xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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/socket.h>
58 #include <sys/time.h>
59 #include <sys/vnode.h>
60 
61 #include <fs/devfs/devfs.h>
62 
63 static int	devfs_access __P((struct vop_access_args *ap));
64 static int	devfs_getattr __P((struct vop_getattr_args *ap));
65 static int	devfs_lookupx __P((struct vop_lookup_args *ap));
66 static int	devfs_mknod __P((struct vop_mknod_args *ap));
67 static int	devfs_print __P((struct vop_print_args *ap));
68 static int	devfs_read __P((struct vop_read_args *ap));
69 static int	devfs_readdir __P((struct vop_readdir_args *ap));
70 static int	devfs_readlink __P((struct vop_readlink_args *ap));
71 static int	devfs_reclaim __P((struct vop_reclaim_args *ap));
72 static int	devfs_remove __P((struct vop_remove_args *ap));
73 static int	devfs_revoke __P((struct vop_revoke_args *ap));
74 static int	devfs_setattr __P((struct vop_setattr_args *ap));
75 static int	devfs_symlink __P((struct vop_symlink_args *ap));
76 
77 /*
78  * Construct the fully qualified path name relative to the mountpoint
79  */
80 static char *
81 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
82 {
83 	int i;
84 	struct devfs_dirent *de, *dd;
85 	struct devfs_mount *dmp;
86 
87 	dmp = VFSTODEVFS(dvp->v_mount);
88 	dd = dvp->v_data;
89 	i = SPECNAMELEN;
90 	buf[i] = '\0';
91 	i -= cnp->cn_namelen;
92 	if (i < 0)
93 		 return (NULL);
94 	bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
95 	de = dd;
96 	while (de != dmp->dm_basedir) {
97 		i--;
98 		if (i < 0)
99 			 return (NULL);
100 		buf[i] = '/';
101 		i -= de->de_dirent->d_namlen;
102 		if (i < 0)
103 			 return (NULL);
104 		bcopy(de->de_dirent->d_name, buf + i,
105 		    de->de_dirent->d_namlen);
106 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
107 		de = TAILQ_NEXT(de, de_list);		/* ".." */
108 		de = de->de_dir;
109 	}
110 	return (buf + i);
111 }
112 
113 int
114 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct proc *p)
115 {
116 	int error;
117 	struct vnode *vp;
118 	dev_t dev;
119 
120 	if (p == NULL)
121 		p = curproc; /* XXX */
122 loop:
123 	vp = de->de_vnode;
124 	if (vp != NULL) {
125 		if (vget(vp, LK_EXCLUSIVE, p ? p : curproc))
126 			goto loop;
127 		*vpp = vp;
128 		return (0);
129 	}
130 	if (de->de_dirent->d_type == DT_CHR) {
131 		dev = *devfs_itod(de->de_inode);
132 		if (dev == NULL)
133 			return (ENOENT);
134 	} else {
135 		dev = NODEV;
136 	}
137 	error = getnewvnode(VT_DEVFS, mp, devfs_vnodeop_p, &vp);
138 	if (error != 0) {
139 		printf("devfs_allocv: failed to allocate new vnode\n");
140 		return (error);
141 	}
142 
143 	if (de->de_dirent->d_type == DT_CHR) {
144 		vp->v_type = VCHR;
145 		vp = addaliasu(vp, dev->si_udev);
146 		vp->v_op = devfs_specop_p;
147 	} else if (de->de_dirent->d_type == DT_DIR) {
148 		vp->v_type = VDIR;
149 	} else if (de->de_dirent->d_type == DT_LNK) {
150 		vp->v_type = VLNK;
151 	} else {
152 		vp->v_type = VBAD;
153 	}
154 	vp->v_data = de;
155 	de->de_vnode = vp;
156 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
157 	*vpp = vp;
158 	return (0);
159 }
160 
161 static int
162 devfs_access(ap)
163 	struct vop_access_args /* {
164 		struct vnode *a_vp;
