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 #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/sbuf.h>
51 #include <sys/stack.h>
52 #include <sys/sysctl.h>
53 #include <sys/vmem.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 /*
79 * Pace is a hint that we've had some trouble recently allocating
80 * bios, so we should back off trying to send I/O down the stack
81 * a bit to let the problem resolve. When pacing, we also turn
82 * off direct dispatch to also reduce memory pressure from I/Os
83 * there, at the expxense of some added latency while the memory
84 * pressures exist. See g_io_schedule_down() for more details
85 * and limitations.
86 */
87 static volatile u_int __read_mostly pace;
88
89 static uma_zone_t __read_mostly biozone;
90
91 #include <machine/atomic.h>
92
93 static void
g_bioq_lock(struct g_bioq * bq)94 g_bioq_lock(struct g_bioq *bq)
95 {
96
97 mtx_lock(&bq->bio_queue_lock);
98 }
99
100 static void
g_bioq_unlock(struct g_bioq * bq)101 g_bioq_unlock(struct g_bioq *bq)
102 {
103
104 mtx_unlock(&bq->bio_queue_lock);
105 }
106
107 #if 0
108 static void
109 g_bioq_destroy(struct g_bioq *bq)
110 {
111
112 mtx_destroy(&bq->bio_queue_lock);
113 }
114 #endif
115
116 static void
g_bioq_init(struct g_bioq * bq)117 g_bioq_init(struct g_bioq *bq)
118 {
119
120 TAILQ_INIT(&bq->bio_queue);
121 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
122 }
123
124 static struct bio *
g_bioq_first(struct g_bioq * bq)125 g_bioq_first(struct g_bioq *bq)
126 {
127 struct bio *bp;
128
129 bp = TAILQ_FIRST(&bq->bio_queue);
130 if (bp != NULL) {
131 KASSERT((bp->bio_flags & BIO_ONQUEUE),
132 ("Bio not on queue bp=%p target %p", bp, bq));
133 bp->bio_flags &= ~BIO_ONQUEUE;
134 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
135 bq->bio_queue_length--;
136 }
137 return (bp);
138 }
139
140 struct bio *
g_new_bio(void)141 g_new_bio(void)
142 {
143 struct bio *bp;
144
145 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
146 #ifdef KTR
147 if (KTR_GEOM_ENABLED) {
148 struct stack st;
149
150 CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
151 stack_save(&st);
152 CTRSTACK(KTR_GEOM, &st, 3);
153 }
154 #endif
155 return (bp);
156 }
157
158 struct bio *
g_alloc_bio(void)159 g_alloc_bio(void)
160 {
161 struct bio *bp;
162
163 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
164 #ifdef KTR
165 if (KTR_GEOM_ENABLED) {
166 struct stack st;
167
168 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
169 stack_save(&st);
170 CTRSTACK(KTR_GEOM, &st, 3);
171 }
172 #endif
173 return (bp);
174 }
175
176 void
g_destroy_bio(struct bio * bp)177 g_destroy_bio(struct bio *bp)
178 {
179 #ifdef KTR
180 if (KTR_GEOM_ENABLED) {
181 struct stack st;
182
183 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
184 stack_save(&st);
185 CTRSTACK(KTR_GEOM, &st, 3);
186 }
187 #endif
188 uma_zfree(biozone, bp);
189 }
190
191 struct bio *
g_clone_bio(struct bio * bp)192 g_clone_bio(struct bio *bp)
193 {
194 struct bio *bp2;
195
196 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
197 if (bp2 != NULL) {
198 bp2->bio_parent = bp;
199 bp2->bio_cmd = bp->bio_cmd;
200 /*
201 * BIO_ORDERED flag may be used by disk drivers to enforce
202 * ordering restrictions, so this flag needs to be cloned.
203 * BIO_UNMAPPED and BIO_VLIST should be inherited, to properly
204 * indicate which way the buffer is passed.
205 * Other bio flags are not suitable for cloning.
