spec_vnops.c revision 1.30
1 /* $NetBSD: spec_vnops.c,v 1.30 1996/09/01 23:48:28 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 53 #include <miscfs/genfs/genfs.h> 54 #include <miscfs/specfs/specdev.h> 55 56 /* symbolic sleep message strings for devices */ 57 char devopn[] = "devopn"; 58 char devio[] = "devio"; 59 char devwait[] = "devwait"; 60 char devin[] = "devin"; 61 char devout[] = "devout"; 62 char devioc[] = "devioc"; 63 char devcls[] = "devcls"; 64 65 int (**spec_vnodeop_p) __P((void *)); 66 struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 67 { &vop_default_desc, vn_default_error }, 68 { &vop_lookup_desc, spec_lookup }, /* lookup */ 69 { &vop_create_desc, spec_create }, /* create */ 70 { &vop_mknod_desc, spec_mknod }, /* mknod */ 71 { &vop_open_desc, spec_open }, /* open */ 72 { &vop_close_desc, spec_close }, /* close */ 73 { &vop_access_desc, spec_access }, /* access */ 74 { &vop_getattr_desc, spec_getattr }, /* getattr */ 75 { &vop_setattr_desc, spec_setattr }, /* setattr */ 76 { &vop_read_desc, spec_read }, /* read */ 77 { &vop_write_desc, spec_write }, /* write */ 78 { &vop_lease_desc, spec_lease_check }, /* lease */ 79 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 80 { &vop_select_desc, spec_select }, /* select */ 81 { &vop_mmap_desc, spec_mmap }, /* mmap */ 82 { &vop_fsync_desc, spec_fsync }, /* fsync */ 83 { &vop_seek_desc, spec_seek }, /* seek */ 84 { &vop_remove_desc, spec_remove }, /* remove */ 85 { &vop_link_desc, spec_link }, /* link */ 86 { &vop_rename_desc, spec_rename }, /* rename */ 87 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 88 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 89 { &vop_symlink_desc, spec_symlink }, /* symlink */ 90 { &vop_readdir_desc, spec_readdir }, /* readdir */ 91 { &vop_readlink_desc, spec_readlink }, /* readlink */ 92 { &vop_abortop_desc, spec_abortop }, /* abortop */ 93 { &vop_inactive_desc, spec_inactive }, /* inactive */ 94 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 95 { &vop_lock_desc, spec_lock }, /* lock */ 96 { &vop_unlock_desc, spec_unlock }, /* unlock */ 97 { &vop_bmap_desc, spec_bmap }, /* bmap */ 98 { &vop_strategy_desc, spec_strategy }, /* strategy */ 99 { &vop_print_desc, spec_print }, /* print */ 100 { &vop_islocked_desc, spec_islocked }, /* islocked */ 101 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 102 { &vop_advlock_desc, spec_advlock }, /* advlock */ 103 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ 104 { &vop_valloc_desc, spec_valloc }, /* valloc */ 105 { &vop_vfree_desc, spec_vfree }, /* vfree */ 106 { &vop_truncate_desc, spec_truncate }, /* truncate */ 107 { &vop_update_desc, spec_update }, /* update */ 108 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 109 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 110 }; 111 struct vnodeopv_desc spec_vnodeop_opv_desc = 112 { &spec_vnodeop_p, spec_vnodeop_entries }; 113 114 /* 115 * Trivial lookup routine that always fails. 116 */ 117 int 118 spec_lookup(v) 119 void *v; 120 { 121 struct vop_lookup_args /* { 122 struct vnode *a_dvp; 123 struct vnode **a_vpp; 124 struct componentname *a_cnp; 125 } */ *ap = v; 126 127 *ap->a_vpp = NULL; 128 return (ENOTDIR); 129 } 130 131 /* 132 * Open a special file. 133 */ 134 /* ARGSUSED */ 135 int 136 spec_open(v) 137 void *v; 138 { 139 struct vop_open_args /* { 140 struct vnode *a_vp; 141 int a_mode; 142 struct ucred *a_cred; 143 struct proc *a_p; 144 } */ *ap = v; 145 struct vnode *bvp, *vp = ap->a_vp; 146 dev_t bdev, dev = (dev_t)vp->v_rdev; 147 register int maj = major(dev); 148 int error; 149 150 /* 151 * Don't allow open if fs is mounted -nodev. 152 */ 153 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 154 return (ENXIO); 155 156 switch (vp->v_type) { 157 158 case VCHR: 159 if ((u_int)maj >= nchrdev) 160 return (ENXIO); 161 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 162 /* 163 * When running in very secure mode, do not allow 164 * opens for writing of any disk character devices. 