spec_vnops.c revision 1.66
1 /* $NetBSD: spec_vnops.c,v 1.66 2002/10/26 13:50:17 jdolecek 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 8.15 (Berkeley) 7/14/95 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.66 2002/10/26 13:50:17 jdolecek Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/proc.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/conf.h> 46 #include <sys/buf.h> 47 #include <sys/mount.h> 48 #include <sys/namei.h> 49 #include <sys/vnode.h> 50 #include <sys/stat.h> 51 #include <sys/errno.h> 52 #include <sys/ioctl.h> 53 #include <sys/file.h> 54 #include <sys/disklabel.h> 55 #include <sys/lockf.h> 56 57 #include <miscfs/genfs/genfs.h> 58 #include <miscfs/specfs/specdev.h> 59 60 /* symbolic sleep message strings for devices */ 61 const char devopn[] = "devopn"; 62 const char devio[] = "devio"; 63 const char devwait[] = "devwait"; 64 const char devin[] = "devin"; 65 const char devout[] = "devout"; 66 const char devioc[] = "devioc"; 67 const char devcls[] = "devcls"; 68 69 struct vnode *speclisth[SPECHSZ]; 70 71 /* 72 * This vnode operations vector is used for two things only: 73 * - special device nodes created from whole cloth by the kernel. 74 * - as a temporary vnodeops replacement for vnodes which were found to 75 * be aliased by callers of checkalias(). 76 * For the ops vector for vnodes built from special devices found in a 77 * filesystem, see (e.g) ffs_specop_entries[] in ffs_vnops.c or the 78 * equivalent for other filesystems. 79 */ 80 81 int (**spec_vnodeop_p) __P((void *)); 82 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = { 83 { &vop_default_desc, vn_default_error }, 84 { &vop_lookup_desc, spec_lookup }, /* lookup */ 85 { &vop_create_desc, spec_create }, /* create */ 86 { &vop_mknod_desc, spec_mknod }, /* mknod */ 87 { &vop_open_desc, spec_open }, /* open */ 88 { &vop_close_desc, spec_close }, /* close */ 89 { &vop_access_desc, spec_access }, /* access */ 90 { &vop_getattr_desc, spec_getattr }, /* getattr */ 91 { &vop_setattr_desc, spec_setattr }, /* setattr */ 92 { &vop_read_desc, spec_read }, /* read */ 93 { &vop_write_desc, spec_write }, /* write */ 94 { &vop_lease_desc, spec_lease_check }, /* lease */ 95 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */ 96 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */ 97 { &vop_poll_desc, spec_poll }, /* poll */ 98 { &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */ 99 { &vop_revoke_desc, spec_revoke }, /* revoke */ 100 { &vop_mmap_desc, spec_mmap }, /* mmap */ 101 { &vop_fsync_desc, spec_fsync }, /* fsync */ 102 { &vop_seek_desc, spec_seek }, /* seek */ 103 { &vop_remove_desc, spec_remove }, /* remove */ 104 { &vop_link_desc, spec_link }, /* link */ 105 { &vop_rename_desc, spec_rename }, /* rename */ 106 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */ 107 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */ 108 { &vop_symlink_desc, spec_symlink }, /* symlink */ 109 { &vop_readdir_desc, spec_readdir }, /* readdir */ 110 { &vop_readlink_desc, spec_readlink }, /* readlink */ 111 { &vop_abortop_desc, spec_abortop }, /* abortop */ 112 { &vop_inactive_desc, spec_inactive }, /* inactive */ 113 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */ 114 { &vop_lock_desc, spec_lock }, /* lock */ 115 { &vop_unlock_desc, spec_unlock }, /* unlock */ 116 { &vop_bmap_desc, spec_bmap }, /* bmap */ 117 { &vop_strategy_desc, spec_strategy }, /* strategy */ 118 { &vop_print_desc, spec_print }, /* print */ 119 { &vop_islocked_desc, spec_islocked }, /* islocked */ 120 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */ 121 { &vop_advlock_desc, spec_advlock }, /* advlock */ 122 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */ 123 { &vop_valloc_desc, spec_valloc }, /* valloc */ 124 { &vop_vfree_desc, spec_vfree }, /* vfree */ 125 { &vop_truncate_desc, spec_truncate }, /* truncate */ 126 { &vop_update_desc, spec_update }, /* update */ 127 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */ 128 { &vop_getpages_desc, spec_getpages }, /* getpages */ 129 { &vop_putpages_desc, spec_putpages }, /* putpages */ 130 { NULL, NULL } 131 }; 132 const struct vnodeopv_desc spec_vnodeop_opv_desc = 133 { &spec_vnodeop_p, spec_vnodeop_entries }; 134 135 /* 136 * Trivial lookup routine that always fails. 137 */ 138 int 139 spec_lookup(v) 140 void *v; 141 { 142 struct vop_lookup_args /* { 143 struct vnode *a_dvp; 144 struct vnode **a_vpp; 145 struct componentname *a_cnp; 146 } */ *ap = v; 147 148 *ap->a_vpp = NULL; 149 return (ENOTDIR); 150 } 151 152 /* 153 * Returns true if dev is /dev/mem or /dev/kmem. 154 */ 155 static int 156 iskmemdev(dev_t dev) 157 { 158 /* mem_no is emitted by config(8) to generated devsw.c */ 159 extern const int mem_no; 160 161 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 162 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 163 } 164 165 /* 166 * Open a special file. 167 */ 168 /* ARGSUSED */ 169 int 170 spec_open(v) 171 void *v; 172 { 173 struct vop_open_args /* { 174 struct vnode *a_vp; 175 int a_mode; 176 struct ucred *a_cred; 177 struct proc *a_p; 178 } */ *ap = v; 179 struct proc *p = ap->a_p; 180 struct vnode *bvp, *vp = ap->a_vp; 181 const struct bdevsw *bdev; 182 const struct cdevsw *cdev; 183 dev_t blkdev, dev = (dev_t)vp->v_rdev; 184 int error; 185 struct partinfo pi; 186 187 /* 188 * Don't allow open if fs is mounted -nodev. 189 */ 190 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 191 return (ENXIO); 192 193 switch (vp->v_type) { 194 195 case VCHR: 196 cdev = cdevsw_lookup(dev); 197 if (cdev == NULL) 198 return (ENXIO); 199 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) { 200 /* 201 * When running in very secure mode, do not allow 202 * opens for writing of any disk character devices. 203 */ 204 if (securelevel >= 2 && cdev->d_type == D_DISK) 205 return (EPERM); 206 /* 207 * When running in secure mode, do not allow opens 208 * for writing of /dev/mem, /dev/kmem, or character 209 * devices whose corresponding block devices are 210 * currently mounted. 211 */ 212 if (securelevel >= 1) { 213 blkdev = devsw_chr2blk(dev); 214 if (blkdev != (dev_t)NODEV && 215 vfinddev(blkdev, VBLK, &bvp) && 216 (error = vfs_mountedon(bvp))) 217 return (error); 218 if (iskmemdev(dev)) 219 return (EPERM); 220 } 221 } 222 if (cdev->d_type == D_TTY) 223 vp->v_flag |= VISTTY; 224 VOP_UNLOCK(vp, 0); 225 error = (*cdev->d_open)(dev, ap->a_mode, S_IFCHR, p); 226 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 227 return (error); 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 if (error) { 248 return error; 249 } 250 error = (*bdev->d_ioctl)(vp->v_rdev, 