1 /* 2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * ---------------------------------------------------------------------------- 35 * "THE BEER-WARE LICENSE" (Revision 42): 36 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 37 * can do whatever you want with this stuff. If we meet some day, and you think 38 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 39 * ---------------------------------------------------------------------------- 40 * 41 * Copyright (c) 1982, 1986, 1988, 1993 42 * The Regents of the University of California. All rights reserved. 43 * (c) UNIX System Laboratories, Inc. 44 * All or some portions of this file are derived from material licensed 45 * to the University of California by American Telephone and Telegraph 46 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 47 * the permission of UNIX System Laboratories, Inc. 48 * 49 * Redistribution and use in source and binary forms, with or without 50 * modification, are permitted provided that the following conditions 51 * are met: 52 * 1. Redistributions of source code must retain the above copyright 53 * notice, this list of conditions and the following disclaimer. 54 * 2. Redistributions in binary form must reproduce the above copyright 55 * notice, this list of conditions and the following disclaimer in the 56 * documentation and/or other materials provided with the distribution. 57 * 3. All advertising materials mentioning features or use of this software 58 * must display the following acknowledgement: 59 * This product includes software developed by the University of 60 * California, Berkeley and its contributors. 61 * 4. Neither the name of the University nor the names of its contributors 62 * may be used to endorse or promote products derived from this software 63 * without specific prior written permission. 64 * 65 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 66 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 67 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 68 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 69 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 70 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 71 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 72 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 73 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 74 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 75 * SUCH DAMAGE. 76 * 77 * @(#)ufs_disksubr.c 8.5 (Berkeley) 1/21/94 78 * $FreeBSD: src/sys/kern/subr_disk.c,v 1.20.2.6 2001/10/05 07:14:57 peter Exp $ 79 * $FreeBSD: src/sys/ufs/ufs/ufs_disksubr.c,v 1.44.2.3 2001/03/05 05:42:19 obrien Exp $ 80 * $DragonFly: src/sys/kern/subr_disk.c,v 1.40 2008/06/05 18:06:32 swildner Exp $ 81 */ 82 83 #include <sys/param.h> 84 #include <sys/systm.h> 85 #include <sys/kernel.h> 86 #include <sys/proc.h> 87 #include <sys/sysctl.h> 88 #include <sys/buf.h> 89 #include <sys/conf.h> 90 #include <sys/diskslice.h> 91 #include <sys/disk.h> 92 #include <sys/malloc.h> 93 #include <sys/sysctl.h> 94 #include <machine/md_var.h> 95 #include <sys/ctype.h> 96 #include <sys/syslog.h> 97 #include <sys/device.h> 98 #include <sys/msgport.h> 99 #include <sys/msgport2.h> 100 #include <sys/buf2.h> 101 102 static MALLOC_DEFINE(M_DISK, "disk", "disk data"); 103 104 static d_open_t diskopen; 105 static d_close_t diskclose; 106 static d_ioctl_t diskioctl; 107 static d_strategy_t diskstrategy; 108 static d_psize_t diskpsize; 109 static d_clone_t diskclone; 110 static d_dump_t diskdump; 111 112 static LIST_HEAD(, disk) disklist = LIST_HEAD_INITIALIZER(&disklist); 113 114 static struct dev_ops disk_ops = { 115 { "disk", 0, D_DISK }, 116 .d_open = diskopen, 117 .d_close = diskclose, 118 .d_read = physread, 119 .d_write = physwrite, 120 .d_ioctl = diskioctl, 121 .d_strategy = diskstrategy, 122 .d_dump = diskdump, 123 .d_psize = diskpsize, 124 .d_clone = diskclone 125 }; 126 127 /* 128 * Create a raw device for the dev_ops template (which is returned). Also 129 * create a slice and unit managed disk and overload the user visible 130 * device space with it. 131 * 132 * NOTE: The returned raw device is NOT a slice and unit managed device. 