spec_vnops.c revision 1.59 1 /* $NetBSD: spec_vnops.c,v 1.59 2001/09/23 04:39:25 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;
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_SHARED | LK_RETRY);
288 return (error);
289
290 case VBLK:
291 if (uio->uio_offset < 0)
292 return (EINVAL);
293 bsize = BLKDEV_IOSIZE;
294 if ((majordev = major(vp->v_rdev)) < nblkdev &&
295 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
296 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
297 if (dpart.part->p_fstype == FS_BSDFFS &&
298 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
299 bsize = dpart.part->p_frag *
300 dpart.part->p_fsize;
301 }
302 bscale = bsize >> DEV_BSHIFT;
303 do {
304 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1);
305 on = uio->uio_offset % bsize;
306 n = min((unsigned)(bsize - on), uio->uio_resid);
307 error = bread(vp, bn, bsize, NOCRED, &bp);
308 n = min(n, bsize - bp->b_resid);
309 if (error) {
310 brelse(bp);
311 return (error);
312 }
313 error = uiomove((char *)bp->b_data + on, n, uio);
314 brelse(bp);
315 } while (error == 0 && uio->uio_resid > 0 && n != 0);
316 return (error);
317
318 default:
319 panic("spec_read type");
320 }
321 /* NOTREACHED */
322 }
323
324 /*
325 * Vnode op for write
326 */
327 /* ARGSUSED */
328 int
329 spec_write(v)
330 void *v;
331 {
332 struct vop_write_args /* {
333 struct vnode *a_vp;
334 struct uio *a_uio;
335 int a_ioflag;
336 struct ucred *a_cred;
337 } */ *ap = v;
338 struct vnode *vp = ap->a_vp;
339 struct uio *uio = ap->a_uio;
340 struct proc *p = uio->uio_procp;
341 struct buf *bp;
342 daddr_t bn;
343 int bsize, bscale;
344 struct partinfo dpart;
345 int n, on, majordev;
346 int (*ioctl) __P((dev_t, u_long, caddr_t, int, struct proc *));
347 int error = 0;
348
349 #ifdef DIAGNOSTIC
350 if (uio->uio_rw != UIO_WRITE)
351 panic("spec_write mode");
352 if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
353 panic("spec_write proc");
354 #endif
355
356 switch (vp->v_type) {
357
358 case VCHR:
359 VOP_UNLOCK(vp, 0);
360 error = (*cdevsw[major(vp->v_rdev)].d_write)
361 (vp->v_rdev, uio, ap->a_ioflag);
362 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
363 return (error);
364
365 case VBLK:
366 if (uio->uio_resid == 0)
367 return (0);
368 if (uio->uio_offset < 0)
369 return (EINVAL);
370 bsize = BLKDEV_IOSIZE;
371 if ((majordev = major(vp->v_rdev)) < nblkdev &&
372 (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
373 (*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
374 if (dpart.part->p_fstype == FS_BSDFFS &&
375 dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
376 bsize = dpart.part->p_frag *
377 dpart.part->p_fsize;
378 }
379 bscale = bsize >> DEV_BSHIFT;
380 do {
381 bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1);
382 on = uio->uio_offset % bsize;
383 n = min((unsigned)(bsize - on), uio->uio_resid);
384 if (n == bsize)
385 bp = getblk(vp, bn, bsize, 0, 0);
386 else
387 error = bread(vp, bn, bsize, NOCRED, &bp);
388 if (error) {
389 brelse(bp);
390 return (error);
391 }
392 n = min(n, bsize - bp->b_resid);
393 error = uiomove((char *)bp->b_data + on, n, uio);
394 if (error)
395 brelse(bp);
396 else {
397 if (n + on == bsize)
398 bawrite(bp);
399 else
400 bdwrite(bp);
401 if (bp->b_flags & B_ERROR)
402 error = bp->b_error;
403 }
404 } while (error == 0 && uio->uio_resid > 0 && n != 0);
405 return (error);
406
407 default:
408 panic("spec_write type");
409 }
410 /* NOTREACHED */
411 }
412
413 /*
414 * Device ioctl operation.