206 */
207 bp2->bio_flags = bp->bio_flags &
208 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST);
209 bp2->bio_length = bp->bio_length;
210 bp2->bio_offset = bp->bio_offset;
211 bp2->bio_data = bp->bio_data;
212 bp2->bio_ma = bp->bio_ma;
213 bp2->bio_ma_n = bp->bio_ma_n;
214 bp2->bio_ma_offset = bp->bio_ma_offset;
215 bp2->bio_attribute = bp->bio_attribute;
216 if (bp->bio_cmd == BIO_ZONE)
217 bcopy(&bp->bio_zone, &bp2->bio_zone,
218 sizeof(bp->bio_zone));
219 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING)
220 bp2->bio_track_bp = bp->bio_track_bp;
221 #endif
222 bp->bio_children++;
223 }
224 #ifdef KTR
225 if (KTR_GEOM_ENABLED) {
226 struct stack st;
227
228 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2);
229 stack_save(&st);
230 CTRSTACK(KTR_GEOM, &st, 3);
231 }
232 #endif
233 return(bp2);
234 }
235
236 struct bio *
g_duplicate_bio(struct bio * bp)237 g_duplicate_bio(struct bio *bp)
238 {
239 struct bio *bp2;
240
241 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO);
242 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST);
243 bp2->bio_parent = bp;
244 bp2->bio_cmd = bp->bio_cmd;
245 bp2->bio_length = bp->bio_length;
246 bp2->bio_offset = bp->bio_offset;
247 bp2->bio_data = bp->bio_data;
248 bp2->bio_ma = bp->bio_ma;
249 bp2->bio_ma_n = bp->bio_ma_n;
250 bp2->bio_ma_offset = bp->bio_ma_offset;
251 bp2->bio_attribute = bp->bio_attribute;
252 bp->bio_children++;
253 #ifdef KTR
254 if (KTR_GEOM_ENABLED) {
255 struct stack st;
256
257 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2);
258 stack_save(&st);
259 CTRSTACK(KTR_GEOM, &st, 3);
260 }
261 #endif
262 return(bp2);
263 }
264
265 void
g_reset_bio(struct bio * bp)266 g_reset_bio(struct bio *bp)
267 {
268
269 bzero(bp, sizeof(*bp));
270 }
271
272 void
g_io_init(void)273 g_io_init(void)
274 {
275
276 g_bioq_init(&g_bio_run_down);
277 g_bioq_init(&g_bio_run_up);
278 biozone = uma_zcreate("g_bio", sizeof (struct bio),
279 NULL, NULL,
280 NULL, NULL,
281 0, 0);
282 }
283
284 int
g_io_getattr(const char * attr,struct g_consumer * cp,int * len,void * ptr)285 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
286 {
287 struct bio *bp;
288 int error;
289
290 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
291 bp = g_alloc_bio();
292 bp->bio_cmd = BIO_GETATTR;
293 bp->bio_done = NULL;
294 bp->bio_attribute = attr;
295 bp->bio_length = *len;
296 bp->bio_data = ptr;
297 g_io_request(bp, cp);
298 error = biowait(bp, "ggetattr");
299 *len = bp->bio_completed;
300 g_destroy_bio(bp);
301 return (error);
302 }
303
304 int
g_io_zonecmd(struct disk_zone_args * zone_args,struct g_consumer * cp)305 g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp)
306 {
307 struct bio *bp;
308 int error;
309
310 g_trace(G_T_BIO, "bio_zone(%d)", zone_args->zone_cmd);
311 bp = g_alloc_bio();
312 bp->bio_cmd = BIO_ZONE;
313 bp->bio_done = NULL;
314 /*
315 * XXX KDM need to handle report zone data.
316 */
317 bcopy(zone_args, &bp->bio_zone, sizeof(*zone_args));
318 if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES)
319 bp->bio_length =
320 zone_args->zone_params.report.entries_allocated *
321 sizeof(struct disk_zone_rep_entry);
322 else
323 bp->bio_length = 0;
324
325 g_io_request(bp, cp);
326 error = biowait(bp, "gzone");
327 bcopy(&bp->bio_zone, zone_args, sizeof(*zone_args));
328 g_destroy_bio(bp);
329 return (error);
330 }
331
332 /*
333 * Send a BIO_SPEEDUP down the stack. This is used to tell the lower layers that
334 * the upper layers have detected a resource shortage. The lower layers are
335 * advised to stop delaying I/O that they might be holding for performance
336 * reasons and to schedule it (non-trims) or complete it successfully (trims) as
337 * quickly as it can. bio_length is the amount of the shortage. This call
338 * should be non-blocking. bio_resid is used to communicate back if the lower
339 * layers couldn't find bio_length worth of I/O to schedule or discard. A length
340 * of 0 means to do as much as you can (schedule the h/w queues full, discard
341 * all trims). flags are a hint from the upper layers to the lower layers what
342 * operation should be done.
