spec_vnops.c revision 1.70
1 /* $NetBSD: spec_vnops.c,v 1.70 2003/10/15 08:41:26 dsl 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)spec_vnops.c 8.15 (Berkeley) 7/14/95 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.70 2003/10/15 08:41:26 dsl Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/proc.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/conf.h> 42 #include <sys/buf.h> 43 #include <sys/mount.h> 44 #include <sys/namei.h> 45 #include <sys/vnode.h> 46 #include <sys/stat.h> 47 #include <sys/errno.h> 48 #include <sys/ioctl.h> 49 #include <sys/file.h> 50 #include <sys/disklabel.h> 51 #include <sys/lockf.h> 52 53 #include <miscfs/genfs/genfs.h> 54 #include <miscfs/specfs/specdev.h> 55 56 /* symbolic sleep message strings for devices */ 57 const char devopn[] = "devopn"; 58 const char devio[] = "devio"; 59 const char devwait[] = "devwait"; 60 const char devin[] = "devin"; 61 const char devout[] = "devout"; 62 const char devioc[] = "devioc"; 63 const char devcls[] = "devcls"; 64 65 struct vnode *speclisth[SPECHSZ]; 66 67 /* 68 * This vnode operations vector is used for two things only: 69 * - special device nodes created from whole cloth by the kernel. 70 * - as a temporary vnodeops replacement for vnodes which were found to 71 * be aliased by callers of checkalias(). 72 * For the ops vector for vnodes built from special devices found in a 73 * filesystem, see (e.g) ffs_specop_entries[] in ffs_vnops.c or the 74 * equivalent for other filesystems. 75 */ 76 77 int (**spec_vnodeop_p) __P((void *)); 78 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 79 { &vop_default_desc, vn_default_error }, 80 { &vop_lookup_desc, spec_lookup }, /* lookup */ 81 { &vop_create_desc, spec_create }, /* create */ 82 { &vop_mknod_desc, spec_mknod }, /* mknod */ 83 { &vop_open_desc, spec_open }, /* open */ 84 { &vop_close_desc, spec_close }, /* close */ 85 { &vop_access_desc, spec_access }, /* access */ 86 { &vop_getattr_desc, spec_getattr }, /* getattr */ 87 { &vop_setattr_desc, spec_setattr }, /* setattr */ 88 { &vop_read_desc, spec_read }, /* read */ 89 { &vop_write_desc, spec_write }, /* write */ 90 { &vop_lease_desc, spec_lease_check }, /* lease */ 91 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */ 92 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 93 { &vop_poll_desc, spec_poll }, /* poll */ 94 { &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */ 95 { &vop_revoke_desc, spec_revoke }, /* revoke */ 96 { &vop_mmap_desc, spec_mmap }, /* mmap */ 97 { &vop_fsync_desc, spec_fsync }, /* fsync */ 98 { &vop_seek_desc, spec_seek }, /* seek */ 99 { &vop_remove_desc, spec_remove }, /* remove */ 100 { &vop_link_desc, spec_link }, /* link */ 101 { &vop_rename_desc, spec_rename }, /* rename */ 102 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 103 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 104 { &vop_symlink_desc, spec_symlink }, /* symlink */ 105 { &vop_readdir_desc, spec_readdir }, /* readdir */ 106 { &vop_readlink_desc, spec_readlink }, /* readlink */ 107 { &vop_abortop_desc, spec_abortop }, /* abortop */ 108 { &vop_inactive_desc, spec_inactive }, /* inactive */ 109 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 110 { &vop_lock_desc, spec_lock }, /* lock */ 111 { &vop_unlock_desc, spec_unlock }, /* unlock */ 112 { &vop_bmap_desc, spec_bmap }, /* bmap */ 113 { &vop_strategy_desc, spec_strategy }, /* strategy */ 114 { &vop_print_desc, spec_print }, /* print */ 115 { &vop_islocked_desc, spec_islocked }, /* islocked */ 116 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 117 { &vop_advlock_desc, spec_advlock }, /* advlock */ 118 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ 119 { &vop_valloc_desc, spec_valloc }, /* valloc */ 120 { &vop_vfree_desc, spec_vfree }, /* vfree */ 121 { &vop_truncate_desc, spec_truncate }, /* truncate */ 122 { &vop_update_desc, spec_update }, /* update */ 123 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 124 { &vop_getpages_desc, spec_getpages }, /* getpages */ 125 { &vop_putpages_desc, spec_putpages }, /* putpages */ 126 { NULL, NULL } 127 }; 128 const struct vnodeopv_desc spec_vnodeop_opv_desc = 129 { &spec_vnodeop_p, spec_vnodeop_entries }; 130 131 /* 132 * Trivial lookup routine that always fails. 133 */ 134 int 135 spec_lookup(v) 136 void *v; 137 { 138 struct vop_lookup_args /* { 139 struct vnode *a_dvp; 140 struct vnode **a_vpp; 141 struct componentname *a_cnp; 142 } */ *ap = v; 143 144 *ap->a_vpp = NULL; 145 return (ENOTDIR); 146 } 147 148 /* 149 * Returns true if dev is /dev/mem or /dev/kmem. 150 */ 151 static int 152 iskmemdev(dev_t dev) 153 { 154 /* mem_no is emitted by config(8) to generated devsw.c */ 155 extern const int mem_no; 156 157 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 158 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 159 } 160 161 /* 162 * Open a special file. 163 */ 164 /* ARGSUSED */ 165 int 166 spec_open(v) 167 void *v; 168 { 169 struct vop_open_args /* { 170 struct vnode *a_vp; 171 int a_mode; 172 struct ucred *a_cred; 173 struct proc *a_p; 174 } */ *ap = v; 175 struct proc *p = ap->a_p; 176 struct vnode *bvp, *vp = ap->a_vp; 177 const struct bdevsw *bdev; 178 const struct cdevsw *cdev; 179 dev_t blkdev, dev = (dev_t)vp->v_rdev; 180 int error; 181 struct partinfo pi; 182 int (*d_ioctl)(dev_t, u_long, caddr_t, int, struct proc *); 183 184 /* 185 * Don't allow open if fs is mounted -nodev. 186 */ 187 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 188 return (ENXIO); 189 190 switch (vp->v_type) { 191 192 case VCHR: 193 cdev = cdevsw_lookup(dev); 194 if (cdev == NULL) 195 return (ENXIO); 196 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 197 /* 198 * When running in very secure mode, do not allow 199 * opens for writing of any disk character devices. 200 */ 201 if (securelevel >= 2 && cdev->d_type == D_DISK) 202 return (EPERM); 203 /* 204 * When running in secure mode, do not allow opens 205 * for writing of /dev/mem, /dev/kmem, or character 206 * devices whose corresponding block devices are 207 * currently mounted. 208 */ 209 if (securelevel >= 1) { 210 blkdev = devsw_chr2blk(dev); 211 if (blkdev != (dev_t)NODEV && 212 vfinddev(blkdev, VBLK, &bvp) && 213 (error = vfs_mountedon(bvp))) 214 return (error); 215 if (iskmemdev(dev)) 216 return (EPERM); 217 } 218 } 219 if (cdev->d_type == D_TTY) 220 vp->v_flag |= VISTTY; 221 VOP_UNLOCK(vp, 0); 222 error = (*cdev->d_open)(dev, ap->a_mode, S_IFCHR, p); 223 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 224 if (cdev->d_type != D_DISK) 225 return error; 226 d_ioctl = cdev->d_ioctl; 227 break; 228 229 case VBLK: 230 bdev = bdevsw_lookup(dev); 231 if (bdev == NULL) 232 return (ENXIO); 233 /* 234 * When running in very secure mode, do not allow 235 * opens for writing of any disk block devices. 