165 		int  a_mode;
166 		struct ucred *a_cred;
167 		struct proc *a_p;
168 	} */ *ap;
169 {
170 	struct vnode *vp = ap->a_vp;
171 	struct devfs_dirent *de;
172 
173 	de = vp->v_data;
174 	if (vp->v_type == VDIR)
175 		de = de->de_dir;
176 
177 	return (vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
178 	    ap->a_mode, ap->a_cred, NULL));
179 }
180 
181 static int
182 devfs_getattr(ap)
183 	struct vop_getattr_args /* {
184 		struct vnode *a_vp;
185 		struct vattr *a_vap;
186 		struct ucred *a_cred;
187 		struct proc *a_p;
188 	} */ *ap;
189 {
190 	struct vnode *vp = ap->a_vp;
191 	struct vattr *vap = ap->a_vap;
192 	int error = 0;
193 	struct devfs_dirent *de;
194 	dev_t dev;
195 
196 	de = vp->v_data;
197 	if (vp->v_type == VDIR)
198 		de = de->de_dir;
199 	bzero((caddr_t) vap, sizeof(*vap));
200 	vattr_null(vap);
201 	vap->va_uid = de->de_uid;
202 	vap->va_gid = de->de_gid;
203 	vap->va_mode = de->de_mode;
204 	if (vp->v_type == VLNK)
205 		vap->va_size = de->de_dirent->d_namlen;
206 	else
207 		vap->va_size = 0;
208 	vap->va_blocksize = DEV_BSIZE;
209 	vap->va_type = vp->v_type;
210 
211 #define fix(aa)							\
212 	do {							\
213 		if ((aa).tv_sec == 0) {				\
214 			(aa).tv_sec = boottime.tv_sec;		\
215 			(aa).tv_nsec = boottime.tv_usec * 1000; \
216 		}						\
217 	} while (0)
218 
219 	if (vp->v_type != VCHR)  {
220 		fix(de->de_atime);
221 		vap->va_atime = de->de_atime;
222 		fix(de->de_mtime);
223 		vap->va_mtime = de->de_mtime;
224 		fix(de->de_ctime);
225 		vap->va_ctime = de->de_ctime;
226 	} else {
227 		dev = vp->v_rdev;
228 		fix(dev->si_atime);
229 		vap->va_atime = dev->si_atime;
230 		fix(dev->si_mtime);
231 		vap->va_mtime = dev->si_mtime;
232 		fix(dev->si_ctime);
233 		vap->va_ctime = dev->si_ctime;
234 		vap->va_rdev = dev->si_udev;
235 	}
236 	vap->va_gen = 0;
237 	vap->va_flags = 0;
238 	vap->va_bytes = 0;
239 	vap->va_nlink = de->de_links;
240 	vap->va_fileid = de->de_inode;
241 
242 	return (error);
243 }
244 
245 static int
246 devfs_lookupx(ap)
247 	struct vop_lookup_args /* {
248 		struct vnode * a_dvp;
249 		struct vnode ** a_vpp;
250 		struct componentname * a_cnp;
251 	} */ *ap;
252 {
253 	struct componentname *cnp;
254 	struct vnode *dvp, **vpp;
255 	struct proc *p;
256 	struct devfs_dirent *de, *dd;
257 	struct devfs_mount *dmp;
258 	dev_t cdev, *cpdev;
259 	int error, cloned, flags, nameiop;
260 	char specname[SPECNAMELEN + 1], *pname;
261 
262 	cnp = ap->a_cnp;
263 	vpp = ap->a_vpp;
264 	dvp = ap->a_dvp;
265 	pname = cnp->cn_nameptr;
266 	p = cnp->cn_proc;
267 	flags = cnp->cn_flags;
268 	nameiop = cnp->cn_nameiop;
269 	dmp = VFSTODEVFS(dvp->v_mount);
270 	cloned = 0;
271 	dd = dvp->v_data;
272 
273 	*vpp = NULLVP;
274 
275 	if (nameiop == RENAME)
276 		return (EOPNOTSUPP);
277 
278 	if (dvp->v_type != VDIR)
279 		return (ENOTDIR);
280 
281 	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
282 		return (EIO);
283 
284 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_proc);
285 	if (error)
286 		return (error);
287 
288 	if (cnp->cn_namelen == 1 && *pname == '.') {
289 		if (nameiop != LOOKUP)
290 			return (EINVAL);
291 		*vpp = dvp;
292 		VREF(dvp);
293 		return (0);
294 	}
295 
296 	if (flags & ISDOTDOT) {
