geom_io.c revision 295707
1/*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * Copyright (c) 2013 The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 8 * and NAI Labs, the Security Research Division of Network Associates, Inc. 9 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 10 * DARPA CHATS research program. 11 * 12 * Portions of this software were developed by Konstantin Belousov 13 * under sponsorship from the FreeBSD Foundation. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. The names of the authors may not be used to endorse or promote 24 * products derived from this software without specific prior written 25 * permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD: head/sys/geom/geom_io.c 295707 2016-02-17 17:16:02Z imp $"); 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/malloc.h> 47#include <sys/bio.h> 48#include <sys/ktr.h> 49#include <sys/proc.h> 50#include <sys/stack.h> 51#include <sys/sysctl.h> 52#include <sys/vmem.h> 53 54#include <sys/errno.h> 55#include <geom/geom.h> 56#include <geom/geom_int.h> 57#include <sys/devicestat.h> 58 59#include <vm/uma.h> 60#include <vm/vm.h> 61#include <vm/vm_param.h> 62#include <vm/vm_kern.h> 63#include <vm/vm_page.h> 64#include <vm/vm_object.h> 65#include <vm/vm_extern.h> 66#include <vm/vm_map.h> 67 68static int g_io_transient_map_bio(struct bio *bp); 69 70static struct g_bioq g_bio_run_down; 71static struct g_bioq g_bio_run_up; 72static struct g_bioq g_bio_run_task; 73 74/* 75 * Pace is a hint that we've had some trouble recently allocating 76 * bios, so we should back off trying to send I/O down the stack 77 * a bit to let the problem resolve. When pacing, we also turn 78 * off direct dispatch to also reduce memory pressure from I/Os 79 * there, at the expxense of some added latency while the memory 80 * pressures exist. See g_io_schedule_down() for more details 81 * and limitations. 82 */ 83static volatile u_int pace; 84 85static uma_zone_t biozone; 86 87/* 88 * The head of the list of classifiers used in g_io_request. 89 * Use g_register_classifier() and g_unregister_classifier() 90 * to add/remove entries to the list. 91 * Classifiers are invoked in registration order. 92 */ 93static TAILQ_HEAD(g_classifier_tailq, g_classifier_hook) 94 g_classifier_tailq = TAILQ_HEAD_INITIALIZER(g_classifier_tailq); 95 96#include <machine/atomic.h> 97 98static void 99g_bioq_lock(struct g_bioq *bq) 100{ 101 102 mtx_lock(&bq->bio_queue_lock); 103} 104 105static void 106g_bioq_unlock(struct g_bioq *bq) 107{ 108 109 mtx_unlock(&bq->bio_queue_lock); 110} 111 112#if 0 113static void 114g_bioq_destroy(struct g_bioq *bq) 115{ 116 117 mtx_destroy(&bq->bio_queue_lock); 118} 119#endif 120 121static void 122g_bioq_init(struct g_bioq *bq) 123{ 124 125 TAILQ_INIT(&bq->bio_queue); 126 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 127} 128 129static struct bio * 130g_bioq_first(struct g_bioq *bq) 131{ 132 struct bio *bp; 133 134 bp = TAILQ_FIRST(&bq->bio_queue); 135 if (bp != NULL) { 136 KASSERT((bp->bio_flags & BIO_ONQUEUE), 137 ("Bio not on queue bp=%p target %p", bp, bq)); 138 bp->bio_flags &= ~BIO_ONQUEUE; 139 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 140 bq->bio_queue_length--; 141 } 142 return (bp); 143} 144 145struct bio * 146g_new_bio(void) 147{ 148 struct bio *bp; 149 150 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 151#ifdef KTR 152 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 153 struct stack st; 154 155 CTR1(KTR_GEOM, "g_new_bio(): %p", bp); 156 stack_save(&st); 157 CTRSTACK(KTR_GEOM, &st, 3, 0); 