spec_vnops.c revision 1.38
1 /* $NetBSD: spec_vnops.c,v 1.38 1997/10/16 23:57:51 christos 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 <sys/lockf.h> 53 54 #include <miscfs/genfs/genfs.h> 55 #include <miscfs/specfs/specdev.h> 56 57 /* symbolic sleep message strings for devices */ 58 const char devopn[] = "devopn"; 59 const char devio[] = "devio"; 60 const char devwait[] = "devwait"; 61 const char devin[] = "devin"; 62 const char devout[] = "devout"; 63 const char devioc[] = "devioc"; 64 const char devcls[] = "devcls"; 65 66 int (**spec_vnodeop_p) __P((void *)); 67 struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 68 { &vop_default_desc, vn_default_error }, 69 { &vop_lookup_desc, spec_lookup }, /* lookup */ 70 { &vop_create_desc, spec_create }, /* create */ 71 { &vop_mknod_desc, spec_mknod }, /* mknod */ 72 { &vop_open_desc, spec_open }, /* open */ 73 { &vop_close_desc, spec_close }, /* close */ 74 { &vop_access_desc, spec_access }, /* access */ 75 { &vop_getattr_desc, spec_getattr }, /* getattr */ 76 { &vop_setattr_desc, spec_setattr }, /* setattr */ 77 { &vop_read_desc, spec_read }, /* read */ 78 { &vop_write_desc, spec_write }, /* write */ 79 { &vop_lease_desc, spec_lease_check }, /* lease */ 80 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 81 { &vop_poll_desc, spec_poll }, /* poll */ 82 { &vop_mmap_desc, spec_mmap }, /* mmap */ 83 { &vop_fsync_desc, spec_fsync }, /* fsync */ 84 { &vop_seek_desc, spec_seek }, /* seek */ 85 { &vop_remove_desc, spec_remove }, /* remove */ 86 { &vop_link_desc, spec_link }, /* link */ 87 { &vop_rename_desc, spec_rename }, /* rename */ 88 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 89 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 90 { &vop_symlink_desc, spec_symlink }, /* symlink */ 91 { &vop_readdir_desc, spec_readdir }, /* readdir */ 92 { &vop_readlink_desc, spec_readlink }, /* readlink */ 93 { &vop_abortop_desc, spec_abortop }, /* abortop */ 94 { &vop_inactive_desc, spec_inactive }, /* inactive */ 95 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 96 { &vop_lock_desc, spec_lock }, /* lock */ 97 { &vop_unlock_desc, spec_unlock }, /* unlock */ 98 { &vop_bmap_desc, spec_bmap }, /* bmap */ 99 { &vop_strategy_desc, spec_strategy }, /* strategy */ 100 { &vop_print_desc, spec_print }, /* print */ 101 { &vop_islocked_desc, spec_islocked }, /* islocked */ 102 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 103 { &vop_advlock_desc, spec_advlock }, /* advlock */ 104 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ 105 { &vop_valloc_desc, spec_valloc }, /* valloc */ 106 { &vop_vfree_desc, spec_vfree }, /* vfree */ 107 { &vop_truncate_desc, spec_truncate }, /* truncate */ 108 { &vop_update_desc, spec_update }, /* update */ 109 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 110 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL } 111 }; 112 struct vnodeopv_desc spec_vnodeop_opv_desc = 113 { &spec_vnodeop_p, spec_vnodeop_entries }; 114 115 /* 116 * Trivial lookup routine that always fails. 