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 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2002 Poul-Henning Kamp 5 * Copyright (c) 2002 Networks Associates Technology, Inc. 6 * Copyright (c) 2013 The FreeBSD Foundation 7 * All rights reserved. 8 * 9 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 10 * and NAI Labs, the Security Research Division of Network Associates, Inc. 11 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 12 * DARPA CHATS research program. 13 * 14 * Portions of this software were developed by Konstantin Belousov 15 * under sponsorship from the FreeBSD Foundation. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 3. The names of the authors may not be used to endorse or promote 26 * products derived from this software without specific prior written 27 * permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 */ 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/malloc.h> 49 #include <sys/bio.h> 50 #include <sys/ktr.h> 51 #include <sys/proc.h> 52 #include <sys/stack.h> 53 #include <sys/sysctl.h> 54 #include <sys/vmem.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 static int g_io_transient_map_bio(struct bio *bp); 71 72 static struct g_bioq g_bio_run_down; 73 static struct g_bioq g_bio_run_up; 74 75 /* 76 * Pace is a hint that we've had some trouble recently allocating 77 * bios, so we should back off trying to send I/O down the stack 78 * a bit to let the problem resolve. When pacing, we also turn 79 * off direct dispatch to also reduce memory pressure from I/Os 80 * there, at the expxense of some added latency while the memory 81 * pressures exist. See g_io_schedule_down() for more details 82 * and limitations. 83 */ 84 static volatile u_int __read_mostly pace; 85 86 static uma_zone_t __read_mostly biozone; 87 88 /* 89 * The head of the list of classifiers used in g_io_request. 90 * Use g_register_classifier() and g_unregister_classifier() 91 * to add/remove entries to the list. 92 * Classifiers are invoked in registration order. 93 */ 94 static TAILQ_HEAD(, g_classifier_hook) g_classifier_tailq __read_mostly = 95 TAILQ_HEAD_INITIALIZER(g_classifier_tailq); 96 97 #include <machine/atomic.h> 98 99 static void 100 g_bioq_lock(struct g_bioq *bq) 101 { 102 103 mtx_lock(&bq->bio_queue_lock); 104 } 105 106 static void 107 g_bioq_unlock(struct g_bioq *bq) 108 { 109 110 mtx_unlock(&bq->bio_queue_lock); 111 } 112 113 #if 0 114 static void 115 g_bioq_destroy(struct g_bioq *bq) 116 { 117 118 mtx_destroy(&bq->bio_queue_lock); 119 } 120 #endif 121 122 static void 123 g_bioq_init(struct g_bioq *bq) 124 { 125 126 TAILQ_INIT(&bq->bio_queue); 127 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 128 } 129 130 static struct bio * 131 g_bioq_first(struct g_bioq *bq) 132 { 133 struct bio *bp; 134 135 bp = TAILQ_FIRST(&bq->bio_queue); 136 if (bp != NULL) { 137 KASSERT((bp->bio_flags & BIO_ONQUEUE), 138 ("Bio not on queue bp=%p target %p", bp, bq)); 139 bp->bio_flags &= ~BIO_ONQUEUE; 140 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 141 bq->bio_queue_length--; 142 } 143 return (bp); 144 } 145 146 struct bio * 147 g_new_bio(void) 148 { 149 struct bio *bp; 150 151 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 152 #ifdef KTR 153 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 154 struct stack st; 155 156 CTR1(KTR_GEOM, "g_new_bio(): %p", bp); 157 stack_save(&st); 158 CTRSTACK(KTR_GEOM, &st, 3, 0); 159 } 160 #endif 161 return (bp); 162 } 163 164 struct bio * 165 g_alloc_bio(void) 166 { 167 struct bio *bp; 168 169 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO); 170 #ifdef KTR 171 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 172 struct stack st; 173 174 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp); 175 