1 /* $NetBSD: spec_vnops.c,v 1.108 2007/10/10 20:42:30 ad 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 1.108 2007/10/10 20:42:30 ad 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/poll.h> 50 #include <sys/file.h> 51 #include <sys/disklabel.h> 52 #include <sys/lockf.h> 53 #include <sys/tty.h> 54 #include <sys/kauth.h> 55 #include <sys/fstrans.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)(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_bwrite_desc, spec_bwrite }, /* bwrite */ 123 { &vop_getpages_desc, spec_getpages }, /* getpages */ 124 { &vop_putpages_desc, spec_putpages }, /* putpages */ 125 { NULL, NULL } 126 }; 127 const struct vnodeopv_desc spec_vnodeop_opv_desc = 128 { &spec_vnodeop_p, spec_vnodeop_entries }; 129 130 /* 131 * Trivial lookup routine that always fails. 132 */ 133 int 134 spec_lookup(void *v) 135 { 136 struct vop_lookup_args /* { 137 struct vnode *a_dvp; 138 struct vnode **a_vpp; 139 struct componentname *a_cnp; 140 } */ *ap = v; 141 142 *ap->a_vpp = NULL; 143 return (ENOTDIR); 144 } 145 146 /* 147 * Returns true if dev is /dev/mem or /dev/kmem. 148 */ 149 int 150 iskmemdev(dev_t dev) 151 { 152 /* mem_no is emitted by config(8) to generated devsw.c */ 153 extern const int mem_no; 154 155 /* minor 14 is /dev/io on i386 with COMPAT_10 */ 156 return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14)); 157 } 158 159 /* 160 * Open a special file. 161 */ 162 /* ARGSUSED */ 163 int 164 spec_open(void *v) 165 { 166 struct vop_open_args /* { 167 struct vnode *a_vp; 168 int a_mode; 169 kauth_cred_t a_cred; 170 struct lwp *a_l; 171 } */ *ap = v; 172 struct lwp *l = ap->a_l; 173 struct vnode *vp = ap->a_vp; 174 dev_t dev = (dev_t)vp->v_rdev; 175 int error; 176 struct partinfo pi; 177 enum kauth_device_req req; 178 179 /* 180 * Don't allow open if fs is mounted -nodev. 181 */ 182 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV)) 183 return (ENXIO); 184 185 #define M2K(m) (((m) & FREAD) && ((m) & FWRITE) ? \ 186 KAUTH_REQ_DEVICE_RAWIO_SPEC_RW : \ 187 (m) & FWRITE ? KAUTH_REQ_DEVICE_RAWIO_SPEC_WRITE : \ 188 KAUTH_REQ_DEVICE_RAWIO_SPEC_READ) 189 190 switch (vp->v_type) { 191 192 case VCHR: 193 req = M2K(ap->a_mode); 194 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 195 if (error) 196 return (error); 197 198 if (cdev_type(dev) == D_TTY) 199 vp->v_vflag |= VV_ISTTY; 200 VOP_UNLOCK(vp, 0); 201 error = cdev_open(dev, ap->a_mode, S_IFCHR, l); 202 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 203 if (cdev_type(dev) != D_DISK) 204 return error; 205 break; 206 207 case VBLK: 208 req = M2K(ap->a_mode); 209 error = kauth_authorize_device_spec(ap->a_cred, req, vp); 210 if (error) 211 return (error); 212 error = bdev_open(dev, ap->a_mode, S_IFBLK, l); 213 break; 214 215 case VNON: 216 case VLNK: 217 case VDIR: 218 case VREG: 219 case VBAD: 220 case VFIFO: 221 case VSOCK: 222 default: 223 return 0; 224 } 225 226 #undef M2K 227 228 if (error) 229 return error; 230 if (vp->v_type == VCHR) 231 error = cdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 232 else 233 error = bdev_ioctl(vp->v_rdev, DIOCGPART, &pi, FREAD, curlwp); 234 if (error == 0) 235 uvm_vnp_setsize(vp, 236 (voff_t)pi.disklab->d_secsize * pi.part->p_size); 237 return 0; 238 } 239 