FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_io.c
1 /*-
2 * Copyright (c) 2002 Poul-Henning Kamp
3 * Copyright (c) 2002 Networks Associates Technology, Inc.
4 * Copyright (c) 2013 The FreeBSD Foundation
5 * All rights reserved.
6 *
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.
11 *
12 * Portions of this software were developed by Konstantin Belousov
13 * under sponsorship from the FreeBSD Foundation.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
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
25 * permission.
26 *
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
37 * SUCH DAMAGE.
38 */
39
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD: releng/10.4/sys/geom/geom_io.c 292348 2015-12-16 19:01:14Z ken $");
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/bio.h>
48 #include <sys/ktr.h>
49 #include <sys/proc.h>
50 #include <sys/stack.h>
51 #include <sys/sysctl.h>
52 #include <sys/vmem.h>
53
54 #include <sys/errno.h>
55 #include <geom/geom.h>
56 #include <geom/geom_int.h>
57 #include <sys/devicestat.h>
58
59 #include <vm/uma.h>
60 #include <vm/vm.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>
67
68 static int g_io_transient_map_bio(struct bio *bp);
69
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;
73
74 /*
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
81 * and limitations.
82 */
83 static volatile u_int pace;
84
85 static uma_zone_t biozone;
86
87 /*
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.
92 */
93 static TAILQ_HEAD(g_classifier_tailq, g_classifier_hook)
94 g_classifier_tailq = TAILQ_HEAD_INITIALIZER(g_classifier_tailq);
95
96 #include <machine/atomic.h>
97
98 static void
99 g_bioq_lock(struct g_bioq *bq)
100 {
101
102 mtx_lock(&bq->bio_queue_lock);
103 }
104
105 static void
106 g_bioq_unlock(struct g_bioq *bq)
107 {
108
109 mtx_unlock(&bq->bio_queue_lock);
110 }
111
112 #if 0
113 static void
114 g_bioq_destroy(struct g_bioq *bq)
115 {
116
117 mtx_destroy(&bq->bio_queue_lock);
118 }
119 #endif
120
121 static void
122 g_bioq_init(struct g_bioq *bq)
123 {
124
125 TAILQ_INIT(&bq->bio_queue);
126 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
127 }
128
129 static struct bio *
130 g_bioq_first(struct g_bioq *bq)
131 {
132 struct bio *bp;
133
134 bp = TAILQ_FIRST(&bq->bio_queue);
135 if (bp != NULL) {
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--;
141 }
142 return (bp);
143 }
144
145 struct bio *
146 g_new_bio(void)
147 {
148 struct bio *bp;
149
150 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
151 #ifdef KTR
152 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
153 struct stack st;
154
155 CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
156 stack_save(&st);
157 CTRSTACK(KTR_GEOM, &st, 3, 0);
158 }
159 #endif
160 return (bp);
161 }
162
163 struct bio *
164 g_alloc_bio(void)
165 {
166 struct bio *bp;
167
168 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
169 #ifdef KTR
170 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
171 struct stack st;
172
173 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
174 stack_save(&st);
175 CTRSTACK(KTR_GEOM, &st, 3, 0);
176 }
177 #endif
178 return (bp);
179 }
180
181 void
182 g_destroy_bio(struct bio *bp)
183 {
184 #ifdef KTR
185 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
186 struct stack st;
187
188 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
189 stack_save(&st);
190 CTRSTACK(KTR_GEOM, &st, 3, 0);
191 }
192 #endif
193 uma_zfree(biozone, bp);
194 }
195
196 struct bio *
197 g_clone_bio(struct bio *bp)
198 {
199 struct bio *bp2;
200
201 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
202 if (bp2 != NULL) {
203 bp2->bio_parent = bp;
204 bp2->bio_cmd = bp->bio_cmd;
205 /*
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 and BIO_VLIST should be inherited, to properly
209 * indicate which way the buffer is passed.
210 * Other bio flags are not suitable for cloning.