stack_save(&st); 176 CTRSTACK(KTR_GEOM, &st, 3, 0); 177 } 178 #endif 179 return (bp); 180 } 181 182 void 183 g_destroy_bio(struct bio *bp) 184 { 185 #ifdef KTR 186 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 187 struct stack st; 188 189 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp); 190 stack_save(&st); 191 CTRSTACK(KTR_GEOM, &st, 3, 0); 192 } 193 #endif 194 uma_zfree(biozone, bp); 195 } 196 197 struct bio * 198 g_clone_bio(struct bio *bp) 199 { 200 struct bio *bp2; 201 202 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 203 if (bp2 != NULL) { 204 bp2->bio_parent = bp; 205 bp2->bio_cmd = bp->bio_cmd; 206 /* 207 * BIO_ORDERED flag may be used by disk drivers to enforce 208 * ordering restrictions, so this flag needs to be cloned. 209 * BIO_UNMAPPED and BIO_VLIST should be inherited, to properly 210 * indicate which way the buffer is passed. 211 * Other bio flags are not suitable for cloning. 212 */ 213 bp2->bio_flags = bp->bio_flags & 214 (BIO_ORDERED | BIO_UNMAPPED | BIO_VLIST); 215 bp2->bio_length = bp->bio_length; 216 bp2->bio_offset = bp->bio_offset; 217 bp2->bio_data = bp->bio_data; 218 bp2->bio_ma = bp->bio_ma; 219 bp2->bio_ma_n = bp->bio_ma_n; 220 bp2->bio_ma_offset = bp->bio_ma_offset; 221 bp2->bio_attribute = bp->bio_attribute; 222 if (bp->bio_cmd == BIO_ZONE) 223 bcopy(&bp->bio_zone, &bp2->bio_zone, 224 sizeof(bp->bio_zone)); 225 /* Inherit classification info from the parent */ 226 bp2->bio_classifier1 = bp->bio_classifier1; 227 bp2->bio_classifier2 = bp->bio_classifier2; 228 #if defined(BUF_TRACKING) || defined(FULL_BUF_TRACKING) 229 bp2->bio_track_bp = bp->bio_track_bp; 230 #endif 231 bp->bio_children++; 232 } 233 #ifdef KTR 234 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 235 struct stack st; 236 237 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2); 238 stack_save(&st); 239 CTRSTACK(KTR_GEOM, &st, 3, 0); 240 } 241 #endif 242 return(bp2); 243 } 244 245 struct bio * 246 g_duplicate_bio(struct bio *bp) 247 { 248 struct bio *bp2; 249 250 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO); 251 bp2->bio_flags = bp->bio_flags & (BIO_UNMAPPED | BIO_VLIST); 252 bp2->bio_parent = bp; 253 bp2->bio_cmd = bp->bio_cmd; 254 bp2->bio_length = bp->bio_length; 255 bp2->bio_offset = bp->bio_offset; 256 bp2->bio_data = bp->bio_data; 257 bp2->bio_ma = bp->bio_ma; 258 bp2->bio_ma_n = bp->bio_ma_n; 259 bp2->bio_ma_offset = bp->bio_ma_offset; 260 bp2->bio_attribute = bp->bio_attribute; 261 bp->bio_children++; 262 #ifdef KTR 263 if ((KTR_COMPILE & KTR_GEOM) && (ktr_mask & KTR_GEOM)) { 264 struct stack st; 265 266 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2); 267 stack_save(&st); 268 CTRSTACK(KTR_GEOM, &st, 3, 0); 269 } 270 #endif 271 return(bp2); 272 } 273 274 void 275 g_reset_bio(struct bio *bp) 276 { 277 278 bzero(bp, sizeof(*bp)); 279 } 280 281 void 282 g_io_init(void) 283 { 284 285 g_bioq_init(&g_bio_run_down); 286 g_bioq_init(&g_bio_run_up); 287 biozone = uma_zcreate("g_bio", sizeof (struct bio), 288 NULL, NULL, 289 NULL, NULL, 290 0, 0); 291 } 292 293 int 294 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 295 { 296 struct bio *bp; 297 int error; 298 299 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 300 bp = g_alloc_bio(); 301 bp->bio_cmd = BIO_GETATTR; 302 bp->bio_done = NULL; 303 bp->bio_attribute = attr; 304 bp->bio_length = *len; 305 bp->bio_data = ptr; 306 g_io_request(bp, cp); 307 error = biowait(bp, "ggetattr"); 308 *len = bp->bio_completed; 309 g_destroy_bio(bp); 310 return (error); 311 } 312 313 int 314 g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp) 315 { 316 struct bio *bp; 317 int error; 318 319 g_trace(G_T_BIO, "bio_zone(%d)", zone_args->zone_cmd); 320 bp = g_alloc_bio(); 321 bp->bio_cmd = BIO_ZONE; 322 