ex(&hmp
->flusher
.finalize_lock
);
574 * If this isn't the final sync several threads may have hit the
575 * meta-limit at the same time and raced. Only sync if we really
576 * have to, after acquiring the lock.
578 if (final
== 0 && !hammer_flusher_meta_limit(hmp
))
581 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
585 * Flush data buffers. This can occur asynchronously and at any
586 * time. We must interlock against the frontend direct-data write
587 * but do not have to acquire the sync-lock yet.
590 while ((io
= TAILQ_FIRST(&hmp
->data_list
)) != NULL
) {
593 if (io
->lock
.refs
== 0)
594 ++hammer_count_refedbufs
;
595 hammer_ref(&io
->lock
);
596 hammer_io_write_interlock(io
);
597 KKASSERT(io
->type
!= HAMMER_STRUCTURE_VOLUME
);
599 hammer_io_done_interlock(io
);
600 hammer_rel_buffer((hammer_buffer_t
)io
, 0);
605 * The sync-lock is required for the remaining sequence. This lock
606 * prevents meta-data from being modified.
608 hammer_sync_lock_ex(trans
);
611 * If we have been asked to finalize the volume header sync the
612 * cached blockmap to the on-disk blockmap. Generate an UNDO
613 * record for the update.
616 cundomap
= &hmp
->blockmap
[0];
617 dundomap
= &root_volume
->ondisk
->vol0_blockmap
[0];
618 if (root_volume
->io
.modified
) {
619 hammer_modify_volume(trans
, root_volume
,
620 dundomap
, sizeof(hmp
->blockmap
));
621 for (i
= 0; i
< HAMMER_MAX_ZONES
; ++i
)
622 hammer_crc_set_blockmap(&cundomap
[i
]);
623 bcopy(cundomap
, dundomap
, sizeof(hmp
->blockmap
));
624 hammer_modify_volume_done(root_volume
);
632 while ((io
= TAILQ_FIRST(&hmp
->undo_list
)) != NULL
) {
635 KKASSERT(io
->modify_refs
== 0);
636 if (io
->lock
.refs
== 0)
637 ++hammer_count_refedbufs
;
638 hammer_ref(&io
->lock
);
639 KKASSERT(io
->type
!= HAMMER_STRUCTURE_VOLUME
);
641 hammer_rel_buffer((hammer_buffer_t
)io
, 0);
646 * Wait for I/Os to complete
648 hammer_flusher_clean_loose_ios(hmp
);
649 hammer_io_wait_all(hmp
, "hmrfl1");
651 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
655 * Update the on-disk volume header with new UNDO FIFO end position
656 * (do not generate new UNDO records for this change). We have to
657 * do this for the UNDO FIFO whether (final) is set or not.
659 * Also update the on-disk next_tid field. This does not require
660 * an UNDO. However, because our TID is generated before we get
661 * the sync lock another sync may have beat us to the punch.
663 * This also has the side effect of updating first_offset based on
664 * a prior finalization when the first finalization of the next flush
665 * cycle occurs, removing any undo info from the prior finalization
666 * from consideration.
668 * The volume header will be flushed out synchronously.
670 dundomap
= &root_volume
->ondisk
->vol0_blockmap
[HAMMER_ZONE_UNDO_INDEX
];
671 cundomap
= &hmp
->blockmap
[HAMMER_ZONE_UNDO_INDEX
];
673 if (dundomap
->first_offset
!= cundomap
->first_offset
||
674 dundomap
->next_offset
!= cundomap
->next_offset
) {
675 hammer_modify_volume(NULL
, root_volume
, NULL
, 0);
676 dundomap
->first_offset
= cundomap
->first_offset
;
677 dundomap
->next_offset
= cundomap
->next_offset
;
678 hammer_crc_set_blockmap(dundomap
);
679 hammer_modify_volume_done(root_volume
);
683 * vol0_next_tid is used for TID selection and is updated without
684 * an UNDO so we do not reuse a TID that may have been rolled-back.
686 * vol0_last_tid is the highest fully-synchronized TID. It is
687 * set-up when the UNDO fifo is fully synced, later on (not here).