165 */ 166 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK) 167 return (EPERM); 168 /* 169 * When running in secure mode, do not allow opens 170 * for writing of /dev/mem, /dev/kmem, or character 171 * devices whose corresponding block devices are 172 * currently mounted. 173 */ 174 if (securelevel >= 1) { 175 if ((bdev = chrtoblk(dev)) != NODEV && 176 vfinddev(bdev, VBLK, &bvp) && 177 bvp->v_usecount > 0 && 178 (error = vfs_mountedon(bvp))) 179 return (error); 180 if (iskmemdev(dev)) 181 return (EPERM); 182 } 183 } 184 if (cdevsw[maj].d_type == D_TTY) 185 vp->v_flag |= VISTTY; 186 VOP_UNLOCK(vp); 187 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p); 188 VOP_LOCK(vp); 189 return (error); 190 191 case VBLK: 192 if ((u_int)maj >= nblkdev) 193 return (ENXIO); 194 /* 195 * When running in very secure mode, do not allow 196 * opens for writing of any disk block devices. 197 */ 198 if (securelevel >= 2 && ap->a_cred != FSCRED && 199 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) 200 return (EPERM); 201 /* 202 * Do not allow opens of block devices that are 203 * currently mounted. 204 */ 205 if ((error = vfs_mountedon(vp)) != 0) 206 return (error); 207 return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p)); 208 case VNON: 209 case VLNK: 210 case VDIR: 211 case VREG: 212 case VBAD: 213 case VFIFO: 214 case VSOCK: 215 break; 216 } 217 return (0); 218 } 219 220 /* 221 * Vnode op for read 222 */ 223 /* ARGSUSED */ 224 int 225 spec_read(v) 226 void *v; 227 { 228 struct vop_read_args /* { 229 struct vnode *a_vp; 230 struct uio *a_uio; 231 int a_ioflag; 232 struct ucred *a_cred; 233 } */ *ap = v; 234 register struct vnode *vp = ap->a_vp; 235 register struct uio *uio = ap->a_uio; 236 struct proc *p = uio->uio_procp; 237 struct buf *bp; 238 daddr_t bn, nextbn; 239 long bsize, bscale, ssize; 240 struct partinfo dpart; 241 int n, on, majordev; 242 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *)); 243 int error = 0; 244 245 #ifdef DIAGNOSTIC 246 if (uio->uio_rw != UIO_READ) 247 panic("spec_read mode"); 248 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 249 panic("spec_read proc"); 250 #endif 251 if (uio->uio_resid == 0) 252 return (0); 253 254 switch (vp->v_type) { 255 256 case VCHR: 257 VOP_UNLOCK(vp); 258 error = (*cdevsw[major(vp->v_rdev)].d_read) 259 (vp->v_rdev, uio, ap->a_ioflag); 260 VOP_LOCK(vp); 261 return (error); 262 263 case VBLK: 264 if (uio->uio_resid == 0) 265 return (0); 266 if (uio->uio_offset < 0) 267 return (EINVAL); 268 bsize = BLKDEV_IOSIZE; 269 ssize = DEV_BSIZE; 270 if ((majordev = major(vp->v_rdev)) < nblkdev && 271 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 272 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 273 if (dpart.part->p_fstype == FS_BSDFFS && 274 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 275 bsize = dpart.part->p_frag * 276 dpart.part->p_fsize; 277 if (dpart.disklab->d_secsize != 0) 278 ssize = dpart.disklab->d_secsize; 279 } 280 bscale = bsize / ssize; 281 do { 282 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 283 on = uio->uio_offset % bsize; 284 n = min((unsigned)(bsize - on), uio->uio_resid); 285 if (vp->v_lastr + bscale == bn) { 286 nextbn = bn + bscale; 287 error = breadn(vp, bn, (int)bsize, &nextbn, 288 (int *)&bsize, 1, NOCRED, &bp); 289 } else 290 error = bread(vp, bn, (int)bsize, NOCRED, &bp); 291 vp->v_lastr = bn; 292 n = min(n, bsize - bp->b_resid); 293 if (error) { 294 brelse(bp); 295 return (error); 296 } 297 error = uiomove((char *)bp->b_data + on, n, uio); 298 brelse(bp); 299 } while (error == 0 && uio->uio_resid > 0 && n != 0); 300 return (error); 301 302 default: 303 panic("spec_read type"); 304 } 305 /* NOTREACHED */ 306 } 307 308 /* 309 * Vnode op for write 310 */ 311 /* ARGSUSED */ 312 int 313 spec_write(v) 314 void *v; 315 { 316 struct vop_write_args /* { 317 struct vnode *a_vp; 318 struct uio *a_uio; 319 int a_ioflag; 320 struct ucred *a_cred; 321 } */ *ap = v; 322 register struct vnode *vp = ap->a_vp; 323 register struct uio *uio = ap->a_uio; 324 struct proc *p = uio->uio_procp; 325 struct buf *bp; 326 daddr_t bn; 327 long bsize, bscale, ssize; 328 struct partinfo dpart; 329 int n, on, majordev; 330 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *)); 331 int error = 0; 332 333 #ifdef DIAGNOSTIC 334 if (uio->uio_rw != UIO_WRITE) 335 panic("spec_write mode"); 336 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 337 panic("spec_write proc"); 338 #endif 339 340 switch (vp->v_type) { 341 342 case VCHR: 343 VOP_UNLOCK(vp); 344 error = (*cdevsw[major(vp->v_rdev)].d_write) 345 (vp->v_rdev, uio, ap->a_ioflag); 346 VOP_LOCK(vp); 347 return (error); 348 349 case VBLK: 350 if (uio->uio_resid == 0) 351 return (0); 352 if (uio->uio_offset < 0) 353 return (EINVAL); 354 bsize = BLKDEV_IOSIZE; 355 ssize = DEV_BSIZE; 356 if ((majordev = major(vp->v_rdev)) < nblkdev && 357 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 358 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 359 if (dpart.part->p_fstype == FS_BSDFFS && 360 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 361 bsize = dpart.part->p_frag * 362 dpart.part->p_fsize; 363 if (dpart.disklab->d_secsize != 0) 364 ssize = dpart.disklab->d_secsize; 365 } 366 bscale = bsize / ssize; 367 do { 368 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 369 on = uio->uio_offset % bsize; 370 n = min((unsigned)(bsize - on), uio->uio_resid); 371 if (n == bsize) 372 bp = getblk(vp, bn, bsize, 0, 0); 373 else 374 error = bread(vp, bn, bsize, NOCRED, &bp); 375 n = min(n, bsize - bp->b_resid); 376 if (error) { 377 brelse(bp); 378 return (error); 379 } 380 error = uiomove((char *)bp->b_data + on, n, uio); 381 if (n + on == bsize) 382 bawrite(bp); 383 else 384 bdwrite(bp); 385 } while (error == 0 && uio->uio_resid > 0 && n != 0); 386 return (error); 387 388 default: 389 panic("spec_write type"); 390 } 391 /* NOTREACHED */ 392 } 393 394 /* 395 * Device ioctl operation. 396 */ 397 /* ARGSUSED */ 398 int 399 spec_ioctl(v) 400 void *v; 401 { 402 struct vop_ioctl_args /* { 403 struct vnode *a_vp; 404 u_long a_command; 405 caddr_t a_data; 406 int a_fflag; 407 struct ucred *a_cred; 408 struct proc *a_p; 409 } */ *ap = v; 410 dev_t dev = ap->a_vp->v_rdev; 411 int maj = major(dev); 412 413 switch (ap->a_vp->v_type) { 414 415 case VCHR: 416 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 417 ap->a_fflag, ap->a_p)); 418 419 case VBLK: 420 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) 421 if (bdevsw[maj].d_type == D_TAPE) 422 return (0); 423 else 424 return (1); 425 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 426 ap->a_fflag, ap->a_p)); 427 428 default: 429 panic("spec_ioctl"); 430 /* NOTREACHED */ 431 } 432 } 433 434 /* ARGSUSED */ 435 int 436 spec_select(v) 437 void *v; 438 { 439 struct vop_select_args /* { 440 struct vnode *a_vp; 441 int a_which; 442 int a_fflags; 443 struct ucred *a_cred; 444 struct proc *a_p; 445 } */ *ap = v; 446 register dev_t dev; 447 448 switch (ap->a_vp->v_type) { 449 450 case VCHR: 451 dev = ap->a_vp->v_rdev; 452 return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p); 453 454 default: 455 return (genfs_select(v)); 456 } 457 } 458 /* 459 * Synch buffers associated with a block device 460 */ 461 /* ARGSUSED */ 462 int 463 spec_fsync(v) 464 void *v; 465 { 466 struct vop_fsync_args /* { 467 struct vnode *a_vp; 468 struct ucred *a_cred; 469 int a_waitfor; 470 struct proc *a_p; 471 } */ *ap = v; 472 register struct vnode *vp = ap->a_vp; 473 register struct buf *bp; 474 struct buf *nbp; 475 int s; 476 477 if (vp->v_type == VBLK) 478 vflushbuf(vp, ap->a_waitfor == MNT_WAIT); 479 return (0); 480 } 481 482 /* 483 * Just call the device strategy routine 484 */ 485 int 486 spec_strategy(v) 487 void *v; 488 { 489 struct vop_strategy_args /* { 490 struct buf *a_bp; 491 } */ *ap = v; 492 493 (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); 494 return (0); 495 } 496 497 /* 498 * This is a noop, simply returning what one has been given. 