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/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/bio.h>
47 #include <sys/ktr.h>
48 #include <sys/proc.h>
49 #include <sys/sbuf.h>
50 #include <sys/stack.h>
51 #include <sys/sysctl.h>
52 #include <sys/vmem.h>
53 #include <machine/stack.h>
54 #include <machine/stdarg.h>
55
56 #include <sys/errno.h>
57 #include <geom/geom.h>
58 #include <geom/geom_int.h>
59 #include <sys/devicestat.h>
60
61 #include <vm/uma.h>
62 #include <vm/vm.h>
63 #include <vm/vm_param.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_page.h>
66 #include <vm/vm_object.h>
67 #include <vm/vm_extern.h>
68 #include <vm/vm_map.h>
69
70 #define KTR_GEOM_ENABLED \
71 ((KTR_COMPILE & KTR_GEOM) != 0 && (ktr_mask & KTR_GEOM) != 0)
72
73 static int g_io_transient_map_bio(struct bio *bp);
74
75 static struct g_bioq g_bio_run_down;
76 static struct g_bioq g_bio_run_up;
77
78 static u_long nomem_count;
79 static u_long pause_count;
80
81 /*
82 * Pace is a hint that we've had some trouble recently allocating
83 * bios, so we should back off trying to send I/O down the stack
84 * a bit to let the problem resolve. When pacing, we also turn
85 * off direct dispatch to also reduce memory pressure from I/Os
86 * there, at the expxense of some added latency while the memory
87 * pressures exist. See g_io_schedule_down() for more details
88 * and limitations.
89 */
90 static volatile u_int __read_mostly pace;
91
92 static uma_zone_t __read_mostly biozone;
93
94 #include <machine/atomic.h>
95
96 static void
g_bioq_lock(struct g_bioq * bq)97 g_bioq_lock(struct g_bioq *bq)
98 {
99
100 mtx_lock(&bq->bio_queue_lock);
101 }
102
103 static void
g_bioq_unlock(struct g_bioq * bq)104 g_bioq_unlock(struct g_bioq *bq)
105 {
106
107 mtx_unlock(&bq->bio_queue_lock);
108 }
109
110 #if 0
111 static void
112 g_bioq_destroy(struct g_bioq *bq)
113 {
114
115 mtx_destroy(&bq->bio_queue_lock);
116 }
117 #endif
118
119 static void
g_bioq_init(struct g_bioq * bq)120 g_bioq_init(struct g_bioq *bq)
121 {
122
123 TAILQ_INIT(&bq->bio_queue);
124 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
125 }
126
127 static struct bio *
g_bioq_first(struct g_bioq * bq)128 g_bioq_first(struct g_bioq *bq)
129 {
130 struct bio *bp;
131
132 bp = TAILQ_FIRST(&bq->bio_queue);
133 if (bp != NULL) {
134 KASSERT((bp->bio_flags & BIO_ONQUEUE),
135 ("Bio not on queue bp=%p target %p", bp, bq));
136 bp->bio_flags &= ~BIO_ONQUEUE;
137 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
138 bq->bio_queue_length--;
139 }
140 return (bp);
141 }
142
143 struct bio *
g_new_bio(void)144 g_new_bio(void)
145 {
146 struct bio *bp;
147
148 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
149 #ifdef KTR
150 if (KTR_GEOM_ENABLED) {
151 struct stack st;
152
153 CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
154 stack_save(&st);
155 CTRSTACK(KTR_GEOM, &st, 3);
156 }
157 #endif
158 return (bp);
159 }
160
161 struct bio *
g_alloc_bio(void)162 g_alloc_bio(void)
163 {
164 struct bio *bp;
165
166 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
167 #ifdef KTR
168 if (KTR_GEOM_ENABLED) {
169 struct stack st;
170
171 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
172 stack_save(&st);
173 CTRSTACK(KTR_GEOM, &st, 3);
174 }
175 #endif
176 return (bp);
177 }
178
179 void
g_destroy_bio(struct bio * bp)180 g_destroy_bio(struct bio *bp)
181 {
182 #ifdef KTR
183 if (KTR_GEOM_ENABLED) {
184 struct stack st;
185
186 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
187 stack_save(&st);
188 CTRSTACK(KTR_GEOM, &st, 3);
189 }
190 #endif
191 uma_zfree(biozone, bp);
192 }
193
194 struct bio *
g_clone_bio(struct bio * bp)195 g_clone_bio(struct bio *bp)
196 {
197 struct bio *bp2;
198
199 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
200 if (bp2 != NULL) {
201 bp2->bio_parent = bp;
202 bp2->bio_cmd = bp->bio_cmd;
203 /*
204 * BIO_ORDERED flag may be used by disk drivers to enforce
205 * ordering restrictions, so this flag needs to be cloned.
