Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/geom/geom_io.c
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1 /*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * Copyright (c) 2013 The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 8 * and NAI Labs, the Security Research Division of Network Associates, Inc. 9 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 10 * DARPA CHATS research program. 11 * 12 * Portions of this software were developed by Konstantin Belousov 13 * under sponsorship from the FreeBSD Foundation. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 3. The names of the authors may not be used to endorse or promote 24 * products derived from this software without specific prior written 25 * permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD: releng/11.2/sys/geom/geom_io.c 300207 2016-05-19 14:08:36Z ken $"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/malloc.h> 47 #include <sys/bio.h> 48 #include <sys/ktr.h> 49 #include <sys/proc.h> 50 #include <sys/stack.h> 51 #include <sys/sysctl.h> 52 #include <sys/vmem.h> 53 54 #include <sys/errno.h> 55 #include <geom/geom.h> 56 #include <geom/geom_int.h> 57 #include <sys/devicestat.h> 58 59 #include <vm/uma.h> 60 #include <vm/vm.h> 61 #include <vm/vm_param.h> 62 #include <vm/vm_kern.h> 63 #include <vm/vm_page.h> 64 #include <vm/vm_object.h> 65 #include <vm/vm_extern.h> 66 #include <vm/vm_map.h> 67 68 static int g_io_transient_map_bio(struct bio *bp); 69 70 static struct g_bioq g_bio_run_down; 71 static struct g_bioq g_bio_run_up; 72 static struct g_bioq g_bio_run_task; 73 74 /* 75 * Pace is a hint that we've had some trouble recently allocating 76 * bios, so we should back off trying to send I/O down the stack 77 * a bit to let the problem resolve. When pacing, we also turn 78 * off direct dispatch to also reduce memory pressure from I/Os 79 * there, at the expxense of some added latency while the memory 80 * pressures exist. See g_io_schedule_down() for more details 81 * and limitations. 82 */ 83 static volatile u_int pace; 84 85 static uma_zone_t biozone; 86 87 /* 88 * The head of the list of classifiers used in g_io_request. 89 * Use g_register_classifier() and g_unregister_classifier() 90 * to add/remove entries to the list. 91 * Classifiers are invoked in registration order. 92 */ 93 static TAILQ_HEAD(g_classifier_tailq, g_classifier_hook) 94 g_classifier_tailq = TAILQ_HEAD_INITIALIZER(g_classifier_tailq); 95 96 #include <machine/atomic.h> 97 98 static void 99 g_bioq_lock(struct g_bioq *bq) 100 { 101 102 mtx_lock(&bq->bio_queue_lock); 103 } 104 105 static void 106 g_bioq_unlock(struct g_bioq *bq) 107 { 108 109 mtx_unlock(&bq->bio_queue_lock); 110 } 111 112 #if 0 113 static void 114 g_bioq_destroy(struct g_bioq *bq) 115 { 116 117 mtx_destroy(&bq->bio_queue_lock); 118 } 119 #endif 120 121 static void 122 g_bioq_init(struct g_bioq *bq) 123 { 124 125 TAILQ_INIT(&bq->bio_queue); 126 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 127 } 128 129 static struct bio * 130 g_bioq_first(struct g_bioq *bq) 131 { 132 struct bio *bp; 133 134 bp = TAILQ_FIRST(&bq->bio_queue); 135 if (bp != NULL) { 136 KASSERT((bp->bio_flags & BIO_ONQUEUE), 137 ("Bio not on queue bp=%p target %p", bp, bq)); 138 bp->bio_flags &= ~BIO_ONQUEUE; 139 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 140 bq->bio_queue_length--; 141 } 142 return (bp); 143 } 144 145 struct bio * 146 g_new_bio(void) 147 { 148 struct bio *bp; 149 150 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 151 #ifdef KTR 152 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 153 struct stack st; 154 155 CTR1(KTR_GEOM, "g_new_bio(): %p", bp); 156 stack_save(&st); 157 CTRSTACK(KTR_GEOM, &st, 3, 0); 158 } 159 #endif 160 return (bp); 161 } 162 