1 /* $NetBSD: spec_vnops.c,v 1.27 1995/10/15 05:18:12 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 * @(#)spec_vnops.c 8.8 (Berkeley) 11/21/94 36 */ 37 38 #include <sys/param.h> 39 #include <sys/proc.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/conf.h> 43 #include <sys/buf.h> 44 #include <sys/mount.h> 45 #include <sys/namei.h> 46 #include <sys/vnode.h> 47 #include <sys/stat.h> 48 #include <sys/errno.h> 49 #include <sys/ioctl.h> 50 #include <sys/file.h> 51 #include <sys/disklabel.h> 52 #include <miscfs/specfs/specdev.h> 53 54 /* symbolic sleep message strings for devices */ 55 char devopn[] = "devopn"; 56 char devio[] = "devio"; 57 char devwait[] = "devwait"; 58 char devin[] = "devin"; 59 char devout[] = "devout"; 60 char devioc[] = "devioc"; 61 char devcls[] = "devcls"; 62 63 int (**spec_vnodeop_p)(); 64 struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 65 { &vop_default_desc, vn_default_error }, 66 { &vop_lookup_desc, spec_lookup }, /* lookup */ 67 { &vop_create_desc, spec_create }, /* create */ 68 { &vop_mknod_desc, spec_mknod }, /* mknod */ 69 { &vop_open_desc, spec_open }, /* open */ 70 { &vop_close_desc, spec_close }, /* close */ 71 { &vop_access_desc, spec_access }, /* access */ 72 { &vop_getattr_desc, spec_getattr }, /* getattr */ 73 { &vop_setattr_desc, spec_setattr }, /* setattr */ 74 { &vop_read_desc, spec_read }, /* read */ 75 { &vop_write_desc, spec_write }, /* write */ 76 { &vop_lease_desc, spec_lease_check }, /* lease */ 77 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 78 { &vop_select_desc, spec_select }, /* select */ 79 { &vop_mmap_desc, spec_mmap }, /* mmap */ 80 { &vop_fsync_desc, spec_fsync }, /* fsync */ 81 { &vop_seek_desc, spec_seek }, /* seek */ 82 { &vop_remove_desc, spec_remove }, /* remove */ 83 { &vop_link_desc, spec_link }, /* link */ 84 { &vop_rename_desc, spec_rename }, /* rename */ 85 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 86 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 87 { &vop_symlink_desc, spec_symlink }, /* symlink */ 88 { &vop_readdir_desc, spec_readdir }, /* readdir */ 89 { &vop_readlink_desc, spec_readlink }, /* readlink */ 90 { &vop_abortop_desc, spec_abortop }, /* abortop */ 91 { &vop_inactive_desc, spec_inactive }, /* inactive */ 92 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 93 { &vop_lock_desc, spec_lock }, /* lock */ 94 { &vop_unlock_desc, spec_unlock }, /* unlock */ 95 { &vop_bmap_desc, spec_bmap }, /* bmap */ 96 { &vop_strategy_desc, spec_strategy }, /* strategy */ 97 { &vop_print_desc, spec_print }, /* print */ 98 { &vop_islocked_desc, spec_islocked }, /* islocked */ 99 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 100 { &vop_advlock_desc, spec_advlock }, /* advlock */ 101 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ 102 { &vop_valloc_desc, spec_valloc }, /* valloc */ 103 { &vop_vfree_desc, spec_vfree }, /* vfree */ 104 { &vop_truncate_desc, spec_truncate }, /* truncate */ 105 { &vop_update_desc, spec_update }, /* update */ 106 { &vop_bwrite_desc, vn_bwrite }, /* bwrite */ 107 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 108 }; 109 struct vnodeopv_desc spec_vnodeop_opv_desc = 110 { &spec_vnodeop_p, spec_vnodeop_entries }; 111 112 /* 113 * Trivial lookup routine that always fails. 