spec_vnops.c revision 1.57 1 /* $NetBSD: spec_vnops.c,v 1.57 2001/09/15 20:36:38 chs 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/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 /*
67 * This vnode operations vector is used for two things only:
68 * - special device nodes created from whole cloth by the kernel.
69 * - as a temporary vnodeops replacement for vnodes which were found to
70 * be aliased by callers of checkalias().
71 * For the ops vector for vnodes built from special devices found in a
72 * filesystem, see (e.g) ffs_specop_entries[] in ffs_vnops.c or the
73 * equivalent for other filesystems.
74 */
75
76 int (**spec_vnodeop_p) __P((void *));
77 const struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
78 { &vop_default_desc, vn_default_error },
79 { &vop_lookup_desc, spec_lookup }, /* lookup */
80 { &vop_create_desc, spec_create }, /* create */
81 { &vop_mknod_desc, spec_mknod }, /* mknod */
82 { &vop_open_desc, spec_open }, /* open */
83 { &vop_close_desc, spec_close }, /* close */
84 { &vop_access_desc, spec_access }, /* access */
85 { &vop_getattr_desc, spec_getattr }, /* getattr */
86 { &vop_setattr_desc, spec_setattr }, /* setattr */
87 { &vop_read_desc, spec_read }, /* read */
88 { &vop_write_desc, spec_write }, /* write */
89 { &vop_lease_desc, spec_lease_check }, /* lease */
90 { &vop_fcntl_desc, spec_fcntl }, /* fcntl */
91 { &vop_ioctl_desc, spec_ioctl }, /* ioctl */
92 { &vop_poll_desc, spec_poll }, /* poll */
93 { &vop_revoke_desc, spec_revoke }, /* revoke */
94 { &vop_mmap_desc, spec_mmap }, /* mmap */
95 { &vop_fsync_desc, spec_fsync }, /* fsync */
96 { &vop_seek_desc, spec_seek }, /* seek */
97 { &vop_remove_desc, spec_remove }, /* remove */
98 { &vop_link_desc, spec_link }, /* link */
99 { &vop_rename_desc, spec_rename }, /* rename */
100 { &vop_mkdir_desc, spec_mkdir }, /* mkdir */
101 { &vop_rmdir_desc, spec_rmdir }, /* rmdir */
102 { &vop_symlink_desc, spec_symlink }, /* symlink */
103 { &vop_readdir_desc, spec_readdir }, /* readdir */
104 { &vop_readlink_desc, spec_readlink }, /* readlink */
105 { &vop_abortop_desc, spec_abortop }, /* abortop */
106 { &vop_inactive_desc, spec_inactive }, /* inactive */
107 { &vop_reclaim_desc, spec_reclaim }, /* reclaim */
108 { &vop_lock_desc, spec_lock }, /* lock */
109 { &vop_unlock_desc, spec_unlock }, /* unlock */
110 { &vop_bmap_desc, spec_bmap }, /* bmap */
111 { &vop_strategy_desc, spec_strategy }, /* strategy */
112 { &vop_print_desc, spec_print }, /* print */
113 { &vop_islocked_desc, spec_islocked }, /* islocked */
114 { &vop_pathconf_desc, spec_pathconf }, /* pathconf */
115 { &vop_advlock_desc, spec_advlock }, /* advlock */
116 { &vop_blkatoff_desc, spec_blkatoff }, /* blkatoff */
117 { &vop_valloc_desc, spec_valloc }, /* valloc */
118 { &vop_vfree_desc, spec_vfree }, /* vfree */
119 { &vop_truncate_desc, spec_truncate }, /* truncate */
120 { &vop_update_desc, spec_update }, /* update */
121 { &vop_bwrite_desc, spec_bwrite }, /* bwrite */
122 { &vop_getpages_desc, spec_getpages }, /* getpages */
123 { &vop_putpages_desc, spec_putpages }, /* putpages */
124 { NULL, NULL }
125 };
126 const struct vnodeopv_desc spec_vnodeop_opv_desc =
127 { &spec_vnodeop_p, spec_vnodeop_entries };
128
129 /*
130 * Trivial lookup routine that always fails.
131 */
132 int
133 spec_lookup(v)
134 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 * Open a special file.
