spec_vnops.c revision 1.53 1 /* $NetBSD: spec_vnops.c,v 1.53 2001/01/22 12:17:40 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/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 { (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
123 };
124 const struct vnodeopv_desc spec_vnodeop_opv_desc =
125 { &spec_vnodeop_p, spec_vnodeop_entries };
126
127 /*
128 * Trivial lookup routine that always fails.
129 */
130 int
131 spec_lookup(v)
132 void *v;
133 {
134 struct vop_lookup_args /* {
135 struct vnode *a_dvp;
136 struct vnode **a_vpp;
137 struct componentname *a_cnp;
138 } */ *ap = v;
139
140 *ap->a_vpp = NULL;
141 return (ENOTDIR);
142 }
143
144 /*
145 * Open a special file.
146 */
147 /* ARGSUSED */
148 int
149 spec_open(v)
150 void *v;
151 {
152 struct vop_open_args /* {
153 struct vnode *a_vp;
154 int a_mode;
155 struct ucred *a_cred;
156 struct proc *a_p;
157 } */ *ap = v;
158 struct proc *p = ap->a_p;
159 struct vnode *bvp, *vp = ap->a_vp;
160 dev_t bdev, dev = (dev_t)vp->v_rdev;
161 int maj = major(dev);
162 int error;
163
164 /*
165 * Don't allow open if fs is mounted -nodev.
166 */
167 if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
168 return (ENXIO);
169
170 switch (vp->v_type) {
171
172 case VCHR:
173 if ((u_int)maj >= nchrdev)
174 return (ENXIO);
175 if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
176 /*
177 * When running in very secure mode, do not allow
178 * opens for writing of any disk character devices.
179 */
180 if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK)
181 return (EPERM);
182 /*
183 * When running in secure mode, do not allow opens
184 * for writing of /dev/mem, /dev/kmem, or character
185 * devices whose corresponding block devices are
186 * currently mounted.
187 */
188 if (securelevel >= 1) {
189 if ((bdev = chrtoblk(dev)) != (dev_t)NODEV &&
190 vfinddev(bdev, VBLK, &bvp) &&
191 (error = vfs_mountedon(bvp)))
192 return (error);
193 if (iskmemdev(dev))
194 return (EPERM);
195 }
196 }
197 if (cdevsw[maj].d_type == D_TTY)
198 vp->v_flag |= VISTTY;
199 VOP_UNLOCK(vp, 0);
200 error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, p);
201 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
202 return (error);
203
204 case VBLK:
205 if ((u_int)maj >= nblkdev)
206 return (ENXIO);
207 /*
208 * When running in very secure mode, do not allow
209 * opens for writing of any disk block devices.
210 */
211 if (securelevel >= 2 && ap->a_cred != FSCRED &&
212 (ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK)
213 return (EPERM);
214 /*
215 * Do not allow opens of block devices that are
216 * currently mounted.
217 */
218 if ((error = vfs_mountedon(vp)) != 0)
219 return (error);
220 return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, p));
221 case VNON:
222 case VLNK:
223 case VDIR:
224 case VREG:
225 case VBAD:
226 case VFIFO:
227 case VSOCK:
228 break;
229 }
230 return (0);
231 }
232
233 /*
234 * Vnode op for read
235 */
236 /* ARGSUSED */
237 int
238 spec_read(v)
239 void *v;
240 {
241 struct vop_read_args /* {
242 struct vnode *a_vp;
243 struct uio *a_uio;
244 int a_ioflag;
245 struct ucred *a_cred;
246 } */ *ap = v;
247 struct vnode *vp = ap->a_vp;
248 struct uio *uio = ap->a_uio;
249 struct proc *p = uio->uio_procp;
250 struct buf *bp;
251 daddr_t bn, nextbn;
252 int bsize, bscale, ssize;
253 struct partinfo dpart;
254 int n, on, majordev;
255 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *));
256 int error = 0;
257
258 #ifdef DIAGNOSTIC
259 if (uio->uio_rw != UIO_READ)
260 panic("spec_read mode");
261 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
262 panic("spec_read proc");
263 #endif
264 if (uio->uio_resid == 0)
265 return (0);
266
267 switch (vp->v_type) {
268
269 case VCHR:
270 VOP_UNLOCK(vp, 0);