158 } 159#endif 160 return (bp); 161} 162 163struct bio * 164g_alloc_bio(void) 165{ 166 struct bio *bp; 167 168 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO); 169#ifdef KTR 170 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 171 struct stack st; 172 173 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp); 174 stack_save(&st); 175 CTRSTACK(KTR_GEOM, &st, 3, 0); 176 } 177#endif 178 return (bp); 179} 180 181void 182g_destroy_bio(struct bio *bp) 183{ 184#ifdef KTR 185 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 186 struct stack st; 187 188 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp); 189 stack_save(&st); 190 CTRSTACK(KTR_GEOM, &st, 3, 0); 191 } 192#endif 193 uma_zfree(biozone, bp); 194} 195 196struct bio * 197g_clone_bio(struct bio *bp) 198{ 199 struct bio *bp2; 200 201 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 202 if (bp2 != NULL) { 203 bp2->bio_parent = bp; 204 bp2->bio_cmd = bp->bio_cmd; 205 /* 206 * BIO_ORDERED flag may be used by disk drivers to enforce 207 * ordering restrictions, so this flag needs to be cloned. 208 * BIO_UNMAPPED and BIO_VLIST should be inherited, to properly 209 * indicate which way the buffer is passed. 210 * Other bio flags are not suitable for cloning. 211 */ 212 bp2->bio_flags = bp->bio_flags & 213 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST); 214 bp2->bio_length = bp->bio_length; 215 bp2->bio_offset = bp->bio_offset; 216 bp2->bio_data = bp->bio_data; 217 bp2->bio_ma = bp->bio_ma; 218 bp2->bio_ma_n = bp->bio_ma_n; 219 bp2->bio_ma_offset = bp->bio_ma_offset; 220 bp2->bio_attribute = bp->bio_attribute; 221 /* Inherit classification info from the parent */ 222 bp2->bio_classifier1 = bp->bio_classifier1; 223 bp2->bio_classifier2 = bp->bio_classifier2; 224 bp->bio_children++; 225 } 226#ifdef KTR 227 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 228 struct stack st; 229 230 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2); 231 stack_save(&st); 232 CTRSTACK(KTR_GEOM, &st, 3, 0); 233 } 234#endif 235 return(bp2); 236} 237 238struct bio * 239g_duplicate_bio(struct bio *bp) 240{ 241 struct bio *bp2; 242 243 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO); 244 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST); 245 bp2->bio_parent = bp; 246 bp2->bio_cmd = bp->bio_cmd; 247 bp2->bio_length = bp->bio_length; 248 bp2->bio_offset = bp->bio_offset; 249 bp2->bio_data = bp->bio_data; 250 bp2->bio_ma = bp->bio_ma; 251 bp2->bio_ma_n = bp->bio_ma_n; 252 bp2->bio_ma_offset = bp->bio_ma_offset; 253 bp2->bio_attribute = bp->bio_attribute; 254 bp->bio_children++; 255#ifdef KTR 256 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 257 struct stack st; 258 259 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2); 260 stack_save(&st); 261 CTRSTACK(KTR_GEOM, &st, 3, 0); 262 } 263#endif 264 return(bp2); 265} 266 267void 268g_reset_bio(struct bio *bp) 269{ 270 271 bzero(bp, sizeof(bp)); 272} 273 274void 275g_io_init() 276{ 277 278 g_bioq_init(&g_bio_run_down); 279 g_bioq_init(&g_bio_run_up); 280 g_bioq_init(&g_bio_run_task); 281 biozone = uma_zcreate("g_bio", sizeof (struct bio), 282 NULL, NULL, 283 NULL, NULL, 284 0, 0); 285} 286 287int 288g_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 307int 308g_io_flush(struct g_consumer *cp) 309{ 310 struct bio *bp; 311 int error; 312 313 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name); 314 bp = g_alloc_bio(); 315 bp->bio_cmd = BIO_FLUSH; 316 bp->bio_flags |= BIO_ORDERED; 317 bp->bio_done = NULL; 318 bp->bio_attribute = NULL; 319 bp->bio_offset = cp->provider->mediasize; 320 bp->bio_length = 0; 321 bp->bio_data = NULL; 322 g_io_request(bp, cp); 323 error = biowait(bp, "gflush"); 324 g_destroy_bio(bp); 325 return (error); 326} 327 328static int 329g_io_check(struct bio *bp) 330{ 331 struct g_consumer *cp; 332 struct g_provider *pp; 333 off_t excess; 334 int error; 335 336 cp = bp->bio_from; 337 pp = bp->bio_to; 338 339 /* Fail if access counters dont allow the operation */ 340 switch(bp->bio_cmd) { 341 case BIO_READ: 342 case BIO_GETATTR: 343 if (cp->acr == 0) 344 return (EPERM); 345 break; 346 case BIO_WRITE: 347 case BIO_DELETE: 348 case BIO_FLUSH: 349 if (cp->acw == 0) 350 return (EPERM); 351 break; 352 default: 353 return (EPERM); 354 } 355 /* if provider is marked for error, don't disturb. */ 356 if (pp->error) 357 return (pp->error); 358 if (cp->flags & G_CF_ORPHAN) 359 return (ENXIO); 360 361 switch(bp->bio_cmd) { 362 case BIO_READ: 363 case BIO_WRITE: 364 case BIO_DELETE: 365 /* Zero sectorsize or mediasize is probably a lack of media. */ 366 if (pp->sectorsize == 0 || pp->mediasize == 0) 367 return (ENXIO); 368 /* Reject I/O not on sector boundary */ 369 if (bp->bio_offset % pp->sectorsize) 370 return (EINVAL); 371 /* Reject I/O not integral sector long */ 372 if (bp->bio_length % pp->sectorsize) 373 return (EINVAL); 374 /* Reject requests before or past the end of media. */ 375 if (bp->bio_offset < 0) 376 return (EIO); 377 if (bp->bio_offset > pp->mediasize) 378 return (EIO); 379 380 /* Truncate requests to the end of providers media. */ 381 excess = bp->bio_offset + bp->bio_length; 382 if (excess > bp->bio_to->mediasize) { 383 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 || 384 round_page(bp->bio_ma_offset + 385 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n, 386 ("excess bio %p too short", bp)); 387 excess -= bp->bio_to->mediasize; 388 bp->bio_length -= excess; 389 if ((bp->bio_flags & BIO_UNMAPPED) != 0) { 390 bp->bio_ma_n = round_page(bp->bio_ma_offset + 391 bp->bio_length) / PAGE_SIZE; 392 } 393 if (excess > 0) 394 CTR3(KTR_GEOM, "g_down truncated bio " 395 "%p provider %s by %d", bp, 396 bp->bio_to->name, excess); 397 } 398 399 /* Deliver zero length transfers right here. */ 400 if (bp->bio_length == 0) { 401 CTR2(KTR_GEOM, "g_down terminated 0-length " 402 "bp %p provider %s", bp, bp->bio_to->name); 403 return (0); 404 } 405 406 if ((bp->bio_flags & BIO_UNMAPPED) != 0 && 407 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 && 408 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 409 if ((error = g_io_transient_map_bio(bp)) >= 0) 410 return (error); 411 } 412 break; 413 default: 414 break; 415 } 416 return (EJUSTRETURN); 417} 418 419/* 420 * bio classification support. 421 * 422 * g_register_classifier() and g_unregister_classifier() 423 * are used to add/remove a classifier from the list. 424 * The list is protected using the g_bio_run_down lock, 425 * because the classifiers are called in this path. 426 * 427 * g_io_request() passes bio's that are not already classified 428 * (i.e. those with bio_classifier1 == NULL) to g_run_classifiers(). 429 * Classifiers can store their result in the two fields 430 * bio_classifier1 and bio_classifier2. 431 * A classifier that updates one of the fields should 432 * return a non-zero value. 433 * If no classifier updates the field, g_run_classifiers() sets 434 * bio_classifier1 = BIO_NOTCLASSIFIED to avoid further calls. 