133 * It is an actual raw device representing the raw disk as specified by 134 * the passed dev_ops. The disk layer not only returns such a raw device, 135 * it also uses it internally when passing (modified) commands through. 136 */ 137 cdev_t 138 disk_create(int unit, struct disk *dp, struct dev_ops *raw_ops) 139 { 140 cdev_t rawdev; 141 struct dev_ops *dev_ops; 142 143 /* 144 * Create the raw backing device 145 */ 146 compile_dev_ops(raw_ops); 147 rawdev = make_dev(raw_ops, dkmakewholedisk(unit), 148 UID_ROOT, GID_OPERATOR, 0640, 149 "%s%d", raw_ops->head.name, unit); 150 151 bzero(dp, sizeof(*dp)); 152 153 /* 154 * We install a custom cdevsw rather then the passed cdevsw, 155 * and save our disk structure in d_data so we can get at it easily 156 * without any complex cloning code. 157 */ 158 dev_ops = dev_ops_add_override(rawdev, &disk_ops, 159 dkunitmask(), dkmakeunit(unit)); 160 dev_ops->head.data = dp; 161 162 dp->d_rawdev = rawdev; 163 dp->d_raw_ops = raw_ops; 164 dp->d_dev_ops = dev_ops; 165 dp->d_cdev = make_dev(dev_ops, 166 dkmakewholedisk(unit), 167 UID_ROOT, GID_OPERATOR, 0640, 168 "%s%d", dev_ops->head.name, unit); 169 170 LIST_INSERT_HEAD(&disklist, dp, d_list); 171 return (dp->d_rawdev); 172 } 173 174 /* 175 * Disk drivers must call this routine when media parameters are available 176 * or have changed. 177 */ 178 void 179 disk_setdiskinfo(struct disk *disk, struct disk_info *info) 180 { 181 bcopy(info, &disk->d_info, sizeof(disk->d_info)); 182 info = &disk->d_info; 183 184 KKASSERT(info->d_media_size == 0 || info->d_media_blksize == 0); 185 if (info->d_media_size == 0 && info->d_media_blocks) { 186 info->d_media_size = (u_int64_t)info->d_media_blocks * 187 info->d_media_blksize; 188 } else if (info->d_media_size && info->d_media_blocks == 0 && 189 info->d_media_blksize) { 190 info->d_media_blocks = info->d_media_size / 191 info->d_media_blksize; 192 } 193 } 194 195 /* 196 * This routine is called when an adapter detaches. The higher level 197 * managed disk device is destroyed while the lower level raw device is 198 * released. 199 */ 200 void 201 disk_destroy(struct disk *disk) 202 { 203 if (disk->d_dev_ops) { 204 dev_ops_remove(disk->d_dev_ops, dkunitmask(), 205 dkmakeunit(dkunit(disk->d_cdev))); 206 LIST_REMOVE(disk, d_list); 207 } 208 if (disk->d_raw_ops) { 209 destroy_all_devs(disk->d_raw_ops, dkunitmask(), 210 dkmakeunit(dkunit(disk->d_rawdev))); 211 } 212 bzero(disk, sizeof(*disk)); 213 } 214 215 int 216 disk_dumpcheck(cdev_t dev, u_int64_t *count, u_int64_t *blkno, u_int *secsize) 217 { 218 struct partinfo pinfo; 219 int error; 220 221 bzero(&pinfo, sizeof(pinfo)); 222 error = dev_dioctl(dev, DIOCGPART, (void *)&pinfo, 0, proc0.p_ucred); 223 if (error) 224 return (error); 225 if (pinfo.media_blksize == 0) 226 return (ENXIO); 227 *count = (u_int64_t)Maxmem * PAGE_SIZE / pinfo.media_blksize; 228 if (dumplo64 < pinfo.reserved_blocks || 229 dumplo64 + *count > pinfo.media_blocks) { 230 return (ENOSPC); 231 } 232 *blkno = dumplo64 + pinfo.media_offset / pinfo.media_blksize; 233 *secsize = pinfo.media_blksize; 234 return (0); 235 } 236 237 void 238 disk_invalidate (struct disk *disk) 239 { 240 if (disk->d_slice) 241 dsgone(&disk->d_slice); 242 } 243 244 struct disk * 245 disk_enumerate(struct disk *disk) 246 { 247 if (!disk) 248 return (LIST_FIRST(&disklist)); 249 else 250 return (LIST_NEXT(disk, d_list)); 