297 		if (nameiop != LOOKUP)
298 			return (EINVAL);
299 		VOP_UNLOCK(dvp, 0, p);
300 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
301 		de = TAILQ_NEXT(de, de_list);		/* ".." */
302 		de = de->de_dir;
303 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
304 		if (error) {
305 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
306 			return (error);
307 		}
308 		if ((flags & LOCKPARENT) && (flags & ISLASTCN))
309 			error = vn_lock(dvp, LK_EXCLUSIVE, p);
310 		if (error)
311 			vput(*vpp);
312 		return (error);
313 	}
314 
315 	devfs_populate(dmp);
316 	dd = dvp->v_data;
317 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
318 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
319 			continue;
320 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
321 		    de->de_dirent->d_namlen) != 0)
322 			continue;
323 		if (de->de_flags & DE_WHITEOUT)
324 			goto notfound;
325 		goto found;
326 	}
327 
328 	if (nameiop == DELETE)
329 		goto notfound;
330 
331 	/*
332 	 * OK, we didn't have an entry for the name we were asked for
333 	 * so we try to see if anybody can create it on demand.
334 	 */
335 	pname = devfs_fqpn(specname, dvp, cnp);
336 	if (pname == NULL)
337 		goto notfound;
338 
339 	cdev = NODEV;
340 	EVENTHANDLER_INVOKE(dev_clone, pname, strlen(pname), &cdev);
341 	if (cdev == NODEV)
342 		goto notfound;
343 
344 	devfs_populate(dmp);
345 	dd = dvp->v_data;
346 
347 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
348 		cpdev = devfs_itod(de->de_inode);
349 		if (cpdev != NULL && cdev == *cpdev)
350 			goto found;
351 		continue;
352 	}
353 
354 notfound:
355 
356 	if ((nameiop == CREATE || nameiop == RENAME) &&
357 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
358 		cnp->cn_flags |= SAVENAME;
359 		if (!(flags & LOCKPARENT))
360 			VOP_UNLOCK(dvp, 0, p);
361 		return (EJUSTRETURN);
362 	}
363 	return (ENOENT);
364 
365 
366 found:
367 
368 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
369 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, p);
370 		if (error)
371 			return (error);
372 		if (*vpp == dvp) {
373 			VREF(dvp);
374 			*vpp = dvp;
375 			return (0);
376 		}
377 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
378 		if (error)
379 			return (error);
380 		if (!(flags & LOCKPARENT))
381 			VOP_UNLOCK(dvp, 0, p);
382 		return (0);
383 	}
384 	error = devfs_allocv(de, dvp->v_mount, vpp, p);
385 	if (error)
386 		return (error);
387 	if (!(flags & LOCKPARENT) || !(flags & ISLASTCN))
388 		VOP_UNLOCK(dvp, 0, p);
389 	return (0);
390 }
391 
392 static int
393 devfs_lookup(struct vop_lookup_args *ap)
394 {
395 	int j;
396 	struct devfs_mount *dmp;
397 
398 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
399 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
400 	j = devfs_lookupx(ap);
401 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
402 	return (j);
403 }
404 
405 static int
406 devfs_mknod(struct vop_mknod_args *ap)
407 /*
408 struct vop_mknod_args {
409         struct vnodeop_desc *a_desc;
410         struct vnode *a_dvp;
411         struct vnode **a_vpp;
412         struct componentname *a_cnp;
413         struct vattr *a_vap;
414 };
415 */
416 {
417 	struct componentname *cnp;