435 */ 436 437int 438g_register_classifier(struct g_classifier_hook *hook) 439{ 440 441 g_bioq_lock(&g_bio_run_down); 442 TAILQ_INSERT_TAIL(&g_classifier_tailq, hook, link); 443 g_bioq_unlock(&g_bio_run_down); 444 445 return (0); 446} 447 448void 449g_unregister_classifier(struct g_classifier_hook *hook) 450{ 451 struct g_classifier_hook *entry; 452 453 g_bioq_lock(&g_bio_run_down); 454 TAILQ_FOREACH(entry, &g_classifier_tailq, link) { 455 if (entry == hook) { 456 TAILQ_REMOVE(&g_classifier_tailq, hook, link); 457 break; 458 } 459 } 460 g_bioq_unlock(&g_bio_run_down); 461} 462 463static void 464g_run_classifiers(struct bio *bp) 465{ 466 struct g_classifier_hook *hook; 467 int classified = 0; 468 469 TAILQ_FOREACH(hook, &g_classifier_tailq, link) 470 classified |= hook->func(hook->arg, bp); 471 472 if (!classified) 473 bp->bio_classifier1 = BIO_NOTCLASSIFIED; 474} 475 476void 477g_io_request(struct bio *bp, struct g_consumer *cp) 478{ 479 struct g_provider *pp; 480 struct mtx *mtxp; 481 int direct, error, first; 482 483 KASSERT(cp != NULL, ("NULL cp in g_io_request")); 484 KASSERT(bp != NULL, ("NULL bp in g_io_request")); 485 pp = cp->provider; 486 KASSERT(pp != NULL, ("consumer not attached in g_io_request")); 487#ifdef DIAGNOSTIC 488 KASSERT(bp->bio_driver1 == NULL, 489 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name)); 490 KASSERT(bp->bio_driver2 == NULL, 491 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name)); 492 KASSERT(bp->bio_pflags == 0, 493 ("bio_pflags used by the consumer (geom %s)", cp->geom->name)); 494 /* 495 * Remember consumer's private fields, so we can detect if they were 496 * modified by the provider. 497 */ 498 bp->_bio_caller1 = bp->bio_caller1; 499 bp->_bio_caller2 = bp->bio_caller2; 500 bp->_bio_cflags = bp->bio_cflags; 501#endif 502 503 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_GETATTR)) { 504 KASSERT(bp->bio_data != NULL, 505 ("NULL bp->data in g_io_request(cmd=%hhu)", bp->bio_cmd)); 506 } 507 if (bp->bio_cmd & (BIO_DELETE|BIO_FLUSH)) { 508 KASSERT(bp->bio_data == NULL, 509 ("non-NULL bp->data in g_io_request(cmd=%hhu)", 510 bp->bio_cmd)); 511 } 512 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) { 513 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0, 514 ("wrong offset %jd for sectorsize %u", 515 bp->bio_offset, cp->provider->sectorsize)); 516 KASSERT(bp->bio_length % cp->provider->sectorsize == 0, 517 ("wrong length %jd for sectorsize %u", 518 bp->bio_length, cp->provider->sectorsize)); 519 } 520 521 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 522 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd); 523 524 bp->bio_from = cp; 525 bp->bio_to = pp; 526 bp->bio_error = 0; 527 bp->bio_completed = 0; 528 529 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 530 ("Bio already on queue bp=%p", bp)); 531 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 532 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 533 binuptime(&bp->bio_t0); 534 else 535 getbinuptime(&bp->bio_t0); 536 537#ifdef GET_STACK_USAGE 538 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 && 539 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 && 540 !g_is_geom_thread(curthread) && 541 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 || 542 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) && 543 pace == 0; 544 if (direct) { 545 /* Block direct execution if less then half of stack left. */ 546 size_t st, su; 547 GET_STACK_USAGE(st, su); 548 if (su * 2 > st) 549 direct = 0; 550 } 551#else 552 direct = 0; 553#endif 554 555 if (!TAILQ_EMPTY(&g_classifier_tailq) && !bp->bio_classifier1) { 556 g_bioq_lock(&g_bio_run_down); 557 g_run_classifiers(bp); 558 g_bioq_unlock(&g_bio_run_down); 559 } 560 561 /* 562 * The statistics collection is lockless, as such, but we 563 * can not update one instance of the statistics from more 564 * than one thread at a time, so grab the lock first. 