bp->bio_done = NULL; 323 /* 324 * XXX KDM need to handle report zone data. 325 */ 326 bcopy(zone_args, &bp->bio_zone, sizeof(*zone_args)); 327 if (zone_args->zone_cmd == DISK_ZONE_REPORT_ZONES) 328 bp->bio_length = 329 zone_args->zone_params.report.entries_allocated * 330 sizeof(struct disk_zone_rep_entry); 331 else 332 bp->bio_length = 0; 333 334 g_io_request(bp, cp); 335 error = biowait(bp, "gzone"); 336 bcopy(&bp->bio_zone, zone_args, sizeof(*zone_args)); 337 g_destroy_bio(bp); 338 return (error); 339 } 340 341 int 342 g_io_flush(struct g_consumer *cp) 343 { 344 struct bio *bp; 345 int error; 346 347 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name); 348 bp = g_alloc_bio(); 349 bp->bio_cmd = BIO_FLUSH; 350 bp->bio_flags |= BIO_ORDERED; 351 bp->bio_done = NULL; 352 bp->bio_attribute = NULL; 353 bp->bio_offset = cp->provider->mediasize; 354 bp->bio_length = 0; 355 bp->bio_data = NULL; 356 g_io_request(bp, cp); 357 error = biowait(bp, "gflush"); 358 g_destroy_bio(bp); 359 return (error); 360 } 361 362 static int 363 g_io_check(struct bio *bp) 364 { 365 struct g_consumer *cp; 366 struct g_provider *pp; 367 off_t excess; 368 int error; 369 370 biotrack(bp, __func__); 371 372 cp = bp->bio_from; 373 pp = bp->bio_to; 374 375 /* Fail if access counters dont allow the operation */ 376 switch(bp->bio_cmd) { 377 case BIO_READ: 378 case BIO_GETATTR: 379 if (cp->acr == 0) 380 return (EPERM); 381 break; 382 case BIO_WRITE: 383 case BIO_DELETE: 384 case BIO_FLUSH: 385 if (cp->acw == 0) 386 return (EPERM); 387 break; 388 case BIO_ZONE: 389 if ((bp->bio_zone.zone_cmd == DISK_ZONE_REPORT_ZONES) || 390 (bp->bio_zone.zone_cmd == DISK_ZONE_GET_PARAMS)) { 391 if (cp->acr == 0) 392 return (EPERM); 393 } else if (cp->acw == 0) 394 return (EPERM); 395 break; 396 default: 397 return (EPERM); 398 } 399 /* if provider is marked for error, don't disturb. */ 400 if (pp->error) 401 return (pp->error); 402 if (cp->flags & G_CF_ORPHAN) 403 return (ENXIO); 404 405 switch(bp->bio_cmd) { 406 case BIO_READ: 407 case BIO_WRITE: 408 case BIO_DELETE: 409 /* Zero sectorsize or mediasize is probably a lack of media. */ 410 if (pp->sectorsize == 0 || pp->mediasize == 0) 411 return (ENXIO); 412 /* Reject I/O not on sector boundary */ 413 if (bp->bio_offset % pp->sectorsize) 414 return (EINVAL); 415 /* Reject I/O not integral sector long */ 416 if (bp->bio_length % pp->sectorsize) 417 return (EINVAL); 418 /* Reject requests before or past the end of media. */ 419 if (bp->bio_offset < 0) 420 return (EIO); 421 if (bp->bio_offset > pp->mediasize) 422 return (EIO); 423 424 /* Truncate requests to the end of providers media. */ 425 excess = bp->bio_offset + bp->bio_length; 426 if (excess > bp->bio_to->mediasize) { 427 KASSERT((bp->bio_flags & BIO_UNMAPPED) == 0 || 428 round_page(bp->bio_ma_offset + 429 bp->bio_length) / PAGE_SIZE == bp->bio_ma_n, 430 ("excess bio %p too short", bp)); 431 excess -= bp->bio_to->mediasize; 432 bp->bio_length -= excess; 433 if ((bp->bio_flags & BIO_UNMAPPED) != 0) { 434 bp->bio_ma_n = round_page(bp->bio_ma_offset + 435 bp->bio_length) / PAGE_SIZE; 436 } 437 if (excess > 0) 438 CTR3(KTR_GEOM, "g_down truncated bio " 439 "%p provider %s by %d", bp, 440 bp->bio_to->name, excess); 441 } 442 443 /* Deliver zero length transfers right here. */ 444 if (bp->bio_length == 0) { 445 CTR2(KTR_GEOM, "g_down terminated 0-length " 446 "bp %p provider %s", bp, bp->bio_to->name); 447 return (0); 448 } 449 450 if ((bp->bio_flags & BIO_UNMAPPED) != 0 && 451 (bp->bio_to->flags & G_PF_ACCEPT_UNMAPPED) == 0 && 452 (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE)) { 453 if ((error = g_io_transient_map_bio(bp)) >= 0) 454 return (error); 455 } 456 break; 457 default: 458 break; 459 } 460 return (EJUSTRETURN); 461 } 462 463 /* 464 * bio classification support. 