689 if (root_volume
->io
.modified
) {
690 hammer_modify_volume(NULL
, root_volume
, NULL
, 0);
691 if (root_volume
->ondisk
->vol0_next_tid
< trans
->tid
)
692 root_volume
->ondisk
->vol0_next_tid
= trans
->tid
;
693 hammer_crc_set_volume(root_volume
->ondisk
);
694 hammer_modify_volume_done(root_volume
);
695 hammer_io_flush(&root_volume
->io
);
699 * Wait for I/Os to complete
701 hammer_flusher_clean_loose_ios(hmp
);
702 hammer_io_wait_all(hmp
, "hmrfl2");
704 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
708 * Flush meta-data. The meta-data will be undone if we crash
709 * so we can safely flush it asynchronously.
711 * Repeated catchups will wind up flushing this update's meta-data
712 * and the UNDO buffers for the next update simultaniously. This
716 while ((io
= TAILQ_FIRST(&hmp
->meta_list
)) != NULL
) {
719 KKASSERT(io
->modify_refs
== 0);
720 if (io
->lock
.refs
== 0)
721 ++hammer_count_refedbufs
;
722 hammer_ref(&io
->lock
);
723 KKASSERT(io
->type
!= HAMMER_STRUCTURE_VOLUME
);
725 hammer_rel_buffer((hammer_buffer_t
)io
, 0);
730 * If this is the final finalization for the flush group set
731 * up for the next sequence by setting a new first_offset in
732 * our cached blockmap and clearing the undo history.
734 * Even though we have updated our cached first_offset, the on-disk
735 * first_offset still governs available-undo-space calculations.
738 cundomap
= &hmp
->blockmap
[HAMMER_ZONE_UNDO_INDEX
];
739 if (cundomap
->first_offset
== cundomap
->next_offset
) {
740 hmp
->hflags
&= ~HMNT_UNDO_DIRTY
;
742 cundomap
->first_offset
= cundomap
->next_offset
;
743 hmp
->hflags
|= HMNT_UNDO_DIRTY
;
745 hammer_clear_undo_history(hmp
);
748 * Flush tid sequencing. flush_tid1 is fully synchronized,
749 * meaning a crash will not roll it back. flush_tid2 has
750 * been written out asynchronously and a crash will roll
751 * it back. flush_tid1 is used for all mirroring masters.
753 if (hmp
->flush_tid1
!= hmp
->flush_tid2
) {
754 hmp
->flush_tid1
= hmp
->flush_tid2
;
755 wakeup(&hmp
->flush_tid1
);
757 hmp
->flush_tid2
= trans
->tid
;
761 * Cleanup. Report any critical errors.
764 hammer_sync_unlock(trans
);
766 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
) {
767 kprintf("HAMMER(%s): Critical write error during flush, "
768 "refusing to sync UNDO FIFO\n",
769 root_volume
->ondisk
->vol_name
);
773 hammer_unlock(&hmp
->flusher
.finalize_lock
);
775 if (--hmp
->flusher
.finalize_want
== 0)
776 wakeup(&hmp
->flusher
.finalize_want
);
777 hammer_stats_commits
+= final
;
781 * Return non-zero if too many dirty meta-data buffers have built up.
783 * Since we cannot allow such buffers to flush until we have dealt with
784 * the UNDOs, we risk deadlocking the kernel's buffer cache.
787 hammer_flusher_meta_limit(hammer_mount_t hmp
)
789 if (hmp
->locked_dirty_space
+ hmp
->io_running_space
>
790 hammer_limit_dirtybufspace
) {
797 * Return non-zero if too many dirty meta-data buffers have built up.
799 * This version is used by background operations (mirror, prune, reblock)
800 * to leave room for foreground operations.
803 hammer_flusher_meta_halflimit(hammer_mount_t hmp
)
805 if (hmp
->locked_dirty_space
+ hmp
->io_running_space
>
806 hammer_limit_dirtybufspace
/ 2) {
813 * Return non-zero if the flusher still has something to flush.
816 hammer_flusher_haswork(hammer_mount_t hmp
)
818 if (hmp
->flags
& HAMMER_MOUNT_CRITICAL_ERROR
)
820 if (TAILQ_FIRST(&hmp
->flush_group_list
) || /* dirty inodes */
821 TAILQ_FIRST(&hmp
->volu_list
) || /* dirty bufffers */
822 TAILQ_FIRST(&hmp
->undo_list
) ||
823 TAILQ_FIRST(&hmp
->data_list
) ||
824 TAILQ_FIRST(&hmp
->meta_list
) ||
825 (hmp
->hflags
& HMNT_UNDO_DIRTY
) /* UNDO FIFO sync */