geom_io.c revision 163832
1/*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: head/sys/geom/geom_io.c 163832 2006-10-31 21:11:21Z pjd $"); 38 39#include <sys/param.h> 40#include <sys/systm.h> 41#include <sys/kernel.h> 42#include <sys/malloc.h> 43#include <sys/bio.h> 44#include <sys/ktr.h> 45#include <sys/proc.h> 46#include <sys/stack.h> 47 48#include <sys/errno.h> 49#include <geom/geom.h> 50#include <geom/geom_int.h> 51#include <sys/devicestat.h> 52 53#include <vm/uma.h> 54 55static struct g_bioq g_bio_run_down; 56static struct g_bioq g_bio_run_up; 57static struct g_bioq g_bio_run_task; 58 59static u_int pace; 60static uma_zone_t biozone; 61 62#include <machine/atomic.h> 63 64static void 65g_bioq_lock(struct g_bioq *bq) 66{ 67 68 mtx_lock(&bq->bio_queue_lock); 69} 70 71static void 72g_bioq_unlock(struct g_bioq *bq) 73{ 74 75 mtx_unlock(&bq->bio_queue_lock); 76} 77 78#if 0 79static void 80g_bioq_destroy(struct g_bioq *bq) 81{ 82 83 mtx_destroy(&bq->bio_queue_lock); 84} 85#endif 86 87static void 88g_bioq_init(struct g_bioq *bq) 89{ 90 91 TAILQ_INIT(&bq->bio_queue); 92 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF); 93} 94 95static struct bio * 96g_bioq_first(struct g_bioq *bq) 97{ 98 struct bio *bp; 99 100 bp = TAILQ_FIRST(&bq->bio_queue); 101 if (bp != NULL) { 102 KASSERT((bp->bio_flags & BIO_ONQUEUE), 103 ("Bio not on queue bp=%p target %p", bp, bq)); 104 bp->bio_flags &= ~BIO_ONQUEUE; 105 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue); 106 bq->bio_queue_length--; 107 } 108 return (bp); 109} 110 111struct bio * 112g_new_bio(void) 113{ 114 struct bio *bp; 115 116 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 117#ifdef KTR 118 if (KTR_COMPILE & KTR_GEOM) { 119 struct stack st; 120 121 CTR1(KTR_GEOM, "g_new_bio(): %p", bp); 122 stack_save(&st); 123 CTRSTACK(KTR_GEOM, &st, 3, 0); 124 } 125#endif 126 return (bp); 127} 128 129struct bio * 130g_alloc_bio(void) 131{ 132 struct bio *bp; 133 134 bp = uma_zalloc(biozone, M_WAITOK | M_ZERO); 135#ifdef KTR 136 if (KTR_COMPILE & KTR_GEOM) { 137 struct stack st; 138 139 CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp); 140 stack_save(&st); 141 CTRSTACK(KTR_GEOM, &st, 3, 0); 142 } 143#endif 144 return (bp); 145} 146 147void 148g_destroy_bio(struct bio *bp) 149{ 150#ifdef KTR 151 if (KTR_COMPILE & KTR_GEOM) { 152 struct stack st; 153 154 CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp); 155 stack_save(&st); 156 CTRSTACK(KTR_GEOM, &st, 3, 0); 157 } 158#endif 159 uma_zfree(biozone, bp); 160} 161 162struct bio * 163g_clone_bio(struct bio *bp) 164{ 165 struct bio *bp2; 166 167 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO); 168 if (bp2 != NULL) { 169 bp2->bio_parent = bp; 170 bp2->bio_cmd = bp->bio_cmd; 171 bp2->bio_length = bp->bio_length; 172 bp2->bio_offset = bp->bio_offset; 173 bp2->bio_data = bp->bio_data; 174 bp2->bio_attribute = bp->bio_attribute; 175 bp->bio_children++; 176 } 177#ifdef KTR 178 if (KTR_COMPILE & KTR_GEOM) { 179 struct stack st; 180 181 CTR2(KTR_GEOM, "g_clone_bio(%p): %p", bp, bp2); 182 stack_save(&st); 183 CTRSTACK(KTR_GEOM, &st, 3, 0); 184 } 185#endif 186 return(bp2); 187} 188 189struct bio * 190g_duplicate_bio(struct bio *bp) 191{ 192 struct bio *bp2; 193 194 bp2 = uma_zalloc(biozone, M_WAITOK | M_ZERO); 195 