Super User's BSD Cross Reference: /FreeBSD/sys/geom/geom_io.c

1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2002 Poul-Henning Kamp
5 * Copyright (c) 2002 Networks Associates Technology, Inc.
6 * Copyright (c) 2013 The FreeBSD Foundation
7 * All rights reserved.
8 *
9 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
10 * and NAI Labs, the Security Research Division of Network Associates, Inc.
11 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
12 * DARPA CHATS research program.
13 *
14 * Portions of this software were developed by Konstantin Belousov
15 * under sponsorship from the FreeBSD Foundation.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 * 3. The names of the authors may not be used to endorse or promote
26 * products derived from this software without specific prior written
27 * permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41
42#include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/kernel.h>
48#include <sys/malloc.h>
49#include <sys/bio.h>
50#include <sys/ktr.h>
51#include <sys/proc.h>
52#include <sys/sbuf.h>
53#include <sys/stack.h>
54#include <sys/sysctl.h>
55#include <sys/vmem.h>
56#include <machine/stdarg.h>
57
58#include <sys/errno.h>
59#include <geom/geom.h>
60#include <geom/geom_int.h>
61#include <sys/devicestat.h>
62
63#include <vm/uma.h>
64#include <vm/vm.h>
65#include <vm/vm_param.h>
66#include <vm/vm_kern.h>
67#include <vm/vm_page.h>
68#include <vm/vm_object.h>
69#include <vm/vm_extern.h>
70#include <vm/vm_map.h>
71
72 static int g_io_transient_map_bio(struct bio *bp);
73
74 static struct g_bioq g_bio_run_down;
75 static struct g_bioq g_bio_run_up;
76
77 /*
78 * Pace is a hint that we've had some trouble recently allocating
79 * bios, so we should back off trying to send I/O down the stack
80 * a bit to let the problem resolve. When pacing, we also turn
81 * off direct dispatch to also reduce memory pressure from I/Os
82 * there, at the expxense of some added latency while the memory
83 * pressures exist. See g_io_schedule_down() for more details
84 * and limitations.
85 */
86 static volatile u_int __read_mostly pace;
87
88 static uma_zone_t __read_mostly biozone;
89
90#include <machine/atomic.h>
91
92 static void
93 g_bioq_lock(struct g_bioq *bq)
94{
95
96 mtx_lock(&bq->bio_queue_lock);
97}
98
99 static void
100 g_bioq_unlock(struct g_bioq *bq)
101{
102
103 mtx_unlock(&bq->bio_queue_lock);
104}
105
106#if 0
107 static void
108 g_bioq_destroy(struct g_bioq *bq)
109{
110
111 mtx_destroy(&bq->bio_queue_lock);
112}
113#endif
114
115 static void
116 g_bioq_init(struct g_bioq *bq)
117{
118
119 TAILQ_INIT(&bq->bio_queue);
120 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
121}
122
123 static struct bio *
124 g_bioq_first(struct g_bioq *bq)
125{
126 struct bio *bp;
127
128 bp = TAILQ_FIRST(&bq->bio_queue);
129 if (bp != NULL) {
130 KASSERT((bp->bio_flags & BIO_ONQUEUE),
131 ("Bio not on queue bp=%p target %p", bp, bq));
132 bp->bio_flags &= ~BIO_ONQUEUE;
133 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
134 bq->bio_queue_length--;
135 }
136 return (bp);
137}
138
139 struct bio *
140 g_new_bio(void)
141{
142 struct bio *bp;
143
144 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
145#ifdef KTR
146 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
147 struct stack st;
148
149 CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
150 stack_save(&st);
151 CTRSTACK(KTR_GEOM, &st, 3);
152 }
153#endif
154 return (bp);
155}
156
157 struct bio *
158 g_alloc_bio(void)
159{
160 struct bio *bp;
161
162 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
163#ifdef KTR
164 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
165 struct stack st;
166
167 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
168 stack_save(&st);
169 CTRSTACK(KTR_GEOM, &st, 3);
170 }
171#endif
172 return (bp);
173}
174
175 void
176 g_destroy_bio(struct bio *bp)
177{
178#ifdef KTR
179 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
180 struct stack st;
181
182 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
183 stack_save(&st);
184 CTRSTACK(KTR_GEOM, &st, 3);
185 }
186#endif
187 uma_zfree(biozone, bp);
188}
189
190 struct bio *
191 g_clone_bio(struct bio *bp)
192{
193 struct bio *bp2;
194
195 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
196 if (bp2 != NULL) {
197 bp2->bio_parent = bp;
198 bp2->bio_cmd = bp->bio_cmd;
199 /*
200 * BIO_ORDERED flag may be used by disk drivers to enforce
201 * ordering restrictions, so this flag needs to be cloned.