117 */ 118 int 119 spec_lookup(v) 120 void *v; 121 { 122 struct vop_lookup_args /* { 123 struct vnode *a_dvp; 124 struct vnode **a_vpp; 125 struct componentname *a_cnp; 126 } */ *ap = v; 127 128 *ap->a_vpp = NULL; 129 return (ENOTDIR); 130 } 131 132 /* 133 * Open a special file. 134 */ 135 /* ARGSUSED */ 136 int 137 spec_open(v) 138 void *v; 139 { 140 struct vop_open_args /* { 141 struct vnode *a_vp; 142 int a_mode; 143 struct ucred *a_cred; 144 struct proc *a_p; 145 } */ *ap = v; 146 struct vnode *bvp, *vp = ap->a_vp; 147 dev_t bdev, dev = (dev_t)vp->v_rdev; 148 register int maj = major(dev); 149 int error; 150 151 /* 152 * Don't allow open if fs is mounted -nodev. 153 */ 154 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 155 return (ENXIO); 156 157 switch (vp->v_type) { 158 159 case VCHR: 160 if ((u_int)maj >= nchrdev) 161 return (ENXIO); 162 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 163 /* 164 * When running in very secure mode, do not allow 165 * opens for writing of any disk character devices. 166 */ 167 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK) 168 return (EPERM); 169 /* 170 * When running in secure mode, do not allow opens 171 * for writing of /dev/mem, /dev/kmem, or character 172 * devices whose corresponding block devices are 173 * currently mounted. 174 */ 175 if (securelevel >= 1) { 176 if ((bdev = chrtoblk(dev)) != (dev_t)NODEV && 177 vfinddev(bdev, VBLK, &bvp) && 178 bvp->v_usecount > 0 && 179 (error = vfs_mountedon(bvp))) 180 return (error); 181 if (iskmemdev(dev)) 182 return (EPERM); 183 } 184 } 185 if (cdevsw[maj].d_type == D_TTY) 186 vp->v_flag |= VISTTY; 187 VOP_UNLOCK(vp); 188 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p); 189 VOP_LOCK(vp); 190 return (error); 191 192 case VBLK: 193 if ((u_int)maj >= nblkdev) 194 return (ENXIO); 195 /* 196 * When running in very secure mode, do not allow 197 * opens for writing of any disk block devices. 198 */ 199 if (securelevel >= 2 && ap->a_cred != FSCRED && 200 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK) 201 return (EPERM); 202 /* 203 * Do not allow opens of block devices that are 204 * currently mounted. 205 */ 206 if ((error = vfs_mountedon(vp)) != 0) 207 return (error); 208 return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p)); 209 case VNON: 210 case VLNK: 211 case VDIR: 212 case VREG: 213 case VBAD: 214 case VFIFO: 215 case VSOCK: 216 break; 217 } 218 return (0); 219 } 220 221 /* 222 * Vnode op for read 223 */ 224 /* ARGSUSED */ 225 int 226 spec_read(v) 227 void *v; 228 { 229 struct vop_read_args /* { 230 struct vnode *a_vp; 231 struct uio *a_uio; 232 int a_ioflag; 233 struct ucred *a_cred; 234 } */ *ap = v; 235 register struct vnode *vp = ap->a_vp; 236 register struct uio *uio = ap->a_uio; 237 struct proc *p = uio->uio_procp; 238 struct buf *bp; 239 daddr_t bn, nextbn; 240 long bsize, bscale, ssize; 241 struct partinfo dpart; 242 int n, on, majordev; 243 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *)); 244 int error = 0; 245 246 #ifdef DIAGNOSTIC 247 if (uio->uio_rw != UIO_READ) 248 panic("spec_read mode"); 249 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 250 panic("spec_read proc"); 251 #endif 252 if (uio->uio_resid == 0) 253 return (0); 254 255 switch (vp->v_type) { 256 257 case VCHR: 258 VOP_UNLOCK(vp); 259 error = (*cdevsw[major(vp->v_rdev)].d_read) 260 (vp->v_rdev, uio, ap->a_ioflag); 261 VOP_LOCK(vp); 262 return (error); 263 264 case VBLK: 265 if (uio->uio_offset < 0) 