240 /* 241 * Vnode op for read 242 */ 243 /* ARGSUSED */ 244 int 245 spec_read(void *v) 246 { 247 struct vop_read_args /* { 248 struct vnode *a_vp; 249 struct uio *a_uio; 250 int a_ioflag; 251 kauth_cred_t a_cred; 252 } */ *ap = v; 253 struct vnode *vp = ap->a_vp; 254 struct uio *uio = ap->a_uio; 255 struct lwp *l = curlwp; 256 struct buf *bp; 257 daddr_t bn; 258 int bsize, bscale; 259 struct partinfo dpart; 260 int n, on; 261 int error = 0; 262 263 #ifdef DIAGNOSTIC 264 if (uio->uio_rw != UIO_READ) 265 panic("spec_read mode"); 266 if (&uio->uio_vmspace->vm_map != kernel_map && 267 uio->uio_vmspace != curproc->p_vmspace) 268 panic("spec_read proc"); 269 #endif 270 if (uio->uio_resid == 0) 271 return (0); 272 273 switch (vp->v_type) { 274 275 case VCHR: 276 VOP_UNLOCK(vp, 0); 277 error = cdev_read(vp->v_rdev, uio, ap->a_ioflag); 278 vn_lock(vp, LK_SHARED | LK_RETRY); 279 return (error); 280 281 case VBLK: 282 if (uio->uio_offset < 0) 283 return (EINVAL); 284 bsize = BLKDEV_IOSIZE; 285 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 0) { 286 if (dpart.part->p_fstype == FS_BSDFFS && 287 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0) 288 bsize = dpart.part->p_frag * 289 dpart.part->p_fsize; 290 } 291 bscale = bsize >> DEV_BSHIFT; 292 do { 293 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 294 on = uio->uio_offset % bsize; 295 n = min((unsigned)(bsize - on), uio->uio_resid); 296 error = bread(vp, bn, bsize, NOCRED, &bp); 297 n = min(n, bsize - bp->b_resid); 298 if (error) { 299 brelse(bp, 0); 300 return (error); 301 } 302 error = uiomove((char *)bp->b_data + on, n, uio); 303 brelse(bp, 0); 304 } while (error == 0 && uio->uio_resid > 0 && n != 0); 305 return (error); 306 307 default: 308 panic("spec_read type"); 309 } 310 /* NOTREACHED */ 311 } 312 313 /* 314 * Vnode op for write 315 */ 316 /* ARGSUSED */ 317 int 318 spec_write(void *v) 319 { 320 struct vop_write_args /* { 321 struct vnode *a_vp; 322 struct uio *a_uio; 323 int a_ioflag; 324 kauth_cred_t a_cred; 325 } */ *ap = v; 326 struct vnode *vp = ap->a_vp; 327 struct uio *uio = ap->a_uio; 328 struct lwp *l = curlwp; 329 struct buf *bp; 330 daddr_t bn; 331 int bsize, bscale; 332 struct partinfo dpart; 333 int n, on; 334 int error = 0; 335 336 #ifdef DIAGNOSTIC 337 if (uio->uio_rw != UIO_WRITE) 338 panic("spec_write mode"); 339 if (&uio->uio_vmspace->vm_map != kernel_map && 340 uio->uio_vmspace != curproc->p_vmspace) 341 panic("spec_write proc"); 342 #endif 343 344 switch (vp->v_type) { 345 346 case VCHR: 347 VOP_UNLOCK(vp, 0); 348 error = cdev_write(vp->v_rdev, uio, ap->a_ioflag); 349 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 350 return (error); 351 352 case VBLK: 353 if (uio->uio_resid == 0) 354 return (0); 355 if (uio->uio_offset < 0) 356 return (EINVAL); 357 bsize = BLKDEV_IOSIZE; 358 if (bdev_ioctl(vp->v_rdev, DIOCGPART, &dpart, FREAD, l) == 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 } 364 bscale = bsize >> DEV_BSHIFT; 365 do { 366 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1); 367 on = uio->uio_offset % bsize; 368 n = min((unsigned)(bsize - on), uio->uio_resid); 369 if (n == bsize) 370 bp = getblk(vp, bn, bsize, 0, 0); 371 else 372 error = bread(vp, bn, bsize, NOCRED, &bp); 373 if (error) { 374 brelse(bp, 0); 375 return (error); 376 } 377 n = min(n, bsize - bp->b_resid); 378 error = uiomove((char *)bp->b_data + on, n, uio); 379 if (error) 380 brelse(bp, 0); 381 else { 382 if (n + on == bsize) 383 bawrite(bp); 384 else 385 bdwrite(bp); 386 error = bp->b_error; 387 } 388 } while (error == 0 && uio->uio_resid > 0 && n != 0); 389 return (error); 390 391 default: 392 panic("spec_write type"); 393 } 394 /* NOTREACHED */ 395 } 396 397 /* 398 * Device ioctl operation. 