206 * BIO_UNMAPPED, BIO_VLIST, and BIO_SWAP should be inherited,
207 * to properly indicate which way the buffer is passed.
208 * Other bio flags are not suitable for cloning.
209 */
210 bp2->bio_flags = bp->bio_flags &
211 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST | BIO_SWAP);
212 bp2->bio_length = bp->bio_length;
213 bp2->bio_offset = bp->bio_offset;
214 bp2->bio_data = bp->bio_data;
215 bp2->bio_ma = bp->bio_ma;
216 bp2->bio_ma_n = bp->bio_ma_n;
217 bp2->bio_ma_offset = bp->bio_ma_offset;
218 bp2->bio_attribute = bp->bio_attribute;
219 if (bp->bio_cmd == BIO_ZONE)
220 bcopy(&bp->bio_zone, &bp2->bio_zone,
221 sizeof(bp->bio_zone));
222 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
223 bp2->bio_track_bp = bp->bio_track_bp;
224 #endif
225 bp->bio_children++;
226 }
227 #ifdef KTR
228 if (KTR_GEOM_ENABLED) {
229 struct stack st;
230
231 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2);
232 stack_save(&st);
233 CTRSTACK(KTR_GEOM, &st, 3);
234 }
235 #endif
236 return(bp2);
237 }
238
239 struct bio *
g_duplicate_bio(struct bio * bp)240 g_duplicate_bio(struct bio *bp)
241 {
242 struct bio *bp2;
243
244 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO);
245 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST | BIO_SWAP);
246 bp2->bio_parent = bp;
247 bp2->bio_cmd = bp->bio_cmd;
248 bp2->bio_length = bp->bio_length;
249 bp2->bio_offset = bp->bio_offset;
250 bp2->bio_data = bp->bio_data;
251 bp2->bio_ma = bp->bio_ma;
252 bp2->bio_ma_n = bp->bio_ma_n;
253 bp2->bio_ma_offset = bp->bio_ma_offset;
254 bp2->bio_attribute = bp->bio_attribute;
255 bp->bio_children++;
256 #ifdef KTR
257 if (KTR_GEOM_ENABLED) {
258 struct stack st;
259
260 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2);
261 stack_save(&st);
262 CTRSTACK(KTR_GEOM, &st, 3);
263 }
264 #endif
265 return(bp2);
266 }
267
268 void
g_reset_bio(struct bio * bp)269 g_reset_bio(struct bio *bp)
270 {
271
272 bzero(bp, sizeof(*bp));
273 }
274
275 void
g_io_init(void)276 g_io_init(void)
277 {
278
279 g_bioq_init(&g_bio_run_down);
280 g_bioq_init(&g_bio_run_up);
281 biozone = uma_zcreate("g_bio", sizeof (struct bio),
282 NULL, NULL,
283 NULL, NULL,
284 0, 0);
285 }
286
287 int
g_io_getattr(const char * attr,struct g_consumer * cp,int * len,void * ptr)288 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
289 {
290 struct bio *bp;
291 int error;
292
293 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
294 bp = g_alloc_bio();
295 bp->bio_cmd = BIO_GETATTR;
296 bp->bio_done = NULL;
297 bp->bio_attribute = attr;
298 bp->bio_length = *len;
299 bp->bio_data = ptr;
300 g_io_request(bp, cp);
301 error = biowait(bp, "ggetattr");
302 *len = bp->bio_completed;
303 g_destroy_bio(bp);
304 return (error);
305 }
306
307 int
g_io_zonecmd(struct disk_zone_args * zone_args,struct g_consumer * cp)308 g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp)
309 {
310 struct bio *bp;
311 int error;
312
313 g_trace(G_T_BIO, "bio_zone(%d)", zone_args->zone_cmd);
314 bp = g_alloc_bio();
315 bp->bio_cmd = BIO_ZONE;
316 bp->bio_done = NULL;
317 /*
318 * XXX KDM need to handle report zone data.