163 struct bio * 164 g_alloc_bio(void) 165 { 166 struct bio *bp; 167 168 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO); 169 #ifdef KTR 170 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 171 struct stack st; 172 173 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp); 174 stack_save(&st); 175 CTRSTACK(KTR_GEOM, &st, 3, 0); 176 } 177 #endif 178 return (bp); 179 } 180 181 void 182 g_destroy_bio(struct bio *bp) 183 { 184 #ifdef KTR 185 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 186 struct stack st; 187 188 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp); 189 stack_save(&st); 190 CTRSTACK(KTR_GEOM, &st, 3, 0); 191 } 192 #endif 193 uma_zfree(biozone, bp); 194 } 195 196 struct bio * 197 g_clone_bio(struct bio *bp) 198 { 199 struct bio *bp2; 200 201 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 202 if (bp2 != NULL) { 203 bp2->bio_parent = bp; 204 bp2->bio_cmd = bp->bio_cmd; 205 /* 206 * BIO_ORDERED flag may be used by disk drivers to enforce 207 * ordering restrictions, so this flag needs to be cloned. 208 * BIO_UNMAPPED and BIO_VLIST should be inherited, to properly 209 * indicate which way the buffer is passed. 210 * Other bio flags are not suitable for cloning. 211 */ 212 bp2->bio_flags = bp->bio_flags & 213 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST); 214 bp2->bio_length = bp->bio_length; 215 bp2->bio_offset = bp->bio_offset; 216 bp2->bio_data = bp->bio_data; 217 bp2->bio_ma = bp->bio_ma; 218 bp2->bio_ma_n = bp->bio_ma_n; 219 bp2->bio_ma_offset = bp->bio_ma_offset; 220 bp2->bio_attribute = bp->bio_attribute; 221 if (bp->bio_cmd == BIO_ZONE) 222 bcopy(&bp->bio_zone, &bp2->bio_zone, 223 sizeof(bp->bio_zone)); 224 /* Inherit classification info from the parent */ 225 bp2->bio_classifier1 = bp->bio_classifier1; 226 bp2->bio_classifier2 = bp->bio_classifier2; 227 bp->bio_children++; 228 } 229 #ifdef KTR 230 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 231 struct stack st; 232 233 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2); 234 stack_save(&st); 235 CTRSTACK(KTR_GEOM, &st, 3, 0); 236 } 237 #endif 238 return(bp2); 239 } 240 241 struct bio * 242 g_duplicate_bio(struct bio *bp) 243 { 244 struct bio *bp2; 245 246 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO); 247 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST); 248 bp2->bio_parent = bp; 249 bp2->bio_cmd = bp->bio_cmd; 250 bp2->bio_length = bp->bio_length; 251 bp2->bio_offset = bp->bio_offset; 252 bp2->bio_data = bp->bio_data; 253 bp2->bio_ma = bp->bio_ma; 254 bp2->bio_ma_n = bp->bio_ma_n; 255 bp2->bio_ma_offset = bp->bio_ma_offset; 256 bp2->bio_attribute = bp->bio_attribute; 257 bp->bio_children++; 258 #ifdef KTR 259 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 260 struct stack st; 261 262 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2); 263 stack_save(&st); 264 CTRSTACK(KTR_GEOM, &st, 3, 0); 265 } 266 #endif 267 return(bp2); 268 } 269 270 void 271 g_reset_bio(struct bio *bp) 272 { 273 274 bzero(bp, sizeof(*bp)); 275 } 276 277 void 278 g_io_init() 279 { 280 281 g_bioq_init(&g_bio_run_down); 282 g_bioq_init(&g_bio_run_up); 283 g_bioq_init(&g_bio_run_task); 284 biozone = uma_zcreate("g_bio", sizeof (struct bio), 285 NULL, NULL, 286 NULL, NULL, 287 0, 0); 288 } 289 290 int 291 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 292 { 293 struct bio *bp; 294 int error; 295 296 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 297 bp = g_alloc_bio(); 298 bp->bio_cmd = BIO_GETATTR; 299 bp->bio_done = NULL; 300 bp->bio_attribute = attr; 301 bp->bio_length = *len; 302 bp->bio_data = ptr; 303 g_io_request(bp, cp); 304 error = biowait(bp, "ggetattr"); 305 *len = bp->bio_completed; 306 g_destroy_bio(bp); 307 return (error); 308 } 309 310 int 311 