465 * 466 * g_register_classifier() and g_unregister_classifier() 467 * are used to add/remove a classifier from the list. 468 * The list is protected using the g_bio_run_down lock, 469 * because the classifiers are called in this path. 470 * 471 * g_io_request() passes bio's that are not already classified 472 * (i.e. those with bio_classifier1 == NULL) to g_run_classifiers(). 473 * Classifiers can store their result in the two fields 474 * bio_classifier1 and bio_classifier2. 475 * A classifier that updates one of the fields should 476 * return a non-zero value. 477 * If no classifier updates the field, g_run_classifiers() sets 478 * bio_classifier1 = BIO_NOTCLASSIFIED to avoid further calls. 479 */ 480 481 int 482 g_register_classifier(struct g_classifier_hook *hook) 483 { 484 485 g_bioq_lock(&g_bio_run_down); 486 TAILQ_INSERT_TAIL(&g_classifier_tailq, hook, link); 487 g_bioq_unlock(&g_bio_run_down); 488 489 return (0); 490 } 491 492 void 493 g_unregister_classifier(struct g_classifier_hook *hook) 494 { 495 struct g_classifier_hook *entry; 496 497 g_bioq_lock(&g_bio_run_down); 498 TAILQ_FOREACH(entry, &g_classifier_tailq, link) { 499 if (entry == hook) { 500 TAILQ_REMOVE(&g_classifier_tailq, hook, link); 501 break; 502 } 503 } 504 g_bioq_unlock(&g_bio_run_down); 505 } 506 507 static void 508 g_run_classifiers(struct bio *bp) 509 { 510 struct g_classifier_hook *hook; 511 int classified = 0; 512 513 biotrack(bp, __func__); 514 515 TAILQ_FOREACH(hook, &g_classifier_tailq, link) 516 classified |= hook->func(hook->arg, bp); 517 518 if (!classified) 519 bp->bio_classifier1 = BIO_NOTCLASSIFIED; 520 } 521 522 void 523 g_io_request(struct bio *bp, struct g_consumer *cp) 524 { 525 struct g_provider *pp; 526 struct mtx *mtxp; 527 int direct, error, first; 528 uint8_t cmd; 529 530 biotrack(bp, __func__); 531 532 KASSERT(cp != NULL, ("NULL cp in g_io_request")); 533 KASSERT(bp != NULL, ("NULL bp in g_io_request")); 534 pp = cp->provider; 535 KASSERT(pp != NULL, ("consumer not attached in g_io_request")); 536 #ifdef DIAGNOSTIC 537 KASSERT(bp->bio_driver1 == NULL, 538 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name)); 539 KASSERT(bp->bio_driver2 == NULL, 540 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name)); 541 KASSERT(bp->bio_pflags == 0, 542 ("bio_pflags used by the consumer (geom %s)", cp->geom->name)); 543 /* 544 * Remember consumer's private fields, so we can detect if they were 545 * modified by the provider. 546 */ 547 bp->_bio_caller1 = bp->bio_caller1; 548 bp->_bio_caller2 = bp->bio_caller2; 549 bp->_bio_cflags = bp->bio_cflags; 550 #endif 551 552 cmd = bp->bio_cmd; 553 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_GETATTR) { 554 KASSERT(bp->bio_data != NULL, 555 ("NULL bp->data in g_io_request(cmd=%hu)", bp->bio_cmd)); 556 } 557 if (cmd == BIO_DELETE || cmd == BIO_FLUSH) { 558 KASSERT(bp->bio_data == NULL, 559 ("non-NULL bp->data in g_io_request(cmd=%hu)", 560 bp->bio_cmd)); 561 } 562 if (cmd == BIO_READ || cmd == BIO_WRITE || cmd == BIO_DELETE) { 563 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0, 564 ("wrong offset %jd for sectorsize %u", 565 bp->bio_offset, cp->provider->sectorsize)); 566 KASSERT(bp->bio_length % cp->provider->sectorsize == 0, 567 ("wrong length %jd for sectorsize %u", 568 bp->bio_length, cp->provider->sectorsize)); 569 } 570 571 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 572 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd); 573 574 bp->bio_from = cp; 575 bp->bio_to = pp; 576 bp->bio_error = 0; 577 bp->bio_completed = 0; 578 579 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 580 ("Bio already on queue bp=%p", bp)); 581 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 