418 	struct vnode *dvp, **vpp;
419 	struct proc *p;
420 	struct devfs_dirent *dd, *de;
421 	struct devfs_mount *dmp;
422 	int cloned, flags, nameiop;
423 	int error;
424 
425 	dvp = ap->a_dvp;
426 	dmp = VFSTODEVFS(dvp->v_mount);
427 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
428 
429 	cnp = ap->a_cnp;
430 	vpp = ap->a_vpp;
431 	p = cnp->cn_proc;
432 	flags = cnp->cn_flags;
433 	nameiop = cnp->cn_nameiop;
434 	cloned = 0;
435 	dd = dvp->v_data;
436 
437 	error = ENOENT;
438 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
439 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
440 			continue;
441 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
442 		    de->de_dirent->d_namlen) != 0)
443 			continue;
444 		if (de->de_flags & DE_WHITEOUT)
445 			break;
446 		goto notfound;
447 	}
448 	if (de == NULL)
449 		goto notfound;
450 	de->de_flags &= ~DE_WHITEOUT;
451 	error = devfs_allocv(de, dvp->v_mount, vpp, p);
452 notfound:
453 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
454 	return (error);
455 }
456 
457 
458 /* ARGSUSED */
459 static int
460 devfs_print(ap)
461 	struct vop_print_args /* {
462 		struct vnode *a_vp;
463 	} */ *ap;
464 {
465 
466 	printf("tag VT_DEVFS, devfs vnode\n");
467 	return (0);
468 }
469 
470 static int
471 devfs_read(ap)
472 	struct vop_read_args /* {
473 		struct vnode *a_vp;
474 		struct uio *a_uio;
475 		int a_ioflag;
476 		struct ucred *a_cred;
477 	} */ *ap;
478 {
479 
480 	if (ap->a_vp->v_type != VDIR)
481 		return (EINVAL);
482 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
483 }
484 
485 static int
486 devfs_readdir(ap)
487 	struct vop_readdir_args /* {
488 		struct vnode *a_vp;
489 		struct uio *a_uio;
490 		struct ucred *a_cred;
491 		int *a_eofflag;
492 		int *a_ncookies;
493 		u_long **a_cookies;
494 	} */ *ap;
495 {
496 	int error;
497 	struct uio *uio;
498 	struct dirent *dp;
499 	struct devfs_dirent *dd;
500 	struct devfs_dirent *de;
501 	struct devfs_mount *dmp;
502 	off_t off;
503 
504 	if (ap->a_vp->v_type != VDIR)
505 		return (ENOTDIR);
506 
507 	if (ap->a_ncookies)
508 		return (EOPNOTSUPP);
509 
510 	uio = ap->a_uio;
511 	if (uio->uio_offset < 0)
512 		return (EINVAL);
513 
514 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
515 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
516 	devfs_populate(dmp);
517 	error = 0;
518 	de = ap->a_vp->v_data;
519 	off = 0;
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 			error = uiomove((caddr_t)dp, dp->d_reclen, uio);
533 			if (error)
534 				break;
535 		}
536 		off += dp->d_reclen;
537 	}
538 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
539 	uio->uio_offset = off;
540 	return (error);
541 }
542 
543 static int
544 devfs_readlink(ap)
545 	struct vop_readlink_args /* {
546 		struct vnode *a_vp;
547 		struct uio *a_uio;
548 		struct ucred *a_cead;
549 	} */ *ap;
550 {
551 	int error;
552 	struct devfs_dirent *de;
553 
554 	de = ap->a_vp->v_data;
555 	error = uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio);
556 	return (error);
557 }
558 
559 static int
560 devfs_reclaim(ap)
561 	struct vop_reclaim_args /* {
562 		struct vnode *a_vp;
563 	} */ *ap;
564 {
565 	struct vnode *vp = ap->a_vp;
566 	struct devfs_dirent *de;