266 return (EINVAL); 267 bsize = BLKDEV_IOSIZE; 268 ssize = DEV_BSIZE; 269 if ((majordev = major(vp->v_rdev)) < nblkdev && 270 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 271 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 272 if (dpart.part->p_fstype == FS_BSDFFS && 273 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 274 bsize = dpart.part->p_frag * 275 dpart.part->p_fsize; 276 if (dpart.disklab->d_secsize != 0) 277 ssize = dpart.disklab->d_secsize; 278 } 279 bscale = bsize / ssize; 280 do { 281 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 282 on = uio->uio_offset % bsize; 283 n = min((unsigned)(bsize - on), uio->uio_resid); 284 if (vp->v_lastr + bscale == bn) { 285 nextbn = bn + bscale; 286 error = breadn(vp, bn, (int)bsize, &nextbn, 287 (int *)&bsize, 1, NOCRED, &bp); 288 } else 289 error = bread(vp, bn, (int)bsize, NOCRED, &bp); 290 vp->v_lastr = bn; 291 n = min(n, bsize - bp->b_resid); 292 if (error) { 293 brelse(bp); 294 return (error); 295 } 296 error = uiomove((char *)bp->b_data + on, n, uio); 297 brelse(bp); 298 } while (error == 0 && uio->uio_resid > 0 && n != 0); 299 return (error); 300 301 default: 302 panic("spec_read type"); 303 } 304 /* NOTREACHED */ 305 } 306 307 /* 308 * Vnode op for write 309 */ 310 /* ARGSUSED */ 311 int 312 spec_write(v) 313 void *v; 314 { 315 struct vop_write_args /* { 316 struct vnode *a_vp; 317 struct uio *a_uio; 318 int a_ioflag; 319 struct ucred *a_cred; 320 } */ *ap = v; 321 register struct vnode *vp = ap->a_vp; 322 register struct uio *uio = ap->a_uio; 323 struct proc *p = uio->uio_procp; 324 struct buf *bp; 325 daddr_t bn; 326 long bsize, bscale, ssize; 327 struct partinfo dpart; 328 int n, on, majordev; 329 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *)); 330 int error = 0; 331 332 #ifdef DIAGNOSTIC 333 if (uio->uio_rw != UIO_WRITE) 334 panic("spec_write mode"); 335 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 336 panic("spec_write proc"); 337 #endif 338 339 switch (vp->v_type) { 340 341 case VCHR: 342 VOP_UNLOCK(vp); 343 error = (*cdevsw[major(vp->v_rdev)].d_write) 344 (vp->v_rdev, uio, ap->a_ioflag); 345 VOP_LOCK(vp); 346 return (error); 347 348 case VBLK: 349 if (uio->uio_resid == 0) 350 return (0); 351 if (uio->uio_offset < 0) 352 return (EINVAL); 353 bsize = BLKDEV_IOSIZE; 354 ssize = DEV_BSIZE; 355 if ((majordev = major(vp->v_rdev)) < nblkdev && 356 (ioctl = bdevsw[majordev].d_ioctl) != NULL && 357 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) { 358 if (dpart.part->p_fstype == FS_BSDFFS && 359 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 360 bsize = dpart.part->p_frag * 361 dpart.part->p_fsize; 362 if (dpart.disklab->d_secsize != 0) 363 ssize = dpart.disklab->d_secsize; 364 } 365 bscale = bsize / ssize; 366 do { 367 bn = (uio->uio_offset / ssize) &~ (bscale - 1); 368 on = uio->uio_offset % bsize; 369 n = min((unsigned)(bsize - on), uio->uio_resid); 370 if (n == bsize) 371 bp = getblk(vp, bn, bsize, 0, 0); 372 else 373 error = bread(vp, bn, bsize, NOCRED, &bp); 374 n = min(n, bsize - bp->b_resid); 375 if (error) { 376 brelse(bp); 377 return (error); 378 } 379 error = uiomove((char *)bp->b_data + on, n, uio); 380 if (n + on == bsize) 381 bawrite(bp); 382 else 383 bdwrite(bp); 384 } while (error == 0 && uio->uio_resid > 0 && n != 0); 385 return (error); 386 387 default: 388 panic("spec_write type"); 389 } 390 /* NOTREACHED */ 391 } 392 393 /* 394 * Device ioctl operation. 