g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp) 312 { 313 struct bio *bp; 314 int error; 315 316 g_trace(G_T_BIO, "bio_zone(%d)", zone_args->zone_cmd); 317 bp = g_alloc_bio(); 318 bp->bio_cmd = BIO_ZONE; 319 bp->bio_done = NULL; 320 /* 321 * XXX KDM need to handle report zone data. 322 */ 323 bcopy(zone_args, &bp->bio_zone, sizeof(*zone_args)); 324 if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES) 325 bp->bio_length = 326 zone_args->zone_params.report.entries_allocated * 327 sizeof(struct disk_zone_rep_entry); 328 else 329 bp->bio_length = 0; 330 331 g_io_request(bp, cp); 332 error = biowait(bp, "gzone"); 333 bcopy(&bp->bio_zone, zone_args, sizeof(*zone_args)); 334 g_destroy_bio(bp); 335 return (error); 336 } 337 338 int 339 g_io_flush(struct g_consumer *cp) 340 { 341 struct bio *bp; 342 int error; 343 344 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name); 345 bp = g_alloc_bio(); 346 bp->bio_cmd = BIO_FLUSH; 347 bp->bio_flags |= BIO_ORDERED; 348 bp->bio_done = NULL; 349 bp->bio_attribute = NULL; 350 bp->bio_offset = cp->provider->mediasize; 351 bp->bio_length = 0; 352 bp->bio_data = NULL; 353 g_io_request(bp, cp); 354 error = biowait(bp, "gflush"); 355 g_destroy_bio(bp); 356 return (error); 357 } 358 359 static int 360 g_io_check(struct bio *bp) 361 { 362 struct g_consumer *cp; 363 struct g_provider *pp; 364 off_t excess; 365 int error; 366 367 cp = bp->bio_from; 368 pp = bp->bio_to; 369 370 /* Fail if access counters dont allow the operation */ 371 switch(bp->bio_cmd) { 372 case BIO_READ: 373 case BIO_GETATTR: 374 if (cp->acr == 0) 375 return (EPERM); 376 break; 377 case BIO_WRITE: 378 case BIO_DELETE: 379 case BIO_FLUSH: 380 if (cp->acw == 0) 381 return (EPERM); 382 break; 383 case BIO_ZONE: 384 if ((bp->bio_zone.zone_cmd == DISK_ZONE_REPORT_ZONES) || 385 (bp->bio_zone.zone_cmd == DISK_ZONE_GET_PARAMS)) { 386 if (cp->acr == 0) 387 return (EPERM); 388 } else if (cp->acw == 0) 389 return (EPERM); 390 break; 391 default: 392 return (EPERM); 393 } 394 /* if provider is marked for error, don't disturb. */ 395 if (pp->error) 396 return (pp->error); 397 if (cp->flags & G_CF_ORPHAN) 398 return (ENXIO); 399 400 switch(bp->bio_cmd) { 401 case BIO_READ: 402 case BIO_WRITE: 403 case BIO_DELETE: 404 /* Zero sectorsize or mediasize is probably a lack of media. */ 405 if (pp->sectorsize == 0 || pp->mediasize == 0) 406 return (ENXIO); 407 /* Reject I/O not on sector boundary */ 408 if (bp->bio_offset % pp->sectorsize) 409 return (EINVAL); 410 /* Reject I/O not integral sector long */ 411 if (bp->bio_length % pp->sectorsize) 412 return (EINVAL); 413 /* Reject requests before or past the end of media. */ 414 if (bp->bio_offset < 0) 415 return (EIO); 416 if (bp->bio_offset > pp->mediasize) 417 return (EIO); 418 419 /* Truncate requests to the end of providers media. */ 420 excess = bp->bio_offset + bp->bio_length; 421 if (excess > bp->bio_to->mediasize) { 422 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 || 423 round_page(bp->bio_ma_offset + 424 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n, 425 ("excess bio %p too short", bp)); 426 excess -= bp->bio_to->mediasize; 427 bp->bio_length -= excess; 428 if ((bp->bio_flags & BIO_UNMAPPED) != 0) { 429 bp->bio_ma_n = round_page(bp->bio_ma_offset + 430 bp->bio_length) / PAGE_SIZE; 431 } 432 if (excess > 0) 433 CTR3(KTR_GEOM, "g_down truncated bio " 434 "%p provider %s by %d", bp, 435 bp->bio_to->name, excess); 436 } 437 438 /* Deliver zero length transfers right here. */ 439 if (bp->bio_length == 0) { 440 CTR2(KTR_GEOM, "g_down terminated 0-length " 441 "bp %p provider %s", bp, bp->bio_to->name); 442 return (0); 443 } 444 445 if ((bp->bio_flags & BIO_UNMAPPED) != 0 && 446 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 && 447 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 448 if ((error = g_io_transient_map_bio(bp)) >= 0) 449 return (error); 450 } 451 break; 452 default: 453 break; 454 } 455 return (EJUSTRETURN); 456 } 457 458 /* 459 * bio classification support. 