2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * Copyright (c) 2013 The FreeBSD Foundation
7 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
8 * and NAI Labs, the Security Research Division of Network Associates, Inc.
9 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
10 * DARPA CHATS research program.
12 * Portions of this software were developed by Konstantin Belousov
13 * under sponsorship from the FreeBSD Foundation.
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. The names of the authors may not be used to endorse or promote
24 * products derived from this software without specific prior written
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
50 #include <sys/stack.h>
51 #include <sys/sysctl.h>
54 #include <sys/errno.h>
55 #include <geom/geom.h>
56 #include <geom/geom_int.h>
57 #include <sys/devicestat.h>
61 #include <vm/vm_param.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_page.h>
64 #include <vm/vm_object.h>
65 #include <vm/vm_extern.h>
66 #include <vm/vm_map.h>
68 static int g_io_transient_map_bio(struct bio *bp);
70 static struct g_bioq g_bio_run_down;
71 static struct g_bioq g_bio_run_up;
72 static struct g_bioq g_bio_run_task;
75 * Pace is a hint that we've had some trouble recently allocating
76 * bios, so we should back off trying to send I/O down the stack
77 * a bit to let the problem resolve. When pacing, we also turn
78 * off direct dispatch to also reduce memory pressure from I/Os
79 * there, at the expxense of some added latency while the memory
80 * pressures exist. See g_io_schedule_down() for more details
83 static volatile u_int pace;
85 static uma_zone_t biozone;
88 * The head of the list of classifiers used in g_io_request.
89 * Use g_register_classifier() and g_unregister_classifier()
90 * to add/remove entries to the list.
91 * Classifiers are invoked in registration order.
93 static TAILQ_HEAD(g_classifier_tailq, g_classifier_hook)
94 g_classifier_tailq = TAILQ_HEAD_INITIALIZER(g_classifier_tailq);
96 #include <machine/atomic.h>
99 g_bioq_lock(struct g_bioq *bq)
102 mtx_lock(&bq->bio_queue_lock);
106 g_bioq_unlock(struct g_bioq *bq)
109 mtx_unlock(&bq->bio_queue_lock);
114 g_bioq_destroy(struct g_bioq *bq)
117 mtx_destroy(&bq->bio_queue_lock);
122 g_bioq_init(struct g_bioq *bq)
125 TAILQ_INIT(&bq->bio_queue);
126 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
130 g_bioq_first(struct g_bioq *bq)
134 bp = TAILQ_FIRST(&bq->bio_queue);
136 KASSERT((bp->bio_flags & BIO_ONQUEUE),
137 ("Bio not on queue bp=%p target %p", bp, bq));
138 bp->bio_flags &= ~BIO_ONQUEUE;
139 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
140 bq->bio_queue_length--;
150 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
152 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
155 CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
157 CTRSTACK(KTR_GEOM, &st, 3, 0);
168 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
170 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
173 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
175 CTRSTACK(KTR_GEOM, &st, 3, 0);
182 g_destroy_bio(struct bio *bp)
185 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
188 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
190 CTRSTACK(KTR_GEOM, &st, 3, 0);
193 uma_zfree(biozone, bp);
197 g_clone_bio(struct bio *bp)
201 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
203 bp2->bio_parent = bp;
204 bp2->bio_cmd = bp->bio_cmd;
206 * BIO_ORDERED flag may be used by disk drivers to enforce
207 * ordering restrictions, so this flag needs to be cloned.
208 * BIO_UNMAPPED should be inherited, to properly indicate
209 * which way the buffer is passed.
210 * Other bio flags are not suitable for cloning.