343 */
344 int
g_io_speedup(off_t shortage,u_int flags,size_t * resid,struct g_consumer * cp)345 g_io_speedup(off_t shortage, u_int flags, size_t *resid, struct g_consumer *cp)
346 {
347 struct bio *bp;
348 int error;
349
350 KASSERT((flags & (BIO_SPEEDUP_TRIM | BIO_SPEEDUP_WRITE)) != 0,
351 ("Invalid flags passed to g_io_speedup: %#x", flags));
352 g_trace(G_T_BIO, "bio_speedup(%s, %jd, %#x)", cp->provider->name,
353 (intmax_t)shortage, flags);
354 bp = g_new_bio();
355 if (bp == NULL)
356 return (ENOMEM);
357 bp->bio_cmd = BIO_SPEEDUP;
358 bp->bio_length = shortage;
359 bp->bio_done = NULL;
360 bp->bio_flags |= flags;
361 g_io_request(bp, cp);
362 error = biowait(bp, "gflush");
363 *resid = bp->bio_resid;
364 g_destroy_bio(bp);
365 return (error);
366 }
367
368 int
g_io_flush(struct g_consumer * cp)369 g_io_flush(struct g_consumer *cp)
370 {
371 struct bio *bp;
372 int error;
373
374 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name);
375 bp = g_alloc_bio();
376 bp->bio_cmd = BIO_FLUSH;
377 bp->bio_flags |= BIO_ORDERED;
378 bp->bio_done = NULL;
379 bp->bio_attribute = NULL;
380 bp->bio_offset = cp->provider->mediasize;
381 bp->bio_length = 0;
382 bp->bio_data = NULL;
383 g_io_request(bp, cp);
384 error = biowait(bp, "gflush");
385 g_destroy_bio(bp);
386 return (error);
387 }
388
389 static int
g_io_check(struct bio * bp)390 g_io_check(struct bio *bp)
391 {
392 struct g_consumer *cp;
393 struct g_provider *pp;
394 off_t excess;
395 int error;
396
397 biotrack(bp, __func__);
398
399 cp = bp->bio_from;
400 pp = bp->bio_to;
401
402 /* Fail if access counters dont allow the operation */
403 switch(bp->bio_cmd) {
404 case BIO_READ:
405 case BIO_GETATTR:
406 if (cp->acr == 0)
407 return (EPERM);
408 break;
409 case BIO_WRITE:
410 case BIO_DELETE:
411 case BIO_SPEEDUP:
412 case BIO_FLUSH:
413 if (cp->acw == 0)
414 return (EPERM);
415 break;
416 case BIO_ZONE:
417 if ((bp->bio_zone.zone_cmd == DISK_ZONE_REPORT_ZONES) ||
418 (bp->bio_zone.zone_cmd == DISK_ZONE_GET_PARAMS)) {
419 if (cp->acr == 0)
420 return (EPERM);
421 } else if (cp->acw == 0)
422 return (EPERM);
423 break;
424 default:
425 return (EPERM);
426 }
427 /* if provider is marked for error, don't disturb. */
428 if (pp->error)
429 return (pp->error);
430 if (cp->flags & G_CF_ORPHAN)
431 return (ENXIO);
432
433 switch(bp->bio_cmd) {
434 case BIO_READ:
435 case BIO_WRITE:
436 case BIO_DELETE:
437 /* Zero sectorsize or mediasize is probably a lack of media. */
438 if (pp->sectorsize == 0 || pp->mediasize == 0)
439 return (ENXIO);
440 /* Reject I/O not on sector boundary */
441 if (bp->bio_offset % pp->sectorsize)
442 return (EINVAL);
443 /* Reject I/O not integral sector long */
444 if (bp->bio_length % pp->sectorsize)
445 return (EINVAL);
446 /* Reject requests before or past the end of media. */
447 if (bp->bio_offset < 0)
448 return (EIO);
449 if (bp->bio_offset > pp->mediasize)
450 return (EIO);
451
452 /* Truncate requests to the end of providers media. */
453 excess = bp->bio_offset + bp->bio_length;
454 if (excess > bp->bio_to->mediasize) {
455 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 ||
456 round_page(bp->bio_ma_offset +
457 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n,
458 ("excess bio %p too short", bp));
459 excess -= bp->bio_to->mediasize;
460 bp->bio_length -= excess;
461 if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
462 bp->bio_ma_n = round_page(bp->bio_ma_offset +
463 bp->bio_length) / PAGE_SIZE;
464 }
465 if (excess > 0)
466 CTR3(KTR_GEOM, "g_down truncated bio "
467 "%p provider %s by %d", bp,
468 bp->bio_to->name, excess);
469 }
470
471 /* Deliver zero length transfers right here. */
472 if (bp->bio_length == 0) {
473 CTR2(KTR_GEOM, "g_down terminated 0-length "
474 "bp %p provider %s", bp, bp->bio_to->name);
475 return (0);
476 }
477
478 if ((bp->bio_flags & BIO_UNMAPPED) != 0 &&
479 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 &&
480 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) {
481 if ((error = g_io_transient_map_bio(bp)) >= 0)
482 return (error);
483 }
484 break;
485 default:
486 break;
487 }
488 return (EJUSTRETURN);
489 }
490
491 void