211 */
212 bp2->bio_flags = bp->bio_flags &
213 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST);
214 bp2->bio_length = bp->bio_length;
215 bp2->bio_offset = bp->bio_offset;
216 bp2->bio_data = bp->bio_data;
217 bp2->bio_ma = bp->bio_ma;
218 bp2->bio_ma_n = bp->bio_ma_n;
219 bp2->bio_ma_offset = bp->bio_ma_offset;
220 bp2->bio_attribute = bp->bio_attribute;
221 /* Inherit classification info from the parent */
222 bp2->bio_classifier1 = bp->bio_classifier1;
223 bp2->bio_classifier2 = bp->bio_classifier2;
224 bp->bio_children++;
225 }
226 #ifdef KTR
227 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
228 struct stack st;
229
230 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2);
231 stack_save(&st);
232 CTRSTACK(KTR_GEOM, &st, 3, 0);
233 }
234 #endif
235 return(bp2);
236 }
237
238 struct bio *
239 g_duplicate_bio(struct bio *bp)
240 {
241 struct bio *bp2;
242
243 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO);
244 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST);
245 bp2->bio_parent = bp;
246 bp2->bio_cmd = bp->bio_cmd;
247 bp2->bio_length = bp->bio_length;
248 bp2->bio_offset = bp->bio_offset;
249 bp2->bio_data = bp->bio_data;
250 bp2->bio_ma = bp->bio_ma;
251 bp2->bio_ma_n = bp->bio_ma_n;
252 bp2->bio_ma_offset = bp->bio_ma_offset;
253 bp2->bio_attribute = bp->bio_attribute;
254 bp->bio_children++;
255 #ifdef KTR
256 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
257 struct stack st;
258
259 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2);
260 stack_save(&st);
261 CTRSTACK(KTR_GEOM, &st, 3, 0);
262 }
263 #endif
264 return(bp2);
265 }
266
267 void
268 g_io_init()
269 {
270
271 g_bioq_init(&g_bio_run_down);
272 g_bioq_init(&g_bio_run_up);
273 g_bioq_init(&g_bio_run_task);
274 biozone = uma_zcreate("g_bio", sizeof (struct bio),
275 NULL, NULL,
276 NULL, NULL,
277 0, 0);
278 }
279
280 int
281 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
282 {
283 struct bio *bp;
284 int error;
285
286 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
287 bp = g_alloc_bio();
288 bp->bio_cmd = BIO_GETATTR;
289 bp->bio_done = NULL;
290 bp->bio_attribute = attr;
291 bp->bio_length = *len;
292 bp->bio_data = ptr;
293 g_io_request(bp, cp);
294 error = biowait(bp, "ggetattr");
295 *len = bp->bio_completed;
296 g_destroy_bio(bp);
297 return (error);
298 }
299
300 int
301 g_io_flush(struct g_consumer *cp)
302 {
303 struct bio *bp;
304 int error;
305
306 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name);
307 bp = g_alloc_bio();
308 bp->bio_cmd = BIO_FLUSH;
309 bp->bio_flags |= BIO_ORDERED;
310 bp->bio_done = NULL;
311 bp->bio_attribute = NULL;
312 bp->bio_offset = cp->provider->mediasize;
313 bp->bio_length = 0;
314 bp->bio_data = NULL;
315 g_io_request(bp, cp);
316 error = biowait(bp, "gflush");
317 g_destroy_bio(bp);
318 return (error);
319 }
320
321 static int
322 g_io_check(struct bio *bp)
323 {
324 struct g_consumer *cp;
325 struct g_provider *pp;
326 off_t excess;
327 int error;
328
329 cp = bp->bio_from;
330 pp = bp->bio_to;
331
332 /* Fail if access counters dont allow the operation */
333 switch(bp->bio_cmd) {
334 case BIO_READ:
335 case BIO_GETATTR:
336 if (cp->acr == 0)
337 return (EPERM);
338 break;
339 case BIO_WRITE:
340 case BIO_DELETE:
341 case BIO_FLUSH:
342 if (cp->acw == 0)
343 return (EPERM);
344 break;
345 default:
346 return (EPERM);
347 }
348 /* if provider is marked for error, don't disturb. */
349 if (pp->error)
350 return (pp->error);
351 if (cp->flags & G_CF_ORPHAN)
352 return (ENXIO);
353
354 switch(bp->bio_cmd) {
355 case BIO_READ:
356 case BIO_WRITE:
357 case BIO_DELETE:
358 /* Zero sectorsize or mediasize is probably a lack of media. */
359 if (pp->sectorsize == 0 || pp->mediasize == 0)
360 return (ENXIO);
361 /* Reject I/O not on sector boundary */
362 if (bp->bio_offset % pp->sectorsize)
363 return (EINVAL);
364 /* Reject I/O not integral sector long */