319 */
320 bcopy(zone_args, &bp->bio_zone, sizeof(*zone_args));
321 if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES)
322 bp->bio_length =
323 zone_args->zone_params.report.entries_allocated *
324 sizeof(struct disk_zone_rep_entry);
325 else
326 bp->bio_length = 0;
327
328 g_io_request(bp, cp);
329 error = biowait(bp, "gzone");
330 bcopy(&bp->bio_zone, zone_args, sizeof(*zone_args));
331 g_destroy_bio(bp);
332 return (error);
333 }
334
335 /*
336 * Send a BIO_SPEEDUP down the stack. This is used to tell the lower layers that
337 * the upper layers have detected a resource shortage. The lower layers are
338 * advised to stop delaying I/O that they might be holding for performance
339 * reasons and to schedule it (non-trims) or complete it successfully (trims) as
340 * quickly as it can. bio_length is the amount of the shortage. This call
341 * should be non-blocking. bio_resid is used to communicate back if the lower
342 * layers couldn't find bio_length worth of I/O to schedule or discard. A length
343 * of 0 means to do as much as you can (schedule the h/w queues full, discard
344 * all trims). flags are a hint from the upper layers to the lower layers what
345 * operation should be done.
346 */
347 int
g_io_speedup(off_t shortage,u_int flags,size_t * resid,struct g_consumer * cp)348 g_io_speedup(off_t shortage, u_int flags, size_t *resid, struct g_consumer *cp)
349 {
350 struct bio *bp;
351 int error;
352
353 KASSERT((flags & (BIO_SPEEDUP_TRIM | BIO_SPEEDUP_WRITE)) != 0,
354 ("Invalid flags passed to g_io_speedup: %#x", flags));
355 g_trace(G_T_BIO, "bio_speedup(%s, %jd, %#x)", cp->provider->name,
356 (intmax_t)shortage, flags);
357 bp = g_new_bio();
358 if (bp == NULL)
359 return (ENOMEM);
360 bp->bio_cmd = BIO_SPEEDUP;
361 bp->bio_length = shortage;
362 bp->bio_done = NULL;
363 bp->bio_flags |= flags;
364 g_io_request(bp, cp);
365 error = biowait(bp, "gflush");
366 *resid = bp->bio_resid;
367 g_destroy_bio(bp);
368 return (error);
369 }
370
371 int
g_io_flush(struct g_consumer * cp)372 g_io_flush(struct g_consumer *cp)
373 {
374 struct bio *bp;
375 int error;
376
377 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name);
378 bp = g_alloc_bio();
379 bp->bio_cmd = BIO_FLUSH;
380 bp->bio_flags |= BIO_ORDERED;
381 bp->bio_done = NULL;
382 bp->bio_attribute = NULL;
383 bp->bio_offset = cp->provider->mediasize;
384 bp->bio_length = 0;
385 bp->bio_data = NULL;
386 g_io_request(bp, cp);
387 error = biowait(bp, "gflush");
388 g_destroy_bio(bp);
389 return (error);
390 }
391
392 static int
g_io_check(struct bio * bp)393 g_io_check(struct bio *bp)
394 {
395 struct g_consumer *cp;
396 struct g_provider *pp;
397 off_t excess;
398 int error;
399
400 biotrack(bp, __func__);
401
402 cp = bp->bio_from;
403 pp = bp->bio_to;
404
405 /* Fail if access counters dont allow the operation */
406 switch(bp->bio_cmd) {
407 case BIO_READ:
408 case BIO_GETATTR:
409 if (cp->acr == 0)
410 return (EPERM);
411 break;
412 case BIO_WRITE:
413 case BIO_DELETE:
414 case BIO_SPEEDUP:
415 case BIO_FLUSH:
416 if (cp->acw == 0)
417 return (EPERM);
418 break;
419 case BIO_ZONE:
420 if ((bp->bio_zone.zone_cmd == DISK_ZONE_REPORT_ZONES) ||
421 (bp->bio_zone.zone_cmd == DISK_ZONE_GET_PARAMS)) {
422 if (cp->acr == 0)
423 return (EPERM);
424 } else if (cp->acw == 0)
425 return (EPERM);
426 break;
427 default:
428 return (EPERM);
429 }
430 /* if provider is marked for error, don't disturb. */
431 if (pp->error)
432 return (pp->error);
433 if (cp->flags & G_CF_ORPHAN)
434 return (ENXIO);
435
436 switch(bp->bio_cmd) {
437 case BIO_READ:
438 case BIO_WRITE:
439 case BIO_DELETE:
440 /* Zero sectorsize or mediasize is probably a lack of media. */
441 if (pp->sectorsize == 0 || pp->mediasize == 0)
442 return (ENXIO);
443 /* Reject I/O not on sector boundary */
444 if (bp->bio_offset % pp->sectorsize)
445 return (EINVAL);
446 /* Reject I/O not integral sector long */
447 if (bp->bio_length % pp->sectorsize)
448 return (EINVAL);
449 /* Reject requests before or past the end of media. */
450 if (bp->bio_offset < 0)
451 return (EIO);
452 if (bp->bio_offset > pp->mediasize)
453 return (EIO);
454
455 /* Truncate requests to the end of providers media. */
456 excess = bp->bio_offset + bp->bio_length;
457 if (excess > bp->bio_to->mediasize) {
458 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 ||
459 round_page(bp->bio_ma_offset +
460 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n,
461 ("excess bio %p too short", bp));
462 excess -= bp->bio_to->mediasize;
463 bp->bio_length -= excess;
464 if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
465 bp->bio_ma_n = round_page(bp->bio_ma_offset +
466 bp->bio_length) / PAGE_SIZE;
467 }
468 if (excess > 0)
469 CTR3(KTR_GEOM, "g_down truncated bio "
470 "%p provider %s by %d", bp,
471 bp->bio_to->name, excess);
472 }
473
474 /* Deliver zero length transfers right here. */
475 if (bp->bio_length == 0) {
476 CTR2(KTR_GEOM, "g_down terminated 0-length "
477 "bp %p provider %s", bp, bp->bio_to->name);
478 return (0);
479 }
480
481 if ((bp->bio_flags & BIO_UNMAPPED) != 0 &&
482 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
483 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
484 if ((error = g_io_transient_map_bio(bp)) >= 0)
485 return (error);
486 }
487 break;
488 default:
489 break;
490 }
491 return (EJUSTRETURN);
492 }
493
494 void
g_io_request(struct bio * bp,struct g_consumer * cp)495 g_io_request(struct bio *bp, struct g_consumer *cp)
496 {
497 struct g_provider *pp;
498 int direct, error, first;
499 uint8_t cmd;
500
501 biotrack(bp, __func__);
502
503 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
504 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
505 pp = cp->provider;
506 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
507 #ifdef DIAGNOSTIC
508 KASSERT(bp->bio_driver1 == NULL,
509 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name));
510 KASSERT(bp->bio_driver2 == NULL,
511 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name));
512 KASSERT(bp->bio_pflags == 0,
513 ("bio_pflags used by the consumer (geom %s)", cp->geom->name));
514 /*
515 * Remember consumer's private fields, so we can detect if they were
516 * modified by the provider.