212 bp2->bio_flags = bp->bio_flags & (BIO_ORDERED | BIO_UNMAPPED);
213 bp2->bio_length = bp->bio_length;
214 bp2->bio_offset = bp->bio_offset;
215 bp2->bio_data = bp->bio_data;
216 bp2->bio_ma = bp->bio_ma;
217 bp2->bio_ma_n = bp->bio_ma_n;
218 bp2->bio_ma_offset = bp->bio_ma_offset;
219 bp2->bio_attribute = bp->bio_attribute;
220 /* Inherit classification info from the parent */
221 bp2->bio_classifier1 = bp->bio_classifier1;
222 bp2->bio_classifier2 = bp->bio_classifier2;
226 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
229 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2);
231 CTRSTACK(KTR_GEOM, &st, 3, 0);
238 g_duplicate_bio(struct bio *bp)
242 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO);
243 bp2->bio_flags = bp->bio_flags & BIO_UNMAPPED;
244 bp2->bio_parent = bp;
245 bp2->bio_cmd = bp->bio_cmd;
246 bp2->bio_length = bp->bio_length;
247 bp2->bio_offset = bp->bio_offset;
248 bp2->bio_data = bp->bio_data;
249 bp2->bio_ma = bp->bio_ma;
250 bp2->bio_ma_n = bp->bio_ma_n;
251 bp2->bio_ma_offset = bp->bio_ma_offset;
252 bp2->bio_attribute = bp->bio_attribute;
255 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
258 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2);
260 CTRSTACK(KTR_GEOM, &st, 3, 0);
270 g_bioq_init(&g_bio_run_down);
271 g_bioq_init(&g_bio_run_up);
272 g_bioq_init(&g_bio_run_task);
273 biozone = uma_zcreate("g_bio", sizeof (struct bio),
280 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
285 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
287 bp->bio_cmd = BIO_GETATTR;
289 bp->bio_attribute = attr;
290 bp->bio_length = *len;
292 g_io_request(bp, cp);
293 error = biowait(bp, "ggetattr");
294 *len = bp->bio_completed;
300 g_io_flush(struct g_consumer *cp)
305 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name);
307 bp->bio_cmd = BIO_FLUSH;
308 bp->bio_flags |= BIO_ORDERED;
310 bp->bio_attribute = NULL;
311 bp->bio_offset = cp->provider->mediasize;
314 g_io_request(bp, cp);
315 error = biowait(bp, "gflush");
321 g_io_check(struct bio *bp)
323 struct g_consumer *cp;
324 struct g_provider *pp;
331 /* Fail if access counters dont allow the operation */
332 switch(bp->bio_cmd) {
347 /* if provider is marked for error, don't disturb. */
350 if (cp->flags & G_CF_ORPHAN)
353 switch(bp->bio_cmd) {
357 /* Zero sectorsize or mediasize is probably a lack of media. */
358 if (pp->sectorsize == 0 || pp->mediasize == 0)
360 /* Reject I/O not on sector boundary */
361 if (bp->bio_offset % pp->sectorsize)
363 /* Reject I/O not integral sector long */
364 if (bp->bio_length % pp->sectorsize)
366 /* Reject requests before or past the end of media. */
367 if (bp->bio_offset < 0)
369 if (bp->bio_offset > pp->mediasize)
372 /* Truncate requests to the end of providers media. */
373 excess = bp->bio_offset + bp->bio_length;
374 if (excess > bp->bio_to->mediasize) {
375 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 ||
376 round_page(bp->bio_ma_offset +
377 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n,
378 ("excess bio %p too short", bp));
379 excess -= bp->bio_to->mediasize;
380 bp->bio_length -= excess;
381 if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
382 bp->bio_ma_n = round_page(bp->bio_ma_offset +
383 bp->bio_length) / PAGE_SIZE;
386 CTR3(KTR_GEOM, "g_down truncated bio "
387 "%p provider %s by %d", bp,
388 bp->bio_to->name, excess);
391 /* Deliver zero length transfers right here. */
392 if (bp->bio_length == 0) {
393 CTR2(KTR_GEOM, "g_down terminated 0-length "
394 "bp %p provider %s", bp, bp->bio_to->name);
398 if ((bp->bio_flags & BIO_UNMAPPED) != 0 &&
399 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
400 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
401 if ((error = g_io_transient_map_bio(bp)) >= 0)
408 return (EJUSTRETURN);
412 * bio classification support.
414 * g_register_classifier() and g_unregister_classifier()
415 * are used to add/remove a classifier from the list.
416 * The list is protected using the g_bio_run_down lock,
417 * because the classifiers are called in this path.
419 * g_io_request() passes bio's that are not already classified
420 * (i.e. those with bio_classifier1 == NULL) to g_run_classifiers().
421 * Classifiers can store their result in the two fields
422 * bio_classifier1 and bio_classifier2.
423 * A classifier that updates one of the fields should
424 * return a non-zero value.
425 * If no classifier updates the field, g_run_classifiers() sets
426 * bio_classifier1 = BIO_NOTCLASSIFIED to avoid further calls.