202 * BIO_UNMAPPED and BIO_VLIST should be inherited, to properly
203 * indicate which way the buffer is passed.
204 * Other bio flags are not suitable for cloning.
205 */
206 bp2->bio_flags = bp->bio_flags &
207 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST);
208 bp2->bio_length = bp->bio_length;
209 bp2->bio_offset = bp->bio_offset;
210 bp2->bio_data = bp->bio_data;
211 bp2->bio_ma = bp->bio_ma;
212 bp2->bio_ma_n = bp->bio_ma_n;
213 bp2->bio_ma_offset = bp->bio_ma_offset;
214 bp2->bio_attribute = bp->bio_attribute;
215 if (bp->bio_cmd == BIO_ZONE)
216 bcopy(&bp->bio_zone, &bp2->bio_zone,
217 sizeof(bp->bio_zone));
218#if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
219 bp2->bio_track_bp = bp->bio_track_bp;
220#endif
221 bp->bio_children++;
222 }
223#ifdef KTR
224 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
225 struct stack st;
226
227 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2);
228 stack_save(&st);
229 CTRSTACK(KTR_GEOM, &st, 3);
230 }
231#endif
232 return(bp2);
233}
234
235 struct bio *
236 g_duplicate_bio(struct bio *bp)
237{
238 struct bio *bp2;
239
240 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO);
241 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST);
242 bp2->bio_parent = bp;
243 bp2->bio_cmd = bp->bio_cmd;
244 bp2->bio_length = bp->bio_length;
245 bp2->bio_offset = bp->bio_offset;
246 bp2->bio_data = bp->bio_data;
247 bp2->bio_ma = bp->bio_ma;
248 bp2->bio_ma_n = bp->bio_ma_n;
249 bp2->bio_ma_offset = bp->bio_ma_offset;
250 bp2->bio_attribute = bp->bio_attribute;
251 bp->bio_children++;
252#ifdef KTR
253 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) {
254 struct stack st;
255
256 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2);
257 stack_save(&st);
258 CTRSTACK(KTR_GEOM, &st, 3);
259 }
260#endif
261 return(bp2);
262}
263
264 void
265 g_reset_bio(struct bio *bp)
266{
267
268 bzero(bp, sizeof(*bp));
269}
270
271 void
272 g_io_init()
273{
274
275 g_bioq_init(&g_bio_run_down);
276 g_bioq_init(&g_bio_run_up);
277 biozone = uma_zcreate("g_bio", sizeof (struct bio),
278 NULL, NULL,
279 NULL, NULL,
280 0, 0);
281}
282
283 int
284 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
285{
286 struct bio *bp;
287 int error;
288
289 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
290 bp = g_alloc_bio();
291 bp->bio_cmd = BIO_GETATTR;
292 bp->bio_done = NULL;
293 bp->bio_attribute = attr;
294 bp->bio_length = *len;
295 bp->bio_data = ptr;
296 g_io_request(bp, cp);
297 error = biowait(bp, "ggetattr");
298 *len = bp->bio_completed;
299 g_destroy_bio(bp);
300 return (error);
301}
302
303 int
304 g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp)
305{
306 struct bio *bp;
307 int error;
308
309 g_trace(G_T_BIO, "bio_zone(%d)", zone_args->zone_cmd);
310 bp = g_alloc_bio();
311 bp->bio_cmd = BIO_ZONE;
312 bp->bio_done = NULL;
313 /*
314 * XXX KDM need to handle report zone data.