567 	int i;
568 
569 	de = vp->v_data;
570 	if (de != NULL)
571 		de->de_vnode = NULL;
572 	vp->v_data = NULL;
573 	if (vp->v_rdev != NODEV && vp->v_rdev != NULL) {
574 		i = vcount(vp);
575 		if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0 &&
576 		    (vp->v_rdev->si_flags & SI_NAMED))
577 			destroy_dev(vp->v_rdev);
578 	}
579 	return (0);
580 }
581 
582 static int
583 devfs_remove(ap)
584 	struct vop_remove_args /* {
585 		struct vnode *a_dvp;
586 		struct vnode *a_vp;
587 		struct componentname *a_cnp;
588 	} */ *ap;
589 {
590 	struct vnode *vp = ap->a_vp;
591 	struct devfs_dirent *dd;
592 	struct devfs_dirent *de;
593 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
594 
595 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
596 	dd = ap->a_dvp->v_data;
597 	de = vp->v_data;
598 	de->de_flags |= DE_WHITEOUT;
599 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
600 	return (0);
601 }
602 
603 /*
604  * Revoke is called on a tty when a terminal session ends.  The vnode
605  * is orphaned by setting v_op to deadfs so we need to let go of it
606  * as well so that we create a new one next time around.
607  */
608 static int
609 devfs_revoke(ap)
610 	struct vop_revoke_args /* {
611 		struct vnode *a_vp;
612 		int a_flags;
613 	} */ *ap;
614 {
615 	struct vnode *vp = ap->a_vp;
616 	struct devfs_dirent *de;
617 
618 	de = vp->v_data;
619 	de->de_vnode = NULL;
620 	vop_revoke(ap);
621 	return (0);
622 }
623 
624 static int
625 devfs_setattr(ap)
626 	struct vop_setattr_args /* {
627 		struct vnode *a_vp;
628 		struct vattr *a_vap;
629 		struct ucred *a_cred;
630 		struct proc *a_p;
631 	} */ *ap;
632 {
633 	struct devfs_dirent *de;
634 	struct vattr *vap;
635 	int c, error;
636 	uid_t uid;
637 	gid_t gid;
638 
639 	vap = ap->a_vap;
640 	if ((vap->va_type != VNON) ||
641 	    (vap->va_nlink != VNOVAL) ||
642 	    (vap->va_fsid != VNOVAL) ||
643 	    (vap->va_fileid != VNOVAL) ||
644 	    (vap->va_blocksize != VNOVAL) ||
645 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
646 	    (vap->va_rdev != VNOVAL) ||
647 	    ((int)vap->va_bytes != VNOVAL) ||
648 	    (vap->va_gen != VNOVAL)) {
649 		return (EINVAL);
650 	}
651 
652 	de = ap->a_vp->v_data;
653 	if (ap->a_vp->v_type == VDIR)
654 		de = de->de_dir;
655 
656 	error = c = 0;
657 	if (vap->va_uid == (uid_t)VNOVAL)
658 		uid = de->de_uid;
659 	else
660 		uid = vap->va_uid;
661 	if (vap->va_gid == (gid_t)VNOVAL)
662 		gid = de->de_gid;
663 	else
664 		gid = vap->va_gid;
665 	if (uid != de->de_uid || gid != de->de_gid) {
666 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
667 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
668 		    (error = suser(ap->a_p)) != 0)
669 			return (error);
670 		de->de_uid = uid;
671 		de->de_gid = gid;
672 		c = 1;
673 	}
674 	if (vap->va_mode != (mode_t)VNOVAL) {
675 		if ((ap->a_cred->cr_uid != de->de_uid) &&
676 		    (error = suser(ap->a_p)))
677 			return (error);
678 		de->de_mode = vap->va_mode;
679 		c = 1;
680 	}
681 	if (vap->va_atime.tv_sec != VNOVAL) {
682 		if ((ap->a_cred->cr_uid != de->de_uid) &&
683 		    (error = suser(ap->a_p)))
684 			return (error);
685 		de->de_atime = vap->va_atime;
686 		c = 1;
687 	}