114 */ 115 int 116 spec_lookup(ap) 117 struct vop_lookup_args /* { 118 struct vnode *a_dvp; 119 struct vnode **a_vpp; 120 struct componentname *a_cnp; 121 } */ *ap; 122 { 123 124 *ap->a_vpp = NULL; 125 return (ENOTDIR); 126 } 127 128 /* 129 * Open a special file. 130 */ 131 /* ARGSUSED */ 132 spec_open(ap) 133 struct vop_open_args /* { 134 struct vnode *a_vp; 135 int a_mode; 136 struct ucred *a_cred; 137 struct proc *a_p; 138 } */ *ap; 139 { 140 struct vnode *bvp, *vp = ap->a_vp; 141 dev_t bdev, dev = (dev_t)vp->v_rdev; 142 register int maj = major(dev); 143 int error; 144 145 /* 146 * Don't allow open if fs is mounted -nodev. 147 */ 148 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 149 return (ENXIO); 150 151 switch (vp->v_type) { 152 153 case VCHR: 154 if ((u_int)maj >= nchrdev) 155 return (ENXIO); 156 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 157 /* 158 * When running in very secure mode, do not allow 159 * opens for writing of any disk character devices. 160 */ 161 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK) 162 return (EPERM); 163 /* 164 * When running in secure mode, do not allow opens 165 * for writing of /dev/mem, /dev/kmem, or character 166 * devices whose corresponding block devices are 167 * currently mounted. 168 */ 169 if (securelevel >= 1) { 170 if ((bdev = chrtoblk(dev)) != NODEV && 171 vfinddev(bdev, VBLK, &bvp) && 172 bvp->v_usecount > 0 && 173 (error = vfs_mountedon(bvp))) 174 return (error); 175 if (iskmemdev(dev)) 176 return (EPERM); 177 } 178 } 179 if (cdevsw[maj].d_type == D_TTY) 180 vp->v_flag |= VISTTY; 181 VOP_UNLOCK(vp); 182 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p); 183 VOP_LOCK(vp); 184 return (error); 185 186 case VBLK: 187 if ((u_int)maj >= nblkdev) 188 return (ENXIO); 189 /* 190 * When running in very secure mode, do not allow 191 * opens for writing of any disk block devices. 192 */ 193 if (securelevel >= 2 && ap->a_cred != FSCRED && 194 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) 195 return (EPERM); 196 /* 197 * Do not allow opens of block devices that are 198 * currently mounted. 199 */ 200 if (error = vfs_mountedon(vp)) 201 return (error); 202 return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p)); 203 } 204 return (0); 205 } 206 207 /* 208 * Vnode op for read 209 */ 210 /* ARGSUSED */ 211 spec_read(ap) 212 struct vop_read_args /* { 213 struct vnode *a_vp; 214 struct uio *a_uio; 215 int a_ioflag; 216 struct ucred *a_cred; 217 } */ *ap; 218 { 219 register struct vnode *vp = ap->a_vp; 220 register struct uio *uio = ap->a_uio; 221 struct proc *p = uio->uio_procp; 222 struct buf *bp; 223 daddr_t bn, nextbn; 224 long bsize, bscale, ssize; 225 struct partinfo dpart; 226 int n, on, majordev, (*ioctl)(); 227 int error = 0; 228 229 #ifdef DIAGNOSTIC 230 if (uio->uio_rw != UIO_READ) 231 panic("spec_read mode"); 232 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 233 panic("spec_read proc"); 234 #endif 235 if (uio->uio_resid == 0) 236 return (0); 237 238 switch (vp->v_type) { 239 240 case VCHR: 241 VOP_UNLOCK(vp); 242 error = (*cdevsw[major(vp->v_rdev)].d_read) 243 (vp->v_rdev, uio, ap->a_ioflag); 244 VOP_LOCK(vp); 245 return (error); 246 247 case VBLK: 248 if (uio->uio_resid == 0) 249 return (0); 250 if (uio->uio_offset < 0) 251 return (EINVAL); 252 bsize = BLKDEV_IOSIZE; 253 ssize = DEV_BSIZE; 254 if ((majordev = major(vp->v_rdev)) < nblkdev && 255 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 256 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 257 if (dpart.part->p_fstype == FS_BSDFFS && 258 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 259 bsize = dpart.part->p_frag * 260 dpart.part->p_fsize; 261 if (dpart.disklab->d_secsize != 0) 262 ssize = dpart.disklab->d_secsize; 263 } 264 bscale = bsize / ssize; 265 do { 266 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 267 on = uio->uio_offset % bsize; 268 n = min((unsigned)(bsize - on), uio->uio_resid); 269 if (vp->v_lastr + bscale == bn) { 270 nextbn = bn + bscale; 271 error = breadn(vp, bn, (int)bsize, &nextbn, 272 (int *)&bsize, 1, NOCRED, &bp); 273 } else 274 error = bread(vp, bn, (int)bsize, NOCRED, &bp); 275 vp->v_lastr = bn; 276 n = min(n, bsize - bp->b_resid); 277 if (error) { 278 brelse(bp); 279 return (error); 280 } 281 error = uiomove((char *)bp->b_data + on, n, uio); 282 brelse(bp); 283 } while (error == 0 && uio->uio_resid > 0 && n != 0); 284 return (error); 285 286 default: 287 panic("spec_read type"); 288 } 289 /* NOTREACHED */ 290 } 291 292 /* 293 * Vnode op for write 294 */ 295 /* ARGSUSED */ 296 spec_write(ap) 297 struct vop_write_args /* { 298 struct vnode *a_vp; 299 struct uio *a_uio; 300 int a_ioflag; 301 struct ucred *a_cred; 302 } */ *ap; 303 { 304 register struct vnode *vp = ap->a_vp; 305 register struct uio *uio = ap->a_uio; 306 struct proc *p = uio->uio_procp; 307 struct buf *bp; 308 daddr_t bn; 309 long bsize, bscale, ssize; 310 struct partinfo dpart; 311 int n, on, majordev, (*ioctl)(); 312 int error = 0; 313 314 #ifdef DIAGNOSTIC 315 if (uio->uio_rw != UIO_WRITE) 316 panic("spec_write mode"); 317 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 318 panic("spec_write proc"); 319 #endif 320 321 switch (vp->v_type) { 322 323 case VCHR: 324 VOP_UNLOCK(vp); 325 error = (*cdevsw[major(vp->v_rdev)].d_write) 326 (vp->v_rdev, uio, ap->a_ioflag); 327 VOP_LOCK(vp); 328 return (error); 329 330 case VBLK: 331 if (uio->uio_resid == 0) 332 return (0); 333 if (uio->uio_offset < 0) 334 return (EINVAL); 335 bsize = BLKDEV_IOSIZE; 336 ssize = DEV_BSIZE; 337 if ((majordev = major(vp->v_rdev)) < nblkdev && 338 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 339 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 340 if (dpart.part->p_fstype == FS_BSDFFS && 341 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 342 bsize = dpart.part->p_frag * 343 dpart.part->p_fsize; 344 if (dpart.disklab->d_secsize != 0) 345 ssize = dpart.disklab->d_secsize; 346 } 347 bscale = bsize / ssize; 348 do { 349 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 350 on = uio->uio_offset % bsize; 351 n = min((unsigned)(bsize - on), uio->uio_resid); 352 if (n == bsize) 353 bp = getblk(vp, bn, bsize, 0, 0); 354 else 355 error = bread(vp, bn, bsize, NOCRED, &bp); 356 n = min(n, bsize - bp->b_resid); 357 if (error) { 358 brelse(bp); 359 return (error); 360 } 361 error = uiomove((char *)bp->b_data + on, n, uio); 362 if (n + on == bsize) 363 bawrite(bp); 364 else 365 bdwrite(bp); 366 } while (error == 0 && uio->uio_resid > 0 && n != 0); 367 return (error); 368 369 default: 370 panic("spec_write type"); 371 } 372 /* NOTREACHED */ 373 } 374 375 /* 376 * Device ioctl operation. 