251 DIOCGPART, (caddr_t)&pi, FREAD, curproc); 252 if (error == 0) { 253 vp->v_size = (voff_t)pi.disklab->d_secsize * 254 pi.part->p_size; 255 } 256 return 0; 257 258 case VNON: 259 case VLNK: 260 case VDIR: 261 case VREG: 262 case VBAD: 263 case VFIFO: 264 case VSOCK: 265 break; 266 } 267 return (0); 268 } 269 270 /* 271 * Vnode op for read 272 */ 273 /* ARGSUSED */ 274 int 275 spec_read(v) 276 void *v; 277 { 278 struct vop_read_args /* { 279 struct vnode *a_vp; 280 struct uio *a_uio; 281 int a_ioflag; 282 struct ucred *a_cred; 283 } */ *ap = v; 284 struct vnode *vp = ap->a_vp; 285 struct uio *uio = ap->a_uio; 286 struct proc *p = uio->uio_procp; 287 struct buf *bp; 288 const struct bdevsw *bdev; 289 const struct cdevsw *cdev; 290 daddr_t bn; 291 int bsize, bscale; 292 struct partinfo dpart; 293 int n, on; 294 int error = 0; 295 296 #ifdef DIAGNOSTIC 297 if (uio->uio_rw != UIO_READ) 298 panic("spec_read mode"); 299 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 300 panic("spec_read proc"); 301 #endif 302 if (uio->uio_resid == 0) 303 return (0); 304 305 switch (vp->v_type) { 306 307 case VCHR: 308 VOP_UNLOCK(vp, 0); 309 cdev = cdevsw_lookup(vp->v_rdev); 310 if (cdev != NULL) 311 error = (*cdev->d_read)(vp->v_rdev, uio, ap->a_ioflag); 312 else 313 error = ENXIO; 314 vn_lock(vp, LK_SHARED | LK_RETRY); 315 return (error); 316 317 case VBLK: 318 if (uio->uio_offset < 0) 319 return (EINVAL); 320 bsize = BLKDEV_IOSIZE; 321 bdev = bdevsw_lookup(vp->v_rdev); 322 if (bdev != NULL && 323 (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, 324 FREAD, p) == 0) { 325 if (dpart.part->p_fstype == FS_BSDFFS && 326 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 327 bsize = dpart.part->p_frag * 328 dpart.part->p_fsize; 329 } 330 bscale = bsize >> DEV_BSHIFT; 331 do { 332 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 333 on = uio->uio_offset % bsize; 334 n = min((unsigned)(bsize - on), uio->uio_resid); 335 error = bread(vp, bn, bsize, NOCRED, &bp); 336 n = min(n, bsize - bp->b_resid); 337 if (error) { 338 brelse(bp); 339 return (error); 340 } 341 error = uiomove((char *)bp->b_data + on, n, uio); 342 brelse(bp); 343 } while (error == 0 && uio->uio_resid > 0 && n != 0); 344 return (error); 345 346 default: 347 panic("spec_read type"); 348 } 349 /* NOTREACHED */ 350 } 351 352 /* 353 * Vnode op for write 354 */ 355 /* ARGSUSED */ 356 int 357 spec_write(v) 358 void *v; 359 { 360 struct vop_write_args /* { 361 struct vnode *a_vp; 362 struct uio *a_uio; 363 int a_ioflag; 364 struct ucred *a_cred; 365 } */ *ap = v; 366 struct vnode *vp = ap->a_vp; 367 struct uio *uio = ap->a_uio; 368 struct proc *p = uio->uio_procp; 369 struct buf *bp; 370 const struct bdevsw *bdev; 371 const struct cdevsw *cdev; 372 daddr_t bn; 373 int bsize, bscale; 374 struct partinfo dpart; 375 int n, on; 376 int error = 0; 377 378 #ifdef DIAGNOSTIC 379 if (uio->uio_rw != UIO_WRITE) 380 panic("spec_write mode"); 381 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) 382 panic("spec_write proc"); 383 #endif 384 385 switch (vp->v_type) { 386 387 case VCHR: 388 VOP_UNLOCK(vp, 0); 389 cdev = cdevsw_lookup(vp->v_rdev); 390 if (cdev != NULL) 391 error = (*cdev->d_write)(vp->v_rdev, uio, ap->a_ioflag); 392 else 393 error = ENXIO; 394 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 