g_io_request(struct bio * bp,struct g_consumer * cp)492 g_io_request(struct bio *bp, struct g_consumer *cp)
493 {
494 struct g_provider *pp;
495 int direct, error, first;
496 uint8_t cmd;
497
498 biotrack(bp, __func__);
499
500 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
501 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
502 pp = cp->provider;
503 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
504 #ifdef DIAGNOSTIC
505 KASSERT(bp->bio_driver1 == NULL,
506 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name));
507 KASSERT(bp->bio_driver2 == NULL,
508 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name));
509 KASSERT(bp->bio_pflags == 0,
510 ("bio_pflags used by the consumer (geom %s)", cp->geom->name));
511 /*
512 * Remember consumer's private fields, so we can detect if they were
513 * modified by the provider.
514 */
515 bp->_bio_caller1 = bp->bio_caller1;
516 bp->_bio_caller2 = bp->bio_caller2;
517 bp->_bio_cflags = bp->bio_cflags;
518 #endif
519
520 cmd = bp->bio_cmd;
521 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) {
522 KASSERT(bp->bio_data != NULL,
523 ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd));
524 }
525 if (cmd == BIO_DELETE || cmd == BIO_FLUSH || cmd == BIO_SPEEDUP) {
526 KASSERT(bp->bio_data == NULL,
527 ("non-NULL bp->data in g_io_request(cmd=%hu)",
528 bp->bio_cmd));
529 }
530 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) {
531 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
532 ("wrong offset %jd for sectorsize %u",
533 bp->bio_offset, cp->provider->sectorsize));
534 KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
535 ("wrong length %jd for sectorsize %u",
536 bp->bio_length, cp->provider->sectorsize));
537 }
538
539 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
540 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
541
542 bp->bio_from = cp;
543 bp->bio_to = pp;
544 bp->bio_error = 0;
545 bp->bio_completed = 0;
546
547 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
548 ("Bio already on queue bp=%p", bp));
549
550 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
551 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
552 binuptime(&bp->bio_t0);
553 else
554 getbinuptime(&bp->bio_t0);
555 if (g_collectstats & G_STATS_CONSUMERS)
556 devstat_start_transaction_bio_t0(cp->stat, bp);
557 if (g_collectstats & G_STATS_PROVIDERS)
558 devstat_start_transaction_bio_t0(pp->stat, bp);
559 #ifdef INVARIANTS
560 atomic_add_int(&cp->nstart, 1);
561 #endif
562
563 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 &&
564 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 &&
565 curthread != g_down_td &&
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
577 if (direct) {
578 error = g_io_check(bp);
579 if (error >= 0) {
580 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p "
581 "provider %s returned %d", bp, bp->bio_to->name,
582 error);
583 g_io_deliver(bp, error);
584 return;
585 }
586 bp->bio_to->geom->start(bp);
587 } else {
588 g_bioq_lock(&g_bio_run_down);
589 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue);
590 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue);
591 bp->bio_flags |= BIO_ONQUEUE;
592 g_bio_run_down.bio_queue_length++;
593 g_bioq_unlock(&g_bio_run_down);
594 /* Pass it on down. */
595 if (first)
596 wakeup(&g_wait_down);
597 }
598 }
599
600 void
g_io_deliver(struct bio * bp,int error)601 g_io_deliver(struct bio *bp, int error)
602 {
603 struct bintime now;
604 struct g_consumer *cp;
605 struct g_provider *pp;
606 struct mtx *mtxp;
607 int direct, first;
608
609 biotrack(bp, __func__);
610
611 KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
612 pp = bp->bio_to;
613 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
614 cp = bp->bio_from;
615 if (cp == NULL) {
616 bp->bio_error = error;
617 bp->bio_done(bp);
618 return;
619 }
620 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
621 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
622 #ifdef DIAGNOSTIC
623 /*
624 * Some classes - GJournal in particular - can modify bio's
625 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO
626 * flag means it's an expected behaviour for that particular geom.