251 } 252 253 static 254 int 255 sysctl_disks(SYSCTL_HANDLER_ARGS) 256 { 257 struct disk *disk; 258 int error, first; 259 260 disk = NULL; 261 first = 1; 262 263 while ((disk = disk_enumerate(disk))) { 264 if (!first) { 265 error = SYSCTL_OUT(req, " ", 1); 266 if (error) 267 return error; 268 } else { 269 first = 0; 270 } 271 error = SYSCTL_OUT(req, disk->d_rawdev->si_name, 272 strlen(disk->d_rawdev->si_name)); 273 if (error) 274 return error; 275 } 276 error = SYSCTL_OUT(req, "", 1); 277 return error; 278 } 279 280 SYSCTL_PROC(_kern, OID_AUTO, disks, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, 281 sysctl_disks, "A", "names of available disks"); 282 283 /* 284 * Open a disk device or partition. 285 */ 286 static 287 int 288 diskopen(struct dev_open_args *ap) 289 { 290 cdev_t dev = ap->a_head.a_dev; 291 struct disk *dp; 292 int error; 293 294 /* 295 * dp can't be NULL here XXX. 296 */ 297 dp = dev->si_disk; 298 if (dp == NULL) 299 return (ENXIO); 300 error = 0; 301 302 /* 303 * Deal with open races 304 */ 305 while (dp->d_flags & DISKFLAG_LOCK) { 306 dp->d_flags |= DISKFLAG_WANTED; 307 error = tsleep(dp, PCATCH, "diskopen", hz); 308 if (error) 309 return (error); 310 } 311 dp->d_flags |= DISKFLAG_LOCK; 312 313 /* 314 * Open the underlying raw device. 315 */ 316 if (!dsisopen(dp->d_slice)) { 317 #if 0 318 if (!pdev->si_iosize_max) 319 pdev->si_iosize_max = dev->si_iosize_max; 320 #endif 321 error = dev_dopen(dp->d_rawdev, ap->a_oflags, 322 ap->a_devtype, ap->a_cred); 323 } 324 325 /* 326 * Inherit properties from the underlying device now that it is 327 * open. 328 */ 329 dev_dclone(dev); 330 331 if (error) 332 goto out; 333 334 error = dsopen(dev, ap->a_devtype, dp->d_info.d_dsflags, 335 &dp->d_slice, &dp->d_info); 336 337 if (!dsisopen(dp->d_slice)) 338 dev_dclose(dp->d_rawdev, ap->a_oflags, ap->a_devtype); 339 out: 340 dp->d_flags &= ~DISKFLAG_LOCK; 341 if (dp->d_flags & DISKFLAG_WANTED) { 342 dp->d_flags &= ~DISKFLAG_WANTED; 343 wakeup(dp); 344 } 345 346 return(error); 347 } 348 349 /* 350 * Close a disk device or partition 351 */ 352 static 353 int 354 diskclose(struct dev_close_args *ap) 355 { 356 cdev_t dev = ap->a_head.a_dev; 357 struct disk *dp; 358 int error; 359 360 error = 0; 361 dp = dev->si_disk; 362 363 dsclose(dev, ap->a_devtype, dp->d_slice); 364 if (!dsisopen(dp->d_slice)) 365 error = dev_dclose(dp->d_rawdev, ap->a_fflag, ap->a_devtype); 366 return (error); 367 } 368 369 /* 370 * First execute the ioctl on the disk device, and if it isn't supported 371 * try running it on the backing device. 372 */ 373 static 374 int 375 diskioctl(struct dev_ioctl_args *ap) 376 { 377 cdev_t dev = ap->a_head.a_dev; 378 struct disk *dp; 379 int error; 380 381 dp = dev->si_disk; 382 if (dp == NULL) 383 return (ENXIO); 384 error = dsioctl(dev, ap->a_cmd, ap->a_data, ap->a_fflag, 385 &dp->d_slice, &dp->d_info); 386 if (error == ENOIOCTL) { 387 error = dev_dioctl(dp->d_rawdev, ap->a_cmd, ap->a_data, 388 ap->a_fflag, ap->a_cred); 389 } 390 return (error); 391 } 392 393 /* 394 * Execute strategy routine 395 */ 396 static 397 int 398 diskstrategy(struct dev_strategy_args *ap) 399 { 400 cdev_t dev = ap->a_head.a_dev; 401 struct bio *bio = ap->a_bio; 402 struct bio *nbio; 403 struct disk *dp; 404 405 dp = dev->si_disk; 406 407 if (dp == NULL) { 408 bio->bio_buf->b_error = ENXIO; 409 bio->bio_buf->b_flags |= B_ERROR; 410 biodone(bio); 411 return(0); 412 } 413 KKASSERT(dev->si_disk == dp); 414 415 /* 416 * The dscheck() function will also transform the slice relative 417 * block number i.e. bio->bio_offset into a block number that can be 418 * passed directly to the underlying raw device. If dscheck() 419 * returns NULL it will have handled the bio for us (e.g. EOF 420 * or error due to being beyond the device size). 