395 return (error); 396 397 case VBLK: 398 if (uio->uio_resid == 0) 399 return (0); 400 if (uio->uio_offset < 0) 401 return (EINVAL); 402 bsize = BLKDEV_IOSIZE; 403 bdev = bdevsw_lookup(vp->v_rdev); 404 if (bdev != NULL && 405 (*bdev->d_ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, 406 FREAD, p) == 0) { 407 if (dpart.part->p_fstype == FS_BSDFFS && 408 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 409 bsize = dpart.part->p_frag * 410 dpart.part->p_fsize; 411 } 412 bscale = bsize >> DEV_BSHIFT; 413 do { 414 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 415 on = uio->uio_offset % bsize; 416 n = min((unsigned)(bsize - on), uio->uio_resid); 417 if (n == bsize) 418 bp = getblk(vp, bn, bsize, 0, 0); 419 else 420 error = bread(vp, bn, bsize, NOCRED, &bp); 421 if (error) { 422 brelse(bp); 423 return (error); 424 } 425 n = min(n, bsize - bp->b_resid); 426 error = uiomove((char *)bp->b_data + on, n, uio); 427 if (error) 428 brelse(bp); 429 else { 430 if (n + on == bsize) 431 bawrite(bp); 432 else 433 bdwrite(bp); 434 if (bp->b_flags & B_ERROR) 435 error = bp->b_error; 436 } 437 } while (error == 0 && uio->uio_resid > 0 && n != 0); 438 return (error); 439 440 default: 441 panic("spec_write type"); 442 } 443 /* NOTREACHED */ 444 } 445 446 /* 447 * Device ioctl operation. 448 */ 449 /* ARGSUSED */ 450 int 451 spec_ioctl(v) 452 void *v; 453 { 454 struct vop_ioctl_args /* { 455 struct vnode *a_vp; 456 u_long a_command; 457 caddr_t a_data; 458 int a_fflag; 459 struct ucred *a_cred; 460 struct proc *a_p; 461 } */ *ap = v; 462 const struct bdevsw *bdev; 463 const struct cdevsw *cdev; 464 dev_t dev = ap->a_vp->v_rdev; 465 466 switch (ap->a_vp->v_type) { 467 468 case VCHR: 469 cdev = cdevsw_lookup(dev); 470 if (cdev == NULL) 471 return (ENXIO); 472 return ((*cdev->d_ioctl)(dev, ap->a_command, ap->a_data, 473 ap->a_fflag, ap->a_p)); 474 475 case VBLK: 476 bdev = bdevsw_lookup(dev); 477 if (bdev == NULL) 478 return (ENXIO); 479 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) { 480 if (bdev->d_type == D_TAPE) 481 return (0); 482 else 483 return (1); 484 } 485 return ((*bdev->d_ioctl)(dev, ap->a_command, ap->a_data, 486 ap->a_fflag, ap->a_p)); 487 488 default: 489 panic("spec_ioctl"); 490 /* NOTREACHED */ 491 } 492 } 493 494 /* ARGSUSED */ 495 int 496 spec_poll(v) 497 void *v; 498 { 499 struct vop_poll_args /* { 500 struct vnode *a_vp; 501 int a_events; 502 struct proc *a_p; 503 } */ *ap = v; 504 const struct cdevsw *cdev; 505 dev_t dev; 506 507 switch (ap->a_vp->v_type) { 508 509 case VCHR: 510 dev = ap->a_vp->v_rdev; 511 cdev = cdevsw_lookup(dev); 512 if (cdev == NULL) 513 return (ENXIO); 514 return (*cdev->d_poll)(dev, ap->a_events, ap->a_p); 515 516 default: 517 return (genfs_poll(v)); 518 } 519 } 520 521 /* ARGSUSED */ 522 int 523 spec_kqfilter(v) 524 void *v; 525 { 526 struct vop_kqfilter_args /* { 527 struct vnode *a_vp; 528 struct proc *a_kn; 529 } */ *ap = v; 530 const struct cdevsw *cdev; 531 dev_t dev; 532 533 switch (ap->a_vp->v_type) { 534 535 case VCHR: 536 dev = ap->a_vp->v_rdev; 537 cdev = cdevsw_lookup(dev); 538 if (cdev == NULL) 539 return (ENXIO); 540 return (*cdev->d_kqfilter)(dev, ap->a_kn); 541 default: 542 /* 543 * Block devices don't support kqfilter, and refuse it 544 * for any other