460 * 461 * g_register_classifier() and g_unregister_classifier() 462 * are used to add/remove a classifier from the list. 463 * The list is protected using the g_bio_run_down lock, 464 * because the classifiers are called in this path. 465 * 466 * g_io_request() passes bio's that are not already classified 467 * (i.e. those with bio_classifier1 == NULL) to g_run_classifiers(). 468 * Classifiers can store their result in the two fields 469 * bio_classifier1 and bio_classifier2. 470 * A classifier that updates one of the fields should 471 * return a non-zero value. 472 * If no classifier updates the field, g_run_classifiers() sets 473 * bio_classifier1 = BIO_NOTCLASSIFIED to avoid further calls. 474 */ 475 476 int 477 g_register_classifier(struct g_classifier_hook *hook) 478 { 479 480 g_bioq_lock(&g_bio_run_down); 481 TAILQ_INSERT_TAIL(&g_classifier_tailq, hook, link); 482 g_bioq_unlock(&g_bio_run_down); 483 484 return (0); 485 } 486 487 void 488 g_unregister_classifier(struct g_classifier_hook *hook) 489 { 490 struct g_classifier_hook *entry; 491 492 g_bioq_lock(&g_bio_run_down); 493 TAILQ_FOREACH(entry, &g_classifier_tailq, link) { 494 if (entry == hook) { 495 TAILQ_REMOVE(&g_classifier_tailq, hook, link); 496 break; 497 } 498 } 499 g_bioq_unlock(&g_bio_run_down); 500 } 501 502 static void 503 g_run_classifiers(struct bio *bp) 504 { 505 struct g_classifier_hook *hook; 506 int classified = 0; 507 508 TAILQ_FOREACH(hook, &g_classifier_tailq, link) 509 classified |= hook->func(hook->arg, bp); 510 511 if (!classified) 512 bp->bio_classifier1 = BIO_NOTCLASSIFIED; 513 } 514 515 void 516 g_io_request(struct bio *bp, struct g_consumer *cp) 517 { 518 struct g_provider *pp; 519 struct mtx *mtxp; 520 int direct, error, first; 521 uint8_t cmd; 522 523 KASSERT(cp != NULL, ("NULL cp in g_io_request")); 524 KASSERT(bp != NULL, ("NULL bp in g_io_request")); 525 pp = cp->provider; 526 KASSERT(pp != NULL, ("consumer not attached in g_io_request")); 527 #ifdef DIAGNOSTIC 528 KASSERT(bp->bio_driver1 == NULL, 529 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name)); 530 KASSERT(bp->bio_driver2 == NULL, 531 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name)); 532 KASSERT(bp->bio_pflags == 0, 533 ("bio_pflags used by the consumer (geom %s)", cp->geom->name)); 534 /* 535 * Remember consumer's private fields, so we can detect if they were 536 * modified by the provider. 537 */ 538 bp->_bio_caller1 = bp->bio_caller1; 539 bp->_bio_caller2 = bp->bio_caller2; 540 bp->_bio_cflags = bp->bio_cflags; 541 #endif 542 543 cmd = bp->bio_cmd; 544 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) { 545 KASSERT(bp->bio_data != NULL, 546 ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd)); 547 } 548 if (cmd == BIO_DELETE || cmd == BIO_FLUSH) { 549 KASSERT(bp->bio_data == NULL, 550 ("non-NULL bp->data in g_io_request(cmd=%hu)", 551 bp->bio_cmd)); 552 } 553 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) { 554 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0, 555 ("wrong offset %jd for sectorsize %u", 556 bp->bio_offset, cp->provider->sectorsize)); 557 KASSERT(bp->bio_length % cp->provider->sectorsize == 0, 558 ("wrong length %jd for sectorsize %u", 559 bp->bio_length, cp->provider->sectorsize)); 560 } 561 562 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 563 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd); 564 565 bp->bio_from = cp; 566 bp->bio_to = pp; 567 bp->bio_error = 0; 568 bp->bio_completed = 0; 569 570 