627 */
628 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) {
629 KASSERT(bp->bio_caller1 == bp->_bio_caller1,
630 ("bio_caller1 used by the provider %s", pp->name));
631 KASSERT(bp->bio_caller2 == bp->_bio_caller2,
632 ("bio_caller2 used by the provider %s", pp->name));
633 KASSERT(bp->bio_cflags == bp->_bio_cflags,
634 ("bio_cflags used by the provider %s", pp->name));
635 }
636 #endif
637 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0"));
638 KASSERT(bp->bio_completed <= bp->bio_length,
639 ("bio_completed can't be greater than bio_length"));
640
641 g_trace(G_T_BIO,
642 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
643 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
644 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
645
646 KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
647 ("Bio already on queue bp=%p", bp));
648
649 /*
650 * XXX: next two doesn't belong here
651 */
652 bp->bio_bcount = bp->bio_length;
653 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
654
655 direct = (pp->flags & G_PF_DIRECT_SEND) &&
656 (cp->flags & G_CF_DIRECT_RECEIVE) &&
657 curthread != g_up_td;
658 if (direct) {
659 /* Block direct execution if less then half of stack left. */
660 size_t st, su;
661 GET_STACK_USAGE(st, su);
662 if (su * 2 > st)
663 direct = 0;
664 }
665
666 /*
667 * The statistics collection is lockless, as such, but we
668 * can not update one instance of the statistics from more
669 * than one thread at a time, so grab the lock first.
670 */
671 if ((g_collectstats & G_STATS_CONSUMERS) != 0 ||
672 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL))
673 binuptime(&now);
674 mtxp = mtx_pool_find(mtxpool_sleep, pp);
675 mtx_lock(mtxp);
676 if (g_collectstats & G_STATS_PROVIDERS)
677 devstat_end_transaction_bio_bt(pp->stat, bp, &now);
678 if (g_collectstats & G_STATS_CONSUMERS)
679 devstat_end_transaction_bio_bt(cp->stat, bp, &now);
680 #ifdef INVARIANTS
681 cp->nend++;
682 #endif
683 mtx_unlock(mtxp);
684
685 if (error != ENOMEM) {
686 bp->bio_error = error;
687 if (direct) {
688 biodone(bp);
689 } else {
690 g_bioq_lock(&g_bio_run_up);
691 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue);
692 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
693 bp->bio_flags |= BIO_ONQUEUE;
694 g_bio_run_up.bio_queue_length++;
695 g_bioq_unlock(&g_bio_run_up);
696 if (first)
697 wakeup(&g_wait_up);
698 }
699 return;
700 }
701
702 if (bootverbose)
703 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
704 bp->bio_children = 0;
705 bp->bio_inbed = 0;
706 bp->bio_driver1 = NULL;
707 bp->bio_driver2 = NULL;
708 bp->bio_pflags = 0;
709 g_io_request(bp, cp);
710 pace = 1;
711 return;
712 }
713
714 SYSCTL_DECL(_kern_geom);
715
716 static long transient_maps;
717 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD,
718 &transient_maps, 0,
719 "Total count of the transient mapping requests");
720 u_int transient_map_retries = 10;
721 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW,
722 &transient_map_retries, 0,
723 "Max count of retries used before giving up on creating transient map");
724 int transient_map_hard_failures;
725 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD,
726 &transient_map_hard_failures, 0,
727 "Failures to establish the transient mapping due to retry attempts "
728 "exhausted");
729 int transient_map_soft_failures;