415 */
416 /* ARGSUSED */
417 int
418 spec_ioctl(v)
419 void *v;
420 {
421 struct vop_ioctl_args /* {
422 struct vnode *a_vp;
423 u_long a_command;
424 caddr_t a_data;
425 int a_fflag;
426 struct ucred *a_cred;
427 struct proc *a_p;
428 } */ *ap = v;
429 dev_t dev = ap->a_vp->v_rdev;
430 int maj = major(dev);
431
432 switch (ap->a_vp->v_type) {
433
434 case VCHR:
435 return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
436 ap->a_fflag, ap->a_p));
437
438 case VBLK:
439 if (ap->a_command == 0 && (long)ap->a_data == B_TAPE) {
440 if (bdevsw[maj].d_type == D_TAPE)
441 return (0);
442 else
443 return (1);
444 }
445 return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
446 ap->a_fflag, ap->a_p));
447
448 default:
449 panic("spec_ioctl");
450 /* NOTREACHED */
451 }
452 }
453
454 /* ARGSUSED */
455 int
456 spec_poll(v)
457 void *v;
458 {
459 struct vop_poll_args /* {
460 struct vnode *a_vp;
461 int a_events;
462 struct proc *a_p;
463 } */ *ap = v;
464 dev_t dev;
465
466 switch (ap->a_vp->v_type) {
467
468 case VCHR:
469 dev = ap->a_vp->v_rdev;
470 return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p);
471
472 default:
473 return (genfs_poll(v));
474 }
475 }
476 /*
477 * Synch buffers associated with a block device
478 */
479 /* ARGSUSED */
480 int
481 spec_fsync(v)
482 void *v;
483 {
484 struct vop_fsync_args /* {
485 struct vnode *a_vp;
486 struct ucred *a_cred;
487 int a_flags;
488 off_t offlo;
489 off_t offhi;
490 struct proc *a_p;
491 } */ *ap = v;
492 struct vnode *vp = ap->a_vp;
493
494 if (vp->v_type == VBLK)
495 vflushbuf(vp, (ap->a_flags & FSYNC_WAIT) != 0);
496 return (0);
497 }
498
499 /*
500 * Just call the device strategy routine
501 */
502 int
503 spec_strategy(v)
504 void *v;
505 {
506 struct vop_strategy_args /* {
507 struct buf *a_bp;
508 } */ *ap = v;
509 struct buf *bp;
510
511 bp = ap->a_bp;
512 if (!(bp->b_flags & B_READ) &&
513 (LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
514 (*bioops.io_start)(bp);
515 (*bdevsw[major(bp->b_dev)].d_strategy)(bp);
516 return (0);
517 }
518
519 int
520 spec_inactive(v)
521 void *v;
522 {
523 struct vop_inactive_args /* {
524 struct vnode *a_vp;
525 struct proc *a_p;
526 } */ *ap = v;
527
528 VOP_UNLOCK(ap->a_vp, 0);
529 return (0);
530 }
531
532 /*
533 * This is a noop, simply returning what one has been given.
534 */
535 int
536 spec_bmap(v)
537 void *v;
538 {
539 struct vop_bmap_args /* {
540 struct vnode *a_vp;
541 daddr_t a_bn;
542 struct vnode **a_vpp;
543 daddr_t *a_bnp;
544 int *a_runp;
545 } */ *ap = v;
546
547 if (ap->a_vpp != NULL)
548 *ap->a_vpp = ap->a_vp;
549 if (ap->a_bnp != NULL)
550 *ap->a_bnp = ap->a_bn;
551 if (ap->a_runp != NULL)
552 *ap->a_runp = (MAXBSIZE >> DEV_BSHIFT) - 1;
553 return (0);
554 }
555
556 /*
557 * Device close routine
558 */
559 /* ARGSUSED */
560 int
561 spec_close(v)
562 void *v;
563 {
564 struct vop_close_args /* {
565 struct vnode *a_vp;
566 int a_fflag;
567 struct ucred *a_cred;
568 struct proc *a_p;
569 } */ *ap = v;
570 struct vnode *vp = ap->a_vp;
571 dev_t dev = vp->v_rdev;
572 int (*devclose) __P((dev_t, int, int, struct proc *));
573 int mode, error, count, flags, flags1;
574
575 count = vcount(vp);
576 simple_lock(&vp->v_interlock);
577 flags = vp->v_flag;
578 simple_unlock(&vp->v_interlock);
579
580 switch (vp->v_type) {
581
582 case VCHR:
583 /*
584 * Hack: a tty device that is a controlling terminal
585 * has a reference from the session structure.
586 * We cannot easily tell that a character device is
587 * a controlling terminal, unless it is the closing
588 * process' controlling terminal. In that case,
589 * if the reference count is 2 (this last descriptor
590 * plus the session), release the reference from the session.