688 	if (vap->va_mtime.tv_sec != VNOVAL) {
689 		if ((ap->a_cred->cr_uid != de->de_uid) &&
690 		    (error = suser(ap->a_p)))
691 			return (error);
692 		de->de_mtime = vap->va_mtime;
693 		c = 1;
694 	}
695 
696 	if (c)
697 		getnanotime(&de->de_ctime);
698 	return (0);
699 }
700 
701 static int
702 devfs_symlink(ap)
703 	struct vop_symlink_args /* {
704 		struct vnode *a_dvp;
705 		struct vnode **a_vpp;
706 		struct componentname *a_cnp;
707 		struct vattr *a_vap;
708 		char *a_target;
709 	} */ *ap;
710 {
711 	int i, error;
712 	struct devfs_dirent *dd;
713 	struct devfs_dirent *de;
714 	struct devfs_mount *dmp;
715 
716 	error = suser(ap->a_cnp->cn_proc);
717 	if (error)
718 		return(error);
719 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
720 	dd = ap->a_dvp->v_data;
721 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
722 	de->de_uid = 0;
723 	de->de_gid = 0;
724 	de->de_mode = 0755;
725 	de->de_inode = dmp->dm_inode++;
726 	de->de_dirent->d_type = DT_LNK;
727 	i = strlen(ap->a_target) + 1;
728 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
729 	bcopy(ap->a_target, de->de_symlink, i);
730 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
731 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
732 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
733 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
734 	return (0);
735 }
736 
737 static vop_t **devfs_vnodeop_p;
738 static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
739 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
740 	{ &vop_access_desc,		(vop_t *) devfs_access },
741 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
742 	{ &vop_lookup_desc,		(vop_t *) devfs_lookup },
743 	{ &vop_mknod_desc,		(vop_t *) devfs_mknod },
744 	{ &vop_pathconf_desc,		(vop_t *) vop_stdpathconf },
745 	{ &vop_print_desc,		(vop_t *) devfs_print },
746 	{ &vop_read_desc,		(vop_t *) devfs_read },
747 	{ &vop_readdir_desc,		(vop_t *) devfs_readdir },
748 	{ &vop_readlink_desc,		(vop_t *) devfs_readlink },
749 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
750 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
751 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
752 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
753 	{ &vop_symlink_desc,		(vop_t *) devfs_symlink },
754 	{ NULL, NULL }
755 };
756 static struct vnodeopv_desc devfs_vnodeop_opv_desc =
757 	{ &devfs_vnodeop_p, devfs_vnodeop_entries };
758 
759 VNODEOP_SET(devfs_vnodeop_opv_desc);
760 
761 static vop_t **devfs_specop_p;
762 static struct vnodeopv_entry_desc devfs_specop_entries[] = {
763 	{ &vop_default_desc,		(vop_t *) spec_vnoperate },
764 	{ &vop_access_desc,		(vop_t *) devfs_access },
765 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
766 	{ &vop_print_desc,		(vop_t *) devfs_print },
767 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
768 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
769 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
770 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
771 	{ NULL, NULL }
772 };
773 static struct vnodeopv_desc devfs_specop_opv_desc =
774 	{ &devfs_specop_p, devfs_specop_entries };
775 
776 VNODEOP_SET(devfs_specop_opv_desc);
777 #endif
778