399 */ 400 /* ARGSUSED */ 401 int 402 spec_ioctl(void *v) 403 { 404 struct vop_ioctl_args /* { 405 struct vnode *a_vp; 406 u_long a_command; 407 void *a_data; 408 int a_fflag; 409 kauth_cred_t a_cred; 410 struct lwp *a_l; 411 } */ *ap = v; 412 struct vnode *vp; 413 dev_t dev; 414 415 /* 416 * Extract all the info we need from the vnode, taking care to 417 * avoid a race with VOP_REVOKE(). 418 */ 419 420 vp = ap->a_vp; 421 dev = NODEV; 422 simple_lock(&vp->v_interlock); 423 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specinfo) { 424 dev = vp->v_rdev; 425 } 426 simple_unlock(&vp->v_interlock); 427 if (dev == NODEV) { 428 return ENXIO; 429 } 430 431 switch (vp->v_type) { 432 433 case VCHR: 434 return cdev_ioctl(dev, ap->a_command, ap->a_data, 435 ap->a_fflag, ap->a_l); 436 437 case VBLK: 438 return bdev_ioctl(dev, ap->a_command, ap->a_data, 439 ap->a_fflag, ap->a_l); 440 441 default: 442 panic("spec_ioctl"); 443 /* NOTREACHED */ 444 } 445 } 446 447 /* ARGSUSED */ 448 int 449 spec_poll(void *v) 450 { 451 struct vop_poll_args /* { 452 struct vnode *a_vp; 453 int a_events; 454 struct lwp *a_l; 455 } */ *ap = v; 456 struct vnode *vp; 457 dev_t dev; 458 459 /* 460 * Extract all the info we need from the vnode, taking care to 461 * avoid a race with VOP_REVOKE(). 462 */ 463 464 vp = ap->a_vp; 465 dev = NODEV; 466 simple_lock(&vp->v_interlock); 467 if ((vp->v_iflag & VI_XLOCK) == 0 && vp->v_specinfo) { 468 dev = vp->v_rdev; 469 } 470 simple_unlock(&vp->v_interlock); 471 if (dev == NODEV) { 472 return POLLERR; 473 } 474 475 switch (vp->v_type) { 476 477 case VCHR: 478 return cdev_poll(dev, ap->a_events, ap->a_l); 479 480 default: 481 return (genfs_poll(v)); 482 } 483 } 484 485 /* ARGSUSED */ 486 int 487 spec_kqfilter(void *v) 488 { 489 struct vop_kqfilter_args /* { 490 struct vnode *a_vp; 491 struct proc *a_kn; 492 } */ *ap = v; 493 dev_t dev; 494 495 switch (ap->a_vp->v_type) { 496 497 case VCHR: 498 dev = ap->a_vp->v_rdev; 499 return cdev_kqfilter(dev, ap->a_kn); 500 default: 501 /* 502 * Block devices don't support kqfilter, and refuse it 503 * for any other files (like those vflush()ed) too. 504 */ 505 return (EOPNOTSUPP); 506 } 507 } 508 509 /* 510 * Allow mapping of only D_DISK. This is called only for VBLK. 511 */ 512 int 513 spec_mmap(void *v) 514 { 515 struct vop_mmap_args /* { 516 struct vnode *a_vp; 517 vm_prot_t a_prot; 518 kauth_cred_t a_cred; 519 struct lwp *a_l; 520 } */ *ap = v; 521 struct vnode *vp = ap->a_vp; 522 523 KASSERT(vp->v_type == VBLK); 524 if (bdev_type(vp->v_rdev) != D_DISK) 525 return EINVAL; 526 527 return 0; 528 } 529 530 /* 531 * Synch buffers associated with a block device 532 */ 533 /* ARGSUSED */ 534 int 535 spec_fsync(void *v) 536 { 537 struct vop_fsync_args /* { 538 struct vnode *a_vp; 