xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision 68344a95478e7f7a30cc2d93820595aad7e7bc5b)
1 /*
2  * Copyright (c) 1992, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 2000
5  *	Poul-Henning Kamp.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. 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  *	@(#)kernfs_vnops.c	8.15 (Berkeley) 5/21/95
32  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43
33  *
34  * $FreeBSD$
35  */
36 
37 /*
38  * TODO:
39  *	remove empty directories
40  *	mknod: hunt down DE_DELETED, compare name, reinstantiate.
41  *	mkdir: want it ?
42  */
43 
44 #include <opt_devfs.h>
45 #ifndef NODEVFS
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/conf.h>
50 #include <sys/dirent.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mount.h>
55 #include <sys/namei.h>
56 #include <sys/proc.h>
57 #include <sys/time.h>
58 #include <sys/vnode.h>
59 
60 #include <fs/devfs/devfs.h>
61 
62 static int	devfs_access __P((struct vop_access_args *ap));
63 static int	devfs_getattr __P((struct vop_getattr_args *ap));
64 static int	devfs_lookupx __P((struct vop_lookup_args *ap));
65 static int	devfs_mknod __P((struct vop_mknod_args *ap));
66 static int	devfs_print __P((struct vop_print_args *ap));
67 static int	devfs_read __P((struct vop_read_args *ap));
68 static int	devfs_readdir __P((struct vop_readdir_args *ap));
69 static int	devfs_readlink __P((struct vop_readlink_args *ap));
70 static int	devfs_reclaim __P((struct vop_reclaim_args *ap));
71 static int	devfs_remove __P((struct vop_remove_args *ap));
72 static int	devfs_revoke __P((struct vop_revoke_args *ap));
73 static int	devfs_setattr __P((struct vop_setattr_args *ap));
74 static int	devfs_symlink __P((struct vop_symlink_args *ap));
75 
76 /*
77  * Construct the fully qualified path name relative to the mountpoint
78  */
79 static char *
80 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
81 {
82 	int i;
83 	struct devfs_dirent *de, *dd;
84 	struct devfs_mount *dmp;
85 
86 	dmp = VFSTODEVFS(dvp->v_mount);
87 	dd = dvp->v_data;
88 	i = SPECNAMELEN;
89 	buf[i] = '\0';
90 	i -= cnp->cn_namelen;
91 	if (i < 0)
92 		 return (NULL);
93 	bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
94 	de = dd;
95 	while (de != dmp->dm_basedir) {
96 		i--;
97 		if (i < 0)
98 			 return (NULL);
99 		buf[i] = '/';
100 		i -= de->de_dirent->d_namlen;
101 		if (i < 0)
102 			 return (NULL);
103 		bcopy(de->de_dirent->d_name, buf + i,
104 		    de->de_dirent->d_namlen);
105 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
106 		de = TAILQ_NEXT(de, de_list);		/* ".." */
107 		de = de->de_dir;
108 	}
109 	return (buf + i);
110 }
111 
112 int
113 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct thread *td)
114 {
115 	int error;
116 	struct vnode *vp;
117 	dev_t dev;
118 
119 	if (td == NULL)
120 		td = curthread; /* XXX */
121 loop:
122 	vp = de->de_vnode;
123 	if (vp != NULL) {
124 		if (vget(vp, LK_EXCLUSIVE, td ? td : curthread))
125 			goto loop;
126 		*vpp = vp;
127 		return (0);
128 	}
129 	if (de->de_dirent->d_type == DT_CHR) {
130 		dev = *devfs_itod(de->de_inode);
131 		if (dev == NULL)
132 			return (ENOENT);
133 	} else {
134 		dev = NODEV;
135 	}
136 	error = getnewvnode(VT_DEVFS, mp, devfs_vnodeop_p, &vp);
137 	if (error != 0) {
138 		printf("devfs_allocv: failed to allocate new vnode\n");
139 		return (error);
140 	}
141 
142 	if (de->de_dirent->d_type == DT_CHR) {
143 		vp->v_type = VCHR;
144 		vp = addaliasu(vp, dev->si_udev);
145 		vp->v_op = devfs_specop_p;
146 	} else if (de->de_dirent->d_type == DT_DIR) {