565 */ 566 mtxp = mtx_pool_find(mtxpool_sleep, pp); 567 mtx_lock(mtxp); 568 if (g_collectstats & G_STATS_PROVIDERS) 569 devstat_start_transaction(pp->stat, &bp->bio_t0); 570 if (g_collectstats & G_STATS_CONSUMERS) 571 devstat_start_transaction(cp->stat, &bp->bio_t0); 572 pp->nstart++; 573 cp->nstart++; 574 mtx_unlock(mtxp); 575 576 if (direct) { 577 error = g_io_check(bp); 578 if (error >= 0) { 579 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p " 580 "provider %s returned %d", bp, bp->bio_to->name, 581 error); 582 g_io_deliver(bp, error); 583 return; 584 } 585 bp->bio_to->geom->start(bp); 586 } else { 587 g_bioq_lock(&g_bio_run_down); 588 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue); 589 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue); 590 bp->bio_flags |= BIO_ONQUEUE; 591 g_bio_run_down.bio_queue_length++; 592 g_bioq_unlock(&g_bio_run_down); 593 /* Pass it on down. */ 594 if (first) 595 wakeup(&g_wait_down); 596 } 597} 598 599void 600g_io_deliver(struct bio *bp, int error) 601{ 602 struct bintime now; 603 struct g_consumer *cp; 604 struct g_provider *pp; 605 struct mtx *mtxp; 606 int direct, first; 607 608 KASSERT(bp != NULL, ("NULL bp in g_io_deliver")); 609 pp = bp->bio_to; 610 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver")); 611 cp = bp->bio_from; 612 if (cp == NULL) { 613 bp->bio_error = error; 614 bp->bio_done(bp); 615 return; 616 } 617 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver")); 618 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver")); 619#ifdef DIAGNOSTIC 620 /* 621 * Some classes - GJournal in particular - can modify bio's 622 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO 623 * flag means it's an expected behaviour for that particular geom. 624 */ 625 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) { 626 KASSERT(bp->bio_caller1 == bp->_bio_caller1, 627 ("bio_caller1 used by the provider %s", pp->name)); 628 KASSERT(bp->bio_caller2 == bp->_bio_caller2, 629 ("bio_caller2 used by the provider %s", pp->name)); 630 KASSERT(bp->bio_cflags == bp->_bio_cflags, 631 ("bio_cflags used by the provider %s", pp->name)); 632 } 633#endif 634 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0")); 635 KASSERT(bp->bio_completed <= bp->bio_length, 636 ("bio_completed can't be greater than bio_length")); 637 638 g_trace(G_T_BIO, 639"g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd", 640 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error, 641 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 642 643 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 644 ("Bio already on queue bp=%p", bp)); 645 646 /* 647 * XXX: next two doesn't belong here 648 */ 649 bp->bio_bcount = bp->bio_length; 650 bp->bio_resid = bp->bio_bcount - bp->bio_completed; 651 652#ifdef GET_STACK_USAGE 653 direct = (pp->flags & G_PF_DIRECT_SEND) && 654 (cp->flags & G_CF_DIRECT_RECEIVE) && 655 !g_is_geom_thread(curthread); 656 if (direct) { 657 /* Block direct execution if less then half of stack left. */ 658 size_t st, su; 659 GET_STACK_USAGE(st, su); 660 if (su * 2 > st) 661 direct = 0; 662 } 663#else 664 direct = 0; 665#endif 666 667 /* 668 * The statistics collection is lockless, as such, but we 669 * can not update one instance of the statistics from more 670 * than one thread at a time, so grab the lock first. 