files (like those vflush()ed) too. 545 */ 546 return (EOPNOTSUPP); 547 } 548 } 549 550 /* 551 * Synch buffers associated with a block device 552 */ 553 /* ARGSUSED */ 554 int 555 spec_fsync(v) 556 void *v; 557 { 558 struct vop_fsync_args /* { 559 struct vnode *a_vp; 560 struct ucred *a_cred; 561 int a_flags; 562 off_t offlo; 563 off_t offhi; 564 struct proc *a_p; 565 } */ *ap = v; 566 struct vnode *vp = ap->a_vp; 567 568 if (vp->v_type == VBLK) 569 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0); 570 return (0); 571 } 572 573 /* 574 * Just call the device strategy routine 575 */ 576 int 577 spec_strategy(v) 578 void *v; 579 { 580 struct vop_strategy_args /* { 581 struct buf *a_bp; 582 } */ *ap = v; 583 struct buf *bp; 584 const struct bdevsw *bdev; 585 586 bp = ap->a_bp; 587 if (!(bp->b_flags & B_READ) && 588 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start) 589 (*bioops.io_start)(bp); 590 bdev = bdevsw_lookup(bp->b_dev); 591 if (bdev != NULL) 592 (*bdev->d_strategy)(bp); 593 return (0); 594 } 595 596 int 597 spec_inactive(v) 598 void *v; 599 { 600 struct vop_inactive_args /* { 601 struct vnode *a_vp; 602 struct proc *a_p; 603 } */ *ap = v; 604 605 VOP_UNLOCK(ap->a_vp, 0); 606 return (0); 607 } 608 609 /* 610 * This is a noop, simply returning what one has been given. 611 */ 612 int 613 spec_bmap(v) 614 void *v; 615 { 616 struct vop_bmap_args /* { 617 struct vnode *a_vp; 618 daddr_t a_bn; 619 struct vnode **a_vpp; 620 daddr_t *a_bnp; 621 int *a_runp; 622 } */ *ap = v; 623 624 if (ap->a_vpp != NULL) 625 *ap->a_vpp = ap->a_vp; 626 if (ap->a_bnp != NULL) 627 *ap->a_bnp = ap->a_bn; 628 if (ap->a_runp != NULL) 629 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 630 return (0); 631 } 632 633 /* 634 * Device close routine 635 */ 636 /* ARGSUSED */ 637 int 638 spec_close(v) 639 void *v; 640 { 641 struct vop_close_args /* { 642 struct vnode *a_vp; 643 int a_fflag; 644 struct ucred *a_cred; 645 struct proc *a_p; 646 } */ *ap = v; 647 struct vnode *vp = ap->a_vp; 648 const struct bdevsw *bdev; 649 const struct cdevsw *cdev; 650 dev_t dev = vp->v_rdev; 651 int (*devclose) __P((dev_t, int, int, struct proc *)); 652 int mode, error, count, flags, flags1; 653 654 count = vcount(vp); 655 simple_lock(&vp->v_interlock); 656 flags = vp->v_flag; 657 simple_unlock(&vp->v_interlock); 658 659 switch (vp->v_type) { 660 661 case VCHR: 662 /* 663 * Hack: a tty device that is a controlling terminal 664 * has a reference from the session structure. 665 * We cannot easily tell that a character device is 666 * a controlling terminal, unless it is the closing 667 * process' controlling terminal. In that case, 668 * if the reference count is 2 (this last descriptor 669 * plus the session), release the reference from the session. 670 */ 671 if (count == 2 && ap->a_p && 672 vp == ap->a_p->p_session->s_ttyvp) { 673 vrele(vp); 674 count--; 675 ap->a_p->p_session->s_ttyvp = NULL; 676 } 677 /* 678 * If the vnode is locked, then we are in the midst 679 * of forcably closing the device, otherwise we only 680 * close on last reference. 681 */ 682 if (count > 1 && (flags & VXLOCK) == 0) 683 return (0); 684 cdev = cdevsw_lookup(dev); 685 if (cdev != NULL) 686 devclose = cdev->d_close; 687 else 688 devclose = NULL; 689 mode = S_IFCHR; 690 break; 691 692 case VBLK: 693 /* 694 * On last close of a block device (that isn't mounted) 695 * we must invalidate any in core blocks, so that 696 * we can, for instance, change floppy disks. 