517 */
518 bp->_bio_caller1 = bp->bio_caller1;
519 bp->_bio_caller2 = bp->bio_caller2;
520 bp->_bio_cflags = bp->bio_cflags;
521 #endif
522
523 cmd = bp->bio_cmd;
524 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) {
525 KASSERT(bp->bio_data != NULL,
526 ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd));
527 }
528 if (cmd == BIO_DELETE || cmd == BIO_FLUSH || cmd == BIO_SPEEDUP) {
529 KASSERT(bp->bio_data == NULL,
530 ("non-NULL bp->data in g_io_request(cmd=%hu)",
531 bp->bio_cmd));
532 }
533 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) {
534 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
535 ("wrong offset %jd for sectorsize %u",
536 bp->bio_offset, cp->provider->sectorsize));
537 KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
538 ("wrong length %jd for sectorsize %u",
539 bp->bio_length, cp->provider->sectorsize));
540 }
541
542 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
543 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
544
545 bp->bio_from = cp;
546 bp->bio_to = pp;
547 bp->bio_error = 0;
548 bp->bio_completed = 0;
549
550 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
551 ("Bio already on queue bp=%p", bp));
552
553 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
554 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
555 binuptime(&bp->bio_t0);
556 else
557 getbinuptime(&bp->bio_t0);
558 if (g_collectstats & G_STATS_CONSUMERS)
559 devstat_start_transaction_bio_t0(cp->stat, bp);
560 if (g_collectstats & G_STATS_PROVIDERS)
561 devstat_start_transaction_bio_t0(pp->stat, bp);
562 #ifdef INVARIANTS
563 atomic_add_int(&cp->nstart, 1);
564 #endif
565
566 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 &&
567 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 &&
568 curthread != g_down_td &&
569 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 ||
570 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) &&
571 pace == 0;
572 if (direct) {
573 /* Block direct execution if less then half of stack left. */
574 size_t st, su;
575 GET_STACK_USAGE(st, su);
576 if (su * 2 > st)
577 direct = 0;
578 }
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
g_io_deliver(struct bio * bp,int error)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 direct = (pp->flags & G_PF_DIRECT_SEND) &&
659 (cp->flags & G_CF_DIRECT_RECEIVE) &&
660 curthread != g_up_td;
661 if (direct) {
662 /* Block direct execution if less then half of stack left. */
663 size_t st, su;
664 GET_STACK_USAGE(st, su);
665 if (su * 2 > st)
666 direct = 0;
667 }
668
669 /*
670 * The statistics collection is lockless, as such, but we
671 * can not update one instance of the statistics from more
672 * than one thread at a time, so grab the lock first.
673 */
674 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
675 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
676 binuptime(&now);
677 mtxp = mtx_pool_find(mtxpool_sleep, pp);
678 mtx_lock(mtxp);
679 if (g_collectstats & G_STATS_PROVIDERS)
680 devstat_end_transaction_bio_bt(pp->stat, bp, &now);
681 if (g_collectstats & G_STATS_CONSUMERS)
682 devstat_end_transaction_bio_bt(cp->stat, bp, &now);
683 #ifdef INVARIANTS
684 cp->nend++;
685 #endif
686 mtx_unlock(mtxp);
687
688 if (error != ENOMEM) {
689 bp->bio_error = error;
690 if (direct) {
691 biodone(bp);
692 } else {
693 g_bioq_lock(&g_bio_run_up);
694 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue);
695 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
696 bp->bio_flags |= BIO_ONQUEUE;
697 g_bio_run_up.bio_queue_length++;
698 g_bioq_unlock(&g_bio_run_up);
699 if (first)
700 wakeup(&g_wait_up);
701 }
702 return;
703 }
704
705 if (bootverbose)
706 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
707 atomic_add_long(&nomem_count, 1); /* Rare event, but no locks held */
708 bp->bio_children = 0;
709 bp->bio_inbed = 0;
710 bp->bio_driver1 = NULL;
711 bp->bio_driver2 = NULL;