236 */ 237 if (securelevel >= 2 && ap->a_cred != FSCRED && 238 (ap->a_mode & FWRITE) && bdev->d_type == D_DISK) 239 return (EPERM); 240 /* 241 * Do not allow opens of block devices that are 242 * currently mounted. 243 */ 244 if ((error = vfs_mountedon(vp)) != 0) 245 return (error); 246 error = (*bdev->d_open)(dev, ap->a_mode, S_IFBLK, p); 247 d_ioctl = bdev->d_ioctl; 248 break; 249 250 case VNON: 251 case VLNK: 252 case VDIR: 253 case VREG: 254 case VBAD: 255 case VFIFO: 256 case VSOCK: 257 default: 258 return 0; 259 } 260 261 if (error) 262 return error; 263 if (!(*d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&pi, FREAD, curproc)) 264 vp->v_size = (voff_t)pi.disklab->d_secsize * pi.part->p_size; 265 return 0; 266 } 267 268 /* 269 * Vnode op for read 270 */ 271 /* ARGSUSED */ 272 int 273 spec_read(v) 274 void *v; 275 { 276 struct vop_read_args /* { 277 struct vnode *a_vp; 278 struct uio *a_uio; 279 int a_ioflag; 280 struct ucred *a_cred; 281 } */ *ap = v; 282 struct vnode *vp = ap->a_vp; 283 struct uio *uio = ap->a_uio; 284 struct proc *p = uio->uio_procp; 285 struct buf *bp; 286 const struct bdevsw *bdev; 287 const struct cdevsw *cdev; 288 daddr_t bn; 289 int bsize, bscale; 290 struct partinfo dpart; 291 int n, on; 292 int error = 0; 293 294 #ifdef DIAGNOSTIC 295 if (uio->uio_rw != UIO_READ) 296 panic("spec_read mode"); 297 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 298 panic("spec_read proc"); 299 #endif 300 if (uio->uio_resid == 0) 301 return (0); 302 303 switch (vp->v_type) { 304 305 case VCHR: 306 VOP_UNLOCK(vp, 0); 307 cdev = cdevsw_lookup(vp->v_rdev); 308 if (cdev != NULL) 309 error = (*cdev->d_read)(vp->v_rdev, uio, ap->a_ioflag); 310 else 311 error = ENXIO; 312 vn_lock(vp, LK_SHARED | LK_RETRY); 313 return (error); 314 315 case VBLK: 316 if (uio->uio_offset < 0) 317 return (EINVAL); 318 bsize = BLKDEV_IOSIZE; 319 bdev = bdevsw_lookup(vp->v_rdev); 320 if (bdev != NULL && 321 (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, 322 FREAD, p) == 0) { 323 if (dpart.part->p_fstype == FS_BSDFFS && 324 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 325 bsize = dpart.part->p_frag * 326 dpart.part->p_fsize; 327 } 328 bscale = bsize >> DEV_BSHIFT; 329 do { 330 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 331 on = uio->uio_offset % bsize; 332 n = min((unsigned)(bsize - on), uio->uio_resid); 333 error = bread(vp, bn, bsize, NOCRED, &bp); 334 n = min(n, bsize - bp->b_resid); 335 if (error) { 336 brelse(bp); 337 return (error); 338 } 339 error = uiomove((char *)bp->b_data + on, n, uio); 340 brelse(bp); 341 } while (error == 0 && uio->uio_resid > 0 && n != 0); 342 return (error); 343 344 default: 345 panic("spec_read type"); 346 } 347 /* NOTREACHED */ 348 } 349 350 /* 351 * Vnode op for write 352 */ 353 /* ARGSUSED */ 354 int 355 spec_write(v) 356 void *v; 357 { 358 struct vop_write_args /* { 359 struct vnode *a_vp; 360 struct uio *a_uio; 361 int a_ioflag; 362 struct ucred *a_cred; 363 } */ *ap = v; 364 struct vnode *vp = ap->a_vp; 365 struct uio *uio = ap->a_uio; 366 struct proc *p = uio->uio_procp; 367 struct buf *bp; 368 const struct bdevsw *bdev; 369 const struct cdevsw *cdev; 370 daddr_t bn; 371 int bsize, bscale; 372 struct partinfo dpart; 373 int n, on; 374 int error = 0; 375 376 #ifdef DIAGNOSTIC 377 if (uio->uio_rw != UIO_WRITE) 378 panic("spec_write mode"); 379 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 