395 */ 396 /* ARGSUSED */ 397 int 398 spec_ioctl(v) 399 void *v; 400 { 401 struct vop_ioctl_args /* { 402 struct vnode *a_vp; 403 u_long a_command; 404 caddr_t a_data; 405 int a_fflag; 406 struct ucred *a_cred; 407 struct proc *a_p; 408 } */ *ap = v; 409 dev_t dev = ap->a_vp->v_rdev; 410 int maj = major(dev); 411 412 switch (ap->a_vp->v_type) { 413 414 case VCHR: 415 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 416 ap->a_fflag, ap->a_p)); 417 418 case VBLK: 419 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) 420 if (bdevsw[maj].d_type == D_TAPE) 421 return (0); 422 else 423 return (1); 424 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data, 425 ap->a_fflag, ap->a_p)); 426 427 default: 428 panic("spec_ioctl"); 429 /* NOTREACHED */ 430 } 431 } 432 433 /* ARGSUSED */ 434 int 435 spec_poll(v) 436 void *v; 437 { 438 struct vop_poll_args /* { 439 struct vnode *a_vp; 440 int a_events; 441 struct proc *a_p; 442 } */ *ap = v; 443 register dev_t dev; 444 445 switch (ap->a_vp->v_type) { 446 447 case VCHR: 448 dev = ap->a_vp->v_rdev; 449 return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p); 450 451 default: 452 return (genfs_poll(v)); 453 } 454 } 455 /* 456 * Synch buffers associated with a block device 457 */ 458 /* ARGSUSED */ 459 int 460 spec_fsync(v) 461 void *v; 462 { 463 struct vop_fsync_args /* { 464 struct vnode *a_vp; 465 struct ucred *a_cred; 466 int a_waitfor; 467 struct proc *a_p; 468 } */ *ap = v; 469 register struct vnode *vp = ap->a_vp; 470 471 if (vp->v_type == VBLK) 472 vflushbuf(vp, ap->a_waitfor == MNT_WAIT); 473 return (0); 474 } 475 476 /* 477 * Just call the device strategy routine 478 */ 479 int 480 spec_strategy(v) 481 void *v; 482 { 483 struct vop_strategy_args /* { 484 struct buf *a_bp; 485 } */ *ap = v; 486 487 (*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp); 488 return (0); 489 } 490 491 /* 492 * This is a noop, simply returning what one has been given. 493 */ 494 int 495 spec_bmap(v) 496 void *v; 497 { 498 struct vop_bmap_args /* { 499 struct vnode *a_vp; 500 daddr_t a_bn; 501 struct vnode **a_vpp; 502 daddr_t *a_bnp; 503 } */ *ap = v; 504 505 if (ap->a_vpp != NULL) 506 *ap->a_vpp = ap->a_vp; 507 if (ap->a_bnp != NULL) 508 *ap->a_bnp = ap->a_bn; 509 return (0); 510 } 511 512 /* 513 * At the moment we do not do any locking. 514 */ 515 /* ARGSUSED */ 516 int 517 spec_lock(v) 518 void *v; 519 { 520 521 return (0); 522 } 523 524 /* ARGSUSED */ 525 int 526 spec_unlock(v) 527 void *v; 528 { 529 530 return (0); 531 } 532 533 /* 534 * Device close routine 535 */ 536 /* ARGSUSED */ 537 int 538 spec_close(v) 539 void *v; 540 { 541 struct vop_close_args /* { 542 struct vnode *a_vp; 543 int a_fflag; 544 struct ucred *a_cred; 545 struct proc *a_p; 546 } */ *ap = v; 547 register struct vnode *vp = ap->a_vp; 548 dev_t dev = vp->v_rdev; 549 int (*devclose) __P((dev_t, int, int, struct proc *)); 550 int mode, error; 551 552 switch (vp->v_type) { 553 554 case VCHR: 555 /* 556 * Hack: a tty device that is a controlling terminal 557 * has a reference from the session structure. 