377 */ 378 /* ARGSUSED */ 379 spec_ioctl(ap) 380 struct vop_ioctl_args /* { 381 struct vnode *a_vp; 382 u_long a_command; 383 caddr_t a_data; 384 int a_fflag; 385 struct ucred *a_cred; 386 struct proc *a_p; 387 } */ *ap; 388 { 389 dev_t dev = ap->a_vp->v_rdev; 390 int maj = major(dev); 391 392 switch (ap->a_vp->v_type) { 393 394 case VCHR: 395 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 396 ap->a_fflag, ap->a_p)); 397 398 case VBLK: 399 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) 400 if (bdevsw[maj].d_type == D_TAPE) 401 return (0); 402 else 403 return (1); 404 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 405 ap->a_fflag, ap->a_p)); 406 407 default: 408 panic("spec_ioctl"); 409 /* NOTREACHED */ 410 } 411 } 412 413 /* ARGSUSED */ 414 spec_select(ap) 415 struct vop_select_args /* { 416 struct vnode *a_vp; 417 int a_which; 418 int a_fflags; 419 struct ucred *a_cred; 420 struct proc *a_p; 421 } */ *ap; 422 { 423 register dev_t dev; 424 425 switch (ap->a_vp->v_type) { 426 427 default: 428 return (1); /* XXX */ 429 430 case VCHR: 431 dev = ap->a_vp->v_rdev; 432 return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p); 433 } 434 } 435 /* 436 * Synch buffers associated with a block device 437 */ 438 /* ARGSUSED */ 439 int 440 spec_fsync(ap) 441 struct vop_fsync_args /* { 442 struct vnode *a_vp; 443 struct ucred *a_cred; 444 int a_waitfor; 445 struct proc *a_p; 446 } */ *ap; 447 { 448 register struct vnode *vp = ap->a_vp; 449 register struct buf *bp; 450 struct buf *nbp; 451 int s; 452 453 if (vp->v_type == VCHR) 454 return (0); 455 /* 456 * Flush all dirty buffers associated with a block device. 457 */ 458 loop: 459 s = splbio(); 460 for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) { 461 nbp = bp->b_vnbufs.le_next; 462 if ((bp->b_flags & B_BUSY)) 463 continue; 464 if ((bp->b_flags & B_DELWRI) == 0) 465 panic("spec_fsync: not dirty"); 466 bremfree(bp); 467 bp->b_flags |= B_BUSY; 468 splx(s); 469 bawrite(bp); 470 goto loop; 471 } 472 if (ap->a_waitfor == MNT_WAIT) { 473 while (vp->v_numoutput) { 474 vp->v_flag |= VBWAIT; 475 sleep((caddr_t)&vp->v_numoutput, PRIBIO + 1); 476 } 477 #ifdef DIAGNOSTIC 478 if (vp->v_dirtyblkhd.lh_first) { 479 splx(s); 480 vprint("spec_fsync: dirty", vp); 481 goto loop; 482 } 483 #endif 484 } 485 splx(s); 486 return (0); 487 } 488 489 /* 490 * Just call the device strategy routine 491 */ 492 spec_strategy(ap) 493 struct vop_strategy_args /* { 494 struct buf *a_bp; 495 } */ *ap; 496 { 497 498 (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); 499 return (0); 500 } 501 502 /* 503 * This is a noop, simply returning what one has been given. 504 */ 505 spec_bmap(ap) 506 struct vop_bmap_args /* { 507 struct vnode *a_vp; 508 daddr_t a_bn; 509 struct vnode **a_vpp; 510 daddr_t *a_bnp; 511 } */ *ap; 512 { 513 514 if (ap->a_vpp != NULL) 515 *ap->a_vpp = ap->a_vp; 516 if (ap->a_bnp != NULL) 517 *ap->a_bnp = ap->a_bn; 518 return (0); 519 } 520 521 /* 522 * At the moment we do not do any locking. 523 */ 524 /* ARGSUSED */ 525 spec_lock(ap) 526 struct vop_lock_args /* { 527 struct vnode *a_vp; 528 } */ *ap; 529 { 530 531 return (0); 532 } 533 534 /* ARGSUSED */ 535 spec_unlock(ap) 536 struct vop_unlock_args /* { 537 struct vnode *a_vp; 538 } */ *ap; 539 { 540 541 return (0); 542 } 543 544 /* 545 * Device close routine 546 */ 547 /* ARGSUSED */ 548 spec_close(ap) 549 struct vop_close_args /* { 550 struct vnode *a_vp; 551 int a_fflag; 552 struct ucred *a_cred; 553 struct proc *a_p; 554 } */ *ap; 555 { 556 register struct vnode *vp = ap->a_vp; 557 dev_t dev = vp->v_rdev; 558 int (*devclose) __P((dev_t, int, int, struct proc *)); 559 int mode, error; 560 561 switch (vp->v_type) { 562 563 case VCHR: 564 /* 565 * Hack: a tty device that is a controlling terminal 566 * has a reference from the session structure. 