539 kauth_cred_t a_cred; 540 int a_flags; 541 off_t offlo; 542 off_t offhi; 543 struct lwp *a_l; 544 } */ *ap = v; 545 struct vnode *vp = ap->a_vp; 546 547 if (vp->v_type == VBLK) 548 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0); 549 return (0); 550 } 551 552 /* 553 * Just call the device strategy routine 554 */ 555 int 556 spec_strategy(void *v) 557 { 558 struct vop_strategy_args /* { 559 struct vnode *a_vp; 560 struct buf *a_bp; 561 } */ *ap = v; 562 struct vnode *vp = ap->a_vp; 563 struct buf *bp = ap->a_bp; 564 int error; 565 566 error = 0; 567 bp->b_dev = vp->v_rdev; 568 if (!(bp->b_flags & B_READ) && 569 (LIST_FIRST(&bp->b_dep)) != NULL && bioopsp) 570 bioopsp->io_start(bp); 571 572 if (!(bp->b_flags & B_READ)) 573 error = fscow_run(bp); 574 575 if (error) { 576 bp->b_error = error; 577 biodone(bp); 578 return (error); 579 } 580 581 bdev_strategy(bp); 582 583 return (0); 584 } 585 586 int 587 spec_inactive(void *v) 588 { 589 struct vop_inactive_args /* { 590 struct vnode *a_vp; 591 struct proc *a_l; 592 } */ *ap = v; 593 594 VOP_UNLOCK(ap->a_vp, 0); 595 return (0); 596 } 597 598 /* 599 * This is a noop, simply returning what one has been given. 600 */ 601 int 602 spec_bmap(void *v) 603 { 604 struct vop_bmap_args /* { 605 struct vnode *a_vp; 606 daddr_t a_bn; 607 struct vnode **a_vpp; 608 daddr_t *a_bnp; 609 int *a_runp; 610 } */ *ap = v; 611 612 if (ap->a_vpp != NULL) 613 *ap->a_vpp = ap->a_vp; 614 if (ap->a_bnp != NULL) 615 *ap->a_bnp = ap->a_bn; 616 if (ap->a_runp != NULL) 617 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1; 618 return (0); 619 } 620 621 /* 622 * Device close routine 623 */ 624 /* ARGSUSED */ 625 int 626 spec_close(void *v) 627 { 628 struct vop_close_args /* { 629 struct vnode *a_vp; 630 int a_fflag; 631 kauth_cred_t a_cred; 632 struct lwp *a_l; 633 } */ *ap = v; 634 struct vnode *vp = ap->a_vp; 635 struct session *sess; 636 dev_t dev = vp->v_rdev; 637 int mode, error, count, flags, flags1; 638 639 count = vcount(vp); 640 flags = vp->v_iflag; 641 642 switch (vp->v_type) { 643 644 case VCHR: 645 /* 646 * Hack: a tty device that is a controlling terminal 647 * has a reference from the session structure. 648 * We cannot easily tell that a character device is 649 * a controlling terminal, unless it is the closing 650 * process' controlling terminal. In that case, 651 * if the reference count is 2 (this last descriptor 652 * plus the session), release the reference from the session. 653 * Also remove the link from the tty back to the session 654 * and pgrp - due to the way consoles are handled we cannot 655 * guarantee that the vrele() will do the final close on the 656 * actual tty device. 657 */ 658 mutex_enter(&proclist_lock); 659 if (count == 2 && ap->a_l && 660 vp == (sess = ap->a_l->l_proc->p_session)->s_ttyvp) { 661 sess->s_ttyvp = NULL; 662 if (sess->s_ttyp->t_session != NULL) { 663 sess->s_ttyp->t_pgrp = NULL; 664 sess->s_ttyp->t_session = NULL; 665 mutex_exit(&proclist_lock); 666 SESSRELE(sess); 667 } else { 668 if (sess->s_ttyp->t_pgrp != NULL) 669 panic("spec_close: spurious pgrp ref"); 670 mutex_exit(&proclist_lock); 671 } 672 vrele(vp); 673 count--; 674 } else 675 mutex_exit(&proclist_lock); 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 & VI_XLOCK) == 0) 683 return (0); 684 mode = S_IFCHR; 685 break; 686 687 case VBLK: 688 /* 689 * On last close of a block device (that isn't mounted) 690 * we must invalidate any in core blocks, so that 691 * we can, for instance, change floppy disks. 