148 */
149 /* ARGSUSED */
150 int
151 spec_open(v)
152 void *v;
153 {
154 struct vop_open_args /* {
155 struct vnode *a_vp;
156 int a_mode;
157 struct ucred *a_cred;
158 struct proc *a_p;
159 } */ *ap = v;
160 struct proc *p = ap->a_p;
161 struct vnode *bvp, *vp = ap->a_vp;
162 dev_t bdev, dev = (dev_t)vp->v_rdev;
163 int maj = major(dev);
164 int error;
165 struct partinfo pi;
166
167 /*
168 * Don't allow open if fs is mounted -nodev.
169 */
170 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
171 return (ENXIO);
172
173 switch (vp->v_type) {
174
175 case VCHR:
176 if ((u_int)maj >= nchrdev)
177 return (ENXIO);
178 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
179 /*
180 * When running in very secure mode, do not allow
181 * opens for writing of any disk character devices.
182 */
183 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK)
184 return (EPERM);
185 /*
186 * When running in secure mode, do not allow opens
187 * for writing of /dev/mem, /dev/kmem, or character
188 * devices whose corresponding block devices are
189 * currently mounted.
190 */
191 if (securelevel >= 1) {
192 if ((bdev = chrtoblk(dev)) != (dev_t)NODEV &&
193 vfinddev(bdev, VBLK, &bvp) &&
194 (error = vfs_mountedon(bvp)))
195 return (error);
196 if (iskmemdev(dev))
197 return (EPERM);
198 }
199 }
200 if (cdevsw[maj].d_type == D_TTY)
201 vp->v_flag |= VISTTY;
202 VOP_UNLOCK(vp, 0);
203 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p);
204 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
205 return (error);
206
207 case VBLK:
208 if ((u_int)maj >= nblkdev)
209 return (ENXIO);
210 /*
211 * When running in very secure mode, do not allow
212 * opens for writing of any disk block devices.
213 */
214 if (securelevel >= 2 && ap->a_cred != FSCRED &&
215 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK)
216 return (EPERM);
217 /*
218 * Do not allow opens of block devices that are
219 * currently mounted.
220 */
221 if ((error = vfs_mountedon(vp)) != 0)
222 return (error);
223 error = (*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, p);
224 if (error) {
225 return error;
226 }
227 error = (*bdevsw[major(vp->v_rdev)].d_ioctl)(vp->v_rdev,
228 DIOCGPART, (caddr_t)&pi, FREAD, curproc);
229 if (error == 0) {
230 vp->v_size = (voff_t)pi.disklab->d_secsize *
231 pi.part->p_size;
232 }
233 return 0;
234
235 case VNON:
236 case VLNK:
237 case VDIR:
238 case VREG:
239 case VBAD:
240 case VFIFO:
241 case VSOCK:
242 break;
243 }
244 return (0);
245 }
246
247 /*
248 * Vnode op for read
249 */
250 /* ARGSUSED */
251 int
252 spec_read(v)
253 void *v;
254 {
255 struct vop_read_args /* {
256 struct vnode *a_vp;
257 struct uio *a_uio;
258 int a_ioflag;
259 struct ucred *a_cred;
260 } */ *ap = v;
261 struct vnode *vp = ap->a_vp;
262 struct uio *uio = ap->a_uio;
263 struct proc *p = uio->uio_procp;
264 struct buf *bp;
265 daddr_t bn;
266 int bsize, bscale, ssize;
267 struct partinfo dpart;
268 int n, on, majordev;
269 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *));
270 int error = 0;
271
272 #ifdef DIAGNOSTIC
273 if (uio->uio_rw != UIO_READ)
274 panic("spec_read mode");
275 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
276 panic("spec_read proc");
277 #endif
278 if (uio->uio_resid == 0)
279 return (0);
280
281 switch (vp->v_type) {
282
283 case VCHR:
284 VOP_UNLOCK(vp, 0);
285 error = (*cdevsw[major(vp->v_rdev)].d_read)
286 (vp->v_rdev, uio, ap->a_ioflag);
287 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