697 */ 698 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0); 699 if (error) 700 return (error); 701 /* 702 * We do not want to really close the device if it 703 * is still in use unless we are trying to close it 704 * forcibly. Since every use (buffer, vnode, swap, cmap) 705 * holds a reference to the vnode, and because we mark 706 * any other vnodes that alias this device, when the 707 * sum of the reference counts on all the aliased 708 * vnodes descends to one, we are on last close. 709 */ 710 if (count > 1 && (flags & VXLOCK) == 0) 711 return (0); 712 bdev = bdevsw_lookup(dev); 713 if (bdev != NULL) 714 devclose = bdev->d_close; 715 else 716 devclose = NULL; 717 mode = S_IFBLK; 718 break; 719 720 default: 721 panic("spec_close: not special"); 722 } 723 724 flags1 = ap->a_fflag; 725 726 /* 727 * if VXLOCK is set, then we're going away soon, so make this 728 * non-blocking. Also ensures that we won't wedge in vn_lock below. 729 */ 730 if (flags & VXLOCK) 731 flags1 |= FNONBLOCK; 732 733 /* 734 * If we're able to block, release the vnode lock & reacquire. We 735 * might end up sleaping for someone else who wants our queues. They 736 * won't get them if we hold the vnode locked. Also, if VXLOCK is set, 737 * don't release the lock as we won't be able to regain it. 738 */ 739 if (!(flags1 & FNONBLOCK)) 740 VOP_UNLOCK(vp, 0); 741 742 if (devclose != NULL) 743 error = (*devclose)(dev, flags1, mode, ap->a_p); 744 else 745 error = ENXIO; 746 747 if (!(flags1 & FNONBLOCK)) 748 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 749 750 return (error); 751 } 752 753 /* 754 * Print out the contents of a special device vnode. 755 */ 756 int 757 spec_print(v) 758 void *v; 759 { 760 struct vop_print_args /* { 761 struct vnode *a_vp; 762 } */ *ap = v; 763 764 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 765 minor(ap->a_vp->v_rdev)); 766 return 0; 767 } 768 769 /* 770 * Return POSIX pathconf information applicable to special devices. 771 */ 772 int 773 spec_pathconf(v) 774 void *v; 775 { 776 struct vop_pathconf_args /* { 777 struct vnode *a_vp; 778 int a_name; 779 register_t *a_retval; 780 } */ *ap = v; 781 782 switch (ap->a_name) { 783 case _PC_LINK_MAX: 784 *ap->a_retval = LINK_MAX; 785 return (0); 786 case _PC_MAX_CANON: 787 *ap->a_retval = MAX_CANON; 788 return (0); 789 case _PC_MAX_INPUT: 790 *ap->a_retval = MAX_INPUT; 791 return (0); 792 case _PC_PIPE_BUF: 793 *ap->a_retval = PIPE_BUF; 794 return (0); 795 case _PC_CHOWN_RESTRICTED: 796 *ap->a_retval = 1; 797 return (0); 798 case _PC_VDISABLE: 799 *ap->a_retval = _POSIX_VDISABLE; 800 return (0); 801 case _PC_SYNC_IO: 802 *ap->a_retval = 1; 803 return (0); 804 default: 805 return (EINVAL); 806 } 807 /* NOTREACHED */ 808 } 809 810 /* 811 * Advisory record locking support. 812 */ 813 int 814 spec_advlock(v) 815 void *v; 816 { 817 struct vop_advlock_args /* { 818 struct vnode *a_vp; 819 caddr_t a_id; 820 int a_op; 821 struct flock *a_fl; 822 int a_flags; 823 } */ *ap = v; 824 struct vnode *vp = ap->a_vp; 825 826 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 827 } 828
Indexes created Mon Sep 22 13:09:51 GMT 2025