380 panic("spec_write proc"); 381 #endif 382 383 switch (vp->v_type) { 384 385 case VCHR: 386 VOP_UNLOCK(vp, 0); 387 cdev = cdevsw_lookup(vp->v_rdev); 388 if (cdev != NULL) 389 error = (*cdev->d_write)(vp->v_rdev, uio, ap->a_ioflag); 390 else 391 error = ENXIO; 392 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 393 return (error); 394 395 case VBLK: 396 if (uio->uio_resid == 0) 397 return (0); 398 if (uio->uio_offset < 0) 399 return (EINVAL); 400 bsize = BLKDEV_IOSIZE; 401 bdev = bdevsw_lookup(vp->v_rdev); 402 if (bdev != NULL && 403 (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, 404 FREAD, p) == 0) { 405 if (dpart.part->p_fstype == FS_BSDFFS && 406 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 407 bsize = dpart.part->p_frag * 408 dpart.part->p_fsize; 409 } 410 bscale = bsize >> DEV_BSHIFT; 411 do { 412 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 413 on = uio->uio_offset % bsize; 414 n = min((unsigned)(bsize - on), uio->uio_resid); 415 if (n == bsize) 416 bp = getblk(vp, bn, bsize, 0, 0); 417 else 418 error = bread(vp, bn, bsize, NOCRED, &bp); 419 if (error) { 420 brelse(bp); 421 return (error); 422 } 423 n = min(n, bsize - bp->b_resid); 424 error = uiomove((char *)bp->b_data + on, n, uio); 425 if (error) 426 brelse(bp); 427 else { 428 if (n + on == bsize) 429 bawrite(bp); 430 else 431 bdwrite(bp); 432 if (bp->b_flags & B_ERROR) 433 error = bp->b_error; 434 } 435 } while (error == 0 && uio->uio_resid > 0 && n != 0); 436 return (error); 437 438 default: 439 panic("spec_write type"); 440 } 441 /* NOTREACHED */ 442 } 443 444 /* 445 * Device ioctl operation. 446 */ 447 /* ARGSUSED */ 448 int 449 spec_ioctl(v) 450 void *v; 451 { 452 struct vop_ioctl_args /* { 453 struct vnode *a_vp; 454 u_long a_command; 455 caddr_t a_data; 456 int a_fflag; 457 struct ucred *a_cred; 458 struct proc *a_p; 459 } */ *ap = v; 460 const struct bdevsw *bdev; 461 const struct cdevsw *cdev; 462 dev_t dev = ap->a_vp->v_rdev; 463 464 switch (ap->a_vp->v_type) { 465 466 case VCHR: 467 cdev = cdevsw_lookup(dev); 468 if (cdev == NULL) 469 return (ENXIO); 470 return ((*cdev->d_ioctl)(dev, ap->a_command, ap->a_data, 471 ap->a_fflag, ap->a_p)); 472 473 case VBLK: 474 bdev = bdevsw_lookup(dev); 475 if (bdev == NULL) 476 return (ENXIO); 477 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) { 478 if (bdev->d_type == D_TAPE) 479 return (0); 480 else 481 return (1); 482 } 483 return ((*bdev->d_ioctl)(dev, ap->a_command, ap->a_data, 484 ap->a_fflag, ap->a_p)); 485 486 default: 487 panic("spec_ioctl"); 488 /* NOTREACHED */ 489 } 490 } 491 492 /* ARGSUSED */ 493 int 494 spec_poll(v) 495 void *v; 496 { 497 struct vop_poll_args /* { 498 struct vnode *a_vp; 499 int a_events; 500 struct proc *a_p; 501 } */ *ap = v; 502 const struct cdevsw *cdev; 503 dev_t dev; 504 505 switch (ap->a_vp->v_type) { 506 507 case VCHR: 508 dev = ap->a_vp->v_rdev; 509 cdev = cdevsw_lookup(dev); 510 if (cdev == NULL) 511 return (ENXIO); 512 return (*cdev->d_poll)(dev, ap->a_events, ap->a_p); 513 514 default: 515 return (genfs_poll(v)); 516 } 517 } 518 519 /* ARGSUSED */ 520 int 521 spec_kqfilter(v) 522 void *v; 523 { 524 struct vop_kqfilter_args /* { 525 struct vnode *a_vp; 526 struct proc *a_kn; 527 } */ *ap = v; 528 const struct cdevsw *cdev; 529 dev_t dev; 530 531 switch (ap->a_vp->v_type) { 532 533 case VCHR: 534 dev = ap->a_vp->v_rdev; 535 cdev = cdevsw_lookup(dev); 536 if (cdev == NULL) 537 return (ENXIO); 538 return (*cdev->d_kqfilter)(dev, ap->a_kn); 539 default: 540 /* 541 * Block devices don't support kqfilter, and refuse it 542 * for any other files (like those vflush()ed) too. 543 */ 544 return (EOPNOTSUPP); 545 } 546 } 547 548 /* 549 * Synch buffers associated with a block device 550 */ 551 /* ARGSUSED */ 552 int 553 spec_fsync(v) 554 void *v; 555 { 556 struct vop_fsync_args /* { 557 struct vnode *a_vp; 558 struct ucred *a_cred; 559 int a_flags; 560 off_t offlo; 561 off_t offhi; 562 struct proc *a_p; 563 } */ *ap = v; 564 struct vnode *vp = ap->a_vp; 565 566 if (vp->v_type == VBLK) 567 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0); 568 return (0); 569 } 570 571 /* 572 * Just call the device strategy routine 573 */ 574 int 575 spec_strategy(v) 576 void *v; 577 { 578 struct vop_strategy_args /* { 579 struct buf *a_bp; 580 } */ *ap = v; 581 struct buf *bp; 582 const struct bdevsw *bdev; 583 584 bp = ap->a_bp; 585 if (!(bp->b_flags & B_READ) && 586 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start) 587 (*bioops.io_start)(bp); 588 bdev = bdevsw_lookup(bp->b_dev); 589 if (bdev != NULL) 590 (*bdev->d_strategy)(bp); 591 return (0); 592 } 593 594 int 595 spec_inactive(v) 596 void *v; 597 { 598 struct vop_inactive_args /* { 599 struct vnode *a_vp; 600 struct proc *a_p; 601 } */ *ap = v; 602 603 VOP_UNLOCK(ap->a_vp, 0); 604 return (0); 605 } 606 607 /* 608 * This is a noop, simply returning what one has been given. 609 */ 610 int 611 spec_bmap(v) 612 void *v; 613 { 614 struct vop_bmap_args /* { 615 struct vnode *a_vp; 616 daddr_t a_bn; 617 struct vnode **a_vpp; 618 daddr_t *a_bnp; 619 int *a_runp; 620 } */ *ap = v; 621 622 if (ap->a_vpp != NULL) 623 *ap->a_vpp = ap->a_vp; 624 if (ap->a_bnp != NULL) 625 *ap->a_bnp = ap->a_bn; 626 if (ap->a_runp != NULL) 627 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 628 return (0); 629 } 630 631 /* 632 * Device close routine 633 */ 634 /* ARGSUSED */ 635 int 636 spec_close(v) 637 void *v; 638 { 639 struct vop_close_args /* { 640 struct vnode *a_vp; 641 int a_fflag; 642 struct ucred *a_cred; 643 struct proc *a_p; 644 } */ *ap = v; 645 struct vnode *vp = ap->a_vp; 646 const struct bdevsw *bdev; 647 const struct cdevsw *cdev; 648 dev_t dev = vp->v_rdev; 649 int (*devclose) __P((dev_t, int, int, struct proc *)); 650 int mode, error, count, flags, flags1; 651 652 count = vcount(vp); 653 simple_lock(&vp->v_interlock); 654 flags = vp->v_flag; 655 simple_unlock(&vp->v_interlock); 656 657 switch (vp->v_type) { 658 659 case VCHR: 660 /* 661 * Hack: a tty device that is a controlling terminal 662 * has a reference from the session structure. 663 * We cannot easily tell that a character device is 664 * a controlling terminal, unless it is the closing 665 * process' controlling terminal. In that case, 666 * if the reference count is 2 (this last descriptor 667 * plus the session), release the reference from the session. 668 */ 669 if (count == 2 && ap->a_p && 670 vp == ap->a_p->p_session->s_ttyvp) { 671 vrele(vp); 672 count--; 673 ap->a_p->p_session->s_ttyvp = NULL; 674 } 675 /* 676 * If the vnode is locked, then we are in the midst 677 * of forcably closing the device, otherwise we only 678 * close on last reference. 