365 if (bp->bio_length % pp->sectorsize)
366 return (EINVAL);
367 /* Reject requests before or past the end of media. */
368 if (bp->bio_offset < 0)
369 return (EIO);
370 if (bp->bio_offset > pp->mediasize)
371 return (EIO);
372
373 /* Truncate requests to the end of providers media. */
374 excess = bp->bio_offset + bp->bio_length;
375 if (excess > bp->bio_to->mediasize) {
376 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 ||
377 round_page(bp->bio_ma_offset +
378 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n,
379 ("excess bio %p too short", bp));
380 excess -= bp->bio_to->mediasize;
381 bp->bio_length -= excess;
382 if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
383 bp->bio_ma_n = round_page(bp->bio_ma_offset +
384 bp->bio_length) / PAGE_SIZE;
385 }
386 if (excess > 0)
387 CTR3(KTR_GEOM, "g_down truncated bio "
388 "%p provider %s by %d", bp,
389 bp->bio_to->name, excess);
390 }
391
392 /* Deliver zero length transfers right here. */
393 if (bp->bio_length == 0) {
394 CTR2(KTR_GEOM, "g_down terminated 0-length "
395 "bp %p provider %s", bp, bp->bio_to->name);
396 return (0);
397 }
398
399 if ((bp->bio_flags & BIO_UNMAPPED) != 0 &&
400 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
401 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
402 if ((error = g_io_transient_map_bio(bp)) >= 0)
403 return (error);
404 }
405 break;
406 default:
407 break;
408 }
409 return (EJUSTRETURN);
410 }
411
412 /*
413 * bio classification support.
414 *
415 * g_register_classifier() and g_unregister_classifier()
416 * are used to add/remove a classifier from the list.
417 * The list is protected using the g_bio_run_down lock,
418 * because the classifiers are called in this path.
419 *
420 * g_io_request() passes bio's that are not already classified
421 * (i.e. those with bio_classifier1 == NULL) to g_run_classifiers().
422 * Classifiers can store their result in the two fields
423 * bio_classifier1 and bio_classifier2.
424 * A classifier that updates one of the fields should
425 * return a non-zero value.
426 * If no classifier updates the field, g_run_classifiers() sets
427 * bio_classifier1 = BIO_NOTCLASSIFIED to avoid further calls.
428 */
429
430 int
431 g_register_classifier(struct g_classifier_hook *hook)
432 {
433
434 g_bioq_lock(&g_bio_run_down);
435 TAILQ_INSERT_TAIL(&g_classifier_tailq, hook, link);
436 g_bioq_unlock(&g_bio_run_down);
437
438 return (0);
439 }
440
441 void
442 g_unregister_classifier(struct g_classifier_hook *hook)
443 {
444 struct g_classifier_hook *entry;
445
446 g_bioq_lock(&g_bio_run_down);
447 TAILQ_FOREACH(entry, &g_classifier_tailq, link) {
448 if (entry == hook) {
449 TAILQ_REMOVE(&g_classifier_tailq, hook, link);
450 break;
451 }
452 }
453 g_bioq_unlock(&g_bio_run_down);
454 }
455
456 static void
457 g_run_classifiers(struct bio *bp)
458 {
459 struct g_classifier_hook *hook;
460 int classified = 0;
461
462 TAILQ_FOREACH(hook, &g_classifier_tailq, link)
463 classified |= hook->func(hook->arg, bp);
464
465 if (!classified)
466 bp->bio_classifier1 = BIO_NOTCLASSIFIED;
467 }
468
469 void
470 g_io_request(struct bio *bp, struct g_consumer *cp)
471 {
472 struct g_provider *pp;
473 struct mtx *mtxp;
474 int direct, error, first;
475
476 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
477 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
478 pp = cp->provider;
479 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
480 #ifdef DIAGNOSTIC
481 KASSERT(bp->bio_driver1 == NULL,
482 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name));
483 KASSERT(bp->bio_driver2 == NULL,
484 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name));
485 KASSERT(bp->bio_pflags == 0,
486 ("bio_pflags used by the consumer (geom %s)", cp->geom->name));
487 /*
488 * Remember consumer's private fields, so we can detect if they were
489 * modified by the provider.