730 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD,
731 &transient_map_soft_failures, 0,
732 "Count of retried failures to establish the transient mapping");
733 int inflight_transient_maps;
734 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD,
735 &inflight_transient_maps, 0,
736 "Current count of the active transient maps");
737
738 static int
g_io_transient_map_bio(struct bio * bp)739 g_io_transient_map_bio(struct bio *bp)
740 {
741 vm_offset_t addr;
742 long size;
743 u_int retried;
744
745 KASSERT(unmapped_buf_allowed, ("unmapped disabled"));
746
747 size = round_page(bp->bio_ma_offset + bp->bio_length);
748 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp));
749 addr = 0;
750 retried = 0;
751 atomic_add_long(&transient_maps, 1);
752 retry:
753 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) {
754 if (transient_map_retries != 0 &&
755 retried >= transient_map_retries) {
756 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s",
757 bp, bp->bio_to->name);
758 atomic_add_int(&transient_map_hard_failures, 1);
759 return (EDEADLK/* XXXKIB */);
760 } else {
761 /*
762 * Naive attempt to quisce the I/O to get more
763 * in-flight requests completed and defragment
764 * the transient_arena.
765 */
766 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d",
767 bp, bp->bio_to->name, retried);
768 pause("g_d_tra", hz / 10);
769 retried++;
770 atomic_add_int(&transient_map_soft_failures, 1);
771 goto retry;
772 }
773 }
774 atomic_add_int(&inflight_transient_maps, 1);
775 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size));
776 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset;
777 bp->bio_flags |= BIO_TRANSIENT_MAPPING;
778 bp->bio_flags &= ~BIO_UNMAPPED;
779 return (EJUSTRETURN);
780 }
781
782 void
g_io_schedule_down(struct thread * tp __unused)783 g_io_schedule_down(struct thread *tp __unused)
784 {
785 struct bio *bp;
786 int error;
787
788 for(;;) {
789 g_bioq_lock(&g_bio_run_down);
790 bp = g_bioq_first(&g_bio_run_down);
791 if (bp == NULL) {
792 CTR0(KTR_GEOM, "g_down going to sleep");
793 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
794 PRIBIO | PDROP, "-", 0);
795 continue;
796 }
797 CTR0(KTR_GEOM, "g_down has work to do");
798 g_bioq_unlock(&g_bio_run_down);
799 biotrack(bp, __func__);
800 if (pace != 0) {
801 /*
802 * There has been at least one memory allocation
803 * failure since the last I/O completed. Pause 1ms to
804 * give the system a chance to free up memory. We only
805 * do this once because a large number of allocations
806 * can fail in the direct dispatch case and there's no
807 * relationship between the number of these failures and
808 * the length of the outage. If there's still an outage,
809 * we'll pause again and again until it's
810 * resolved. Older versions paused longer and once per
811 * allocation failure. This was OK for a single threaded
812 * g_down, but with direct dispatch would lead to max of
813 * 10 IOPs for minutes at a time when transient memory
814 * issues prevented allocation for a batch of requests
815 * from the upper layers.
816 *
817 * XXX This pacing is really lame. It needs to be solved
818 * by other methods. This is OK only because the worst
819 * case scenario is so rare. In the worst case scenario
820 * all memory is tied up waiting for I/O to complete
821 * which can never happen since we can't allocate bios
822 * for that I/O.