315 */
316 bcopy(zone_args, &bp->bio_zone, sizeof(*zone_args));
317 if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES)
318 bp->bio_length =
319 zone_args->zone_params.report.entries_allocated *
320 sizeof(struct disk_zone_rep_entry);
321 else
322 bp->bio_length = 0;
323
324 g_io_request(bp, cp);
325 error = biowait(bp, "gzone");
326 bcopy(&bp->bio_zone, zone_args, sizeof(*zone_args));
327 g_destroy_bio(bp);
328 return (error);
329}
330
331 /*
332 * Send a BIO_SPEEDUP down the stack. This is used to tell the lower layers that
333 * the upper layers have detected a resource shortage. The lower layers are
334 * advised to stop delaying I/O that they might be holding for performance
335 * reasons and to schedule it (non-trims) or complete it successfully (trims) as
336 * quickly as it can. bio_length is the amount of the shortage. This call
337 * should be non-blocking. bio_resid is used to communicate back if the lower
338 * layers couldn't find bio_length worth of I/O to schedule or discard. A length
339 * of 0 means to do as much as you can (schedule the h/w queues full, discard
340 * all trims). flags are a hint from the upper layers to the lower layers what
341 * operation should be done.
342 */
343 int
344 g_io_speedup(off_t shortage, u_int flags, size_t *resid, struct g_consumer *cp)
345{
346 struct bio *bp;
347 int error;
348
349 KASSERT((flags & (BIO_SPEEDUP_TRIM | BIO_SPEEDUP_WRITE)) != 0,
350 ("Invalid flags passed to g_io_speedup: %#x", flags));
351 g_trace(G_T_BIO, "bio_speedup(%s, %jd, %#x)", cp->provider->name,
352 (intmax_t)shortage, flags);
353 bp = g_new_bio();
354 if (bp == NULL)
355 return (ENOMEM);
356 bp->bio_cmd = BIO_SPEEDUP;
357 bp->bio_length = shortage;
358 bp->bio_done = NULL;
359 bp->bio_flags |= flags;
360 g_io_request(bp, cp);
361 error = biowait(bp, "gflush");
362 *resid = bp->bio_resid;
363 g_destroy_bio(bp);
364 return (error);
365}
366
367 int
368 g_io_flush(struct g_consumer *cp)
369{
370 struct bio *bp;
371 int error;
372
373 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name);
374 bp = g_alloc_bio();
375 bp->bio_cmd = BIO_FLUSH;
376 bp->bio_flags |= BIO_ORDERED;
377 bp->bio_done = NULL;
378 bp->bio_attribute = NULL;
379 bp->bio_offset = cp->provider->mediasize;
380 bp->bio_length = 0;
381 bp->bio_data = NULL;
382 g_io_request(bp, cp);
383 error = biowait(bp, "gflush");
384 g_destroy_bio(bp);
385 return (error);
386}
387
388 static int
389 g_io_check(struct bio *bp)
390{
391 struct g_consumer *cp;
392 struct g_provider *pp;
393 off_t excess;
394 int error;
395
396 biotrack(bp, __func__);
397
398 cp = bp->bio_from;
399 pp = bp->bio_to;
400
401 /* Fail if access counters dont allow the operation */
402 switch(bp->bio_cmd) {
403 case BIO_READ:
404 case BIO_GETATTR:
405 if (cp->acr == 0)
406 return (EPERM);
407 break;
408 case BIO_WRITE:
409 case BIO_DELETE:
410 case BIO_SPEEDUP:
411 case BIO_FLUSH:
412 if (cp->acw == 0)
413 return (EPERM);
414 break;
415 case BIO_ZONE:
416 if ((bp->bio_zone.zone_cmd == DISK_ZONE_REPORT_ZONES) ||
417 (bp->bio_zone.zone_cmd == DISK_ZONE_GET_PARAMS)) {
418 if (cp->acr == 0)
419 return (EPERM);
420 } else if (cp->acw == 0)
421 return (EPERM);
422 break;
423 default:
424 return (EPERM);
425 }
426 /* if provider is marked for error, don't disturb. */
427 if (pp->error)
428 return (pp->error);
429 if (cp->flags & G_CF_ORPHAN)
430 return (ENXIO);
431
432 switch(bp->bio_cmd) {
433 case BIO_READ:
434 case BIO_WRITE:
435 case BIO_DELETE:
436 /* Zero sectorsize or mediasize is probably a lack of media. */
437 if (pp->sectorsize == 0 || pp->mediasize == 0)
438 return (ENXIO);
439 /* Reject I/O not on sector boundary */
440 if (bp->bio_offset % pp->sectorsize)
441 return (EINVAL);