490 */
491 bp->_bio_caller1 = bp->bio_caller1;
492 bp->_bio_caller2 = bp->bio_caller2;
493 bp->_bio_cflags = bp->bio_cflags;
494 #endif
495
496 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_GETATTR)) {
497 KASSERT(bp->bio_data != NULL,
498 ("NULL bp->data in g_io_request(cmd=%hhu)", bp->bio_cmd));
499 }
500 if (bp->bio_cmd & (BIO_DELETE|BIO_FLUSH)) {
501 KASSERT(bp->bio_data == NULL,
502 ("non-NULL bp->data in g_io_request(cmd=%hhu)",
503 bp->bio_cmd));
504 }
505 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) {
506 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
507 ("wrong offset %jd for sectorsize %u",
508 bp->bio_offset, cp->provider->sectorsize));
509 KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
510 ("wrong length %jd for sectorsize %u",
511 bp->bio_length, cp->provider->sectorsize));
512 }
513
514 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
515 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
516
517 bp->bio_from = cp;
518 bp->bio_to = pp;
519 bp->bio_error = 0;
520 bp->bio_completed = 0;
521
522 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
523 ("Bio already on queue bp=%p", bp));
524 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
525 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
526 binuptime(&bp->bio_t0);
527 else
528 getbinuptime(&bp->bio_t0);
529
530 #ifdef GET_STACK_USAGE
531 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 &&
532 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 &&
533 !g_is_geom_thread(curthread) &&
534 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ||
535 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) &&
536 pace == 0;
537 if (direct) {
538 /* Block direct execution if less then half of stack left. */
539 size_t st, su;
540 GET_STACK_USAGE(st, su);
541 if (su * 2 > st)
542 direct = 0;
543 }
544 #else
545 direct = 0;
546 #endif
547
548 if (!TAILQ_EMPTY(&g_classifier_tailq) && !bp->bio_classifier1) {
549 g_bioq_lock(&g_bio_run_down);
550 g_run_classifiers(bp);
551 g_bioq_unlock(&g_bio_run_down);
552 }
553
554 /*
555 * The statistics collection is lockless, as such, but we
556 * can not update one instance of the statistics from more
557 * than one thread at a time, so grab the lock first.
558 */
559 mtxp = mtx_pool_find(mtxpool_sleep, pp);
560 mtx_lock(mtxp);
561 if (g_collectstats & G_STATS_PROVIDERS)
562 devstat_start_transaction(pp->stat, &bp->bio_t0);
563 if (g_collectstats & G_STATS_CONSUMERS)
564 devstat_start_transaction(cp->stat, &bp->bio_t0);
565 pp->nstart++;
566 cp->nstart++;
567 mtx_unlock(mtxp);
568
569 if (direct) {
570 error = g_io_check(bp);
571 if (error >= 0) {
572 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p "
573 "provider %s returned %d", bp, bp->bio_to->name,
574 error);
575 g_io_deliver(bp, error);
576 return;
577 }
578 bp->bio_to->geom->start(bp);
579 } else {
580 g_bioq_lock(&g_bio_run_down);
581 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue);
582 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue);
583 bp->bio_flags |= BIO_ONQUEUE;
584 g_bio_run_down.bio_queue_length++;
585 g_bioq_unlock(&g_bio_run_down);
586 /* Pass it on down. */
587 if (first)
588 wakeup(&g_wait_down);
589 }
590 }
591
592 void
593 g_io_deliver(struct bio *bp, int error)
594 {
595 struct bintime now;
596 struct g_consumer *cp;
597 struct g_provider *pp;
598 struct mtx *mtxp;
599 int direct, first;
600
601 KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
602 pp = bp->bio_to;
603 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
604 cp = bp->bio_from;
605 if (cp == NULL) {
606 bp->bio_error = error;
607 bp->bio_done(bp);
608 return;
609 }
610 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
611 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
612 #ifdef DIAGNOSTIC
613 /*
614 * Some classes - GJournal in particular - can modify bio's
615 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO
616 * flag means it's an expected behaviour for that particular geom.