499 */ 500 int 501 spec_bmap(v) 502 void *v; 503 { 504 struct vop_bmap_args /* { 505 struct vnode *a_vp; 506 daddr_t a_bn; 507 struct vnode **a_vpp; 508 daddr_t *a_bnp; 509 } */ *ap = v; 510 511 if (ap->a_vpp != NULL) 512 *ap->a_vpp = ap->a_vp; 513 if (ap->a_bnp != NULL) 514 *ap->a_bnp = ap->a_bn; 515 return (0); 516 } 517 518 /* 519 * At the moment we do not do any locking. 520 */ 521 /* ARGSUSED */ 522 int 523 spec_lock(v) 524 void *v; 525 { 526 527 return (0); 528 } 529 530 /* ARGSUSED */ 531 int 532 spec_unlock(v) 533 void *v; 534 { 535 536 return (0); 537 } 538 539 /* 540 * Device close routine 541 */ 542 /* ARGSUSED */ 543 int 544 spec_close(v) 545 void *v; 546 { 547 struct vop_close_args /* { 548 struct vnode *a_vp; 549 int a_fflag; 550 struct ucred *a_cred; 551 struct proc *a_p; 552 } */ *ap = v; 553 register struct vnode *vp = ap->a_vp; 554 dev_t dev = vp->v_rdev; 555 int (*devclose) __P((dev_t, int, int, struct proc *)); 556 int mode, error; 557 558 switch (vp->v_type) { 559 560 case VCHR: 561 /* 562 * Hack: a tty device that is a controlling terminal 563 * has a reference from the session structure. 564 * We cannot easily tell that a character device is 565 * a controlling terminal, unless it is the closing 566 * process' controlling terminal. In that case, 567 * if the reference count is 2 (this last descriptor 568 * plus the session), release the reference from the session. 569 */ 570 if (vcount(vp) == 2 && ap->a_p && 571 vp == ap->a_p->p_session->s_ttyvp) { 572 vrele(vp); 573 ap->a_p->p_session->s_ttyvp = NULL; 574 } 575 /* 576 * If the vnode is locked, then we are in the midst 577 * of forcably closing the device, otherwise we only 578 * close on last reference. 579 */ 580 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 581 return (0); 582 devclose = cdevsw[major(dev)].d_close; 583 mode = S_IFCHR; 584 break; 585 586 case VBLK: 587 /* 588 * On last close of a block device (that isn't mounted) 589 * we must invalidate any in core blocks, so that 590 * we can, for instance, change floppy disks. 591 */ 592 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); 593 if (error) 594 return (error); 595 /* 596 * We do not want to really close the device if it 597 * is still in use unless we are trying to close it 598 * forcibly. Since every use (buffer, vnode, swap, cmap) 599 * holds a reference to the vnode, and because we mark 600 * any other vnodes that alias this device, when the 601 * sum of the reference counts on all the aliased 602 * vnodes descends to one, we are on last close. 603 */ 604 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 605 return (0); 606 devclose = bdevsw[major(dev)].d_close; 607 mode = S_IFBLK; 608 break; 609 610 default: 611 panic("spec_close: not special"); 612 } 613 614 return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); 615 } 616 617 /* 618 * Print out the contents of a special device vnode. 619 */ 620 int 621 spec_print(v) 622 void *v; 623 { 624 struct vop_print_args /* { 625 struct vnode *a_vp; 626 } */ *ap = v; 627 628 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 629 minor(ap->a_vp->v_rdev)); 630 return 0; 631 } 632 633 /* 634 * Return POSIX pathconf information applicable to special devices. 635 */ 636 int 637 spec_pathconf(v) 638 void *v; 639 { 640 struct vop_pathconf_args /* { 641 struct vnode *a_vp; 642 int a_name; 643 register_t *a_retval; 644 } */ *ap = v; 645 646 switch (ap->a_name) { 647 case _PC_LINK_MAX: 648 *ap->a_retval = LINK_MAX; 649 return (0); 650 case _PC_MAX_CANON: 651 *ap->a_retval = MAX_CANON; 652 return (0); 653 case _PC_MAX_INPUT: 654 *ap->a_retval = MAX_INPUT; 655 return (0); 656 case _PC_PIPE_BUF: 657 *ap->a_retval = PIPE_BUF; 658 return (0); 659 case _PC_CHOWN_RESTRICTED: 660 *ap->a_retval = 1; 661 return (0); 662 case _PC_VDISABLE: 663 *ap->a_retval = _POSIX_VDISABLE; 664 return (0); 665 default: 666 return (EINVAL); 667 } 668 /* NOTREACHED */ 669 } 670
Indexes created Mon Sep 22 13:09:51 GMT 2025