288 return (error);
289
290 case VBLK:
291 if (uio->uio_offset < 0)
292 return (EINVAL);
293 bsize = BLKDEV_IOSIZE;
294 ssize = DEV_BSIZE;
295 if ((majordev = major(vp->v_rdev)) < nblkdev &&
296 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
297 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
298 if (dpart.part->p_fstype == FS_BSDFFS &&
299 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
300 bsize = dpart.part->p_frag *
301 dpart.part->p_fsize;
302 if (dpart.disklab->d_secsize != 0)
303 ssize = dpart.disklab->d_secsize;
304 }
305 bscale = bsize / ssize;
306 do {
307 bn = (uio->uio_offset / ssize) &~ (bscale - 1);
308 on = uio->uio_offset % bsize;
309 n = min((unsigned)(bsize - on), uio->uio_resid);
310 error = bread(vp, bn, bsize, NOCRED, &bp);
311 n = min(n, bsize - bp->b_resid);
312 if (error) {
313 brelse(bp);
314 return (error);
315 }
316 error = uiomove((char *)bp->b_data + on, n, uio);
317 brelse(bp);
318 } while (error == 0 && uio->uio_resid > 0 && n != 0);
319 return (error);
320
321 default:
322 panic("spec_read type");
323 }
324 /* NOTREACHED */
325 }
326
327 /*
328 * Vnode op for write
329 */
330 /* ARGSUSED */
331 int
332 spec_write(v)
333 void *v;
334 {
335 struct vop_write_args /* {
336 struct vnode *a_vp;
337 struct uio *a_uio;
338 int a_ioflag;
339 struct ucred *a_cred;
340 } */ *ap = v;
341 struct vnode *vp = ap->a_vp;
342 struct uio *uio = ap->a_uio;
343 struct proc *p = uio->uio_procp;
344 struct buf *bp;
345 daddr_t bn;
346 int bsize, bscale, ssize;
347 struct partinfo dpart;
348 int n, on, majordev;
349 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *));
350 int error = 0;
351
352 #ifdef DIAGNOSTIC
353 if (uio->uio_rw != UIO_WRITE)
354 panic("spec_write mode");
355 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
356 panic("spec_write proc");
357 #endif
358
359 switch (vp->v_type) {
360
361 case VCHR:
362 VOP_UNLOCK(vp, 0);
363 error = (*cdevsw[major(vp->v_rdev)].d_write)
364 (vp->v_rdev, uio, ap->a_ioflag);
365 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
366 return (error);
367
368 case VBLK:
369 if (uio->uio_resid == 0)
370 return (0);
371 if (uio->uio_offset < 0)
372 return (EINVAL);
373 bsize = BLKDEV_IOSIZE;
374 ssize = DEV_BSIZE;
375 if ((majordev = major(vp->v_rdev)) < nblkdev &&
376 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
377 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
378 if (dpart.part->p_fstype == FS_BSDFFS &&
379 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
380 bsize = dpart.part->p_frag *
381 dpart.part->p_fsize;
382 if (dpart.disklab->d_secsize != 0)
383 ssize = dpart.disklab->d_secsize;
384 }
385 bscale = bsize / ssize;
386 do {
387 bn = (uio->uio_offset / ssize) &~ (bscale - 1);
388 on = uio->uio_offset % bsize;
389 n = min((unsigned)(bsize - on), uio->uio_resid);
390 if (n == bsize)
391 bp = getblk(vp, bn, bsize, 0, 0);
392 else
393 error = bread(vp, bn, bsize, NOCRED, &bp);
394 if (error) {
395 brelse(bp);
396 return (error);
397 }
398 n = min(n, bsize - bp->b_resid);
399 error = uiomove((char *)bp->b_data + on, n, uio);
400 if (error)
401 brelse(bp);
402 else {
403 if (n + on == bsize)
404 bawrite(bp);
405 else
406 bdwrite(bp);
407 if (bp->b_flags & B_ERROR)
408 error = bp->b_error;
409 }
410 } while (error == 0 && uio->uio_resid > 0 && n != 0);
411 return (error);
412
413 default:
414 panic("spec_write type");
415 }
416 /* NOTREACHED */
417 }
418
419 /*
420 * Device ioctl operation.