582 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 583 binuptime(&bp->bio_t0); 584 else 585 getbinuptime(&bp->bio_t0); 586 587 direct = (cp->flags & G_CF_DIRECT_SEND) != 0 && 588 (pp->flags & G_PF_DIRECT_RECEIVE) != 0 && 589 !g_is_geom_thread(curthread) && 590 ((pp->flags & G_PF_ACCEPT_UNMAPPED) != 0 || 591 (bp->bio_flags & BIO_UNMAPPED) == 0 || THREAD_CAN_SLEEP()) && 592 pace == 0; 593 if (direct) { 594 /* Block direct execution if less then half of stack left. */ 595 size_t st, su; 596 GET_STACK_USAGE(st, su); 597 if (su * 2 > st) 598 direct = 0; 599 } 600 601 if (!TAILQ_EMPTY(&g_classifier_tailq) && !bp->bio_classifier1) { 602 g_bioq_lock(&g_bio_run_down); 603 g_run_classifiers(bp); 604 g_bioq_unlock(&g_bio_run_down); 605 } 606 607 /* 608 * The statistics collection is lockless, as such, but we 609 * can not update one instance of the statistics from more 610 * than one thread at a time, so grab the lock first. 611 */ 612 mtxp = mtx_pool_find(mtxpool_sleep, pp); 613 mtx_lock(mtxp); 614 if (g_collectstats & G_STATS_PROVIDERS) 615 devstat_start_transaction_bio_t0(pp->stat, bp); 616 if (g_collectstats & G_STATS_CONSUMERS) 617 devstat_start_transaction_bio_t0(cp->stat, bp); 618 pp->nstart++; 619 cp->nstart++; 620 mtx_unlock(mtxp); 621 622 if (direct) { 623 error = g_io_check(bp); 624 if (error >= 0) { 625 CTR3(KTR_GEOM, "g_io_request g_io_check on bp %p " 626 "provider %s returned %d", bp, bp->bio_to->name, 627 error); 628 g_io_deliver(bp, error); 629 return; 630 } 631 bp->bio_to->geom->start(bp); 632 } else { 633 g_bioq_lock(&g_bio_run_down); 634 first = TAILQ_EMPTY(&g_bio_run_down.bio_queue); 635 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue); 636 bp->bio_flags |= BIO_ONQUEUE; 637 g_bio_run_down.bio_queue_length++; 638 g_bioq_unlock(&g_bio_run_down); 639 /* Pass it on down. */ 640 if (first) 641 wakeup(&g_wait_down); 642 } 643 } 644 645 void 646 g_io_deliver(struct bio *bp, int error) 647 { 648 struct bintime now; 649 struct g_consumer *cp; 650 struct g_provider *pp; 651 struct mtx *mtxp; 652 int direct, first; 653 654 biotrack(bp, __func__); 655 656 KASSERT(bp != NULL, ("NULL bp in g_io_deliver")); 657 pp = bp->bio_to; 658 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver")); 659 cp = bp->bio_from; 660 if (cp == NULL) { 661 bp->bio_error = error; 662 bp->bio_done(bp); 663 return; 664 } 665 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver")); 666 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver")); 667 #ifdef DIAGNOSTIC 668 /* 669 * Some classes - GJournal in particular - can modify bio's 670 * private fields while the bio is in transit; G_GEOM_VOLATILE_BIO 671 * flag means it's an expected behaviour for that particular geom. 672 */ 673 if ((cp->geom->flags & G_GEOM_VOLATILE_BIO) == 0) { 674 KASSERT(bp->bio_caller1 == bp->_bio_caller1, 675 ("bio_caller1 used by the provider %s", pp->name)); 676 KASSERT(bp->bio_caller2 == bp->_bio_caller2, 677 ("bio_caller2 used by the provider %s", pp->name)); 678 KASSERT(bp->bio_cflags == bp->_bio_cflags, 679 ("bio_cflags used by the provider %s", pp->name)); 680 } 681 #endif 682 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0")); 683 KASSERT(bp->bio_completed <= bp->bio_length, 684 ("bio_completed can't be greater than bio_length")); 685 686 g_trace(G_T_BIO, 687 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd", 688 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error, 689 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 690 691 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 692 ("Bio already on queue bp=%p", bp)); 693 694 /* 695 * XXX: next two doesn't belong here 696 */ 697 bp->bio_bcount = bp->bio_length; 698 bp->bio_resid = bp->bio_bcount - bp->bio_completed; 699 700 direct = (pp->flags & G_PF_DIRECT_SEND) && 701 (cp->flags & G_CF_DIRECT_RECEIVE) && 702 !g_is_geom_thread(curthread); 703 if (direct) { 704 /* Block direct execution if less then half of stack left. */ 705 size_t st, su; 706 GET_STACK_USAGE(st, su); 707 if (su * 2 > st) 708 direct = 0; 709 } 710 711 /* 712 * The statistics collection is lockless, as such, but we 713 * can not update one instance of the statistics from more 714 * than one thread at a time, so grab the lock first. 