421 */ 422 if ((nbio = dscheck(dev, bio, dp->d_slice)) != NULL) 423 dev_dstrategy(dp->d_rawdev, nbio); 424 else 425 biodone(bio); 426 return(0); 427 } 428 429 /* 430 * Return the partition size in ?blocks? 431 */ 432 static 433 int 434 diskpsize(struct dev_psize_args *ap) 435 { 436 cdev_t dev = ap->a_head.a_dev; 437 struct disk *dp; 438 439 dp = dev->si_disk; 440 if (dp == NULL) 441 return(ENODEV); 442 ap->a_result = dssize(dev, &dp->d_slice); 443 return(0); 444 } 445 446 /* 447 * When new device entries are instantiated, make sure they inherit our 448 * si_disk structure and block and iosize limits from the raw device. 449 * 450 * This routine is always called synchronously in the context of the 451 * client. 452 * 453 * XXX The various io and block size constraints are not always initialized 454 * properly by devices. 455 */ 456 static 457 int 458 diskclone(struct dev_clone_args *ap) 459 { 460 cdev_t dev = ap->a_head.a_dev; 461 struct disk *dp; 462 463 dp = dev->si_ops->head.data; 464 KKASSERT(dp != NULL); 465 dev->si_disk = dp; 466 dev->si_iosize_max = dp->d_rawdev->si_iosize_max; 467 dev->si_bsize_phys = dp->d_rawdev->si_bsize_phys; 468 dev->si_bsize_best = dp->d_rawdev->si_bsize_best; 469 return(0); 470 } 471 472 int 473 diskdump(struct dev_dump_args *ap) 474 { 475 cdev_t dev = ap->a_head.a_dev; 476 struct disk *dp = dev->si_ops->head.data; 477 int error; 478 479 error = disk_dumpcheck(dev, &ap->a_count, &ap->a_blkno, &ap->a_secsize); 480 if (error == 0) { 481 ap->a_head.a_dev = dp->d_rawdev; 482 error = dev_doperate(&ap->a_head); 483 } 484 485 return(error); 486 } 487 488 489 SYSCTL_INT(_debug_sizeof, OID_AUTO, diskslices, CTLFLAG_RD, 490 0, sizeof(struct diskslices), "sizeof(struct diskslices)"); 491 492 SYSCTL_INT(_debug_sizeof, OID_AUTO, disk, CTLFLAG_RD, 493 0, sizeof(struct disk), "sizeof(struct disk)"); 494 495 496 /* 497 * Seek sort for disks. 498 * 499 * The bio_queue keep two queues, sorted in ascending block order. The first 500 * queue holds those requests which are positioned after the current block 501 * (in the first request); the second, which starts at queue->switch_point, 502 * holds requests which came in after their block number was passed. Thus 503 * we implement a one way scan, retracting after reaching the end of the drive 504 * to the first request on the second queue, at which time it becomes the 505 * first queue. 506 * 507 * A one-way scan is natural because of the way UNIX read-ahead blocks are 508 * allocated. 509 */ 510 void 511 bioqdisksort(struct bio_queue_head *bioq, struct bio *bio) 512 { 513 struct bio *bq; 514 struct bio *bn; 515 struct bio *be; 516 517 be = TAILQ_LAST(&bioq->queue, bio_queue); 518 /* 519 * If the queue is empty or we are an 520 * ordered transaction, then it's easy. 521 */ 522 if ((bq = bioq_first(bioq)) == NULL || 523 (bio->bio_buf->b_flags & B_ORDERED) != 0) { 524 bioq_insert_tail(bioq, bio); 525 return; 526 } else if (bioq->insert_point != NULL) { 527 528 /* 529 * A certain portion of the list is 530 * "locked" to preserve ordering, so 531 * we can only insert after the insert 532 * point. 533 */ 534 bq = bioq->insert_point; 535 } else { 536 537 /* 538 * If we lie before the last removed (currently active) 539 * request, and are not inserting ourselves into the 540 * "locked" portion of the list, then we must add ourselves 541 * to the second request list. 542 */ 543 if (bio->bio_offset < bioq->last_offset) { 544 bq = bioq->switch_point; 545 /* 546 * If we are starting a new secondary list, 547 * then it's easy. 548 */ 549 if (bq == NULL) { 550 bioq->switch_point = bio; 551 bioq_insert_tail(bioq, bio); 552 return; 553 } 554 /* 555 * If we lie ahead of the current switch point, 556 * insert us before the switch point and move 557 * the switch point. 