567 * We cannot easily tell that a character device is 568 * a controlling terminal, unless it is the closing 569 * process' controlling terminal. In that case, 570 * if the reference count is 2 (this last descriptor 571 * plus the session), release the reference from the session. 572 */ 573 if (vcount(vp) == 2 && ap->a_p && 574 vp == ap->a_p->p_session->s_ttyvp) { 575 vrele(vp); 576 ap->a_p->p_session->s_ttyvp = NULL; 577 } 578 /* 579 * If the vnode is locked, then we are in the midst 580 * of forcably closing the device, otherwise we only 581 * close on last reference. 582 */ 583 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 584 return (0); 585 devclose = cdevsw[major(dev)].d_close; 586 mode = S_IFCHR; 587 break; 588 589 case VBLK: 590 /* 591 * On last close of a block device (that isn't mounted) 592 * we must invalidate any in core blocks, so that 593 * we can, for instance, change floppy disks. 594 */ 595 if (error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0)) 596 return (error); 597 /* 598 * We do not want to really close the device if it 599 * is still in use unless we are trying to close it 600 * forcibly. Since every use (buffer, vnode, swap, cmap) 601 * holds a reference to the vnode, and because we mark 602 * any other vnodes that alias this device, when the 603 * sum of the reference counts on all the aliased 604 * vnodes descends to one, we are on last close. 605 */ 606 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 607 return (0); 608 devclose = bdevsw[major(dev)].d_close; 609 mode = S_IFBLK; 610 break; 611 612 default: 613 panic("spec_close: not special"); 614 } 615 616 return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); 617 } 618 619 /* 620 * Print out the contents of a special device vnode. 621 */ 622 spec_print(ap) 623 struct vop_print_args /* { 624 struct vnode *a_vp; 625 } */ *ap; 626 { 627 628 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 629 minor(ap->a_vp->v_rdev)); 630 } 631 632 /* 633 * Return POSIX pathconf information applicable to special devices. 634 */ 635 spec_pathconf(ap) 636 struct vop_pathconf_args /* { 637 struct vnode *a_vp; 638 int a_name; 639 register_t *a_retval; 640 } */ *ap; 641 { 642 643 switch (ap->a_name) { 644 case _PC_LINK_MAX: 645 *ap->a_retval = LINK_MAX; 646 return (0); 647 case _PC_MAX_CANON: 648 *ap->a_retval = MAX_CANON; 649 return (0); 650 case _PC_MAX_INPUT: 651 *ap->a_retval = MAX_INPUT; 652 return (0); 653 case _PC_PIPE_BUF: 654 *ap->a_retval = PIPE_BUF; 655 return (0); 656 case _PC_CHOWN_RESTRICTED: 657 *ap->a_retval = 1; 658 return (0); 659 case _PC_VDISABLE: 660 *ap->a_retval = _POSIX_VDISABLE; 661 return (0); 662 default: 663 return (EINVAL); 664 } 665 /* NOTREACHED */ 666 } 667 668 /* 669 * Special device advisory byte-level locks. 670 */ 671 /* ARGSUSED */ 672 spec_advlock(ap) 673 struct vop_advlock_args /* { 674 struct vnode *a_vp; 675 caddr_t a_id; 676 int a_op; 677 struct flock *a_fl; 678 int a_flags; 679 } */ *ap; 680 { 681 682 return (EOPNOTSUPP); 683 } 684 685 /* 686 * Special device failed operation 687 */ 688 spec_ebadf() 689 { 690 691 return (EBADF); 692 } 693 694 /* 695 * Special device bad operation 696 */ 697 spec_badop() 698 { 699 700 panic("spec_badop called"); 701 /* NOTREACHED */ 702 } 703