712 bp->bio_pflags = 0;
713 g_io_request(bp, cp);
714 pace = 1;
715 return;
716 }
717
718 SYSCTL_DECL(_kern_geom);
719
720 static long transient_maps;
721 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD,
722 &transient_maps, 0,
723 "Total count of the transient mapping requests");
724 u_int transient_map_retries = 10;
725 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW,
726 &transient_map_retries, 0,
727 "Max count of retries used before giving up on creating transient map");
728 int transient_map_hard_failures;
729 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD,
730 &transient_map_hard_failures, 0,
731 "Failures to establish the transient mapping due to retry attempts "
732 "exhausted");
733 int transient_map_soft_failures;
734 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD,
735 &transient_map_soft_failures, 0,
736 "Count of retried failures to establish the transient mapping");
737 int inflight_transient_maps;
738 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD,
739 &inflight_transient_maps, 0,
740 "Current count of the active transient maps");
741 SYSCTL_ULONG(_kern_geom, OID_AUTO, nomem_count, CTLFLAG_RD,
742 &nomem_count, 0,
743 "Total count of requests completed with status of ENOMEM");
744 SYSCTL_ULONG(_kern_geom, OID_AUTO, pause_count, CTLFLAG_RD,
745 &pause_count, 0,
746 "Total count of requests stalled due to low memory in g_down");
747
748 static int
g_io_transient_map_bio(struct bio * bp)749 g_io_transient_map_bio(struct bio *bp)
750 {
751 vm_offset_t addr;
752 long size;
753 u_int retried;
754
755 KASSERT(unmapped_buf_allowed, ("unmapped disabled"));
756
757 size = round_page(bp->bio_ma_offset + bp->bio_length);
758 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp));
759 addr = 0;
760 retried = 0;
761 atomic_add_long(&transient_maps, 1);
762 retry:
763 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) {
764 if (transient_map_retries != 0 &&
765 retried >= transient_map_retries) {
766 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s",
767 bp, bp->bio_to->name);
768 atomic_add_int(&transient_map_hard_failures, 1);
769 return (EDEADLK/* XXXKIB */);
770 } else {
771 /*
772 * Naive attempt to quisce the I/O to get more
773 * in-flight requests completed and defragment
774 * the transient_arena.
775 */
776 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d",
777 bp, bp->bio_to->name, retried);
778 pause("g_d_tra", hz / 10);
779 retried++;
780 atomic_add_int(&transient_map_soft_failures, 1);
781 goto retry;
782 }
783 }
784 atomic_add_int(&inflight_transient_maps, 1);
785 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size));
786 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset;
787 bp->bio_flags |= BIO_TRANSIENT_MAPPING;
788 bp->bio_flags &= ~BIO_UNMAPPED;
789 return (EJUSTRETURN);
790 }
791
792 void
g_io_schedule_down(struct thread * tp __unused)793 g_io_schedule_down(struct thread *tp __unused)
794 {
795 struct bio *bp;
796 int error;
797
798 for(;;) {
799 g_bioq_lock(&g_bio_run_down);
800 bp = g_bioq_first(&g_bio_run_down);
801 if (bp == NULL) {
802 CTR0(KTR_GEOM, "g_down going to sleep");
803 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
804 PRIBIO | PDROP, "-", 0);
805 continue;
806 }
807 CTR0(KTR_GEOM, "g_down has work to do");
808 g_bioq_unlock(&g_bio_run_down);
809 biotrack(bp, __func__);
810 if (pace != 0) {
811 /*
812 * There has been at least one memory allocation failure
813 * since the last I/O completed. Pause 1ms to give the
814 * system a chance to free up memory. Pause time is not
815 * scaled to the number of I/O failures since they tend
816 * to cluster and the number is not predictive of how
817 * long a pause is needed.
818 *
819 * Older versions had a longer pause, which limited the
820 * IOPS to 10, which prolonged memory shortages that could
821 * be alleviated by I/O completing since it eliminated
822 * direct dispatch as well.