147 		vp->v_type = VDIR;
148 	} else if (de->de_dirent->d_type == DT_LNK) {
149 		vp->v_type = VLNK;
150 	} else {
151 		vp->v_type = VBAD;
152 	}
153 	vp->v_data = de;
154 	de->de_vnode = vp;
155 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
156 	*vpp = vp;
157 	return (0);
158 }
159 
160 static int
161 devfs_access(ap)
162 	struct vop_access_args /* {
163 		struct vnode *a_vp;
164 		int  a_mode;
165 		struct ucred *a_cred;
166 		struct thread *a_td;
167 	} */ *ap;
168 {
169 	struct vnode *vp = ap->a_vp;
170 	struct devfs_dirent *de;
171 
172 	de = vp->v_data;
173 	if (vp->v_type == VDIR)
174 		de = de->de_dir;
175 
176 	return (vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
177 	    ap->a_mode, ap->a_cred, NULL));
178 }
179 
180 static int
181 devfs_getattr(ap)
182 	struct vop_getattr_args /* {
183 		struct vnode *a_vp;
184 		struct vattr *a_vap;
185 		struct ucred *a_cred;
186 		struct thread *a_td;
187 	} */ *ap;
188 {
189 	struct vnode *vp = ap->a_vp;
190 	struct vattr *vap = ap->a_vap;
191 	int error = 0;
192 	struct devfs_dirent *de;
193 	dev_t dev;
194 
195 	de = vp->v_data;
196 	if (vp->v_type == VDIR)
197 		de = de->de_dir;
198 	bzero((caddr_t) vap, sizeof(*vap));
199 	vattr_null(vap);
200 	vap->va_uid = de->de_uid;
201 	vap->va_gid = de->de_gid;
202 	vap->va_mode = de->de_mode;
203 	if (vp->v_type == VLNK)
204 		vap->va_size = de->de_dirent->d_namlen;
205 	else
206 		vap->va_size = 0;
207 	vap->va_blocksize = DEV_BSIZE;
208 	vap->va_type = vp->v_type;
209 
210 #define fix(aa)							\
211 	do {							\
212 		if ((aa).tv_sec == 0) {				\
213 			(aa).tv_sec = boottime.tv_sec;		\
214 			(aa).tv_nsec = boottime.tv_usec * 1000; \
215 		}						\
216 	} while (0)
217 
218 	if (vp->v_type != VCHR)  {
219 		fix(de->de_atime);
220 		vap->va_atime = de->de_atime;
221 		fix(de->de_mtime);
222 		vap->va_mtime = de->de_mtime;
223 		fix(de->de_ctime);
224 		vap->va_ctime = de->de_ctime;
225 	} else {
226 		dev = vp->v_rdev;
227 		fix(dev->si_atime);
228 		vap->va_atime = dev->si_atime;
229 		fix(dev->si_mtime);
230 		vap->va_mtime = dev->si_mtime;
231 		fix(dev->si_ctime);
232 		vap->va_ctime = dev->si_ctime;
233 		vap->va_rdev = dev->si_udev;
234 	}
235 	vap->va_gen = 0;
236 	vap->va_flags = 0;
237 	vap->va_bytes = 0;
238 	vap->va_nlink = de->de_links;
239 	vap->va_fileid = de->de_inode;
240 
241 	return (error);
242 }
243 
244 static int
245 devfs_lookupx(ap)
246 	struct vop_lookup_args /* {
247 		struct vnode * a_dvp;
248 		struct vnode ** a_vpp;
249 		struct componentname * a_cnp;
250 	} */ *ap;
251 {
252 	struct componentname *cnp;
253 	struct vnode *dvp, **vpp;
254 	struct thread *td;
255 	struct devfs_dirent *de, *dd;
256 	struct devfs_mount *dmp;
257 	dev_t cdev, *cpdev;
258 	int error, cloned, flags, nameiop;
259 	char specname[SPECNAMELEN + 1], *pname;
260 
261 	cnp = ap->a_cnp;
262 	vpp = ap->a_vpp;
263 	dvp = ap->a_dvp;
264 	pname = cnp->cn_nameptr;
265 	td = cnp->cn_thread;
266 	flags = cnp->cn_flags;
267 	nameiop = cnp->cn_nameiop;
268 	dmp = VFSTODEVFS(dvp->v_mount);
269 	cloned = 0;
270 	dd = dvp->v_data;
271 
272 	*vpp = NULLVP;
273 
274 	if (nameiop == RENAME)
275 		return (EOPNOTSUPP);
276 
277 	if (dvp->v_type != VDIR)
278 		return (ENOTDIR);
279 
280 	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
281 		return (EIO);
282 
283 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
284 	if (error)
285 		return (error);
286 
287 	if (cnp->cn_namelen == 1 && *pname == '.') {
288 		if (nameiop != LOOKUP)
289 			return (EINVAL);
290 		*vpp = dvp;