442 /* Reject I/O not integral sector long */
443 if (bp->bio_length % pp->sectorsize)
444 return (EINVAL);
445 /* Reject requests before or past the end of media. */
446 if (bp->bio_offset < 0)
447 return (EIO);
448 if (bp->bio_offset > pp->mediasize)
449 return (EIO);
450
451 /* Truncate requests to the end of providers media. */
452 excess = bp->bio_offset + bp->bio_length;
453 if (excess > bp->bio_to->mediasize) {
454 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 ||
455 round_page(bp->bio_ma_offset +
456 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n,
457 ("excess bio %p too short", bp));
458 excess -= bp->bio_to->mediasize;
459 bp->bio_length -= excess;
460 if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
461 bp->bio_ma_n = round_page(bp->bio_ma_offset +
462 bp->bio_length) / PAGE_SIZE;
463 }
464 if (excess > 0)
465 CTR3(KTR_GEOM, "g_down truncated bio "
466 "%p provider %s by %d", bp,
467 bp->bio_to->name, excess);
468 }
469
470 /* Deliver zero length transfers right here. */
471 if (bp->bio_length == 0) {
472 CTR2(KTR_GEOM, "g_down terminated 0-length "
473 "bp %p provider %s", bp, bp->bio_to->name);
474 return (0);
475 }
476
477 if ((bp->bio_flags & BIO_UNMAPPED) != 0 &&
478 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
479 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
480 if ((error = g_io_transient_map_bio(bp)) >= 0)
481 return (error);
482 }
483 break;
484 default:
485 break;
486 }
487 return (EJUSTRETURN);
488}
489
490 void
491 g_io_request(struct bio *bp, struct g_consumer *cp)
492{
493 struct g_provider *pp;
494 int direct, error, first;
495 uint8_t cmd;
496
497 biotrack(bp, __func__);
498
499 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
500 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
501 pp = cp->provider;
502 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
503#ifdef DIAGNOSTIC
504 KASSERT(bp->bio_driver1 == NULL,
505 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name));
506 KASSERT(bp->bio_driver2 == NULL,
507 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name));
508 KASSERT(bp->bio_pflags == 0,
509 ("bio_pflags used by the consumer (geom %s)", cp->geom->name));
510 /*
511 * Remember consumer's private fields, so we can detect if they were
512 * modified by the provider.
513 */
514 bp->_bio_caller1 = bp->bio_caller1;
515 bp->_bio_caller2 = bp->bio_caller2;
516 bp->_bio_cflags = bp->bio_cflags;
517#endif
518
519 cmd = bp->bio_cmd;
520 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) {
521 KASSERT(bp->bio_data != NULL,
522 ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd));
523 }
524 if (cmd == BIO_DELETE || cmd == BIO_FLUSH) {
525 KASSERT(bp->bio_data == NULL,
526 ("non-NULL bp->data in g_io_request(cmd=%hu)",
527 bp->bio_cmd));
528 }
529 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) {
530 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
531 ("wrong offset %jd for sectorsize %u",
532 bp->bio_offset, cp->provider->sectorsize));
533 KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
534 ("wrong length %jd for sectorsize %u",
535 bp->bio_length, cp->provider->sectorsize));
536 }
537
538 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
539 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
540
541 bp->bio_from = cp;
542 bp->bio_to = pp;
543 bp->bio_error = 0;
544 bp->bio_completed = 0;
545
546 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
547 ("Bio already on queue bp=%p", bp));
548
549 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
550 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
551 binuptime(&bp->bio_t0);
552 else
553 getbinuptime(&bp->bio_t0);
554 if (g_collectstats & G_STATS_CONSUMERS)
555 devstat_start_transaction_bio_t0(cp->stat, bp);