715 */ 716 if ((g_collectstats & G_STATS_CONSUMERS) != 0 || 717 ((g_collectstats & G_STATS_PROVIDERS) != 0 && pp->stat != NULL)) 718 binuptime(&now); 719 mtxp = mtx_pool_find(mtxpool_sleep, cp); 720 mtx_lock(mtxp); 721 if (g_collectstats & G_STATS_PROVIDERS) 722 devstat_end_transaction_bio_bt(pp->stat, bp, &now); 723 if (g_collectstats & G_STATS_CONSUMERS) 724 devstat_end_transaction_bio_bt(cp->stat, bp, &now); 725 cp->nend++; 726 pp->nend++; 727 mtx_unlock(mtxp); 728 729 if (error != ENOMEM) { 730 bp->bio_error = error; 731 if (direct) { 732 biodone(bp); 733 } else { 734 g_bioq_lock(&g_bio_run_up); 735 first = TAILQ_EMPTY(&g_bio_run_up.bio_queue); 736 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue); 737 bp->bio_flags |= BIO_ONQUEUE; 738 g_bio_run_up.bio_queue_length++; 739 g_bioq_unlock(&g_bio_run_up); 740 if (first) 741 wakeup(&g_wait_up); 742 } 743 return; 744 } 745 746 if (bootverbose) 747 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name); 748 bp->bio_children = 0; 749 bp->bio_inbed = 0; 750 bp->bio_driver1 = NULL; 751 bp->bio_driver2 = NULL; 752 bp->bio_pflags = 0; 753 g_io_request(bp, cp); 754 pace = 1; 755 return; 756 } 757 758 SYSCTL_DECL(_kern_geom); 759 760 static long transient_maps; 761 SYSCTL_LONG(_kern_geom, OID_AUTO, transient_maps, CTLFLAG_RD, 762 &transient_maps, 0, 763 "Total count of the transient mapping requests"); 764 u_int transient_map_retries = 10; 765 SYSCTL_UINT(_kern_geom, OID_AUTO, transient_map_retries, CTLFLAG_RW, 766 &transient_map_retries, 0, 767 "Max count of retries used before giving up on creating transient map"); 768 int transient_map_hard_failures; 769 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_hard_failures, CTLFLAG_RD, 770 &transient_map_hard_failures, 0, 771 "Failures to establish the transient mapping due to retry attempts " 772 "exhausted"); 773 int transient_map_soft_failures; 774 SYSCTL_INT(_kern_geom, OID_AUTO, transient_map_soft_failures, CTLFLAG_RD, 775 &transient_map_soft_failures, 0, 776 "Count of retried failures to establish the transient mapping"); 777 int inflight_transient_maps; 778 SYSCTL_INT(_kern_geom, OID_AUTO, inflight_transient_maps, CTLFLAG_RD, 779 &inflight_transient_maps, 0, 780 "Current count of the active transient maps"); 781 782 static int 783 g_io_transient_map_bio(struct bio *bp) 784 { 785 vm_offset_t addr; 786 long size; 787 u_int retried; 788 789 KASSERT(unmapped_buf_allowed, ("unmapped disabled")); 790 791 size = round_page(bp->bio_ma_offset + bp->bio_length); 792 KASSERT(size / PAGE_SIZE == bp->bio_ma_n, ("Bio too short %p", bp)); 793 addr = 0; 794 retried = 0; 795 atomic_add_long(&transient_maps, 1); 796 retry: 797 if (vmem_alloc(transient_arena, size, M_BESTFIT | M_NOWAIT, &addr)) { 798 if (transient_map_retries != 0 && 799 retried >= transient_map_retries) { 800 CTR2(KTR_GEOM, "g_down cannot map bp %p provider %s", 801 bp, bp->bio_to->name); 802 atomic_add_int(&transient_map_hard_failures, 1); 803 return (EDEADLK/* XXXKIB */); 804 } else { 805 /* 806 * Naive attempt to quisce the I/O to get more 807 * in-flight requests completed and defragment 808 * the transient_arena. 