291 		VREF(dvp);
292 		return (0);
293 	}
294 
295 	if (flags & ISDOTDOT) {
296 		if (nameiop != LOOKUP)
297 			return (EINVAL);
298 		VOP_UNLOCK(dvp, 0, td);
299 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
300 		de = TAILQ_NEXT(de, de_list);		/* ".." */
301 		de = de->de_dir;
302 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
303 		if (error) {
304 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
305 			return (error);
306 		}
307 		if ((flags & LOCKPARENT) && (flags & ISLASTCN))
308 			error = vn_lock(dvp, LK_EXCLUSIVE, td);
309 		if (error)
310 			vput(*vpp);
311 		return (error);
312 	}
313 
314 	devfs_populate(dmp);
315 	dd = dvp->v_data;
316 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
317 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
318 			continue;
319 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
320 		    de->de_dirent->d_namlen) != 0)
321 			continue;
322 		if (de->de_flags & DE_WHITEOUT)
323 			goto notfound;
324 		goto found;
325 	}
326 
327 	if (nameiop == DELETE)
328 		goto notfound;
329 
330 	/*
331 	 * OK, we didn't have an entry for the name we were asked for
332 	 * so we try to see if anybody can create it on demand.
333 	 */
334 	pname = devfs_fqpn(specname, dvp, cnp);
335 	if (pname == NULL)
336 		goto notfound;
337 
338 	cdev = NODEV;
339 	EVENTHANDLER_INVOKE(dev_clone, pname, strlen(pname), &cdev);
340 	if (cdev == NODEV)
341 		goto notfound;
342 
343 	devfs_populate(dmp);
344 	dd = dvp->v_data;
345 
346 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
347 		cpdev = devfs_itod(de->de_inode);
348 		if (cpdev != NULL && cdev == *cpdev)
349 			goto found;
350 		continue;
351 	}
352 
353 notfound:
354 
355 	if ((nameiop == CREATE || nameiop == RENAME) &&
356 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
357 		cnp->cn_flags |= SAVENAME;
358 		if (!(flags & LOCKPARENT))
359 			VOP_UNLOCK(dvp, 0, td);
360 		return (EJUSTRETURN);
361 	}
362 	return (ENOENT);
363 
364 
365 found:
366 
367 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
368 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
369 		if (error)
370 			return (error);
371 		if (*vpp == dvp) {
372 			VREF(dvp);
373 			*vpp = dvp;
374 			return (0);
375 		}
376 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
377 		if (error)
378 			return (error);
379 		if (!(flags & LOCKPARENT))
380 			VOP_UNLOCK(dvp, 0, td);
381 		return (0);
382 	}
383 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
384 	if (error)
385 		return (error);
386 	if (!(flags & LOCKPARENT) || !(flags & ISLASTCN))
387 		VOP_UNLOCK(dvp, 0, td);
388 	return (0);
389 }
390 
391 static int
392 devfs_lookup(struct vop_lookup_args *ap)
393 {
394 	int j;
395 	struct devfs_mount *dmp;
396 
397 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
398 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
399 	j = devfs_lookupx(ap);
400 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
401 	return (j);
402 }
403 
404 static int
405 devfs_mknod(struct vop_mknod_args *ap)
406 /*
407 struct vop_mknod_args {
408         struct vnodeop_desc *a_desc;
409         struct vnode *a_dvp;
410         struct vnode **a_vpp;
411         struct componentname *a_cnp;
412         struct vattr *a_vap;
413 };
414 */
415 {
416 	struct componentname *cnp;
417 	struct vnode *dvp, **vpp;
418 	struct thread *td;
419 	struct devfs_dirent *dd, *de;
420 	struct devfs_mount *dmp;
421 	int cloned, flags, nameiop;
422 	int error;
423 
424 	dvp = ap->a_dvp;
425 	dmp = VFSTODEVFS(dvp->v_mount);