556 if (g_collectstats & G_STATS_PROVIDERS)
557 devstat_start_transaction_bio_t0(pp->stat, bp);
558#ifdef INVARIANTS
559 atomic_add_int(&cp->nstart, 1);
560#endif
561
562#ifdef GET_STACK_USAGE
563 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 &&
564 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 &&
565 !g_is_geom_thread(curthread) &&
566 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ||
567 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) &&
568 pace == 0;
569 if (direct) {
570 /* Block direct execution if less then half of stack left. */
571 size_t st, su;
572 GET_STACK_USAGE(st, su);
573 if (su * 2 > st)
574 direct = 0;
575 }
576#else
577 direct = 0;
578#endif
579
580 if (direct) {
581 error = g_io_check(bp);
582 if (error >= 0) {
583 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p "
584 "provider %s returned %d", bp, bp->bio_to->name,
585 error);
586 g_io_deliver(bp, error);
587 return;
588 }
589 bp->bio_to->geom->start(bp);
590 } else {
591 g_bioq_lock(&g_bio_run_down);
592 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue);
593 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue);
594 bp->bio_flags |= BIO_ONQUEUE;
595 g_bio_run_down.bio_queue_length++;
596 g_bioq_unlock(&g_bio_run_down);
597 /* Pass it on down. */
598 if (first)
599 wakeup(&g_wait_down);
600 }
601}
602
603 void
604 g_io_deliver(struct bio *bp, int error)
605{
606 struct bintime now;
607 struct g_consumer *cp;
608 struct g_provider *pp;
609 struct mtx *mtxp;
610 int direct, first;
611
612 biotrack(bp, __func__);
613
614 KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
615 pp = bp->bio_to;
616 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
617 cp = bp->bio_from;
618 if (cp == NULL) {
619 bp->bio_error = error;
620 bp->bio_done(bp);
621 return;
622 }
623 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
624 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
625#ifdef DIAGNOSTIC
626 /*
627 * Some classes - GJournal in particular - can modify bio's
628 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO
629 * flag means it's an expected behaviour for that particular geom.
630 */
631 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) {
632 KASSERT(bp->bio_caller1 == bp->_bio_caller1,
633 ("bio_caller1 used by the provider %s", pp->name));
634 KASSERT(bp->bio_caller2 == bp->_bio_caller2,
635 ("bio_caller2 used by the provider %s", pp->name));
636 KASSERT(bp->bio_cflags == bp->_bio_cflags,
637 ("bio_cflags used by the provider %s", pp->name));
638 }
639#endif
640 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0"));
641 KASSERT(bp->bio_completed <= bp->bio_length,
642 ("bio_completed can't be greater than bio_length"));
643
644 g_trace(G_T_BIO,
645 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
646 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
647 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
648
649 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
650 ("Bio already on queue bp=%p", bp));
651
652 /*
653 * XXX: next two doesn't belong here
654 */
655 bp->bio_bcount = bp->bio_length;
656 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
657
658#ifdef GET_STACK_USAGE
659 direct = (pp->flags & G_PF_DIRECT_SEND) &&
660 (cp->flags & G_CF_DIRECT_RECEIVE) &&
661 !g_is_geom_thread(curthread);
662 if (direct) {
663 /* Block direct execution if less then half of stack left. */
664 size_t st, su;
665 GET_STACK_USAGE(st, su);
666 if (su * 2 > st)
667 direct = 0;
668 }
669#else
670 direct = 0;
671#endif
672
673 /*
674 * The statistics collection is lockless, as such, but we
675 * can not update one instance of the statistics from more
676 * than one thread at a time, so grab the lock first.