421 */
422 /* ARGSUSED */
423 int
424 spec_ioctl(v)
425 void *v;
426 {
427 struct vop_ioctl_args /* {
428 struct vnode *a_vp;
429 u_long a_command;
430 caddr_t a_data;
431 int a_fflag;
432 struct ucred *a_cred;
433 struct proc *a_p;
434 } */ *ap = v;
435 dev_t dev = ap->a_vp->v_rdev;
436 int maj = major(dev);
437
438 switch (ap->a_vp->v_type) {
439
440 case VCHR:
441 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
442 ap->a_fflag, ap->a_p));
443
444 case VBLK:
445 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) {
446 if (bdevsw[maj].d_type == D_TAPE)
447 return (0);
448 else
449 return (1);
450 }
451 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
452 ap->a_fflag, ap->a_p));
453
454 default:
455 panic("spec_ioctl");
456 /* NOTREACHED */
457 }
458 }
459
460 /* ARGSUSED */
461 int
462 spec_poll(v)
463 void *v;
464 {
465 struct vop_poll_args /* {
466 struct vnode *a_vp;
467 int a_events;
468 struct proc *a_p;
469 } */ *ap = v;
470 dev_t dev;
471
472 switch (ap->a_vp->v_type) {
473
474 case VCHR:
475 dev = ap->a_vp->v_rdev;
476 return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p);
477
478 default:
479 return (genfs_poll(v));
480 }
481 }
482 /*
483 * Synch buffers associated with a block device
484 */
485 /* ARGSUSED */
486 int
487 spec_fsync(v)
488 void *v;
489 {
490 struct vop_fsync_args /* {
491 struct vnode *a_vp;
492 struct ucred *a_cred;
493 int a_flags;
494 off_t offlo;
495 off_t offhi;
496 struct proc *a_p;
497 } */ *ap = v;
498 struct vnode *vp = ap->a_vp;
499
500 if (vp->v_type == VBLK)
501 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0);
502 return (0);
503 }
504
505 /*
506 * Just call the device strategy routine
507 */
508 int
509 spec_strategy(v)
510 void *v;
511 {
512 struct vop_strategy_args /* {
513 struct buf *a_bp;
514 } */ *ap = v;
515 struct buf *bp;
516
517 bp = ap->a_bp;
518 if (!(bp->b_flags & B_READ) &&
519 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
520 (*bioops.io_start)(bp);
521 (*bdevsw[major(bp->b_dev)].d_strategy)(bp);
522 return (0);
523 }
524
525 int
526 spec_inactive(v)
527 void *v;
528 {
529 struct vop_inactive_args /* {
530 struct vnode *a_vp;
531 struct proc *a_p;
532 } */ *ap = v;
533
534 VOP_UNLOCK(ap->a_vp, 0);
535 return (0);
536 }
537
538 /*
539 * This is a noop, simply returning what one has been given.
540 */
541 int
542 spec_bmap(v)
543 void *v;
544 {
545 struct vop_bmap_args /* {
546 struct vnode *a_vp;
547 daddr_t a_bn;
548 struct vnode **a_vpp;
549 daddr_t *a_bnp;
550 int *a_runp;
551 } */ *ap = v;
552
553 if (ap->a_vpp != NULL)
554 *ap->a_vpp = ap->a_vp;
555 if (ap->a_bnp != NULL)
556 *ap->a_bnp = ap->a_bn;
557 if (ap->a_runp != NULL)
558 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1;
559 return (0);
560 }
561
562 /*
563 * Device close routine
564 */
565 /* ARGSUSED */
566 int
567 spec_close(v)
568 void *v;
569 {
570 struct vop_close_args /* {
571 struct vnode *a_vp;
572 int a_fflag;
573 struct ucred *a_cred;
574 struct proc *a_p;
575 } */ *ap = v;
576 struct vnode *vp = ap->a_vp;
577 dev_t dev = vp->v_rdev;
578 int (*devclose) __P((dev_t, int, int, struct proc *));
579 int mode, error, count, flags, flags1;
580
581 count = vcount(vp);
582 simple_lock(&vp->v_interlock);
583 flags = vp->v_flag;
584 simple_unlock(&vp->v_interlock);
585
586 switch (vp->v_type) {
587
588 case VCHR:
589 /*
590 * Hack: a tty device that is a controlling terminal
591 * has a reference from the session structure.
592 * We cannot easily tell that a character device is
593 * a controlling terminal, unless it is the closing
594 * process' controlling terminal. In that case,
595 * if the reference count is 2 (this last descriptor
596 * plus the session), release the reference from the session.