426 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
427 
428 	cnp = ap->a_cnp;
429 	vpp = ap->a_vpp;
430 	td = cnp->cn_thread;
431 	flags = cnp->cn_flags;
432 	nameiop = cnp->cn_nameiop;
433 	cloned = 0;
434 	dd = dvp->v_data;
435 
436 	error = ENOENT;
437 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
438 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
439 			continue;
440 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
441 		    de->de_dirent->d_namlen) != 0)
442 			continue;
443 		if (de->de_flags & DE_WHITEOUT)
444 			break;
445 		goto notfound;
446 	}
447 	if (de == NULL)
448 		goto notfound;
449 	de->de_flags &= ~DE_WHITEOUT;
450 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
451 notfound:
452 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
453 	return (error);
454 }
455 
456 
457 /* ARGSUSED */
458 static int
459 devfs_print(ap)
460 	struct vop_print_args /* {
461 		struct vnode *a_vp;
462 	} */ *ap;
463 {
464 
465 	printf("tag VT_DEVFS, devfs vnode\n");
466 	return (0);
467 }
468 
469 static int
470 devfs_read(ap)
471 	struct vop_read_args /* {
472 		struct vnode *a_vp;
473 		struct uio *a_uio;
474 		int a_ioflag;
475 		struct ucred *a_cred;
476 	} */ *ap;
477 {
478 
479 	if (ap->a_vp->v_type != VDIR)
480 		return (EINVAL);
481 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
482 }
483 
484 static int
485 devfs_readdir(ap)
486 	struct vop_readdir_args /* {
487 		struct vnode *a_vp;
488 		struct uio *a_uio;
489 		struct ucred *a_cred;
490 		int *a_eofflag;
491 		int *a_ncookies;
492 		u_long **a_cookies;
493 	} */ *ap;
494 {
495 	int error;
496 	struct uio *uio;
497 	struct dirent *dp;
498 	struct devfs_dirent *dd;
499 	struct devfs_dirent *de;
500 	struct devfs_mount *dmp;
501 	off_t off, oldoff;
502 	int ncookies = 0;
503 	u_long *cookiebuf, *cookiep;
504 	struct dirent *dps, *dpe;
505 
506 	if (ap->a_vp->v_type != VDIR)
507 		return (ENOTDIR);
508 
509 	uio = ap->a_uio;
510 	if (uio->uio_offset < 0)
511 		return (EINVAL);
512 
513 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
514 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
515 	devfs_populate(dmp);
516 	error = 0;
517 	de = ap->a_vp->v_data;
518 	off = 0;
519 	oldoff = uio->uio_offset;
520 	TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
521 		if (dd->de_flags & DE_WHITEOUT)
522 			continue;
523 		if (dd->de_dirent->d_type == DT_DIR)
524 			de = dd->de_dir;
525 		else
526 			de = dd;
527 		dp = dd->de_dirent;
528 		if (dp->d_reclen > uio->uio_resid)
529 			break;
530 		dp->d_fileno = de->de_inode;
531 		if (off >= uio->uio_offset) {
532 			ncookies++;
533 			error = uiomove((caddr_t)dp, dp->d_reclen, uio);
534 			if (error)
535 				break;
536 		}
537 		off += dp->d_reclen;
538 	}
539 	if( !error && ap->a_ncookies != NULL && ap->a_cookies != NULL ) {
540 		MALLOC(cookiebuf, u_long *, ncookies * sizeof(u_long),
541                        M_TEMP, M_WAITOK);
542 		cookiep = cookiebuf;
543 		dps = (struct dirent *)
544 			(uio->uio_iov->iov_base - (uio->uio_offset - oldoff));
545 		dpe = (struct dirent *) uio->uio_iov->iov_base;
546 		for( dp = dps;
547 			dp < dpe;
548 			dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
549 				oldoff += dp->d_reclen;
550 				*cookiep++ = (u_long) oldoff;
551 		}
552 		*ap->a_ncookies = ncookies;
553 		*ap->a_cookies = cookiebuf;
554     }
555 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
556 	uio->uio_offset = off;
557 	return (error);
558 }
559 
560 static int
561 devfs_readlink(ap)
562 	struct vop_readlink_args /* {
563 		struct vnode *a_vp;