558 */ 559 if (bio->bio_offset < bq->bio_offset) { 560 bioq->switch_point = bio; 561 TAILQ_INSERT_BEFORE(bq, bio, bio_act); 562 return; 563 } 564 } else { 565 if (bioq->switch_point != NULL) 566 be = TAILQ_PREV(bioq->switch_point, 567 bio_queue, bio_act); 568 /* 569 * If we lie between last_offset and bq, 570 * insert before bq. 571 */ 572 if (bio->bio_offset < bq->bio_offset) { 573 TAILQ_INSERT_BEFORE(bq, bio, bio_act); 574 return; 575 } 576 } 577 } 578 579 /* 580 * Request is at/after our current position in the list. 581 * Optimize for sequential I/O by seeing if we go at the tail. 582 */ 583 if (bio->bio_offset > be->bio_offset) { 584 TAILQ_INSERT_AFTER(&bioq->queue, be, bio, bio_act); 585 return; 586 } 587 588 /* Otherwise, insertion sort */ 589 while ((bn = TAILQ_NEXT(bq, bio_act)) != NULL) { 590 591 /* 592 * We want to go after the current request if it is the end 593 * of the first request list, or if the next request is a 594 * larger cylinder than our request. 595 */ 596 if (bn == bioq->switch_point 597 || bio->bio_offset < bn->bio_offset) 598 break; 599 bq = bn; 600 } 601 TAILQ_INSERT_AFTER(&bioq->queue, bq, bio, bio_act); 602 } 603 604 /* 605 * Disk error is the preface to plaintive error messages 606 * about failing disk transfers. It prints messages of the form 607 608 hp0g: hard error reading fsbn 12345 of 12344-12347 (hp0 bn %d cn %d tn %d sn %d) 609 610 * if the offset of the error in the transfer and a disk label 611 * are both available. blkdone should be -1 if the position of the error 612 * is unknown; the disklabel pointer may be null from drivers that have not 613 * been converted to use them. The message is printed with kprintf 614 * if pri is LOG_PRINTF, otherwise it uses log at the specified priority. 615 * The message should be completed (with at least a newline) with kprintf 616 * or log(-1, ...), respectively. There is no trailing space. 617 */ 618 void 619 diskerr(struct bio *bio, cdev_t dev, const char *what, int pri, int donecnt) 620 { 621 struct buf *bp = bio->bio_buf; 622 int unit = dkunit(dev); 623 int slice = dkslice(dev); 624 int part = dkpart(dev); 625 char partname[2]; 626 char *sname; 627 const char *term; 628 629 switch(bp->b_cmd) { 630 case BUF_CMD_READ: 631 term = "read"; 632 break; 633 case BUF_CMD_WRITE: 634 term = "write"; 635 break; 636 default: 637 term = "access"; 638 break; 639 } 640 sname = dsname(dev, unit, slice, part, partname); 641 kprintf("%s%s: %s %sing ", sname, partname, what, term); 642 kprintf("offset %012llx for %d", bio->bio_offset, bp->b_bcount); 643 if (donecnt) 644 kprintf(" (%d bytes completed)", donecnt); 645 } 646 647 /* 648 * Locate a disk device 649 */ 650 cdev_t 651 disk_locate(const char *devname) 652 { 653 struct disk *dp; 654 cdev_t dev; 655 char *ptr; 656 int i; 657 int prefix; 658 int slice; 659 int part; 660 661 /* 662 * Device and unit 663 */ 664 for (i = 0; devname[i]; ++i) { 665 if (devname[i] >= '0' && devname[i] <= '9') 666 break; 667 } 668 while (devname[i] >= '0' && devname[i] <= '9') 669 ++i; 670 prefix = i; 671 672 /* 673 * Slice and partition. s1 starts at slice #2. s0 is slice #0. 674 * slice #1 is the WHOLE_DISK_SLICE. 675 */ 676 if (devname[i] == 's') { 677 slice = strtol(devname + i + 1, &ptr, 10); 678 i = (const char *)ptr - devname; 679 if (slice > 0) 680 ++slice; 681 } else { 682 slice = WHOLE_DISK_SLICE; 683 } 684 if (devname[i] >= 'a' && devname[i] <= 'z') { 685 part = devname[i] - 'a'; 686 } else { 687 part = WHOLE_SLICE_PART; 688 } 689 690 /* 691 * Find the device 692 */ 693 LIST_FOREACH(dp, &disklist, d_list) { 694 dev = dp->d_cdev; 695 if (strlen(dev->si_name) == prefix && 696 strncmp(devname, dev->si_name, prefix) == 0 697 ) { 698 return(dkmodpart(dkmodslice(dev, slice), part)); 699 } 700 } 701 return(NULL); 702 } 703 704