692 */ 693 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_l, 0, 0); 694 if (error) 695 return (error); 696 /* 697 * We do not want to really close the device if it 698 * is still in use unless we are trying to close it 699 * forcibly. Since every use (buffer, vnode, swap, cmap) 700 * holds a reference to the vnode, and because we mark 701 * any other vnodes that alias this device, when the 702 * sum of the reference counts on all the aliased 703 * vnodes descends to one, we are on last close. 704 */ 705 if (count > 1 && (flags & VI_XLOCK) == 0) 706 return (0); 707 mode = S_IFBLK; 708 break; 709 710 default: 711 panic("spec_close: not special"); 712 } 713 714 flags1 = ap->a_fflag; 715 716 /* 717 * if VI_XLOCK is set, then we're going away soon, so make this 718 * non-blocking. Also ensures that we won't wedge in vn_lock below. 719 */ 720 if (flags & VI_XLOCK) 721 flags1 |= FNONBLOCK; 722 723 /* 724 * If we're able to block, release the vnode lock & reacquire. We 725 * might end up sleeping for someone else who wants our queues. They 726 * won't get them if we hold the vnode locked. Also, if VI_XLOCK is 727 * set, don't release the lock as we won't be able to regain it. 728 */ 729 if (!(flags1 & FNONBLOCK)) 730 VOP_UNLOCK(vp, 0); 731 732 if (vp->v_type == VBLK) 733 error = bdev_close(dev, flags1, mode, ap->a_l); 734 else 735 error = cdev_close(dev, flags1, mode, ap->a_l); 736 737 if (!(flags1 & FNONBLOCK)) 738 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 739 740 return (error); 741 } 742 743 /* 744 * Print out the contents of a special device vnode. 745 */ 746 int 747 spec_print(void *v) 748 { 749 struct vop_print_args /* { 750 struct vnode *a_vp; 751 } */ *ap = v; 752 753 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev), 754 minor(ap->a_vp->v_rdev)); 755 return 0; 756 } 757 758 /* 759 * Return POSIX pathconf information applicable to special devices. 760 */ 761 int 762 spec_pathconf(void *v) 763 { 764 struct vop_pathconf_args /* { 765 struct vnode *a_vp; 766 int a_name; 767 register_t *a_retval; 768 } */ *ap = v; 769 770 switch (ap->a_name) { 771 case _PC_LINK_MAX: 772 *ap->a_retval = LINK_MAX; 773 return (0); 774 case _PC_MAX_CANON: 775 *ap->a_retval = MAX_CANON; 776 return (0); 777 case _PC_MAX_INPUT: 778 *ap->a_retval = MAX_INPUT; 779 return (0); 780 case _PC_PIPE_BUF: 781 *ap->a_retval = PIPE_BUF; 782 return (0); 783 case _PC_CHOWN_RESTRICTED: 784 *ap->a_retval = 1; 785 return (0); 786 case _PC_VDISABLE: 787 *ap->a_retval = _POSIX_VDISABLE; 788 return (0); 789 case _PC_SYNC_IO: 790 *ap->a_retval = 1; 791 return (0); 792 default: 793 return (EINVAL); 794 } 795 /* NOTREACHED */ 796 } 797 798 /* 799 * Advisory record locking support. 800 */ 801 int 802 spec_advlock(void *v) 803 { 804 struct vop_advlock_args /* { 805 struct vnode *a_vp; 806 void *a_id; 807 int a_op; 808 struct flock *a_fl; 809 int a_flags; 810 } */ *ap = v; 811 struct vnode *vp = ap->a_vp; 812 813 return lf_advlock(ap, &vp->v_speclockf, (off_t)0); 814 } 815