591 */
592 if (count == 2 && ap->a_p &&
593 vp == ap->a_p->p_session->s_ttyvp) {
594 vrele(vp);
595 count--;
596 ap->a_p->p_session->s_ttyvp = NULL;
597 }
598 /*
599 * If the vnode is locked, then we are in the midst
600 * of forcably closing the device, otherwise we only
601 * close on last reference.
602 */
603 if (count > 1 && (flags & VXLOCK) == 0)
604 return (0);
605 devclose = cdevsw[major(dev)].d_close;
606 mode = S_IFCHR;
607 break;
608
609 case VBLK:
610 /*
611 * On last close of a block device (that isn't mounted)
612 * we must invalidate any in core blocks, so that
613 * we can, for instance, change floppy disks.
614 */
615 error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
616 if (error)
617 return (error);
618 /*
619 * We do not want to really close the device if it
620 * is still in use unless we are trying to close it
621 * forcibly. Since every use (buffer, vnode, swap, cmap)
622 * holds a reference to the vnode, and because we mark
623 * any other vnodes that alias this device, when the
624 * sum of the reference counts on all the aliased
625 * vnodes descends to one, we are on last close.
626 */
627 if (count > 1 && (flags & VXLOCK) == 0)
628 return (0);
629 devclose = bdevsw[major(dev)].d_close;
630 mode = S_IFBLK;
631 break;
632
633 default:
634 panic("spec_close: not special");
635 }
636
637 flags1 = ap->a_fflag;
638
639 /*
640 * if VXLOCK is set, then we're going away soon, so make this
641 * non-blocking. Also ensures that we won't wedge in vn_lock below.
642 */
643 if (flags & VXLOCK)
644 flags1 |= FNONBLOCK;
645
646 /*
647 * If we're able to block, release the vnode lock & reaquire. We
648 * might end up sleaping for someone else who wants our queues. They
649 * won't get them if we hold the vnode locked. Also, if VXLOCK is set,
650 * don't release the lock as we won't be able to regain it.
651 */
652 if (!(flags1 & FNONBLOCK))
653 VOP_UNLOCK(vp, 0);
654
655 error = (*devclose)(dev, flags1, mode, ap->a_p);
656
657 if (!(flags1 & FNONBLOCK))
658 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
659
660 return (error);
661 }
662
663 /*
664 * Print out the contents of a special device vnode.
665 */
666 int
667 spec_print(v)
668 void *v;
669 {
670 struct vop_print_args /* {
671 struct vnode *a_vp;
672 } */ *ap = v;
673
674 printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev),
675 minor(ap->a_vp->v_rdev));
676 return 0;
677 }
678
679 /*
680 * Return POSIX pathconf information applicable to special devices.
681 */
682 int
683 spec_pathconf(v)
684 void *v;
685 {
686 struct vop_pathconf_args /* {
687 struct vnode *a_vp;
688 int a_name;
689 register_t *a_retval;
690 } */ *ap = v;
691
692 switch (ap->a_name) {
693 case _PC_LINK_MAX:
694 *ap->a_retval = LINK_MAX;
695 return (0);
696 case _PC_MAX_CANON:
697 *ap->a_retval = MAX_CANON;
698 return (0);
699 case _PC_MAX_INPUT:
700 *ap->a_retval = MAX_INPUT;
701 return (0);
702 case _PC_PIPE_BUF:
703 *ap->a_retval = PIPE_BUF;
704 return (0);
705 case _PC_CHOWN_RESTRICTED:
706 *ap->a_retval = 1;
707 return (0);
708 case _PC_VDISABLE:
709 *ap->a_retval = _POSIX_VDISABLE;
710 return (0);
711 case _PC_SYNC_IO:
712 *ap->a_retval = 1;
713 return (0);
714 default:
715 return (EINVAL);
716 }
717 /* NOTREACHED */
718 }
719
720 /*
721 * Advisory record locking support.
722 */
723 int
724 spec_advlock(v)
725 void *v;
726 {
727 struct vop_advlock_args /* {
728 struct vnode *a_vp;
729 caddr_t a_id;
730 int a_op;
731 struct flock *a_fl;
732 int a_flags;
733 } */ *ap = v;
734 struct vnode *vp = ap->a_vp;
735
736 return lf_advlock(ap, &vp->v_speclockf, (off_t)0);
737 }
738