564 		struct uio *a_uio;
565 		struct ucred *a_cead;
566 	} */ *ap;
567 {
568 	int error;
569 	struct devfs_dirent *de;
570 
571 	de = ap->a_vp->v_data;
572 	error = uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio);
573 	return (error);
574 }
575 
576 static int
577 devfs_reclaim(ap)
578 	struct vop_reclaim_args /* {
579 		struct vnode *a_vp;
580 	} */ *ap;
581 {
582 	struct vnode *vp = ap->a_vp;
583 	struct devfs_dirent *de;
584 	int i;
585 
586 	de = vp->v_data;
587 	if (de != NULL)
588 		de->de_vnode = NULL;
589 	vp->v_data = NULL;
590 	if (vp->v_rdev != NODEV && vp->v_rdev != NULL) {
591 		i = vcount(vp);
592 		if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0 &&
593 		    (vp->v_rdev->si_flags & SI_NAMED))
594 			destroy_dev(vp->v_rdev);
595 	}
596 	return (0);
597 }
598 
599 static int
600 devfs_remove(ap)
601 	struct vop_remove_args /* {
602 		struct vnode *a_dvp;
603 		struct vnode *a_vp;
604 		struct componentname *a_cnp;
605 	} */ *ap;
606 {
607 	struct vnode *vp = ap->a_vp;
608 	struct devfs_dirent *dd;
609 	struct devfs_dirent *de;
610 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
611 
612 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
613 	dd = ap->a_dvp->v_data;
614 	de = vp->v_data;
615 	if (de->de_dirent->d_type == DT_LNK) {
616 		TAILQ_REMOVE(&dd->de_dlist, de, de_list);
617 		if (de->de_vnode)
618 			de->de_vnode->v_data = NULL;
619 		FREE(de, M_DEVFS);
620 	} else {
621 		de->de_flags |= DE_WHITEOUT;
622 	}
623 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
624 	return (0);
625 }
626 
627 /*
628  * Revoke is called on a tty when a terminal session ends.  The vnode
629  * is orphaned by setting v_op to deadfs so we need to let go of it
630  * as well so that we create a new one next time around.
631  */
632 static int
633 devfs_revoke(ap)
634 	struct vop_revoke_args /* {
635 		struct vnode *a_vp;
636 		int a_flags;
637 	} */ *ap;
638 {
639 	struct vnode *vp = ap->a_vp;
640 	struct devfs_dirent *de;
641 
642 	de = vp->v_data;
643 	de->de_vnode = NULL;
644 	vop_revoke(ap);
645 	return (0);
646 }
647 
648 static int
649 devfs_setattr(ap)
650 	struct vop_setattr_args /* {
651 		struct vnode *a_vp;
652 		struct vattr *a_vap;
653 		struct ucred *a_cred;
654 		struct proc *a_p;
655 	} */ *ap;
656 {
657 	struct devfs_dirent *de;
658 	struct vattr *vap;
659 	int c, error;
660 	uid_t uid;
661 	gid_t gid;
662 
663 	vap = ap->a_vap;
664 	if ((vap->va_type != VNON) ||
665 	    (vap->va_nlink != VNOVAL) ||
666 	    (vap->va_fsid != VNOVAL) ||
667 	    (vap->va_fileid != VNOVAL) ||
668 	    (vap->va_blocksize != VNOVAL) ||
669 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
670 	    (vap->va_rdev != VNOVAL) ||
671 	    ((int)vap->va_bytes != VNOVAL) ||
672 	    (vap->va_gen != VNOVAL)) {
673 		return (EINVAL);
674 	}
675 
676 	de = ap->a_vp->v_data;
677 	if (ap->a_vp->v_type == VDIR)
678 		de = de->de_dir;
679 
680 	error = c = 0;
681 	if (vap->va_uid == (uid_t)VNOVAL)
682 		uid = de->de_uid;
683 	else
684 		uid = vap->va_uid;
685 	if (vap->va_gid == (gid_t)VNOVAL)
686 		gid = de->de_gid;
687 	else
688 		gid = vap->va_gid;
689 	if (uid != de->de_uid || gid != de->de_gid) {
690 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
691 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
692 		    (error = suser(ap->a_td->td_proc)) != 0)
693 			return (error);
694 		de->de_uid = uid;
695 		de->de_gid = gid;
696 		c = 1;
697 	}
698 	if (vap->va_mode != (mode_t)VNOVAL) {
699 		if ((ap->a_cred->cr_uid != de->de_uid) &&
700 		    (error = suser(ap->a_td->td_proc)))