271 error = (*cdevsw[major(vp->v_rdev)].d_read)
272 (vp->v_rdev, uio, ap->a_ioflag);
273 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
274 return (error);
275
276 case VBLK:
277 if (uio->uio_offset < 0)
278 return (EINVAL);
279 bsize = BLKDEV_IOSIZE;
280 ssize = DEV_BSIZE;
281 if ((majordev = major(vp->v_rdev)) < nblkdev &&
282 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
283 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
284 if (dpart.part->p_fstype == FS_BSDFFS &&
285 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
286 bsize = dpart.part->p_frag *
287 dpart.part->p_fsize;
288 if (dpart.disklab->d_secsize != 0)
289 ssize = dpart.disklab->d_secsize;
290 }
291 bscale = bsize / ssize;
292 do {
293 bn = (uio->uio_offset / ssize) &~ (bscale - 1);
294 on = uio->uio_offset % bsize;
295 n = min((unsigned)(bsize - on), uio->uio_resid);
296 if (vp->v_lastr + bscale == bn) {
297 nextbn = bn + bscale;
298 error = breadn(vp, bn, bsize, &nextbn,
299 &bsize, 1, NOCRED, &bp);
300 } else
301 error = bread(vp, bn, bsize, NOCRED, &bp);
302 vp->v_lastr = bn;
303 n = min(n, bsize - bp->b_resid);
304 if (error) {
305 brelse(bp);
306 return (error);
307 }
308 error = uiomove((char *)bp->b_data + on, n, uio);
309 brelse(bp);
310 } while (error == 0 && uio->uio_resid > 0 && n != 0);
311 return (error);
312
313 default:
314 panic("spec_read type");
315 }
316 /* NOTREACHED */
317 }
318
319 /*
320 * Vnode op for write
321 */
322 /* ARGSUSED */
323 int
324 spec_write(v)
325 void *v;
326 {
327 struct vop_write_args /* {
328 struct vnode *a_vp;
329 struct uio *a_uio;
330 int a_ioflag;
331 struct ucred *a_cred;
332 } */ *ap = v;
333 struct vnode *vp = ap->a_vp;
334 struct uio *uio = ap->a_uio;
335 struct proc *p = uio->uio_procp;
336 struct buf *bp;
337 daddr_t bn;
338 int bsize, bscale, ssize;
339 struct partinfo dpart;
340 int n, on, majordev;
341 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *));
342 int error = 0;
343
344 #ifdef DIAGNOSTIC
345 if (uio->uio_rw != UIO_WRITE)
346 panic("spec_write mode");
347 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
348 panic("spec_write proc");
349 #endif
350
351 switch (vp->v_type) {
352
353 case VCHR:
354 VOP_UNLOCK(vp, 0);
355 error = (*cdevsw[major(vp->v_rdev)].d_write)
356 (vp->v_rdev, uio, ap->a_ioflag);
357 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
358 return (error);
359
360 case VBLK:
361 if (uio->uio_resid == 0)
362 return (0);
363 if (uio->uio_offset < 0)
364 return (EINVAL);
365 bsize = BLKDEV_IOSIZE;
366 ssize = DEV_BSIZE;
367 if ((majordev = major(vp->v_rdev)) < nblkdev &&
368 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
369 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
370 if (dpart.part->p_fstype == FS_BSDFFS &&
371 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
372 bsize = dpart.part->p_frag *
373 dpart.part->p_fsize;
374 if (dpart.disklab->d_secsize != 0)
375 ssize = dpart.disklab->d_secsize;
376 }
377 bscale = bsize / ssize;
378 do {
379 bn = (uio->uio_offset / ssize) &~ (bscale - 1);
380 on = uio->uio_offset % bsize;
381 n = min((unsigned)(bsize - on), uio->uio_resid);
382 if (n == bsize)
383 bp = getblk(vp, bn, bsize, 0, 0);
384 else
385 error = bread(vp, bn, bsize, NOCRED, &bp);
386 if (error) {
387 brelse(bp);
388 return (error);
389 }
390 n = min(n, bsize - bp->b_resid);
391 error = uiomove((char *)bp->b_data + on, n, uio);
392 if (error)
393 brelse(bp);
394 else {
395 if (n + on == bsize)
396 bawrite(bp);
397 else
398 bdwrite(bp);
399 if (bp->b_flags & B_ERROR)
400 error = bp->b_error;
401 }
402 } while (error == 0 && uio->uio_resid > 0 && n != 0);
403 return (error);
404
405 default:
406 panic("spec_write type");
407 }
408 /* NOTREACHED */
409 }
410
411 /*
412 * Device ioctl operation.