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 571 ("Bio already on queue bp=%p", bp)); 572 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 573 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 574 binuptime(&bp->bio_t0); 575 else 576 getbinuptime(&bp->bio_t0); 577 578 #ifdef GET_STACK_USAGE 579 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 && 580 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 && 581 !g_is_geom_thread(curthread) && 582 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 || 583 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) && 584 pace == 0; 585 if (direct) { 586 /* Block direct execution if less then half of stack left. */ 587 size_t st, su; 588 GET_STACK_USAGE(st, su); 589 if (su * 2 > st) 590 direct = 0; 591 } 592 #else 593 direct = 0; 594 #endif 595 596 if (!TAILQ_EMPTY(&g_classifier_tailq) && !bp->bio_classifier1) { 597 g_bioq_lock(&g_bio_run_down); 598 g_run_classifiers(bp); 599 g_bioq_unlock(&g_bio_run_down); 600 } 601 602 /* 603 * The statistics collection is lockless, as such, but we 604 * can not update one instance of the statistics from more 605 * than one thread at a time, so grab the lock first. 606 */ 607 mtxp = mtx_pool_find(mtxpool_sleep, pp); 608 mtx_lock(mtxp); 609 if (g_collectstats & G_STATS_PROVIDERS) 610 devstat_start_transaction(pp->stat, &bp->bio_t0); 611 if (g_collectstats & G_STATS_CONSUMERS) 612 devstat_start_transaction(cp->stat, &bp->bio_t0); 613 pp->nstart++; 614 cp->nstart++; 615 mtx_unlock(mtxp); 616 617 if (direct) { 618 error = g_io_check(bp); 619 if (error >= 0) { 620 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p " 621 "provider %s returned %d", bp, bp->bio_to->name, 622 error); 623 g_io_deliver(bp, error); 624 return; 625 } 626 bp->bio_to->geom->start(bp); 627 } else { 628 g_bioq_lock(&g_bio_run_down); 629 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue); 630 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue); 631 bp->bio_flags |= BIO_ONQUEUE; 632 g_bio_run_down.bio_queue_length++; 633 g_bioq_unlock(&g_bio_run_down); 634 /* Pass it on down. */ 635 if (first) 636 wakeup(&g_wait_down); 637 } 638 } 639 640 void 641 g_io_deliver(struct bio *bp, int error) 642 { 643 struct bintime now; 644 struct g_consumer *cp; 645 struct g_provider *pp; 646 struct mtx *mtxp; 647 int direct, first; 648 649 KASSERT(bp != NULL, ("NULL bp in g_io_deliver")); 650 pp = bp->bio_to; 651 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver")); 652 cp = bp->bio_from; 653 if (cp == NULL) { 654 bp->bio_error = error; 655 bp->bio_done(bp); 656 return; 657 } 658 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver")); 659 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver")); 660 #ifdef DIAGNOSTIC 661 /* 662 * Some classes - GJournal in particular - can modify bio's 663 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO 664 * flag means it's an expected behaviour for that particular geom. 665 */ 666 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) { 667 KASSERT(bp->bio_caller1 == bp->_bio_caller1, 668 ("bio_caller1 used by the provider %s", pp->name)); 669 KASSERT(bp->bio_caller2 == bp->_bio_caller2, 670 ("bio_caller2 used by the provider %s", pp->name)); 671 KASSERT(bp->bio_cflags == bp->_bio_cflags, 672 ("bio_cflags used by the provider %s", pp->name)); 673 } 674 #endif 675 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0")); 676 KASSERT(bp->bio_completed <= bp->bio_length, 677 ("bio_completed can't be greater than bio_length")); 678 679 g_trace(G_T_BIO, 680 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd", 681 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error, 682 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 683 684 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 685 ("Bio already on queue bp=%p", bp)); 686 687 /* 688 * XXX: next two doesn't belong here 689 */ 690 bp->bio_bcount = bp->bio_length; 691 bp->bio_resid = bp->bio_bcount - bp->bio_completed; 692 693 #ifdef GET_STACK_USAGE 694 direct = (pp->flags & G_PF_DIRECT_SEND) && 695 (cp->flags & G_CF_DIRECT_RECEIVE) && 696 !g_is_geom_thread(curthread); 697 if (direct) { 698 /* Block direct execution if less then half of stack left. */ 699 size_t st, su; 700 GET_STACK_USAGE(st, su); 701 if (su * 2 > st) 702 direct = 0; 703 } 704 #else 705 direct = 0; 706 #endif 707 708 /* 709 * The statistics collection is lockless, as such, but we 710 * can not update one instance of the statistics from more 711 * than one thread at a time, so grab the lock first. 712 */ 713 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 714 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 715 binuptime(&now); 716 mtxp = mtx_pool_find(mtxpool_sleep, cp); 717 mtx_lock(mtxp); 718 if (g_collectstats & G_STATS_PROVIDERS) 719 devstat_end_transaction_bio_bt(pp->stat, bp, &now); 720 if (g_collectstats & G_STATS_CONSUMERS) 721 devstat_end_transaction_bio_bt(cp->stat, bp, &now); 722 cp->nend++; 723 pp->nend++; 724 mtx_unlock(mtxp); 725 726 if (error != ENOMEM) { 727 bp->bio_error = error; 728 if (direct) { 729 biodone(bp); 730 } else { 731 g_bioq_lock(&g_bio_run_up); 732 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue); 733 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue); 734 bp->bio_flags |= BIO_ONQUEUE; 735 g_bio_run_up.bio_queue_length++; 736 g_bioq_unlock(&g_bio_run_up); 737 if (first) 738 wakeup(&g_wait_up); 739 } 740 return; 741 } 742 743 if (bootverbose) 744 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name); 745 bp->bio_children = 0; 746 bp->bio_inbed = 0; 747 bp->bio_driver1 = NULL; 748 bp->bio_driver2 = NULL; 749 bp->bio_pflags = 0; 750 g_io_request(bp, cp); 751 pace = 1; 752 return; 753 } 754 755 SYSCTL_DECL(_kern_geom); 756 757 static long transient_maps; 758 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD, 759 &transient_maps, 0, 760 "Total count of the transient mapping requests"); 761 u_int transient_map_retries = 10; 762 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW, 763 &transient_map_retries, 0, 764 "Max count of retries used before giving up on creating transient map"); 765 int transient_map_hard_failures; 766 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD, 767 &transient_map_hard_failures, 0, 768 "Failures to establish the transient mapping due to retry attempts " 769 "exhausted"); 770 int transient_map_soft_failures; 771 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD, 772 &transient_map_soft_failures, 0, 773 "Count of retried failures to establish the transient mapping"); 774 int inflight_transient_maps; 775 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD, 776 &inflight_transient_maps, 0, 777 "Current count of the active transient maps"); 778 779 static int 780 g_io_transient_map_bio(struct bio *bp) 781 { 782 vm_offset_t addr; 783 long size; 784 u_int retried; 785 786 KASSERT(unmapped_buf_allowed, ("unmapped disabled")); 787 788 size = round_page(bp->bio_ma_offset + bp->bio_length); 789 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp)); 790 addr = 0; 791 retried = 0; 792 atomic_add_long(&transient_maps, 1); 793 retry: 794 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) { 795 if (transient_map_retries != 0 && 796 retried >= transient_map_retries) { 797 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s", 798 bp, bp->bio_to->name); 799 atomic_add_int(&transient_map_hard_failures, 1); 800 return (EDEADLK/* XXXKIB */); 801 } else { 802 /* 803 * Naive attempt to quisce the I/O to get more 804 * in-flight requests completed and defragment 805 * the transient_arena. 