bp2->bio_parent = bp; 196 bp2->bio_cmd = bp->bio_cmd; 197 bp2->bio_length = bp->bio_length; 198 bp2->bio_offset = bp->bio_offset; 199 bp2->bio_data = bp->bio_data; 200 bp2->bio_attribute = bp->bio_attribute; 201 bp->bio_children++; 202#ifdef KTR 203 if (KTR_COMPILE & KTR_GEOM) { 204 struct stack st; 205 206 CTR2(KTR_GEOM, "g_duplicate_bio(%p): %p", bp, bp2); 207 stack_save(&st); 208 CTRSTACK(KTR_GEOM, &st, 3, 0); 209 } 210#endif 211 return(bp2); 212} 213 214void 215g_io_init() 216{ 217 218 g_bioq_init(&g_bio_run_down); 219 g_bioq_init(&g_bio_run_up); 220 g_bioq_init(&g_bio_run_task); 221 biozone = uma_zcreate("g_bio", sizeof (struct bio), 222 NULL, NULL, 223 NULL, NULL, 224 0, 0); 225} 226 227int 228g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr) 229{ 230 struct bio *bp; 231 int error; 232 233 g_trace(G_T_BIO, "bio_getattr(%s)", attr); 234 bp = g_alloc_bio(); 235 bp->bio_cmd = BIO_GETATTR; 236 bp->bio_done = NULL; 237 bp->bio_attribute = attr; 238 bp->bio_length = *len; 239 bp->bio_data = ptr; 240 g_io_request(bp, cp); 241 error = biowait(bp, "ggetattr"); 242 *len = bp->bio_completed; 243 g_destroy_bio(bp); 244 return (error); 245} 246 247int 248g_io_flush(struct g_consumer *cp) 249{ 250 struct bio *bp; 251 int error; 252 253 g_trace(G_T_BIO, "bio_flush(%s)", cp->provider->name); 254 bp = g_alloc_bio(); 255 bp->bio_cmd = BIO_FLUSH; 256 bp->bio_done = NULL; 257 bp->bio_attribute = NULL; 258 bp->bio_offset = cp->provider->mediasize; 259 bp->bio_length = 0; 260 bp->bio_data = NULL; 261 g_io_request(bp, cp); 262 error = biowait(bp, "gflush"); 263 g_destroy_bio(bp); 264 return (error); 265} 266 267static int 268g_io_check(struct bio *bp) 269{ 270 struct g_consumer *cp; 271 struct g_provider *pp; 272 273 cp = bp->bio_from; 274 pp = bp->bio_to; 275 276 /* Fail if access counters dont allow the operation */ 277 switch(bp->bio_cmd) { 278 case BIO_READ: 279 case BIO_GETATTR: 280 if (cp->acr == 0) 281 return (EPERM); 282 break; 283 case BIO_WRITE: 284 case BIO_DELETE: 285 case BIO_FLUSH: 286 if (cp->acw == 0) 287 return (EPERM); 288 break; 289 default: 290 return (EPERM); 291 } 292 /* if provider is marked for error, don't disturb. */ 293 if (pp->error) 294 return (pp->error); 295 296 switch(bp->bio_cmd) { 297 case BIO_READ: 298 case BIO_WRITE: 299 case BIO_DELETE: 300 /* Zero sectorsize is a probably lack of media */ 301 if (pp->sectorsize == 0) 302 return (ENXIO); 303 /* Reject I/O not on sector boundary */ 304 if (bp->bio_offset % pp->sectorsize) 305 return (EINVAL); 306 /* Reject I/O not integral sector long */ 307 if (bp->bio_length % pp->sectorsize) 308 return (EINVAL); 309 /* Reject requests before or past the end of media. */ 310 if (bp->bio_offset < 0) 311 return (EIO); 312 if (bp->bio_offset > pp->mediasize) 313 return (EIO); 314 break; 315 default: 316 break; 317 } 318 return (0); 319} 320 321void 322g_io_request(struct bio *bp, struct g_consumer *cp) 323{ 324 struct g_provider *pp; 325 326 KASSERT(cp != NULL, ("NULL cp in g_io_request")); 327 KASSERT(bp != NULL, ("NULL bp in g_io_request")); 328 pp = cp->provider; 329 KASSERT(pp != NULL, ("consumer not attached in g_io_request")); 330#ifdef DIAGNOSTIC 331 KASSERT(bp->bio_driver1 == NULL, 332 ("bio_driver1 used by the consumer (geom %s)", cp->geom->name)); 333 KASSERT(bp->bio_driver2 == NULL, 334 ("bio_driver2 used by the consumer (geom %s)", cp->geom->name)); 335 KASSERT(bp->bio_pflags == 0, 336 ("bio_pflags used by the consumer (geom %s)", cp->geom->name)); 337 /* 338 * Remember consumer's private fields, so we can detect if they were 339 * modified by the provider. 