809 */ 810 CTR3(KTR_GEOM, "g_down retrymap bp %p provider %s r %d", 811 bp, bp->bio_to->name, retried); 812 pause("g_d_tra", hz / 10); 813 retried++; 814 atomic_add_int(&transient_map_soft_failures, 1); 815 goto retry; 816 } 817 } 818 atomic_add_int(&inflight_transient_maps, 1); 819 pmap_qenter((vm_offset_t)addr, bp->bio_ma, OFF_TO_IDX(size)); 820 bp->bio_data = (caddr_t)addr + bp->bio_ma_offset; 821 bp->bio_flags |= BIO_TRANSIENT_MAPPING; 822 bp->bio_flags &= ~BIO_UNMAPPED; 823 return (EJUSTRETURN); 824 } 825 826 void 827 g_io_schedule_down(struct thread *tp __unused) 828 { 829 struct bio *bp; 830 int error; 831 832 for(;;) { 833 g_bioq_lock(&g_bio_run_down); 834 bp = g_bioq_first(&g_bio_run_down); 835 if (bp == NULL) { 836 CTR0(KTR_GEOM, "g_down going to sleep"); 837 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock, 838 PRIBIO | PDROP, "-", 0); 839 continue; 840 } 841 CTR0(KTR_GEOM, "g_down has work to do"); 842 g_bioq_unlock(&g_bio_run_down); 843 biotrack(bp, __func__); 844 if (pace != 0) { 845 /* 846 * There has been at least one memory allocation 847 * failure since the last I/O completed. Pause 1ms to 848 * give the system a chance to free up memory. We only 849 * do this once because a large number of allocations 850 * can fail in the direct dispatch case and there's no 851 * relationship between the number of these failures and 852 * the length of the outage. If there's still an outage, 853 * we'll pause again and again until it's 854 * resolved. Older versions paused longer and once per 855 * allocation failure. This was OK for a single threaded 856 * g_down, but with direct dispatch would lead to max of 857 * 10 IOPs for minutes at a time when transient memory 858 * issues prevented allocation for a batch of requests 859 * from the upper layers. 860 * 861 * XXX This pacing is really lame. It needs to be solved 862 * by other methods. This is OK only because the worst 863 * case scenario is so rare. In the worst case scenario 864 * all memory is tied up waiting for I/O to complete 865 * which can never happen since we can't allocate bios 866 * for that I/O. 867 */ 868 CTR0(KTR_GEOM, "g_down pacing self"); 869 pause("g_down", min(hz/1000, 1)); 870 pace = 0; 871 } 872 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp, 873 bp->bio_to->name); 874 error = g_io_check(bp); 875 if (error >= 0) { 876 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider " 877 "%s returned %d", bp, bp->bio_to->name, error); 878 g_io_deliver(bp, error); 879 continue; 880 } 881 THREAD_NO_SLEEPING(); 882 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld " 883 "len %ld", bp, bp->bio_to->name, bp->bio_offset, 884 bp->bio_length); 885 bp->bio_to->geom->start(bp); 886 THREAD_SLEEPING_OK(); 887 } 888 } 889 890 void 891 g_io_schedule_up(struct thread *tp __unused) 892 { 893 struct bio *bp; 894 895 for(;;) { 896 g_bioq_lock(&g_bio_run_up); 897 bp = g_bioq_first(&g_bio_run_up); 898 if (bp == NULL) { 899 CTR0(KTR_GEOM, "g_up going to sleep"); 900 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock, 901 PRIBIO | PDROP, "-", 0); 902 continue; 903 } 904 g_bioq_unlock(&g_bio_run_up); 905 THREAD_NO_SLEEPING(); 906 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off " 907 "%jd len %ld", bp, bp->bio_to->name, 908 bp->bio_offset, bp->bio_length); 909 biodone(bp); 910 THREAD_SLEEPING_OK(); 911 } 912 } 913 914 void * 915 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 916 { 917 struct bio *bp; 918 void *ptr; 919 int errorc; 920 921 KASSERT(length > 0 && length >= cp->provider->sectorsize && 922 length <= MAXPHYS, ("g_read_data(): invalid length %jd", 923 (intmax_t)length)); 924 925 bp = g_alloc_bio(); 926 bp->bio_cmd = BIO_READ; 927 bp->bio_done = NULL; 928 bp->bio_offset = offset; 929 bp->bio_length = length; 930 ptr = g_malloc(length, M_WAITOK); 931 bp->bio_data = ptr; 932 g_io_request(bp, cp); 933 errorc = biowait(bp, "gread"); 934 if (error != NULL) 935 *error = errorc; 936 g_destroy_bio(bp); 937 if (errorc) { 938 g_free(ptr); 939 ptr = NULL; 940 } 941 return (ptr); 942 } 943 944 /* 945 * A read function for use by ffs_sbget when used by GEOM-layer routines. 