679 */ 680 if (count > 1 && (flags & VXLOCK) == 0) 681 return (0); 682 cdev = cdevsw_lookup(dev); 683 if (cdev != NULL) 684 devclose = cdev->d_close; 685 else 686 devclose = NULL; 687 mode = S_IFCHR; 688 break; 689 690 case VBLK: 691 /* 692 * On last close of a block device (that isn't mounted) 693 * we must invalidate any in core blocks, so that 694 * we can, for instance, change floppy disks. 695 */ 696 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); 697 if (error) 698 return (error); 699 /* 700 * We do not want to really close the device if it 701 * is still in use unless we are trying to close it 702 * forcibly. Since every use (buffer, vnode, swap, cmap) 703 * holds a reference to the vnode, and because we mark 704 * any other vnodes that alias this device, when the 705 * sum of the reference counts on all the aliased 706 * vnodes descends to one, we are on last close. 707 */ 708 if (count > 1 && (flags & VXLOCK) == 0) 709 return (0); 710 bdev = bdevsw_lookup(dev); 711 if (bdev != NULL) 712 devclose = bdev->d_close; 713 else 714 devclose = NULL; 715 mode = S_IFBLK; 716 break; 717 718 default: 719 panic("spec_close: not special"); 720 } 721 722 flags1 = ap->a_fflag; 723 724 /* 725 * if VXLOCK is set, then we're going away soon, so make this 726 * non-blocking. Also ensures that we won't wedge in vn_lock below. 727 */ 728 if (flags & VXLOCK) 729 flags1 |= FNONBLOCK; 730 731 /* 732 * If we're able to block, release the vnode lock & reacquire. We 733 * might end up sleaping for someone else who wants our queues. They 734 * won't get them if we hold the vnode locked. Also, if VXLOCK is set, 735 * don't release the lock as we won't be able to regain it. 736 */ 737 if (!(flags1 & FNONBLOCK)) 738 VOP_UNLOCK(vp, 0); 739 740 if (devclose != NULL) 741 error = (*devclose)(dev, flags1, mode, ap->a_p); 742 else 743 error = ENXIO; 744 745 if (!(flags1 & FNONBLOCK)) 746 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 747 748 return (error); 749 } 750 751 /* 752 * Print out the contents of a special device vnode. 753 */ 754 int 755 spec_print(v) 756 void *v; 757 { 758 struct vop_print_args /* { 759 struct vnode *a_vp; 760 } */ *ap = v; 761 762 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 763 minor(ap->a_vp->v_rdev)); 764 return 0; 765 } 766 767 /* 768 * Return POSIX pathconf information applicable to special devices. 769 */ 770 int 771 spec_pathconf(v) 772 void *v; 773 { 774 struct vop_pathconf_args /* { 775 struct vnode *a_vp; 776 int a_name; 777 register_t *a_retval; 778 } */ *ap = v; 779 780 switch (ap->a_name) { 781 case _PC_LINK_MAX: 782 *ap->a_retval = LINK_MAX; 783 return (0); 784 case _PC_MAX_CANON: 785 *ap->a_retval = MAX_CANON; 786 return (0); 787 case _PC_MAX_INPUT: 788 *ap->a_retval = MAX_INPUT; 789 return (0); 790 case _PC_PIPE_BUF: 791 *ap->a_retval = PIPE_BUF; 792 return (0); 793 case _PC_CHOWN_RESTRICTED: 794 *ap->a_retval = 1; 795 return (0); 796 case _PC_VDISABLE: 797 *ap->a_retval = _POSIX_VDISABLE; 798 return (0); 799 case _PC_SYNC_IO: 800 *ap->a_retval = 1; 801 return (0); 802 default: 803 return (EINVAL); 804 } 805 /* NOTREACHED */ 806 } 807 808 /* 809 * Advisory record locking support. 810 */ 811 int 812 spec_advlock(v) 813 void *v; 814 { 815 struct vop_advlock_args /* { 816 struct vnode *a_vp; 817 caddr_t a_id; 818 int a_op; 819 struct flock *a_fl; 820 int a_flags; 821 } */ *ap = v; 822 struct vnode *vp = ap->a_vp; 823 824 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 825 } 826
Indexes created Tue Sep 23 22:09:46 GMT 2025