340 */ 341 bp->_bio_caller1 = bp->bio_caller1; 342 bp->_bio_caller2 = bp->bio_caller2; 343 bp->_bio_cflags = bp->bio_cflags; 344#endif 345 346 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE|BIO_GETATTR)) { 347 KASSERT(bp->bio_data != NULL, 348 ("NULL bp->data in g_io_request")); 349 } 350 if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) { 351 KASSERT(bp->bio_offset % cp->provider->sectorsize == 0, 352 ("wrong offset %jd for sectorsize %u", 353 bp->bio_offset, cp->provider->sectorsize)); 354 KASSERT(bp->bio_length % cp->provider->sectorsize == 0, 355 ("wrong length %jd for sectorsize %u", 356 bp->bio_length, cp->provider->sectorsize)); 357 } 358 359 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d", 360 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd); 361 362 bp->bio_from = cp; 363 bp->bio_to = pp; 364 bp->bio_error = 0; 365 bp->bio_completed = 0; 366 367 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 368 ("Bio already on queue bp=%p", bp)); 369 bp->bio_flags |= BIO_ONQUEUE; 370 371 binuptime(&bp->bio_t0); 372 373 /* 374 * The statistics collection is lockless, as such, but we 375 * can not update one instance of the statistics from more 376 * than one thread at a time, so grab the lock first. 377 */ 378 g_bioq_lock(&g_bio_run_down); 379 if (g_collectstats & 1) 380 devstat_start_transaction(pp->stat, &bp->bio_t0); 381 if (g_collectstats & 2) 382 devstat_start_transaction(cp->stat, &bp->bio_t0); 383 384 pp->nstart++; 385 cp->nstart++; 386 TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue); 387 g_bio_run_down.bio_queue_length++; 388 g_bioq_unlock(&g_bio_run_down); 389 390 /* Pass it on down. */ 391 wakeup(&g_wait_down); 392} 393 394void 395g_io_deliver(struct bio *bp, int error) 396{ 397 struct g_consumer *cp; 398 struct g_provider *pp; 399 400 KASSERT(bp != NULL, ("NULL bp in g_io_deliver")); 401 pp = bp->bio_to; 402 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver")); 403#ifdef DIAGNOSTIC 404 KASSERT(bp->bio_caller1 == bp->_bio_caller1, 405 ("bio_caller1 used by the provider %s", pp->name)); 406 KASSERT(bp->bio_caller2 == bp->_bio_caller2, 407 ("bio_caller2 used by the provider %s", pp->name)); 408 KASSERT(bp->bio_cflags == bp->_bio_cflags, 409 ("bio_cflags used by the provider %s", pp->name)); 410#endif 411 cp = bp->bio_from; 412 if (cp == NULL) { 413 bp->bio_error = error; 414 bp->bio_done(bp); 415 return; 416 } 417 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver")); 418 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver")); 419 KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0")); 420 KASSERT(bp->bio_completed <= bp->bio_length, 421 ("bio_completed can't be greater than bio_length")); 422 423 g_trace(G_T_BIO, 424"g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd", 425 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error, 426 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 427 428 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 429 ("Bio already on queue bp=%p", bp)); 430 431 /* 432 * XXX: next two doesn't belong here 433 */ 434 bp->bio_bcount = bp->bio_length; 435 bp->bio_resid = bp->bio_bcount - bp->bio_completed; 436 437 /* 438 * The statistics collection is lockless, as such, but we 439 * can not update one instance of the statistics from more 440 * than one thread at a time, so grab the lock first. 