671 */ 672 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 673 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 674 binuptime(&now); 675 mtxp = mtx_pool_find(mtxpool_sleep, cp); 676 mtx_lock(mtxp); 677 if (g_collectstats & G_STATS_PROVIDERS) 678 devstat_end_transaction_bio_bt(pp->stat, bp, &now); 679 if (g_collectstats & G_STATS_CONSUMERS) 680 devstat_end_transaction_bio_bt(cp->stat, bp, &now); 681 cp->nend++; 682 pp->nend++; 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 714SYSCTL_DECL(_kern_geom); 715 716static long transient_maps; 717SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD, 718 &transient_maps, 0, 719 "Total count of the transient mapping requests"); 720u_int transient_map_retries = 10; 721SYSCTL_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"); 724int transient_map_hard_failures; 725SYSCTL_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"); 729int transient_map_soft_failures; 730SYSCTL_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"); 733int inflight_transient_maps; 734SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD, 735 &inflight_transient_maps, 0, 736 "Current count of the active transient maps"); 737 738static int 739g_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); 752retry: 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 782void 783g_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 if (pace != 0) { 800 /* 801 * There has been at least one memory allocation 802 * failure since the last I/O completed. Pause 1ms to 803 * give the system a chance to free up memory. We only 804 * do this once because a large number of allocations 805 * can fail in the direct dispatch case and there's no 806 * relationship between the number of these failures and 807 * the length of the outage. If there's still an outage, 808 * we'll pause again and again until it's 809 * resolved. Older versions paused longer and once per 810 * allocation failure. This was OK for a single threaded 811 * g_down, but with direct dispatch would lead to max of 812 * 10 IOPs for minutes at a time when transient memory 813 * issues prevented allocation for a batch of requests 814 * from the upper layers. 815 * 816 * XXX This pacing is really lame. It needs to be solved 817 * by other methods. This is OK only because the worst 818 * case scenario is so rare. In the worst case scenario 819 * all memory is tied up waiting for I/O to complete 820 * which can never happen since we can't allocate bios 821 * for that I/O. 822 */ 823 CTR0(KTR_GEOM, "g_down pacing self"); 824 pause("g_down", min(hz/1000, 1)); 825 pace = 0; 826 } 827 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp, 828 bp->bio_to->name); 829 error = g_io_check(bp); 830 if (error >= 0) { 831 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider " 832 "%s returned %d", bp, bp->bio_to->name, error); 833 g_io_deliver(bp, error); 834 continue; 835 } 836 THREAD_NO_SLEEPING(); 837 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld " 838 "len %ld", bp, bp->bio_to->name, bp->bio_offset, 839 bp->bio_length); 840 bp->bio_to->geom->start(bp); 841 THREAD_SLEEPING_OK(); 842 } 843} 844 845void 846bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg) 847{ 848 bp->bio_task = func; 849 bp->bio_task_arg = arg; 850 /* 851 * The taskqueue is actually just a second queue off the "up" 852 * queue, so we use the same lock. 853 */ 854 g_bioq_lock(&g_bio_run_up); 855 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 856 ("Bio already on queue bp=%p target taskq", bp)); 857 bp->bio_flags |= BIO_ONQUEUE; 858 TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue); 859 g_bio_run_task.bio_queue_length++; 860 wakeup(&g_wait_up); 861 g_bioq_unlock(&g_bio_run_up); 862} 863 864 865void 866g_io_schedule_up(struct thread *tp __unused) 867{ 868 struct bio *bp; 869 for(;;) { 870 g_bioq_lock(&g_bio_run_up); 871 bp = g_bioq_first(&g_bio_run_task); 872 if (bp != NULL) { 873 g_bioq_unlock(&g_bio_run_up); 874 THREAD_NO_SLEEPING(); 875 CTR1(KTR_GEOM, "g_up processing task bp %p", bp); 876 bp->bio_task(bp->bio_task_arg); 877 THREAD_SLEEPING_OK(); 878 continue; 879 } 880 bp = g_bioq_first(&g_bio_run_up); 881 if (bp != NULL) { 882 g_bioq_unlock(&g_bio_run_up); 883 THREAD_NO_SLEEPING(); 884 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off " 885 "%jd len %ld", bp, bp->bio_to->name, 886 bp->bio_offset, bp->bio_length); 887 biodone(bp); 888 THREAD_SLEEPING_OK(); 889 continue; 890 } 891 CTR0(KTR_GEOM, "g_up going to sleep"); 892 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock, 893 PRIBIO | PDROP, "-", 0); 894 } 895} 896 897void * 898g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 899{ 900 struct bio *bp; 901 void *ptr; 902 int errorc; 903 904 KASSERT(length > 0 && length >= cp->provider->sectorsize && 905 length <= MAXPHYS, ("g_read_data(): invalid length %jd", 906 (intmax_t)length)); 907 908 bp = g_alloc_bio(); 909 bp->bio_cmd = BIO_READ; 910 bp->bio_done = NULL; 911 bp->bio_offset = offset; 912 bp->bio_length = length; 913 ptr = g_malloc(length, M_WAITOK); 914 bp->bio_data = ptr; 915 g_io_request(bp, cp); 916 errorc = biowait(bp, "gread"); 917 if (error != NULL) 918 *error = errorc; 919 g_destroy_bio(bp); 920 if (errorc) { 921 g_free(ptr); 922 ptr = NULL; 923 } 924 return (ptr); 925} 926 927int 928g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length) 929{ 930 struct bio *bp; 931 int error; 932 933 KASSERT(length > 0 && length >= cp->provider->sectorsize && 934 length <= MAXPHYS, ("g_write_data(): invalid length %jd", 935 (intmax_t)length)); 936 937 bp = g_alloc_bio(); 938 bp->bio_cmd = BIO_WRITE; 939 bp->bio_done = NULL; 940 bp->bio_offset = offset; 941 bp->bio_length = length; 942 bp->bio_data = ptr; 943 g_io_request(bp, cp); 944 error = biowait(bp, "gwrite"); 945 g_destroy_bio(bp); 946 return (error); 947} 948 949int 950g_delete_data(struct g_consumer *cp, off_t offset, off_t length) 951{ 952 struct bio *bp; 953 int error; 954 955 KASSERT(length > 0 && length >= cp->provider->sectorsize, 956 ("g_delete_data(): invalid length %jd", (intmax_t)length)); 957 958 bp = g_alloc_bio(); 959 bp->bio_cmd = BIO_DELETE; 960 bp->bio_done = NULL; 961 bp->bio_offset = offset; 962 bp->bio_length = length; 963 bp->bio_data = NULL; 964 g_io_request(bp, cp); 965 error = biowait(bp, "gdelete"); 966 g_destroy_bio(bp); 967 return (error); 968} 969 970void 971g_print_bio(struct bio *bp) 972{ 973 const char *pname, *cmd = NULL; 974 975 if (bp->bio_to != NULL) 976 pname = bp->bio_to->name; 977 else 978 pname = "[unknown]"; 979 980 switch (bp->bio_cmd) { 981 case BIO_GETATTR: 982 cmd = "GETATTR"; 983 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute); 984 return; 985 case BIO_FLUSH: 986 cmd = "FLUSH"; 987 printf("%s[%s]", pname, cmd); 988 return; 989 case BIO_READ: 990 cmd = "READ"; 991 break; 992 case BIO_WRITE: 993 cmd = "WRITE"; 994 break; 995 case BIO_DELETE: 996 cmd = "DELETE"; 997 break; 998 default: 999 cmd = "UNKNOWN"; 1000 printf("%s[%s()]", pname, cmd); 1001 return; 1002 } 1003 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd, 1004 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 1005} 1006