413 */
414 /* ARGSUSED */
415 int
416 spec_ioctl(v)
417 void *v;
418 {
419 struct vop_ioctl_args /* {
420 struct vnode *a_vp;
421 u_long a_command;
422 caddr_t a_data;
423 int a_fflag;
424 struct ucred *a_cred;
425 struct proc *a_p;
426 } */ *ap = v;
427 dev_t dev = ap->a_vp->v_rdev;
428 int maj = major(dev);
429
430 switch (ap->a_vp->v_type) {
431
432 case VCHR:
433 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
434 ap->a_fflag, ap->a_p));
435
436 case VBLK:
437 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) {
438 if (bdevsw[maj].d_type == D_TAPE)
439 return (0);
440 else
441 return (1);
442 }
443 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
444 ap->a_fflag, ap->a_p));
445
446 default:
447 panic("spec_ioctl");
448 /* NOTREACHED */
449 }
450 }
451
452 /* ARGSUSED */
453 int
454 spec_poll(v)
455 void *v;
456 {
457 struct vop_poll_args /* {
458 struct vnode *a_vp;
459 int a_events;
460 struct proc *a_p;
461 } */ *ap = v;
462 dev_t dev;
463
464 switch (ap->a_vp->v_type) {
465
466 case VCHR:
467 dev = ap->a_vp->v_rdev;
468 return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p);
469
470 default:
471 return (genfs_poll(v));
472 }
473 }
474 /*
475 * Synch buffers associated with a block device
476 */
477 /* ARGSUSED */
478 int
479 spec_fsync(v)
480 void *v;
481 {
482 struct vop_fsync_args /* {
483 struct vnode *a_vp;
484 struct ucred *a_cred;
485 int a_flags;
486 off_t offlo;
487 off_t offhi;
488 struct proc *a_p;
489 } */ *ap = v;
490 struct vnode *vp = ap->a_vp;
491
492 if (vp->v_type == VBLK)
493 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0);
494 return (0);
495 }
496
497 /*
498 * Just call the device strategy routine
499 */
500 int
501 spec_strategy(v)
502 void *v;
503 {
504 struct vop_strategy_args /* {
505 struct buf *a_bp;
506 } */ *ap = v;
507 struct buf *bp;
508
509 bp = ap->a_bp;
510 if (!(bp->b_flags & B_READ) &&
511 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
512 (*bioops.io_start)(bp);
513 (*bdevsw[major(bp->b_dev)].d_strategy)(bp);
514 return (0);
515 }
516
517 int
518 spec_inactive(v)
519 void *v;
520 {
521 struct vop_inactive_args /* {
522 struct vnode *a_vp;
523 struct proc *a_p;
524 } */ *ap = v;
525
526 VOP_UNLOCK(ap->a_vp, 0);
527 return (0);
528 }
529
530 /*
531 * This is a noop, simply returning what one has been given.
532 */
533 int
534 spec_bmap(v)
535 void *v;
536 {
537 struct vop_bmap_args /* {
538 struct vnode *a_vp;
539 daddr_t a_bn;
540 struct vnode **a_vpp;
541 daddr_t *a_bnp;
542 int *a_runp;
543 } */ *ap = v;
544
545 if (ap->a_vpp != NULL)
546 *ap->a_vpp = ap->a_vp;
547 if (ap->a_bnp != NULL)
548 *ap->a_bnp = ap->a_bn;
549 if (ap->a_runp != NULL)
550 *ap->a_runp = 0;
551 return (0);
552 }
553
554 /*
555 * Device close routine
556 */
557 /* ARGSUSED */
558 int
559 spec_close(v)
560 void *v;
561 {
562 struct vop_close_args /* {
563 struct vnode *a_vp;
564 int a_fflag;
565 struct ucred *a_cred;
566 struct proc *a_p;
567 } */ *ap = v;
568 struct vnode *vp = ap->a_vp;
569 dev_t dev = vp->v_rdev;
570 int (*devclose) __P((dev_t, int, int, struct proc *));
571 int mode, error, count, flags, flags1;
572
573 simple_lock(&vp->v_interlock);
574 count = vcount(vp);
575 flags = vp->v_flag;
576 simple_unlock(&vp->v_interlock);
577
578 switch (vp->v_type) {
579
580 case VCHR:
581 /*
582 * Hack: a tty device that is a controlling terminal
583 * has a reference from the session structure.