441 */ 442 g_bioq_lock(&g_bio_run_up); 443 if (g_collectstats & 1) 444 devstat_end_transaction_bio(pp->stat, bp); 445 if (g_collectstats & 2) 446 devstat_end_transaction_bio(cp->stat, bp); 447 448 cp->nend++; 449 pp->nend++; 450 if (error != ENOMEM) { 451 bp->bio_error = error; 452 TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue); 453 bp->bio_flags |= BIO_ONQUEUE; 454 g_bio_run_up.bio_queue_length++; 455 g_bioq_unlock(&g_bio_run_up); 456 wakeup(&g_wait_up); 457 return; 458 } 459 g_bioq_unlock(&g_bio_run_up); 460 461 if (bootverbose) 462 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name); 463 bp->bio_children = 0; 464 bp->bio_inbed = 0; 465 g_io_request(bp, cp); 466 pace++; 467 return; 468} 469 470void 471g_io_schedule_down(struct thread *tp __unused) 472{ 473 struct bio *bp; 474 off_t excess; 475 int error; 476 477 for(;;) { 478 g_bioq_lock(&g_bio_run_down); 479 bp = g_bioq_first(&g_bio_run_down); 480 if (bp == NULL) { 481 CTR0(KTR_GEOM, "g_down going to sleep"); 482 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock, 483 PRIBIO | PDROP, "-", hz/10); 484 continue; 485 } 486 CTR0(KTR_GEOM, "g_down has work to do"); 487 g_bioq_unlock(&g_bio_run_down); 488 if (pace > 0) { 489 CTR1(KTR_GEOM, "g_down pacing self (pace %d)", pace); 490 msleep(&error, NULL, PRIBIO, "g_down", hz/10); 491 pace--; 492 } 493 error = g_io_check(bp); 494 if (error) { 495 CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider " 496 "%s returned %d", bp, bp->bio_to->name, error); 497 g_io_deliver(bp, error); 498 continue; 499 } 500 CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp, 501 bp->bio_to->name); 502 switch (bp->bio_cmd) { 503 case BIO_READ: 504 case BIO_WRITE: 505 case BIO_DELETE: 506 /* Truncate requests to the end of providers media. */ 507 /* 508 * XXX: What if we truncate because of offset being 509 * bad, not length? 510 */ 511 excess = bp->bio_offset + bp->bio_length; 512 if (excess > bp->bio_to->mediasize) { 513 excess -= bp->bio_to->mediasize; 514 bp->bio_length -= excess; 515 if (excess > 0) 516 CTR3(KTR_GEOM, "g_down truncated bio " 517 "%p provider %s by %d", bp, 518 bp->bio_to->name, excess); 519 } 520 /* Deliver zero length transfers right here. */ 521 if (bp->bio_length == 0) { 522 g_io_deliver(bp, 0); 523 CTR2(KTR_GEOM, "g_down terminated 0-length " 524 "bp %p provider %s", bp, bp->bio_to->name); 525 continue; 526 } 527 break; 528 default: 529 break; 530 } 531 THREAD_NO_SLEEPING(); 532 CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld " 533 "len %ld", bp, bp->bio_to->name, bp->bio_offset, 534 bp->bio_length); 535 bp->bio_to->geom->start(bp); 536 THREAD_SLEEPING_OK(); 537 } 538} 539 540void 541bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg) 542{ 543 bp->bio_task = func; 544 bp->bio_task_arg = arg; 545 /* 546 * The taskqueue is actually just a second queue off the "up" 547 * queue, so we use the same lock. 548 */ 549 g_bioq_lock(&g_bio_run_up); 550 KASSERT(!