677 */
678 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
679 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
680 binuptime(&now);
681 mtxp = mtx_pool_find(mtxpool_sleep, cp);
682 mtx_lock(mtxp);
683 if (g_collectstats & G_STATS_PROVIDERS)
684 devstat_end_transaction_bio_bt(pp->stat, bp, &now);
685 if (g_collectstats & G_STATS_CONSUMERS)
686 devstat_end_transaction_bio_bt(cp->stat, bp, &now);
687#ifdef INVARIANTS
688 cp->nend++;
689#endif
690 mtx_unlock(mtxp);
691
692 if (error != ENOMEM) {
693 bp->bio_error = error;
694 if (direct) {
695 biodone(bp);
696 } else {
697 g_bioq_lock(&g_bio_run_up);
698 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue);
699 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
700 bp->bio_flags |= BIO_ONQUEUE;
701 g_bio_run_up.bio_queue_length++;
702 g_bioq_unlock(&g_bio_run_up);
703 if (first)
704 wakeup(&g_wait_up);
705 }
706 return;
707 }
708
709 if (bootverbose)
710 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
711 bp->bio_children = 0;
712 bp->bio_inbed = 0;
713 bp->bio_driver1 = NULL;
714 bp->bio_driver2 = NULL;
715 bp->bio_pflags = 0;
716 g_io_request(bp, cp);
717 pace = 1;
718 return;
719}
720
721 SYSCTL_DECL(_kern_geom);
722
723 static long transient_maps;
724 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD,
725 &transient_maps, 0,
726 "Total count of the transient mapping requests");
727 u_int transient_map_retries = 10;
728 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW,
729 &transient_map_retries, 0,
730 "Max count of retries used before giving up on creating transient map");
731 int transient_map_hard_failures;
732 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD,
733 &transient_map_hard_failures, 0,
734 "Failures to establish the transient mapping due to retry attempts "
735 "exhausted");
736 int transient_map_soft_failures;
737 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD,
738 &transient_map_soft_failures, 0,
739 "Count of retried failures to establish the transient mapping");
740 int inflight_transient_maps;
741 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD,
742 &inflight_transient_maps, 0,
743 "Current count of the active transient maps");
744
745 static int
746 g_io_transient_map_bio(struct bio *bp)
747{
748 vm_offset_t addr;
749 long size;
750 u_int retried;
751
752 KASSERT(unmapped_buf_allowed, ("unmapped disabled"));
753
754 size = round_page(bp->bio_ma_offset + bp->bio_length);
755 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp));
756 addr = 0;
757 retried = 0;
758 atomic_add_long(&transient_maps, 1);
759 retry:
760 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) {
761 if (transient_map_retries != 0 &&
762 retried >= transient_map_retries) {
763 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s",
764 bp, bp->bio_to->name);
765 atomic_add_int(&transient_map_hard_failures, 1);
766 return (EDEADLK /* XXXKIB */);
767 } else {
768 /*
769 * Naive attempt to quisce the I/O to get more
770 * in-flight requests completed and defragment
771 * the transient_arena.
772 */
773 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d",
774 bp, bp->bio_to->name, retried);
775 pause("g_d_tra", hz / 10);
776 retried++;
777 atomic_add_int(&transient_map_soft_failures, 1);
778 goto retry;
779 }
780 }
781 atomic_add_int(&inflight_transient_maps, 1);
782 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size));
783 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset;
784 bp->bio_flags |= BIO_TRANSIENT_MAPPING;
785 bp->bio_flags &= ~BIO_UNMAPPED;
786 return (EJUSTRETURN);
787}
788
789 void
790 g_io_schedule_down(struct thread *tp __unused)
791{
792 struct bio *bp;
793 int error;
794
795 for(;;) {
796 g_bioq_lock(&g_bio_run_down);
797 bp = g_bioq_first(&g_bio_run_down);
798 if (bp == NULL) {
799 CTR0(KTR_GEOM, "g_down going to sleep");
800 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
801 PRIBIO | PDROP, "-", 0);
802 continue;
803 }
804 CTR0(KTR_GEOM, "g_down has work to do");
805 g_bioq_unlock(&g_bio_run_down);
806 biotrack(bp, __func__);
807 if (pace != 0) {
808 /*
809 * There has been at least one memory allocation
810 * failure since the last I/O completed. Pause 1ms to
811 * give the system a chance to free up memory. We only
812 * do this once because a large number of allocations
813 * can fail in the direct dispatch case and there's no
814 * relationship between the number of these failures and
815 * the length of the outage. If there's still an outage,
816 * we'll pause again and again until it's
817 * resolved. Older versions paused longer and once per
818 * allocation failure. This was OK for a single threaded
819 * g_down, but with direct dispatch would lead to max of
820 * 10 IOPs for minutes at a time when transient memory
821 * issues prevented allocation for a batch of requests
822 * from the upper layers.