584 * We cannot easily tell that a character device is
585 * a controlling terminal, unless it is the closing
586 * process' controlling terminal. In that case,
587 * if the reference count is 2 (this last descriptor
588 * plus the session), release the reference from the session.
589 */
590 if (count == 2 && ap->a_p &&
591 vp == ap->a_p->p_session->s_ttyvp) {
592 vrele(vp);
593 count--;
594 ap->a_p->p_session->s_ttyvp = NULL;
595 }
596 /*
597 * If the vnode is locked, then we are in the midst
598 * of forcably closing the device, otherwise we only
599 * close on last reference.
600 */
601 if (count > 1 && (flags & VXLOCK) == 0)
602 return (0);
603 devclose = cdevsw[major(dev)].d_close;
604 mode = S_IFCHR;
605 break;
606
607 case VBLK:
608 /*
609 * On last close of a block device (that isn't mounted)
610 * we must invalidate any in core blocks, so that
611 * we can, for instance, change floppy disks.
612 */
613 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
614 if (error)
615 return (error);
616 /*
617 * We do not want to really close the device if it
618 * is still in use unless we are trying to close it
619 * forcibly. Since every use (buffer, vnode, swap, cmap)
620 * holds a reference to the vnode, and because we mark
621 * any other vnodes that alias this device, when the
622 * sum of the reference counts on all the aliased
623 * vnodes descends to one, we are on last close.
624 */
625 if (count > 1 && (flags & VXLOCK) == 0)
626 return (0);
627 devclose = bdevsw[major(dev)].d_close;
628 mode = S_IFBLK;
629 break;
630
631 default:
632 panic("spec_close: not special");
633 }
634
635 flags1 = ap->a_fflag;
636
637 /*
638 * if VXLOCK is set, then we're going away soon, so make this
639 * non-blocking. Also ensures that we won't wedge in vn_lock below.
640 */
641 if (flags & VXLOCK)
642 flags1 |= FNONBLOCK;
643
644 /*
645 * If we're able to block, release the vnode lock & reaquire. We
646 * might end up sleaping for someone else who wants our queues. They
647 * won't get them if we hold the vnode locked. Also, if VXLOCK is set,
648 * don't release the lock as we won't be able to regain it.
649 */
650 if (!(flags1 & FNONBLOCK))
651 VOP_UNLOCK(vp, 0);
652
653 error = (*devclose)(dev, flags1, mode, ap->a_p);
654
655 if (!(flags1 & FNONBLOCK))
656 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
657
658 return (error);
659 }
660
661 /*
662 * Print out the contents of a special device vnode.
663 */
664 int
665 spec_print(v)
666 void *v;
667 {
668 struct vop_print_args /* {
669 struct vnode *a_vp;
670 } */ *ap = v;
671
672 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev),
673 minor(ap->a_vp->v_rdev));
674 return 0;
675 }
676
677 /*
678 * Return POSIX pathconf information applicable to special devices.
679 */
680 int
681 spec_pathconf(v)
682 void *v;
683 {
684 struct vop_pathconf_args /* {
685 struct vnode *a_vp;
686 int a_name;
687 register_t *a_retval;
688 } */ *ap = v;
689
690 switch (ap->a_name) {
691 case _PC_LINK_MAX:
692 *ap->a_retval = LINK_MAX;
693 return (0);
694 case _PC_MAX_CANON:
695 *ap->a_retval = MAX_CANON;
696 return (0);
697 case _PC_MAX_INPUT:
698 *ap->a_retval = MAX_INPUT;
699 return (0);
700 case _PC_PIPE_BUF:
701 *ap->a_retval = PIPE_BUF;
702 return (0);
703 case _PC_CHOWN_RESTRICTED:
704 *ap->a_retval = 1;
705 return (0);
706 case _PC_VDISABLE:
707 *ap->a_retval = _POSIX_VDISABLE;
708 return (0);
709 case _PC_SYNC_IO:
710 *ap->a_retval = 1;
711 return (0);
712 default:
713 return (EINVAL);
714 }
715 /* NOTREACHED */
716 }
717
718 /*
719 * Advisory record locking support.
720 */
721 int
722 spec_advlock(v)
723 void *v;
724 {
725 struct vop_advlock_args /* {
726 struct vnode *a_vp;
727 caddr_t a_id;
728 int a_op;
729 struct flock *a_fl;
730 int a_flags;
731 } */ *ap = v;
732 struct vnode *vp = ap->a_vp;
733
734 return lf_advlock(ap, &vp->v_speclockf, (off_t)0);
735 }
736