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_count++; /* g_down has only one thread */
833 pause_sbt("g_down", SBT_1MS, 0, 0);
834 pace = 0;
835 }
836 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
837 bp->bio_to->name);
838 error = g_io_check(bp);
839 if (error >= 0) {
840 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
841 "%s returned %d", bp, bp->bio_to->name, error);
842 g_io_deliver(bp, error);
843 continue;
844 }
845 THREAD_NO_SLEEPING();
846 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
847 "len %ld", bp, bp->bio_to->name, bp->bio_offset,
848 bp->bio_length);
849 bp->bio_to->geom->start(bp);
850 THREAD_SLEEPING_OK();
851 }
852 }
853
854 void
g_io_schedule_up(struct thread * tp __unused)855 g_io_schedule_up(struct thread *tp __unused)
856 {
857 struct bio *bp;
858
859 for(;;) {
860 g_bioq_lock(&g_bio_run_up);
861 bp = g_bioq_first(&g_bio_run_up);
862 if (bp == NULL) {
863 CTR0(KTR_GEOM, "g_up going to sleep");
864 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
865 PRIBIO | PDROP, "-", 0);
866 continue;
867 }
868 g_bioq_unlock(&g_bio_run_up);
869 THREAD_NO_SLEEPING();
870 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
871 "%jd len %ld", bp, bp->bio_to->name,
872 bp->bio_offset, bp->bio_length);
873 biodone(bp);
874 THREAD_SLEEPING_OK();
875 }
876 }
877
878 void *
g_read_data(struct g_consumer * cp,off_t offset,off_t length,int * error)879 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
880 {
881 struct bio *bp;
882 void *ptr;
883 int errorc;
884
885 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
886 length <= maxphys, ("g_read_data(): invalid length %jd",
887 (intmax_t)length));
888
889 bp = g_alloc_bio();
890 bp->bio_cmd = BIO_READ;
891 bp->bio_done = NULL;
892 bp->bio_offset = offset;
893 bp->bio_length = length;
894 ptr = g_malloc(length, M_WAITOK);
895 bp->bio_data = ptr;
896 g_io_request(bp, cp);
897 errorc = biowait(bp, "gread");
898 if (errorc == 0 && bp->bio_completed != length)
899 errorc = EIO;
900 if (error != NULL)
901 *error = errorc;
902 g_destroy_bio(bp);
903 if (errorc) {
904 g_free(ptr);
905 ptr = NULL;
906 }
907 return (ptr);
908 }
909
910 /*
911 * A read function for use by ffs_sbget when used by GEOM-layer routines.
912 */
913 int
g_use_g_read_data(void * devfd,off_t loc,void ** bufp,int size)914 g_use_g_read_data(void *devfd, off_t loc, void **bufp, int size)
915 {
916 struct g_consumer *cp;
917
918 KASSERT(*bufp == NULL,
919 ("g_use_g_read_data: non-NULL *bufp %p\n", *bufp));
920
921 cp = (struct g_consumer *)devfd;
922 /*
923 * Take care not to issue an invalid I/O request. The offset of
924 * the superblock candidate must be multiples of the provider's
925 * sector size, otherwise an FFS can't exist on the provider
926 * anyway.
927 */
928 if (loc % cp->provider->sectorsize != 0)
929 return (ENOENT);
930 *bufp = g_read_data(cp, loc, size, NULL);
931 if (*bufp == NULL)
932 return (ENOENT);
933 return (0);
934 }
935
936 int
g_write_data(struct g_consumer * cp,off_t offset,void * ptr,off_t length)937 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
938 {
939 struct bio *bp;
940 int error;
941
942 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
943 length <= maxphys, ("g_write_data(): invalid length %jd",
944 (intmax_t)length));
945
946 bp = g_alloc_bio();
947 bp->bio_cmd = BIO_WRITE;
948 bp->bio_done = NULL;
949 bp->bio_offset = offset;
950 bp->bio_length = length;
951 bp->bio_data = ptr;
952 g_io_request(bp, cp);
953 error = biowait(bp, "gwrite");
954 if (error == 0 && bp->bio_completed != length)
955 error = EIO;
956 g_destroy_bio(bp);
957 return (error);
958 }
959
960 /*
961 * A write function for use by ffs_sbput when used by GEOM-layer routines.