701 			return (error);
702 		de->de_mode = vap->va_mode;
703 		c = 1;
704 	}
705 	if (vap->va_atime.tv_sec != VNOVAL) {
706 		if ((ap->a_cred->cr_uid != de->de_uid) &&
707 		    (error = suser(ap->a_td->td_proc)))
708 			return (error);
709 		de->de_atime = vap->va_atime;
710 		c = 1;
711 	}
712 	if (vap->va_mtime.tv_sec != VNOVAL) {
713 		if ((ap->a_cred->cr_uid != de->de_uid) &&
714 		    (error = suser(ap->a_td->td_proc)))
715 			return (error);
716 		de->de_mtime = vap->va_mtime;
717 		c = 1;
718 	}
719 
720 	if (c)
721 		getnanotime(&de->de_ctime);
722 	return (0);
723 }
724 
725 static int
726 devfs_symlink(ap)
727 	struct vop_symlink_args /* {
728 		struct vnode *a_dvp;
729 		struct vnode **a_vpp;
730 		struct componentname *a_cnp;
731 		struct vattr *a_vap;
732 		char *a_target;
733 	} */ *ap;
734 {
735 	int i, error;
736 	struct devfs_dirent *dd;
737 	struct devfs_dirent *de;
738 	struct devfs_mount *dmp;
739 
740 	error = suser(ap->a_cnp->cn_thread->td_proc);
741 	if (error)
742 		return(error);
743 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
744 	dd = ap->a_dvp->v_data;
745 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
746 	de->de_uid = 0;
747 	de->de_gid = 0;
748 	de->de_mode = 0755;
749 	de->de_inode = dmp->dm_inode++;
750 	de->de_dirent->d_type = DT_LNK;
751 	i = strlen(ap->a_target) + 1;
752 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
753 	bcopy(ap->a_target, de->de_symlink, i);
754 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
755 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
756 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
757 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
758 	return (0);
759 }
760 
761 static vop_t **devfs_vnodeop_p;
762 static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
763 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
764 	{ &vop_access_desc,		(vop_t *) devfs_access },
765 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
766 	{ &vop_lookup_desc,		(vop_t *) devfs_lookup },
767 	{ &vop_mknod_desc,		(vop_t *) devfs_mknod },
768 	{ &vop_pathconf_desc,		(vop_t *) vop_stdpathconf },
769 	{ &vop_print_desc,		(vop_t *) devfs_print },
770 	{ &vop_read_desc,		(vop_t *) devfs_read },
771 	{ &vop_readdir_desc,		(vop_t *) devfs_readdir },
772 	{ &vop_readlink_desc,		(vop_t *) devfs_readlink },
773 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
774 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
775 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
776 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
777 	{ &vop_symlink_desc,		(vop_t *) devfs_symlink },
778 	{ NULL, NULL }
779 };
780 static struct vnodeopv_desc devfs_vnodeop_opv_desc =
781 	{ &devfs_vnodeop_p, devfs_vnodeop_entries };
782 
783 VNODEOP_SET(devfs_vnodeop_opv_desc);
784 
785 static vop_t **devfs_specop_p;
786 static struct vnodeopv_entry_desc devfs_specop_entries[] = {
787 	{ &vop_default_desc,		(vop_t *) spec_vnoperate },
788 	{ &vop_access_desc,		(vop_t *) devfs_access },
789 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
790 	{ &vop_print_desc,		(vop_t *) devfs_print },
791 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
792 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
793 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
794 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
795 	{ NULL, NULL }
796 };
797 static struct vnodeopv_desc devfs_specop_opv_desc =
798 	{ &devfs_specop_p, devfs_specop_entries };
799 
800 VNODEOP_SET(devfs_specop_opv_desc);
801 #endif
802