806 */ 807 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d", 808 bp, bp->bio_to->name, retried); 809 pause("g_d_tra", hz / 10); 810 retried++; 811 atomic_add_int(&transient_map_soft_failures, 1); 812 goto retry; 813 } 814 } 815 atomic_add_int(&inflight_transient_maps, 1); 816 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size)); 817 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset; 818 bp->bio_flags |= BIO_TRANSIENT_MAPPING; 819 bp->bio_flags &= ~BIO_UNMAPPED; 820 return (EJUSTRETURN); 821 } 822 823 void 824 g_io_schedule_down(struct thread *tp __unused) 825 { 826 struct bio *bp; 827 int error; 828 829 for(;;) { 830 g_bioq_lock(&g_bio_run_down); 831 bp = g_bioq_first(&g_bio_run_down); 832 if (bp == NULL) { 833 CTR0(KTR_GEOM, "g_down going to sleep"); 834 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock, 835 PRIBIO | PDROP, "-", 0); 836 continue; 837 } 838 CTR0(KTR_GEOM, "g_down has work to do"); 839 g_bioq_unlock(&g_bio_run_down); 840 if (pace != 0) { 841 /* 842 * There has been at least one memory allocation 843 * failure since the last I/O completed. Pause 1ms to 844 * give the system a chance to free up memory. We only 845 * do this once because a large number of allocations 846 * can fail in the direct dispatch case and there's no 847 * relationship between the number of these failures and 848 * the length of the outage. If there's still an outage, 849 * we'll pause again and again until it's 850 * resolved. Older versions paused longer and once per 851 * allocation failure. This was OK for a single threaded 852 * g_down, but with direct dispatch would lead to max of 853 * 10 IOPs for minutes at a time when transient memory 854 * issues prevented allocation for a batch of requests 855 * from the upper layers. 856 * 857 * XXX This pacing is really lame. It needs to be solved 858 * by other methods. This is OK only because the worst 859 * case scenario is so rare. In the worst case scenario 860 * all memory is tied up waiting for I/O to complete 861 * which can never happen since we can't allocate bios 862 * for that I/O. 863 */ 864 CTR0(KTR_GEOM, "g_down pacing self"); 865 pause("g_down", min(hz/1000, 1)); 866 pace = 0; 867 } 868 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp, 869 bp->bio_to->name); 870 error = g_io_check(bp); 871 if (error >= 0) { 872 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider " 873 "%s returned %d", bp, bp->bio_to->name, error); 874 g_io_deliver(bp, error); 875 continue; 876 } 877 THREAD_NO_SLEEPING(); 878 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld " 879 "len %ld", bp, bp->bio_to->name, bp->bio_offset, 880 bp->bio_length); 881 bp->bio_to->geom->start(bp); 882 THREAD_SLEEPING_OK(); 883 } 884 } 885 886 void 887 bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg) 888 { 889 bp->bio_task = func; 890 bp->bio_task_arg = arg; 891 /* 892 * The taskqueue is actually just a second queue off the "up" 893 * queue, so we use the same lock. 894 */ 895 g_bioq_lock(&g_bio_run_up); 896 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 897 ("Bio already on queue bp=%p target taskq", bp)); 898 bp->bio_flags |= BIO_ONQUEUE; 899 TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue); 900 g_bio_run_task.bio_queue_length++; 901 wakeup(&g_wait_up); 902 g_bioq_unlock(&g_bio_run_up); 903 } 904 905 906 void 907 g_io_schedule_up(struct thread *tp __unused) 908 { 909 struct bio *bp; 910 for(;;) { 911 g_bioq_lock(&g_bio_run_up); 912 bp = g_bioq_first(&g_bio_run_task); 913 if (bp != NULL) { 914 g_bioq_unlock(&g_bio_run_up); 915 THREAD_NO_SLEEPING(); 916 CTR1(KTR_GEOM, "g_up processing task bp %p", bp); 917 bp->bio_task(bp->bio_task_arg); 918 THREAD_SLEEPING_OK(); 919 continue; 920 } 921 bp = g_bioq_first(&g_bio_run_up); 922 if (bp != NULL) { 923 g_bioq_unlock(&g_bio_run_up); 924 THREAD_NO_SLEEPING(); 925 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off " 926 "%jd len %ld", bp, bp->bio_to->name, 927 bp->bio_offset, bp->bio_length); 928 biodone(bp); 929 THREAD_SLEEPING_OK(); 930 continue; 931 } 932 CTR0(KTR_GEOM, "g_up going to sleep"); 933 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock, 934 PRIBIO | PDROP, "-", 0); 935 } 936 } 937 938 void * 939 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 940 { 941 struct bio *bp; 942 void *ptr; 943 int errorc; 944 945 KASSERT(length > 0 && length >= cp->provider->sectorsize && 946 length <= MAXPHYS, ("g_read_data(): invalid length %jd", 947 (intmax_t)length)); 948 949 bp = g_alloc_bio(); 950 bp->bio_cmd = BIO_READ; 951 bp->bio_done = NULL; 952 bp->bio_offset = offset; 953 bp->bio_length = length; 954 ptr = g_malloc(length, M_WAITOK); 955 bp->bio_data = ptr; 956 g_io_request(bp, cp); 957 errorc = biowait(bp, "gread"); 958 if (error != NULL) 959 *error = errorc; 960 g_destroy_bio(bp); 961 if (errorc) { 962 g_free(ptr); 963 ptr = NULL; 964 } 965 return (ptr); 966 } 967 968 int 969 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length) 970 { 971 struct bio *bp; 972 int error; 973 974 KASSERT(length > 0 && length >= cp->provider->sectorsize && 975 length <= MAXPHYS, ("g_write_data(): invalid length %jd", 976 (intmax_t)length)); 977 978 bp = g_alloc_bio(); 979 bp->bio_cmd = BIO_WRITE; 980 bp->bio_done = NULL; 981 bp->bio_offset = offset; 982 bp->bio_length = length; 983 bp->bio_data = ptr; 984 g_io_request(bp, cp); 985 error = biowait(bp, "gwrite"); 986 g_destroy_bio(bp); 987 return (error); 988 } 989 990 int 991 g_delete_data(struct g_consumer *cp, off_t offset, off_t length) 992 { 993 struct bio *bp; 994 int error; 995 996 KASSERT(length > 0 && length >= cp->provider->sectorsize, 997 ("g_delete_data(): invalid length %jd", (intmax_t)length)); 998 999 bp = g_alloc_bio(); 1000 bp->bio_cmd = BIO_DELETE; 1001 bp->bio_done = NULL; 1002 bp->bio_offset = offset; 1003 bp->bio_length = length; 1004 bp->bio_data = NULL; 1005 g_io_request(bp, cp); 1006 error = biowait(bp, "gdelete"); 1007 g_destroy_bio(bp); 1008 return (error); 1009 } 1010 1011 void 1012 g_print_bio(struct bio *bp) 1013 { 1014 const char *pname, *cmd = NULL; 1015 1016 if (bp->bio_to != NULL) 1017 pname = bp->bio_to->name; 1018 else 1019 pname = "[unknown]"; 1020 1021 switch (bp->bio_cmd) { 1022 case BIO_GETATTR: 1023 cmd = "GETATTR"; 1024 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute); 1025 return; 1026 case BIO_FLUSH: 1027 cmd = "FLUSH"; 1028 printf("%s[%s]", pname, cmd); 1029 return; 1030 case BIO_ZONE: { 1031 char *subcmd = NULL; 1032 cmd = "ZONE"; 1033 switch (bp->bio_zone.zone_cmd) { 1034 case DISK_ZONE_OPEN: 1035 subcmd = "OPEN"; 1036 break; 1037 case DISK_ZONE_CLOSE: 1038 subcmd = "CLOSE"; 1039 break; 1040 case DISK_ZONE_FINISH: 1041 subcmd = "FINISH"; 1042 break; 1043 case DISK_ZONE_RWP: 1044 subcmd = "RWP"; 1045 break; 1046 case DISK_ZONE_REPORT_ZONES: 1047 subcmd = "REPORT ZONES"; 1048 break; 1049 case DISK_ZONE_GET_PARAMS: 1050 subcmd = "GET PARAMS"; 1051 break; 1052 default: 1053 subcmd = "UNKNOWN"; 1054 break; 1055 } 1056 printf("%s[%s,%s]", pname, cmd, subcmd); 1057 return; 1058 } 1059 case BIO_READ: 1060 cmd = "READ"; 1061 break; 1062 case BIO_WRITE: 1063 cmd = "WRITE"; 1064 break; 1065 case BIO_DELETE: 1066 cmd = "DELETE"; 1067 break; 1068 default: 1069 cmd = "UNKNOWN"; 1070 printf("%s[%s()]", pname, cmd); 1071 return; 1072 } 1073 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd, 1074 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 1075 }
Cache object: 5e1dae0fae394476c322325de14db185
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