(bp->bio_flags & BIO_ONQUEUE), 551 ("Bio already on queue bp=%p target taskq", bp)); 552 bp->bio_flags |= BIO_ONQUEUE; 553 TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue); 554 g_bio_run_task.bio_queue_length++; 555 wakeup(&g_wait_up); 556 g_bioq_unlock(&g_bio_run_up); 557} 558 559 560void 561g_io_schedule_up(struct thread *tp __unused) 562{ 563 struct bio *bp; 564 for(;;) { 565 g_bioq_lock(&g_bio_run_up); 566 bp = g_bioq_first(&g_bio_run_task); 567 if (bp != NULL) { 568 g_bioq_unlock(&g_bio_run_up); 569 THREAD_NO_SLEEPING(); 570 CTR1(KTR_GEOM, "g_up processing task bp %p", bp); 571 bp->bio_task(bp->bio_task_arg); 572 THREAD_SLEEPING_OK(); 573 continue; 574 } 575 bp = g_bioq_first(&g_bio_run_up); 576 if (bp != NULL) { 577 g_bioq_unlock(&g_bio_run_up); 578 THREAD_NO_SLEEPING(); 579 CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off " 580 "%ld len %ld", bp, bp->bio_to->name, 581 bp->bio_offset, bp->bio_length); 582 biodone(bp); 583 THREAD_SLEEPING_OK(); 584 continue; 585 } 586 CTR0(KTR_GEOM, "g_up going to sleep"); 587 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock, 588 PRIBIO | PDROP, "-", hz/10); 589 } 590} 591 592void * 593g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error) 594{ 595 struct bio *bp; 596 void *ptr; 597 int errorc; 598 599 KASSERT(length > 0 && length >= cp->provider->sectorsize && 600 length <= MAXPHYS, ("g_read_data(): invalid length %jd", 601 (intmax_t)length)); 602 603 bp = g_alloc_bio(); 604 bp->bio_cmd = BIO_READ; 605 bp->bio_done = NULL; 606 bp->bio_offset = offset; 607 bp->bio_length = length; 608 ptr = g_malloc(length, M_WAITOK); 609 bp->bio_data = ptr; 610 g_io_request(bp, cp); 611 errorc = biowait(bp, "gread"); 612 if (error != NULL) 613 *error = errorc; 614 g_destroy_bio(bp); 615 if (errorc) { 616 g_free(ptr); 617 ptr = NULL; 618 } 619 return (ptr); 620} 621 622int 623g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length) 624{ 625 struct bio *bp; 626 int error; 627 628 KASSERT(length > 0 && length >= cp->provider->sectorsize && 629 length <= MAXPHYS, ("g_write_data(): invalid length %jd", 630 (intmax_t)length)); 631 632 bp = g_alloc_bio(); 633 bp->bio_cmd = BIO_WRITE; 634 bp->bio_done = NULL; 635 bp->bio_offset = offset; 636 bp->bio_length = length; 637 bp->bio_data = ptr; 638 g_io_request(bp, cp); 639 error = biowait(bp, "gwrite"); 640 g_destroy_bio(bp); 641 return (error); 642} 643 644void 645g_print_bio(struct bio *bp) 646{ 647 const char *pname, *cmd = NULL; 648 649 if (bp->bio_to != NULL) 650 pname = bp->bio_to->name; 651 else 652 pname = "[unknown]"; 653 654 switch (bp->bio_cmd) { 655 case BIO_GETATTR: 656 cmd = "GETATTR"; 657 printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute); 658 return; 659 case BIO_FLUSH: 660 cmd = "FLUSH"; 661 printf("%s[%s]", pname, cmd); 662 return; 663 case BIO_READ: 664 cmd = "READ"; 665 case BIO_WRITE: 666 if (cmd == NULL) 667 cmd = "WRITE"; 668 case BIO_DELETE: 669 if (cmd == NULL) 670 cmd = "DELETE"; 671 printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd, 672 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length); 673 return; 674 default: 675 cmd = "UNKNOWN"; 676 printf("%s[%s()]", pname, cmd); 677 return; 678 } 679 /* NOTREACHED */ 680} 681