558 * We cannot easily tell that a character device is 559 * a controlling terminal, unless it is the closing 560 * process' controlling terminal. In that case, 561 * if the reference count is 2 (this last descriptor 562 * plus the session), release the reference from the session. 563 */ 564 if (vcount(vp) == 2 && ap->a_p && 565 vp == ap->a_p->p_session->s_ttyvp) { 566 vrele(vp); 567 ap->a_p->p_session->s_ttyvp = NULL; 568 } 569 /* 570 * If the vnode is locked, then we are in the midst 571 * of forcably closing the device, otherwise we only 572 * close on last reference. 573 */ 574 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 575 return (0); 576 devclose = cdevsw[major(dev)].d_close; 577 mode = S_IFCHR; 578 break; 579 580 case VBLK: 581 /* 582 * On last close of a block device (that isn't mounted) 583 * we must invalidate any in core blocks, so that 584 * we can, for instance, change floppy disks. 585 */ 586 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); 587 if (error) 588 return (error); 589 /* 590 * We do not want to really close the device if it 591 * is still in use unless we are trying to close it 592 * forcibly. Since every use (buffer, vnode, swap, cmap) 593 * holds a reference to the vnode, and because we mark 594 * any other vnodes that alias this device, when the 595 * sum of the reference counts on all the aliased 596 * vnodes descends to one, we are on last close. 597 */ 598 if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0) 599 return (0); 600 devclose = bdevsw[major(dev)].d_close; 601 mode = S_IFBLK; 602 break; 603 604 default: 605 panic("spec_close: not special"); 606 } 607 608 return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p)); 609 } 610 611 /* 612 * Print out the contents of a special device vnode. 613 */ 614 int 615 spec_print(v) 616 void *v; 617 { 618 struct vop_print_args /* { 619 struct vnode *a_vp; 620 } */ *ap = v; 621 622 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 623 minor(ap->a_vp->v_rdev)); 624 return 0; 625 } 626 627 /* 628 * Return POSIX pathconf information applicable to special devices. 629 */ 630 int 631 spec_pathconf(v) 632 void *v; 633 { 634 struct vop_pathconf_args /* { 635 struct vnode *a_vp; 636 int a_name; 637 register_t *a_retval; 638 } */ *ap = v; 639 640 switch (ap->a_name) { 641 case _PC_LINK_MAX: 642 *ap->a_retval = LINK_MAX; 643 return (0); 644 case _PC_MAX_CANON: 645 *ap->a_retval = MAX_CANON; 646 return (0); 647 case _PC_MAX_INPUT: 648 *ap->a_retval = MAX_INPUT; 649 return (0); 650 case _PC_PIPE_BUF: 651 *ap->a_retval = PIPE_BUF; 652 return (0); 653 case _PC_CHOWN_RESTRICTED: 654 *ap->a_retval = 1; 655 return (0); 656 case _PC_VDISABLE: 657 *ap->a_retval = _POSIX_VDISABLE; 658 return (0); 659 default: 660 return (EINVAL); 661 } 662 /* NOTREACHED */ 663 } 664 665 /* 666 * Advisory record locking support. 667 */ 668 int 669 spec_advlock(v) 670 void *v; 671 { 672 struct vop_advlock_args /* { 673 struct vnode *a_vp; 674 caddr_t a_id; 675 int a_op; 676 struct flock *a_fl; 677 int a_flags; 678 } */ *ap = v; 679 register struct vnode *vp = ap->a_vp; 680 681 return (lf_advlock(&vp->v_speclockf, (off_t)0, ap->a_id, ap->a_op, 682 ap->a_fl, ap->a_flags)); 683 } 684
Indexes created Tue Sep 23 13:09:54 GMT 2025