430 g_register_classifier(struct g_classifier_hook *hook)
433 g_bioq_lock(&g_bio_run_down);
434 TAILQ_INSERT_TAIL(&g_classifier_tailq, hook, link);
435 g_bioq_unlock(&g_bio_run_down);
441 g_unregister_classifier(struct g_classifier_hook *hook)
443 struct g_classifier_hook *entry;
445 g_bioq_lock(&g_bio_run_down);
446 TAILQ_FOREACH(entry, &g_classifier_tailq, link) {
448 TAILQ_REMOVE(&g_classifier_tailq, hook, link);
452 g_bioq_unlock(&g_bio_run_down);
456 g_run_classifiers(struct bio *bp)
458 struct g_classifier_hook *hook;
461 TAILQ_FOREACH(hook, &g_classifier_tailq, link)
462 classified |= hook->func(hook->arg, bp);
465 bp->bio_classifier1 = BIO_NOTCLASSIFIED;
469 g_io_request(struct bio *bp, struct g_consumer *cp)
471 struct g_provider *pp;
473 int direct, error, first;
475 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
476 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
478 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
480 KASSERT(bp->bio_driver1 == NULL,
481 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name));
482 KASSERT(bp->bio_driver2 == NULL,
483 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name));
484 KASSERT(bp->bio_pflags == 0,
485 ("bio_pflags used by the consumer (geom %s)", cp->geom->name));
487 * Remember consumer's private fields, so we can detect if they were
488 * modified by the provider.
490 bp->_bio_caller1 = bp->bio_caller1;
491 bp->_bio_caller2 = bp->bio_caller2;
492 bp->_bio_cflags = bp->bio_cflags;
495 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_GETATTR)) {
496 KASSERT(bp->bio_data != NULL,
497 ("NULL bp->data in g_io_request(cmd=%hhu)", bp->bio_cmd));
499 if (bp->bio_cmd & (BIO_DELETE|BIO_FLUSH)) {
500 KASSERT(bp->bio_data == NULL,
501 ("non-NULL bp->data in g_io_request(cmd=%hhu)",
504 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) {
505 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
506 ("wrong offset %jd for sectorsize %u",
507 bp->bio_offset, cp->provider->sectorsize));
508 KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
509 ("wrong length %jd for sectorsize %u",
510 bp->bio_length, cp->provider->sectorsize));
513 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
514 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
519 bp->bio_completed = 0;
521 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
522 ("Bio already on queue bp=%p", bp));
523 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
524 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
525 binuptime(&bp->bio_t0);
527 getbinuptime(&bp->bio_t0);
529 #ifdef GET_STACK_USAGE
530 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 &&
531 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 &&
532 !g_is_geom_thread(curthread) &&
533 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ||
534 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) &&
537 /* Block direct execution if less then half of stack left. */
539 GET_STACK_USAGE(st, su);
547 if (!TAILQ_EMPTY(&g_classifier_tailq) && !bp->bio_classifier1) {
548 g_bioq_lock(&g_bio_run_down);
549 g_run_classifiers(bp);
550 g_bioq_unlock(&g_bio_run_down);
554 * The statistics collection is lockless, as such, but we
555 * can not update one instance of the statistics from more
556 * than one thread at a time, so grab the lock first.
558 mtxp = mtx_pool_find(mtxpool_sleep, pp);
560 if (g_collectstats & G_STATS_PROVIDERS)
561 devstat_start_transaction(pp->stat, &bp->bio_t0);
562 if (g_collectstats & G_STATS_CONSUMERS)
563 devstat_start_transaction(cp->stat, &bp->bio_t0);
569 error = g_io_check(bp);
571 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p "
572 "provider %s returned %d", bp, bp->bio_to->name,
574 g_io_deliver(bp, error);
577 bp->bio_to->geom->start(bp);
579 g_bioq_lock(&g_bio_run_down);
580 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue);
581 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue);
582 bp->bio_flags |= BIO_ONQUEUE;
583 g_bio_run_down.bio_queue_length++;
584 g_bioq_unlock(&g_bio_run_down);
585 /* Pass it on down. */
587 wakeup(&g_wait_down);
592 g_io_deliver(struct bio *bp, int error)
595 struct g_consumer *cp;
596 struct g_provider *pp;
600 KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
602 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
605 bp->bio_error = error;
609 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
610 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
613 * Some classes - GJournal in particular - can modify bio's
614 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO
615 * flag means it's an expected behaviour for that particular geom.