823 *
824 * XXX This pacing is really lame. It needs to be solved
825 * by other methods. This is OK only because the worst
826 * case scenario is so rare. In the worst case scenario
827 * all memory is tied up waiting for I/O to complete
828 * which can never happen since we can't allocate bios
829 * for that I/O.
830 */
831 CTR0(KTR_GEOM, "g_down pacing self");
832 pause("g_down", min(hz/1000, 1));
833 pace = 0;
834 }
835 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
836 bp->bio_to->name);
837 error = g_io_check(bp);
838 if (error >= 0) {
839 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
840 "%s returned %d", bp, bp->bio_to->name, error);
841 g_io_deliver(bp, error);
842 continue;
843 }
844 THREAD_NO_SLEEPING();
845 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
846 "len %ld", bp, bp->bio_to->name, bp->bio_offset,
847 bp->bio_length);
848 bp->bio_to->geom->start(bp);
849 THREAD_SLEEPING_OK();
850 }
851}
852
853 void
854 g_io_schedule_up(struct thread *tp __unused)
855{
856 struct bio *bp;
857
858 for(;;) {
859 g_bioq_lock(&g_bio_run_up);
860 bp = g_bioq_first(&g_bio_run_up);
861 if (bp == NULL) {
862 CTR0(KTR_GEOM, "g_up going to sleep");
863 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
864 PRIBIO | PDROP, "-", 0);
865 continue;
866 }
867 g_bioq_unlock(&g_bio_run_up);
868 THREAD_NO_SLEEPING();
869 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
870 "%jd len %ld", bp, bp->bio_to->name,
871 bp->bio_offset, bp->bio_length);
872 biodone(bp);
873 THREAD_SLEEPING_OK();
874 }
875}
876
877 void *
878 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
879{
880 struct bio *bp;
881 void *ptr;
882 int errorc;
883
884 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
885 length <= maxphys, ("g_read_data(): invalid length %jd",
886 (intmax_t)length));
887
888 bp = g_alloc_bio();
889 bp->bio_cmd = BIO_READ;
890 bp->bio_done = NULL;
891 bp->bio_offset = offset;
892 bp->bio_length = length;
893 ptr = g_malloc(length, M_WAITOK);
894 bp->bio_data = ptr;
895 g_io_request(bp, cp);
896 errorc = biowait(bp, "gread");
897 if (error != NULL)
898 *error = errorc;
899 g_destroy_bio(bp);
900 if (errorc) {
901 g_free(ptr);
902 ptr = NULL;
903 }
904 return (ptr);
905}
906
907 /*
908 * A read function for use by ffs_sbget when used by GEOM-layer routines.
909 */
910 int
911 g_use_g_read_data(void *devfd, off_t loc, void **bufp, int size)
912{
913 struct g_consumer *cp;
914
915 KASSERT(*bufp == NULL,
916 ("g_use_g_read_data: non-NULL *bufp %p\n", *bufp));
917
918 cp = (struct g_consumer *)devfd;
919 /*
920 * Take care not to issue an invalid I/O request. The offset of
921 * the superblock candidate must be multiples of the provider's
922 * sector size, otherwise an FFS can't exist on the provider
923 * anyway.
924 */
925 if (loc % cp->provider->sectorsize != 0)
926 return (ENOENT);
927 *bufp = g_read_data(cp, loc, size, NULL);
928 if (*bufp == NULL)
929 return (ENOENT);
930 return (0);
931}
932
933 int
934 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
935{
936 struct bio *bp;
937 int error;
938
939 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
940 length <= maxphys, ("g_write_data(): invalid length %jd",
941 (intmax_t)length));
942
943 bp = g_alloc_bio();
944 bp->bio_cmd = BIO_WRITE;
945 bp->bio_done = NULL;
946 bp->bio_offset = offset;
947 bp->bio_length = length;
948 bp->bio_data = ptr;
949 g_io_request(bp, cp);
950 error = biowait(bp, "gwrite");
951 g_destroy_bio(bp);
952 return (error);
953}
954
955 /*
956 * A write function for use by ffs_sbput when used by GEOM-layer routines.