597 */
598 if (count == 2 && ap->a_p &&
599 vp == ap->a_p->p_session->s_ttyvp) {
600 vrele(vp);
601 count--;
602 ap->a_p->p_session->s_ttyvp = NULL;
603 }
604 /*
605 * If the vnode is locked, then we are in the midst
606 * of forcably closing the device, otherwise we only
607 * close on last reference.
608 */
609 if (count > 1 && (flags & VXLOCK) == 0)
610 return (0);
611 devclose = cdevsw[major(dev)].d_close;
612 mode = S_IFCHR;
613 break;
614
615 case VBLK:
616 /*
617 * On last close of a block device (that isn't mounted)
618 * we must invalidate any in core blocks, so that
619 * we can, for instance, change floppy disks.
620 */
621 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
622 if (error)
623 return (error);
624 /*
625 * We do not want to really close the device if it
626 * is still in use unless we are trying to close it
627 * forcibly. Since every use (buffer, vnode, swap, cmap)
628 * holds a reference to the vnode, and because we mark
629 * any other vnodes that alias this device, when the
630 * sum of the reference counts on all the aliased
631 * vnodes descends to one, we are on last close.
632 */
633 if (count > 1 && (flags & VXLOCK) == 0)
634 return (0);
635 devclose = bdevsw[major(dev)].d_close;
636 mode = S_IFBLK;
637 break;
638
639 default:
640 panic("spec_close: not special");
641 }
642
643 flags1 = ap->a_fflag;
644
645 /*
646 * if VXLOCK is set, then we're going away soon, so make this
647 * non-blocking. Also ensures that we won't wedge in vn_lock below.
648 */
649 if (flags & VXLOCK)
650 flags1 |= FNONBLOCK;
651
652 /*
653 * If we're able to block, release the vnode lock & reaquire. We
654 * might end up sleaping for someone else who wants our queues. They
655 * won't get them if we hold the vnode locked. Also, if VXLOCK is set,
656 * don't release the lock as we won't be able to regain it.
657 */
658 if (!(flags1 & FNONBLOCK))
659 VOP_UNLOCK(vp, 0);
660
661 error = (*devclose)(dev, flags1, mode, ap->a_p);
662
663 if (!(flags1 & FNONBLOCK))
664 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
665
666 return (error);
667 }
668
669 /*
670 * Print out the contents of a special device vnode.
671 */
672 int
673 spec_print(v)
674 void *v;
675 {
676 struct vop_print_args /* {
677 struct vnode *a_vp;
678 } */ *ap = v;
679
680 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev),
681 minor(ap->a_vp->v_rdev));
682 return 0;
683 }
684
685 /*
686 * Return POSIX pathconf information applicable to special devices.
687 */
688 int
689 spec_pathconf(v)
690 void *v;
691 {
692 struct vop_pathconf_args /* {
693 struct vnode *a_vp;
694 int a_name;
695 register_t *a_retval;
696 } */ *ap = v;
697
698 switch (ap->a_name) {
699 case _PC_LINK_MAX:
700 *ap->a_retval = LINK_MAX;
701 return (0);
702 case _PC_MAX_CANON:
703 *ap->a_retval = MAX_CANON;
704 return (0);
705 case _PC_MAX_INPUT:
706 *ap->a_retval = MAX_INPUT;
707 return (0);
708 case _PC_PIPE_BUF:
709 *ap->a_retval = PIPE_BUF;
710 return (0);
711 case _PC_CHOWN_RESTRICTED:
712 *ap->a_retval = 1;
713 return (0);
714 case _PC_VDISABLE:
715 *ap->a_retval = _POSIX_VDISABLE;
716 return (0);
717 case _PC_SYNC_IO:
718 *ap->a_retval = 1;
719 return (0);
720 default:
721 return (EINVAL);
722 }
723 /* NOTREACHED */
724 }
725
726 /*
727 * Advisory record locking support.
728 */
729 int
730 spec_advlock(v)
731 void *v;
732 {
733 struct vop_advlock_args /* {
734 struct vnode *a_vp;
735 caddr_t a_id;
736 int a_op;
737 struct flock *a_fl;
738 int a_flags;
739 } */ *ap = v;
740 struct vnode *vp = ap->a_vp;
741
742 return lf_advlock(ap, &vp->v_speclockf, (off_t)0);
743 }
744