823 */
824 CTR0(KTR_GEOM, "g_down pacing self");
825 pause("g_down", min(hz/1000, 1));
826 pace = 0;
827 }
828 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
829 bp->bio_to->name);
830 error = g_io_check(bp);
831 if (error >= 0) {
832 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
833 "%s returned %d", bp, bp->bio_to->name, error);
834 g_io_deliver(bp, error);
835 continue;
836 }
837 THREAD_NO_SLEEPING();
838 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
839 "len %ld", bp, bp->bio_to->name, bp->bio_offset,
840 bp->bio_length);
841 bp->bio_to->geom->start(bp);
842 THREAD_SLEEPING_OK();
843 }
844 }
845
846 void
g_io_schedule_up(struct thread * tp __unused)847 g_io_schedule_up(struct thread *tp __unused)
848 {
849 struct bio *bp;
850
851 for(;;) {
852 g_bioq_lock(&g_bio_run_up);
853 bp = g_bioq_first(&g_bio_run_up);
854 if (bp == NULL) {
855 CTR0(KTR_GEOM, "g_up going to sleep");
856 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
857 PRIBIO | PDROP, "-", 0);
858 continue;
859 }
860 g_bioq_unlock(&g_bio_run_up);
861 THREAD_NO_SLEEPING();
862 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
863 "%jd len %ld", bp, bp->bio_to->name,
864 bp->bio_offset, bp->bio_length);
865 biodone(bp);
866 THREAD_SLEEPING_OK();
867 }
868 }
869
870 void *
g_read_data(struct g_consumer * cp,off_t offset,off_t length,int * error)871 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
872 {
873 struct bio *bp;
874 void *ptr;
875 int errorc;
876
877 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
878 length <= maxphys, ("g_read_data(): invalid length %jd",
879 (intmax_t)length));
880
881 bp = g_alloc_bio();
882 bp->bio_cmd = BIO_READ;
883 bp->bio_done = NULL;
884 bp->bio_offset = offset;
885 bp->bio_length = length;
886 ptr = g_malloc(length, M_WAITOK);
887 bp->bio_data = ptr;
888 g_io_request(bp, cp);
889 errorc = biowait(bp, "gread");
890 if (errorc == 0 && bp->bio_completed != length)
891 errorc = EIO;
892 if (error != NULL)
893 *error = errorc;
894 g_destroy_bio(bp);
895 if (errorc) {
896 g_free(ptr);
897 ptr = NULL;
898 }
899 return (ptr);
900 }
901
902 /*
903 * A read function for use by ffs_sbget when used by GEOM-layer routines.
904 */
905 int
g_use_g_read_data(void * devfd,off_t loc,void ** bufp,int size)906 g_use_g_read_data(void *devfd, off_t loc, void **bufp, int size)
907 {
908 struct g_consumer *cp;
909
910 KASSERT(*bufp == NULL,
911 ("g_use_g_read_data: non-NULL *bufp %p\n", *bufp));
912
913 cp = (struct g_consumer *)devfd;
914 /*
915 * Take care not to issue an invalid I/O request. The offset of
916 * the superblock candidate must be multiples of the provider's
917 * sector size, otherwise an FFS can't exist on the provider
918 * anyway.
919 */
920 if (loc % cp->provider->sectorsize != 0)
921 return (ENOENT);
922 *bufp = g_read_data(cp, loc, size, NULL);
923 if (*bufp == NULL)
924 return (ENOENT);
925 return (0);
926 }
927
928 int
g_write_data(struct g_consumer * cp,off_t offset,void * ptr,off_t length)929 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
930 {
931 struct bio *bp;
932 int error;
933
934 KASSERT(length > 0 && length >= cp->provider->sectorsize &&
935 length <= maxphys, ("g_write_data(): invalid length %jd",
936 (intmax_t)length));
937
938 bp = g_alloc_bio();
939 bp->bio_cmd = BIO_WRITE;
940 bp->bio_done = NULL;
941 bp->bio_offset = offset;
942 bp->bio_length = length;
943 bp->bio_data = ptr;
944 g_io_request(bp, cp);
945 error = biowait(bp, "gwrite");
946 if (error == 0 && bp->bio_completed != length)
947 error = EIO;
948 g_destroy_bio(bp);
949 return (error);
950 }
951
952 /*
953 * A write function for use by ffs_sbput when used by GEOM-layer routines.