962 */
963 int
g_use_g_write_data(void * devfd,off_t loc,void * buf,int size)964 g_use_g_write_data(void *devfd, off_t loc, void *buf, int size)
965 {
966
967 return (g_write_data((struct g_consumer *)devfd, loc, buf, size));
968 }
969
970 int
g_delete_data(struct g_consumer * cp,off_t offset,off_t length)971 g_delete_data(struct g_consumer *cp, off_t offset, off_t length)
972 {
973 struct bio *bp;
974 int error;
975
976 KASSERT(length > 0 && length >= cp->provider->sectorsize,
977 ("g_delete_data(): invalid length %jd", (intmax_t)length));
978
979 bp = g_alloc_bio();
980 bp->bio_cmd = BIO_DELETE;
981 bp->bio_done = NULL;
982 bp->bio_offset = offset;
983 bp->bio_length = length;
984 bp->bio_data = NULL;
985 g_io_request(bp, cp);
986 error = biowait(bp, "gdelete");
987 if (error == 0 && bp->bio_completed != length)
988 error = EIO;
989 g_destroy_bio(bp);
990 return (error);
991 }
992
993 void
g_print_bio(const char * prefix,const struct bio * bp,const char * fmtsuffix,...)994 g_print_bio(const char *prefix, const struct bio *bp, const char *fmtsuffix,
995 ...)
996 {
997 #ifndef PRINTF_BUFR_SIZE
998 #define PRINTF_BUFR_SIZE 64
999 #endif
1000 char bufr[PRINTF_BUFR_SIZE];
1001 struct sbuf sb, *sbp __unused;
1002 va_list ap;
1003
1004 sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
1005 KASSERT(sbp != NULL, ("sbuf_new misused?"));
1006
1007 sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
1008
1009 sbuf_cat(&sb, prefix);
1010 g_format_bio(&sb, bp);
1011
1012 va_start(ap, fmtsuffix);
1013 sbuf_vprintf(&sb, fmtsuffix, ap);
1014 va_end(ap);
1015
1016 sbuf_nl_terminate(&sb);
1017
1018 sbuf_finish(&sb);
1019 sbuf_delete(&sb);
1020 }
1021
1022 void
g_format_bio(struct sbuf * sb,const struct bio * bp)1023 g_format_bio(struct sbuf *sb, const struct bio *bp)
1024 {
1025 const char *pname, *cmd = NULL;
1026
1027 if (bp->bio_to != NULL)
1028 pname = bp->bio_to->name;
1029 else if (bp->bio_parent != NULL && bp->bio_parent->bio_to != NULL)
1030 pname = bp->bio_parent->bio_to->name;
1031 else
1032 pname = "[unknown]";
1033
1034 switch (bp->bio_cmd) {
1035 case BIO_GETATTR:
1036 cmd = "GETATTR";
1037 sbuf_printf(sb, "%s[%s(attr=%s)]", pname, cmd,
1038 bp->bio_attribute);
1039 return;
1040 case BIO_FLUSH:
1041 cmd = "FLUSH";
1042 sbuf_printf(sb, "%s[%s]", pname, cmd);
1043 return;
1044 case BIO_ZONE: {
1045 char *subcmd = NULL;
1046 cmd = "ZONE";
1047 switch (bp->bio_zone.zone_cmd) {
1048 case DISK_ZONE_OPEN:
1049 subcmd = "OPEN";
1050 break;
1051 case DISK_ZONE_CLOSE:
1052 subcmd = "CLOSE";
1053 break;
1054 case DISK_ZONE_FINISH:
1055 subcmd = "FINISH";
1056 break;
1057 case DISK_ZONE_RWP:
1058 subcmd = "RWP";
1059 break;
1060 case DISK_ZONE_REPORT_ZONES:
1061 subcmd = "REPORT ZONES";
1062 break;
1063 case DISK_ZONE_GET_PARAMS:
1064 subcmd = "GET PARAMS";
1065 break;
1066 default:
1067 subcmd = "UNKNOWN";
1068 break;
1069 }
1070 sbuf_printf(sb, "%s[%s,%s]", pname, cmd, subcmd);
1071 return;
1072 }
1073 case BIO_READ:
1074 cmd = "READ";
1075 break;
1076 case BIO_WRITE:
1077 cmd = "WRITE";
1078 break;
1079 case BIO_DELETE:
1080 cmd = "DELETE";
1081 break;
1082 default:
1083 cmd = "UNKNOWN";
1084 sbuf_printf(sb, "%s[%s()]", pname, cmd);
1085 return;
1086 }
1087 sbuf_printf(sb, "%s[%s(offset=%jd, length=%jd)]", pname, cmd,
1088 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
1089 }
1090