617 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) {
618 KASSERT(bp->bio_caller1 == bp->_bio_caller1,
619 ("bio_caller1 used by the provider %s", pp->name));
620 KASSERT(bp->bio_caller2 == bp->_bio_caller2,
621 ("bio_caller2 used by the provider %s", pp->name));
622 KASSERT(bp->bio_cflags == bp->_bio_cflags,
623 ("bio_cflags used by the provider %s", pp->name));
626 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0"));
627 KASSERT(bp->bio_completed <= bp->bio_length,
628 ("bio_completed can't be greater than bio_length"));
631 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
632 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
633 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
635 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
636 ("Bio already on queue bp=%p", bp));
639 * XXX: next two doesn't belong here
641 bp->bio_bcount = bp->bio_length;
642 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
644 #ifdef GET_STACK_USAGE
645 direct = (pp->flags & G_PF_DIRECT_SEND) &&
646 (cp->flags & G_CF_DIRECT_RECEIVE) &&
647 !g_is_geom_thread(curthread);
649 /* Block direct execution if less then half of stack left. */
651 GET_STACK_USAGE(st, su);
660 * The statistics collection is lockless, as such, but we
661 * can not update one instance of the statistics from more
662 * than one thread at a time, so grab the lock first.
664 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
665 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
667 mtxp = mtx_pool_find(mtxpool_sleep, cp);
669 if (g_collectstats & G_STATS_PROVIDERS)
670 devstat_end_transaction_bio_bt(pp->stat, bp, &now);
671 if (g_collectstats & G_STATS_CONSUMERS)
672 devstat_end_transaction_bio_bt(cp->stat, bp, &now);
677 if (error != ENOMEM) {
678 bp->bio_error = error;
682 g_bioq_lock(&g_bio_run_up);
683 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue);
684 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
685 bp->bio_flags |= BIO_ONQUEUE;
686 g_bio_run_up.bio_queue_length++;
687 g_bioq_unlock(&g_bio_run_up);
695 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
696 bp->bio_children = 0;
698 bp->bio_driver1 = NULL;
699 bp->bio_driver2 = NULL;
701 g_io_request(bp, cp);
706 SYSCTL_DECL(_kern_geom);
708 static long transient_maps;
709 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD,
711 "Total count of the transient mapping requests");
712 u_int transient_map_retries = 10;
713 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW,
714 &transient_map_retries, 0,
715 "Max count of retries used before giving up on creating transient map");
716 int transient_map_hard_failures;
717 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD,
718 &transient_map_hard_failures, 0,
719 "Failures to establish the transient mapping due to retry attempts "
721 int transient_map_soft_failures;
722 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD,
723 &transient_map_soft_failures, 0,
724 "Count of retried failures to establish the transient mapping");
725 int inflight_transient_maps;
726 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD,
727 &inflight_transient_maps, 0,
728 "Current count of the active transient maps");
731 g_io_transient_map_bio(struct bio *bp)
737 KASSERT(unmapped_buf_allowed, ("unmapped disabled"));
739 size = round_page(bp->bio_ma_offset + bp->bio_length);
740 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp));
743 atomic_add_long(&transient_maps, 1);
745 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) {
746 if (transient_map_retries != 0 &&
747 retried >= transient_map_retries) {
748 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s",
749 bp, bp->bio_to->name);
750 atomic_add_int(&transient_map_hard_failures, 1);
751 return (EDEADLK/* XXXKIB */);
754 * Naive attempt to quisce the I/O to get more
755 * in-flight requests completed and defragment
756 * the transient_arena.
758 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d",
759 bp, bp->bio_to->name, retried);
760 pause("g_d_tra", hz / 10);
762 atomic_add_int(&transient_map_soft_failures, 1);
766 atomic_add_int(&inflight_transient_maps, 1);
767 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size));
768 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset;
769 bp->bio_flags |= BIO_TRANSIENT_MAPPING;
770 bp->bio_flags &= ~BIO_UNMAPPED;
771 return (EJUSTRETURN);
775 g_io_schedule_down(struct thread *tp __unused)
781 g_bioq_lock(&g_bio_run_down);
782 bp = g_bioq_first(&g_bio_run_down);
784 CTR0(KTR_GEOM, "g_down going to sleep");
785 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
786 PRIBIO | PDROP, "-", 0);
789 CTR0(KTR_GEOM, "g_down has work to do");
790 g_bioq_unlock(&g_bio_run_down);
793 * There has been at least one memory allocation
794 * failure since the last I/O completed. Pause 1ms to
795 * give the system a chance to free up memory. We only
796 * do this once because a large number of allocations
797 * can fail in the direct dispatch case and there's no
798 * relationship between the number of these failures and
799 * the length of the outage. If there's still an outage,
800 * we'll pause again and again until it's
801 * resolved. Older versions paused longer and once per
802 * allocation failure. This was OK for a single threaded
803 * g_down, but with direct dispatch would lead to max of
804 * 10 IOPs for minutes at a time when transient memory
805 * issues prevented allocation for a batch of requests
806 * from the upper layers.