954 */
955 int
g_use_g_write_data(void * devfd,off_t loc,void * buf,int size)956 g_use_g_write_data(void *devfd, off_t loc, void *buf, int size)
957 {
958
959 return (g_write_data((struct g_consumer *)devfd, loc, buf, size));
960 }
961
962 int
g_delete_data(struct g_consumer * cp,off_t offset,off_t length)963 g_delete_data(struct g_consumer *cp, off_t offset, off_t length)
964 {
965 struct bio *bp;
966 int error;
967
968 KASSERT(length > 0 && length >= cp->provider->sectorsize,
969 ("g_delete_data(): invalid length %jd", (intmax_t)length));
970
971 bp = g_alloc_bio();
972 bp->bio_cmd = BIO_DELETE;
973 bp->bio_done = NULL;
974 bp->bio_offset = offset;
975 bp->bio_length = length;
976 bp->bio_data = NULL;
977 g_io_request(bp, cp);
978 error = biowait(bp, "gdelete");
979 if (error == 0 && bp->bio_completed != length)
980 error = EIO;
981 g_destroy_bio(bp);
982 return (error);
983 }
984
985 void
g_print_bio(const char * prefix,const struct bio * bp,const char * fmtsuffix,...)986 g_print_bio(const char *prefix, const struct bio *bp, const char *fmtsuffix,
987 ...)
988 {
989 #ifndef PRINTF_BUFR_SIZE
990 #define PRINTF_BUFR_SIZE 64
991 #endif
992 char bufr[PRINTF_BUFR_SIZE];
993 struct sbuf sb, *sbp __unused;
994 va_list ap;
995
996 sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
997 KASSERT(sbp != NULL, ("sbuf_new misused?"));
998
999 sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
1000
1001 sbuf_cat(&sb, prefix);
1002 g_format_bio(&sb, bp);
1003
1004 va_start(ap, fmtsuffix);
1005 sbuf_vprintf(&sb, fmtsuffix, ap);
1006 va_end(ap);
1007
1008 sbuf_nl_terminate(&sb);
1009
1010 sbuf_finish(&sb);
1011 sbuf_delete(&sb);
1012 }
1013
1014 void
g_format_bio(struct sbuf * sb,const struct bio * bp)1015 g_format_bio(struct sbuf *sb, const struct bio *bp)
1016 {
1017 const char *pname, *cmd = NULL;
1018
1019 if (bp->bio_to != NULL)
1020 pname = bp->bio_to->name;
1021 else if (bp->bio_parent != NULL && bp->bio_parent->bio_to != NULL)
1022 pname = bp->bio_parent->bio_to->name;
1023 else
1024 pname = "[unknown]";
1025
1026 switch (bp->bio_cmd) {
1027 case BIO_GETATTR:
1028 cmd = "GETATTR";
1029 sbuf_printf(sb, "%s[%s(attr=%s)]", pname, cmd,
1030 bp->bio_attribute);
1031 return;
1032 case BIO_FLUSH:
1033 cmd = "FLUSH";
1034 sbuf_printf(sb, "%s[%s]", pname, cmd);
1035 return;
1036 case BIO_ZONE: {
1037 char *subcmd = NULL;
1038 cmd = "ZONE";
1039 switch (bp->bio_zone.zone_cmd) {
1040 case DISK_ZONE_OPEN:
1041 subcmd = "OPEN";
1042 break;
1043 case DISK_ZONE_CLOSE:
1044 subcmd = "CLOSE";
1045 break;
1046 case DISK_ZONE_FINISH:
1047 subcmd = "FINISH";
1048 break;
1049 case DISK_ZONE_RWP:
1050 subcmd = "RWP";
1051 break;
1052 case DISK_ZONE_REPORT_ZONES:
1053 subcmd = "REPORT ZONES";
1054 break;
1055 case DISK_ZONE_GET_PARAMS:
1056 subcmd = "GET PARAMS";
1057 break;
1058 default:
1059 subcmd = "UNKNOWN";
1060 break;
1061 }
1062 sbuf_printf(sb, "%s[%s,%s]", pname, cmd, subcmd);
1063 return;
1064 }
1065 case BIO_READ:
1066 cmd = "READ";
1067 break;
1068 case BIO_WRITE:
1069 cmd = "WRITE";
1070 break;
1071 case BIO_DELETE:
1072 cmd = "DELETE";
1073 break;
1074 default:
1075 cmd = "UNKNOWN";
1076 sbuf_printf(sb, "%s[%s()]", pname, cmd);
1077 return;
1078 }
1079 sbuf_printf(sb, "%s[%s(offset=%jd, length=%jd)]", pname, cmd,
1080 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
1081 }
1082