617 */
618 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) {
619 KASSERT(bp->bio_caller1 == bp->_bio_caller1,
620 ("bio_caller1 used by the provider %s", pp->name));
621 KASSERT(bp->bio_caller2 == bp->_bio_caller2,
622 ("bio_caller2 used by the provider %s", pp->name));
623 KASSERT(bp->bio_cflags == bp->_bio_cflags,
624 ("bio_cflags used by the provider %s", pp->name));
625 }
626 #endif
627 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0"));
628 KASSERT(bp->bio_completed <= bp->bio_length,
629 ("bio_completed can't be greater than bio_length"));
630
631 g_trace(G_T_BIO,
632 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
633 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
634 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
635
636 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
637 ("Bio already on queue bp=%p", bp));
638
639 /*
640 * XXX: next two doesn't belong here
641 */
642 bp->bio_bcount = bp->bio_length;
643 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
644
645 #ifdef GET_STACK_USAGE
646 direct = (pp->flags & G_PF_DIRECT_SEND) &&
647 (cp->flags & G_CF_DIRECT_RECEIVE) &&
648 !g_is_geom_thread(curthread);
649 if (direct) {
650 /* Block direct execution if less then half of stack left. */
651 size_t st, su;
652 GET_STACK_USAGE(st, su);
653 if (su * 2 > st)
654 direct = 0;
655 }
656 #else
657 direct = 0;
658 #endif
659
660 /*
661 * The statistics collection is lockless, as such, but we
662 * can not update one instance of the statistics from more
663 * than one thread at a time, so grab the lock first.
664 */
665 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
666 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
667 binuptime(&now);
668 mtxp = mtx_pool_find(mtxpool_sleep, cp);
669 mtx_lock(mtxp);
670 if (g_collectstats & G_STATS_PROVIDERS)
671 devstat_end_transaction_bio_bt(pp->stat, bp, &now);
672 if (g_collectstats & G_STATS_CONSUMERS)
673 devstat_end_transaction_bio_bt(cp->stat, bp, &now);
674 cp->nend++;
675 pp->nend++;
676 mtx_unlock(mtxp);
677
678 if (error != ENOMEM) {
679 bp->bio_error = error;
680 if (direct) {
681 biodone(bp);
682 } else {
683 g_bioq_lock(&g_bio_run_up);
684 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue);
685 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
686 bp->bio_flags |= BIO_ONQUEUE;
687 g_bio_run_up.bio_queue_length++;
688 g_bioq_unlock(&g_bio_run_up);
689 if (first)
690 wakeup(&g_wait_up);
691 }
692 return;
693 }
694
695 if (bootverbose)
696 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
697 bp->bio_children = 0;
698 bp->bio_inbed = 0;
699 bp->bio_driver1 = NULL;
700 bp->bio_driver2 = NULL;
701 bp->bio_pflags = 0;
702 g_io_request(bp, cp);
703 pace = 1;
704 return;
705 }
706
707 SYSCTL_DECL(_kern_geom);
708
709 static long transient_maps;
710 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD,
711 &transient_maps, 0,
712 "Total count of the transient mapping requests");
713 u_int transient_map_retries = 10;
714 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW,
715 &transient_map_retries, 0,
716 "Max count of retries used before giving up on creating transient map");
717 int transient_map_hard_failures;
718 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD,
719 &transient_map_hard_failures, 0,
720 "Failures to establish the transient mapping due to retry attempts "
721 "exhausted");
722 int transient_map_soft_failures;
723 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD,
724 &transient_map_soft_failures, 0,
725 "Count of retried failures to establish the transient mapping");
726 int inflight_transient_maps;
727 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD,
728 &inflight_transient_maps, 0,
729 "Current count of the active transient maps");
730
731 static int
732 g_io_transient_map_bio(struct bio *bp)
733 {
734 vm_offset_t addr;
735 long size;
736 u_int retried;
737
738 KASSERT(unmapped_buf_allowed, ("unmapped disabled"));
739
740 size = round_page(bp->bio_ma_offset + bp->bio_length);
741 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp));
742 addr = 0;
743 retried = 0;
744 atomic_add_long(&transient_maps, 1);
745 retry:
746 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) {
747 if (transient_map_retries != 0 &&
748 retried >= transient_map_retries) {
749 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s",
750 bp, bp->bio_to->name);
751 atomic_add_int(&transient_map_hard_failures, 1);
752 return (EDEADLK/* XXXKIB */);
753 } else {
754 /*
755 * Naive attempt to quisce the I/O to get more
756 * in-flight requests completed and defragment
757 * the transient_arena.