957 */
958 int
959 g_use_g_write_data(void *devfd, off_t loc, void *buf, int size)
960{
961
962 return (g_write_data((struct g_consumer *)devfd, loc, buf, size));
963}
964
965 int
966 g_delete_data(struct g_consumer *cp, off_t offset, off_t length)
967{
968 struct bio *bp;
969 int error;
970
971 KASSERT(length > 0 && length >= cp->provider->sectorsize,
972 ("g_delete_data(): invalid length %jd", (intmax_t)length));
973
974 bp = g_alloc_bio();
975 bp->bio_cmd = BIO_DELETE;
976 bp->bio_done = NULL;
977 bp->bio_offset = offset;
978 bp->bio_length = length;
979 bp->bio_data = NULL;
980 g_io_request(bp, cp);
981 error = biowait(bp, "gdelete");
982 g_destroy_bio(bp);
983 return (error);
984}
985
986 void
987 g_print_bio(const char *prefix, const struct bio *bp, const char *fmtsuffix,
988 ...)
989{
990#ifndef PRINTF_BUFR_SIZE
991#define PRINTF_BUFR_SIZE 64
992#endif
993 char bufr[PRINTF_BUFR_SIZE];
994 struct sbuf sb, *sbp __unused;
995 va_list ap;
996
997 sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
998 KASSERT(sbp != NULL, ("sbuf_new misused?"));
999
1000 sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
1001
1002 sbuf_cat(&sb, prefix);
1003 g_format_bio(&sb, bp);
1004
1005 va_start(ap, fmtsuffix);
1006 sbuf_vprintf(&sb, fmtsuffix, ap);
1007 va_end(ap);
1008
1009 sbuf_nl_terminate(&sb);
1010
1011 sbuf_finish(&sb);
1012 sbuf_delete(&sb);
1013}
1014
1015 void
1016 g_format_bio(struct sbuf *sb, const struct bio *bp)
1017{
1018 const char *pname, *cmd = NULL;
1019
1020 if (bp->bio_to != NULL)
1021 pname = bp->bio_to->name;
1022 else
1023 pname = "[unknown]";
1024
1025 switch (bp->bio_cmd) {
1026 case BIO_GETATTR:
1027 cmd = "GETATTR";
1028 sbuf_printf(sb, "%s[%s(attr=%s)]", pname, cmd,
1029 bp->bio_attribute);
1030 return;
1031 case BIO_FLUSH:
1032 cmd = "FLUSH";
1033 sbuf_printf(sb, "%s[%s]", pname, cmd);
1034 return;
1035 case BIO_ZONE: {
1036 char *subcmd = NULL;
1037 cmd = "ZONE";
1038 switch (bp->bio_zone.zone_cmd) {
1039 case DISK_ZONE_OPEN:
1040 subcmd = "OPEN";
1041 break;
1042 case DISK_ZONE_CLOSE:
1043 subcmd = "CLOSE";
1044 break;
1045 case DISK_ZONE_FINISH:
1046 subcmd = "FINISH";
1047 break;
1048 case DISK_ZONE_RWP:
1049 subcmd = "RWP";
1050 break;
1051 case DISK_ZONE_REPORT_ZONES:
1052 subcmd = "REPORT ZONES";
1053 break;
1054 case DISK_ZONE_GET_PARAMS:
1055 subcmd = "GET PARAMS";
1056 break;
1057 default:
1058 subcmd = "UNKNOWN";
1059 break;
1060 }
1061 sbuf_printf(sb, "%s[%s,%s]", pname, cmd, subcmd);
1062 return;
1063 }
1064 case BIO_READ:
1065 cmd = "READ";
1066 break;
1067 case BIO_WRITE:
1068 cmd = "WRITE";
1069 break;
1070 case BIO_DELETE:
1071 cmd = "DELETE";
1072 break;
1073 default:
1074 cmd = "UNKNOWN";
1075 sbuf_printf(sb, "%s[%s()]", pname, cmd);
1076 return;
1077 }
1078 sbuf_printf(sb, "%s[%s(offset=%jd, length=%jd)]", pname, cmd,
1079 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
1080}
1081 

AltStyle によって変換されたページ (->オリジナル) /