946 */ 947 int 948 g_use_g_read_data(void *devfd, off_t loc, void **bufp, int size) 949 { 950 struct g_consumer *cp; 951 952 KASSERT(*bufp == NULL, 953 ("g_use_g_read_data: non-NULL *bufp %p\n", *bufp)); 954 955 cp = (struct g_consumer *)devfd; 956 /* 957 * Take care not to issue an invalid I/O request. The offset of 958 * the superblock candidate must be multiples of the provider's 959 * sector size, otherwise an FFS can't exist on the provider 960 * anyway. 961 */ 962 if (loc % cp->provider->sectorsize != 0) 963 return (ENOENT); 964 *bufp = g_read_data(cp, loc, size, NULL); 965 if (*bufp == NULL) 966 return (ENOENT); 967 return (0); 968 } 969 970 int 971 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length) 972 { 973 struct bio *bp; 974 int error; 975 976 KASSERT(length > 0 && length >= cp->provider->sectorsize && 977 length <= MAXPHYS, ("g_write_data(): invalid length %jd", 978 (intmax_t)length)); 979 980 bp = g_alloc_bio(); 981 bp->bio_cmd = BIO_WRITE; 982 bp->bio_done = NULL; 983 bp->bio_offset = offset; 984 bp->bio_length = length; 985 bp->bio_data = ptr; 986 g_io_request(bp, cp); 987 error = biowait(bp, "gwrite"); 988 g_destroy_bio(bp); 989 return (error); 990 } 991 992 /* 993 * A write function for use by ffs_sbput when used by GEOM-layer routines. 994 */ 995 int 996 g_use_g_write_data(void *devfd, off_t loc, void *buf, int size) 997 { 998 999 return (g_write_data((struct g_consumer *)devfd, loc, buf, size)); 1000 } 1001 1002 int 1003 g_delete_data(struct g_consumer *cp, off_t offset, off_t length) 1004 { 1005 struct bio *bp; 1006 int error; 1007 1008 KASSERT(length > 0 && length >= cp->provider->sectorsize, 1009 ("g_delete_data(): invalid length %jd", (intmax_t)length)); 1010 1011 bp = g_alloc_bio(); 1012 bp->bio_cmd = BIO_DELETE; 1013 bp->bio_done = NULL; 1014 bp->bio_offset = offset; 1015 bp->bio_length = length; 1016 bp->bio_data = NULL; 1017 g_io_request(bp, cp); 1018 error = biowait(bp, "gdelete"); 1019 g_destroy_bio(bp); 1020 return (error); 1021 } 1022 1023 void 1024 g_print_bio(struct bio *bp) 1025 { 1026 const char *pname, *cmd = NULL; 1027 1028 if (bp->bio_to != NULL) 1029 pname = bp->bio_to->name; 1030 else 1031 pname = "[unknown]"; 1032 1033 switch (bp->bio_cmd) { 1034 case BIO_GETATTR: 1035 cmd = "GETATTR"; 1036 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute); 1037 return; 1038 case BIO_FLUSH: 1039 cmd = "FLUSH"; 1040 printf("%s[%s]", pname, cmd); 1041 return; 1042 case BIO_ZONE: { 1043 char *subcmd = NULL; 1044 cmd = "ZONE"; 1045 switch (bp->bio_zone.zone_cmd) { 1046 case DISK_ZONE_OPEN: 1047 subcmd = "OPEN"; 1048 break; 1049 case DISK_ZONE_CLOSE: 1050 subcmd = "CLOSE"; 1051 break; 1052 case DISK_ZONE_FINISH: 1053 subcmd = "FINISH"; 1054 break; 1055 case DISK_ZONE_RWP: 1056 subcmd = "RWP"; 1057 break; 1058 case DISK_ZONE_REPORT_ZONES: 1059 subcmd = "REPORT ZONES"; 1060 break; 1061 case DISK_ZONE_GET_PARAMS: 1062 subcmd = "GET PARAMS"; 1063 break; 1064 default: 1065 subcmd = "UNKNOWN"; 1066 break; 1067 } 1068 printf("%s[%s,%s]", pname, cmd, subcmd); 1069 return; 1070 } 1071 case BIO_READ: 1072 cmd = "READ"; 1073 break; 1074 case BIO_WRITE: 1075 cmd = "WRITE"; 1076 break; 1077 case BIO_DELETE: 1078 cmd = "DELETE"; 1079 break; 1080 default: 1081 cmd = "UNKNOWN"; 1082 printf("%s[%s()]", pname, cmd); 1083 return; 1084 } 1085 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd, 1086 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 1087 }
Cache object: e7dcae6c5aa485ad30a75e5ac4618c2e
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