758 */
759 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d",
760 bp, bp->bio_to->name, retried);
761 pause("g_d_tra", hz / 10);
762 retried++;
763 atomic_add_int(&transient_map_soft_failures, 1);
764 goto retry;
765 }
766 }
767 atomic_add_int(&inflight_transient_maps, 1);
768 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size));
769 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset;
770 bp->bio_flags |= BIO_TRANSIENT_MAPPING;
771 bp->bio_flags &= ~BIO_UNMAPPED;
772 return (EJUSTRETURN);
773 }
774
775 void
776 g_io_schedule_down(struct thread *tp __unused)
777 {
778 struct bio *bp;
779 int error;
780
781 for(;;) {
782 g_bioq_lock(&g_bio_run_down);
783 bp = g_bioq_first(&g_bio_run_down);
784 if (bp == NULL) {
785 CTR0(KTR_GEOM, "g_down going to sleep");
786 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
787 PRIBIO | PDROP, "-", 0);
788 continue;
789 }
790 CTR0(KTR_GEOM, "g_down has work to do");
791 g_bioq_unlock(&g_bio_run_down);
792 if (pace != 0) {
793 /*
794 * There has been at least one memory allocation
795 * failure since the last I/O completed. Pause 1ms to
796 * give the system a chance to free up memory. We only
797 * do this once because a large number of allocations
798 * can fail in the direct dispatch case and there's no
799 * relationship between the number of these failures and
800 * the length of the outage. If there's still an outage,
801 * we'll pause again and again until it's
802 * resolved. Older versions paused longer and once per
803 * allocation failure. This was OK for a single threaded
804 * g_down, but with direct dispatch would lead to max of
805 * 10 IOPs for minutes at a time when transient memory
806 * issues prevented allocation for a batch of requests
807 * from the upper layers.
808 *
809 * XXX This pacing is really lame. It needs to be solved
810 * by other methods. This is OK only because the worst
811 * case scenario is so rare. In the worst case scenario
812 * all memory is tied up waiting for I/O to complete
813 * which can never happen since we can't allocate bios
814 * for that I/O.
815 */
816 CTR0(KTR_GEOM, "g_down pacing self");
817 pause("g_down", min(hz/1000, 1));
818 pace = 0;
819 }
820 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
821 bp->bio_to->name);
822 error = g_io_check(bp);
823 if (error >= 0) {
824 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
825 "%s returned %d", bp, bp->bio_to->name, error);
826 g_io_deliver(bp, error);
827 continue;
828 }
829 THREAD_NO_SLEEPING();
830 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
831 "len %ld", bp, bp->bio_to->name, bp->bio_offset,
832 bp->bio_length);
833 bp->bio_to->geom->start(bp);
834 THREAD_SLEEPING_OK();
835 }
836 }
837
838 void
839 bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg)
840 {
841 bp->bio_task = func;
842 bp->bio_task_arg = arg;
843 /*
844 * The taskqueue is actually just a second queue off the "up"
845 * queue, so we use the same lock.