808 * XXX This pacing is really lame. It needs to be solved
809 * by other methods. This is OK only because the worst
810 * case scenario is so rare. In the worst case scenario
811 * all memory is tied up waiting for I/O to complete
812 * which can never happen since we can't allocate bios
815 CTR0(KTR_GEOM, "g_down pacing self");
816 pause("g_down", min(hz/1000, 1));
819 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
821 error = g_io_check(bp);
823 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
824 "%s returned %d", bp, bp->bio_to->name, error);
825 g_io_deliver(bp, error);
828 THREAD_NO_SLEEPING();
829 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
830 "len %ld", bp, bp->bio_to->name, bp->bio_offset,
832 bp->bio_to->geom->start(bp);
833 THREAD_SLEEPING_OK();
838 bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg)
841 bp->bio_task_arg = arg;
843 * The taskqueue is actually just a second queue off the "up"
844 * queue, so we use the same lock.
846 g_bioq_lock(&g_bio_run_up);
847 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
848 ("Bio already on queue bp=%p target taskq", bp));
849 bp->bio_flags |= BIO_ONQUEUE;
850 TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue);
851 g_bio_run_task.bio_queue_length++;
853 g_bioq_unlock(&g_bio_run_up);
858 g_io_schedule_up(struct thread *tp __unused)
862 g_bioq_lock(&g_bio_run_up);
863 bp = g_bioq_first(&g_bio_run_task);
865 g_bioq_unlock(&g_bio_run_up);
866 THREAD_NO_SLEEPING();
867 CTR1(KTR_GEOM, "g_up processing task bp %p", bp);
868 bp->bio_task(bp->bio_task_arg);
869 THREAD_SLEEPING_OK();
872 bp = g_bioq_first(&g_bio_run_up);
874 g_bioq_unlock(&g_bio_run_up);
875 THREAD_NO_SLEEPING();
876 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
877 "%jd len %ld", bp, bp->bio_to->name,
878 bp->bio_offset, bp->bio_length);
880 THREAD_SLEEPING_OK();
883 CTR0(KTR_GEOM, "g_up going to sleep");
884 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
885 PRIBIO | PDROP, "-", 0);
890 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
896 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
897 length <= MAXPHYS, ("g_read_data(): invalid length %jd",
901 bp->bio_cmd = BIO_READ;
903 bp->bio_offset = offset;
904 bp->bio_length = length;
905 ptr = g_malloc(length, M_WAITOK);
907 g_io_request(bp, cp);
908 errorc = biowait(bp, "gread");
920 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
925 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
926 length <= MAXPHYS, ("g_write_data(): invalid length %jd",
930 bp->bio_cmd = BIO_WRITE;
932 bp->bio_offset = offset;
933 bp->bio_length = length;
935 g_io_request(bp, cp);
936 error = biowait(bp, "gwrite");
942 g_delete_data(struct g_consumer *cp, off_t offset, off_t length)
947 KASSERT(length > 0 && length >= cp->provider->sectorsize,
948 ("g_delete_data(): invalid length %jd", (intmax_t)length));
951 bp->bio_cmd = BIO_DELETE;
953 bp->bio_offset = offset;
954 bp->bio_length = length;
956 g_io_request(bp, cp);
957 error = biowait(bp, "gdelete");
963 g_print_bio(struct bio *bp)
965 const char *pname, *cmd = NULL;
967 if (bp->bio_to != NULL)
968 pname = bp->bio_to->name;
972 switch (bp->bio_cmd) {
975 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute);
979 printf("%s[%s]", pname, cmd);
992 printf("%s[%s()]", pname, cmd);
995 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd,
996 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);