846 */
847 g_bioq_lock(&g_bio_run_up);
848 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
849 ("Bio already on queue bp=%p target taskq", bp));
850 bp->bio_flags |= BIO_ONQUEUE;
851 TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue);
852 g_bio_run_task.bio_queue_length++;
853 wakeup(&g_wait_up);
854 g_bioq_unlock(&g_bio_run_up);
855 }
856
857
858 void
859 g_io_schedule_up(struct thread *tp __unused)
860 {
861 struct bio *bp;
862 for(;;) {
863 g_bioq_lock(&g_bio_run_up);
864 bp = g_bioq_first(&g_bio_run_task);
865 if (bp != NULL) {
866 g_bioq_unlock(&g_bio_run_up);
867 THREAD_NO_SLEEPING();
868 CTR1(KTR_GEOM, "g_up processing task bp %p", bp);
869 bp->bio_task(bp->bio_task_arg);
870 THREAD_SLEEPING_OK();
871 continue;
872 }
873 bp = g_bioq_first(&g_bio_run_up);
874 if (bp != NULL) {
875 g_bioq_unlock(&g_bio_run_up);
876 THREAD_NO_SLEEPING();
877 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
878 "%jd len %ld", bp, bp->bio_to->name,
879 bp->bio_offset, bp->bio_length);
880 biodone(bp);
881 THREAD_SLEEPING_OK();
882 continue;
883 }
884 CTR0(KTR_GEOM, "g_up going to sleep");
885 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
886 PRIBIO | PDROP, "-", 0);
887 }
888 }
889
890 void *
891 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
892 {
893 struct bio *bp;
894 void *ptr;
895 int errorc;
896
897 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
898 length <= MAXPHYS, ("g_read_data(): invalid length %jd",
899 (intmax_t)length));
900
901 bp = g_alloc_bio();
902 bp->bio_cmd = BIO_READ;
903 bp->bio_done = NULL;
904 bp->bio_offset = offset;
905 bp->bio_length = length;
906 ptr = g_malloc(length, M_WAITOK);
907 bp->bio_data = ptr;
908 g_io_request(bp, cp);
909 errorc = biowait(bp, "gread");
910 if (error != NULL)
911 *error = errorc;
912 g_destroy_bio(bp);
913 if (errorc) {
914 g_free(ptr);
915 ptr = NULL;
916 }
917 return (ptr);
918 }
919
920 int
921 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
922 {
923 struct bio *bp;
924 int error;
925
926 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
927 length <= MAXPHYS, ("g_write_data(): invalid length %jd",
928 (intmax_t)length));
929
930 bp = g_alloc_bio();
931 bp->bio_cmd = BIO_WRITE;
932 bp->bio_done = NULL;
933 bp->bio_offset = offset;
934 bp->bio_length = length;
935 bp->bio_data = ptr;
936 g_io_request(bp, cp);
937 error = biowait(bp, "gwrite");
938 g_destroy_bio(bp);
939 return (error);
940 }
941
942 int
943 g_delete_data(struct g_consumer *cp, off_t offset, off_t length)
944 {
945 struct bio *bp;
946 int error;
947
948 KASSERT(length > 0 && length >= cp->provider->sectorsize,
949 ("g_delete_data(): invalid length %jd", (intmax_t)length));
950
951 bp = g_alloc_bio();
952 bp->bio_cmd = BIO_DELETE;
953 bp->bio_done = NULL;
954 bp->bio_offset = offset;
955 bp->bio_length = length;
956 bp->bio_data = NULL;
957 g_io_request(bp, cp);
958 error = biowait(bp, "gdelete");
959 g_destroy_bio(bp);
960 return (error);
961 }
962
963 void
964 g_print_bio(struct bio *bp)
965 {
966 const char *pname, *cmd = NULL;
967
968 if (bp->bio_to != NULL)
969 pname = bp->bio_to->name;
970 else
971 pname = "[unknown]";
972
973 switch (bp->bio_cmd) {
974 case BIO_GETATTR:
975 cmd = "GETATTR";
976 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute);
977 return;
978 case BIO_FLUSH:
979 cmd = "FLUSH";
980 printf("%s[%s]", pname, cmd);
981 return;
982 case BIO_READ:
983 cmd = "READ";
984 break;
985 case BIO_WRITE:
986 cmd = "WRITE";
987 break;
988 case BIO_DELETE:
989 cmd = "DELETE";
990 break;
991 default:
992 cmd = "UNKNOWN";
993 printf("%s[%s()]", pname, cmd);
994 return;
995 }
996 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd,
997 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
998 }
Cache object: d6f79702beed5591c16b17036d44b16f
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