xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision 1a2cdef4962b47be5057809ce730a733b7f3c27c)
1 #define DEBUG 1
2 /*
3  * Copyright (c) 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  * Copyright (c) 2000
6  *	Poul-Henning Kamp.  All rights reserved.
7  *
8  * This code is derived from software donated to Berkeley by
9  * Jan-Simon Pendry.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)kernfs_vnops.c	8.15 (Berkeley) 5/21/95
33  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43
34  *
35  * $FreeBSD$
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/time.h>
42 #include <sys/conf.h>
43 #include <sys/vnode.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/namei.h>
47 #include <sys/dirent.h>
48 
49 #include <fs/devfs/devfs.h>
50 
51 static int	devfs_access __P((struct vop_access_args *ap));
52 static int	devfs_badop __P((void));
53 static int	devfs_getattr __P((struct vop_getattr_args *ap));
54 static int	devfs_lookupx __P((struct vop_lookup_args *ap));
55 static int	devfs_print __P((struct vop_print_args *ap));
56 static int	devfs_read __P((struct vop_read_args *ap));
57 static int	devfs_readdir __P((struct vop_readdir_args *ap));
58 static int	devfs_readlink __P((struct vop_readlink_args *ap));
59 static int	devfs_reclaim __P((struct vop_reclaim_args *ap));
60 static int	devfs_remove __P((struct vop_remove_args *ap));
61 static int	devfs_revoke __P((struct vop_revoke_args *ap));
62 static int	devfs_setattr __P((struct vop_setattr_args *ap));
63 static int	devfs_symlink __P((struct vop_symlink_args *ap));
64 
65 int
66 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct proc *p)
67 {
68 	int error;
69 	struct vnode *vp;
70 	dev_t dev;
71 
72 	if (p == NULL)
73 		p = curproc; /* XXX */
74 loop:
75 	vp = de->de_vnode;
76 	if (vp != NULL) {
77 		if (vget(vp, LK_EXCLUSIVE, p ? p : curproc))
78 			goto loop;
79 		*vpp = vp;
80 		return (0);
81 	}
82 	if (de->de_dirent->d_type == DT_CHR) {
83 		dev = *devfs_itod(de->de_inode);
84 		if (dev == NULL)
85 			return (ENOENT);
86 	} else {
87 		dev = NODEV;
88 	}
89 	error = getnewvnode(VT_DEVFS, mp, devfs_vnodeop_p, &vp);
90 	if (error != 0) {
91 		printf("devfs_allocv: failed to allocate new vnode\n");
92 		return (error);
93 	}
94 
95 	if (de->de_dirent->d_type == DT_CHR) {
96 		vp->v_type = VCHR;
97 		vp = addaliasu(vp, dev->si_udev);
98 		vp->v_op = devfs_specop_p;
99 	} else if (de->de_dirent->d_type == DT_DIR) {
100 		vp->v_type = VDIR;
101 	} else if (de->de_dirent->d_type == DT_LNK) {
102 		vp->v_type = VLNK;
103 	} else {
104 		vp->v_type = VBAD;
105 	}
106 	vp->v_data = de;
107 	de->de_vnode = vp;
108 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
109 	*vpp = vp;
110 	return (0);
111 }
112 
113 static int
114 devfs_access(ap)
115 	struct vop_access_args /* {
116 		struct vnode *a_vp;
117 		int  a_mode;
118 		struct ucred *a_cred;
119 		struct proc *a_p;
120 	} */ *ap;
121 {
122 	struct vnode *vp = ap->a_vp;
123 	struct devfs_dirent *de;
124 
125 	de = vp->v_data;
126 	if (vp->v_type == VDIR)
127 		de = de->de_dir;
128 
129 	return (vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
130 	    ap->a_mode, ap->a_cred, NULL));
131 }
132 
133 static int
134 devfs_getattr(ap)
135 	struct vop_getattr_args /* {
136 		struct vnode *a_vp;
137 		struct vattr *a_vap;
138 		struct ucred *a_cred;
139 		struct proc *a_p;
140 	} */ *ap;
141 {
142 	struct vnode *vp = ap->a_vp;
143 	struct vattr *vap = ap->a_vap;
144 	int error = 0;
145 	struct devfs_dirent *de;
146 	dev_t dev;
147 
148 	de = vp->v_data;
149 	if (vp->v_type == VDIR)
150 		de = de->de_dir;
151 	bzero((caddr_t) vap, sizeof(*vap));
152 	vattr_null(vap);
153 	vap->va_uid = de->de_uid;
154 	vap->va_gid = de->de_gid;
155 	vap->va_mode = de->de_mode;
156 	if (vp->v_type == VLNK)
157 		vap->va_size = de->de_dirent->d_namlen;
158 	else
159 		vap->va_size = 0;
160 	vap->va_blocksize = DEV_BSIZE;
161 	vap->va_type = vp->v_type;
162 
163 #define fix(aa)							\
164 	do {							\
165 		if ((aa).tv_sec == 0) {				\
166 			(aa).tv_sec = boottime.tv_sec;		\
167 			(aa).tv_nsec = boottime.tv_usec * 1000; \
168 		}						\
169 	} while (0)
170 
171 	if (vp->v_type != VCHR)  {
172 		fix(de->de_atime);
173 		vap->va_atime = de->de_atime;
174 		fix(de->de_mtime);
175 		vap->va_mtime = de->de_mtime;
176 		fix(de->de_ctime);
177 		vap->va_ctime = de->de_ctime;
178 	} else {
179 		dev = vp->v_rdev;
180 		fix(dev->si_atime);
181 		vap->va_atime = dev->si_atime;
182 		fix(dev->si_mtime);
183 		vap->va_mtime = dev->si_mtime;
184 		fix(dev->si_ctime);
185 		vap->va_ctime = dev->si_ctime;
186 		vap->va_rdev = dev->si_udev;
187 	}
188 	vap->va_gen = 0;
189 	vap->va_flags = 0;
190 	vap->va_bytes = 0;
191 	vap->va_nlink = de->de_links;
192 	vap->va_fileid = de->de_inode;
193 
194 #ifdef DEBUG
195 	if (error)
196 		printf("devfs_getattr: return error %d\n", error);
197 #endif
198 	return (error);
199 }
200 
201 static int
202 devfs_lookupx(ap)
203 	struct vop_lookup_args /* {
204 		struct vnode * a_dvp;
205 		struct vnode ** a_vpp;
206 		struct componentname * a_cnp;
207 	} */ *ap;
208 {
209 	struct componentname *cnp;
210 	struct vnode *dvp, **vpp;
211 	struct proc *p;
212 	struct devfs_dirent *de, *dd;
213 	struct devfs_mount *dmp;
214 	dev_t cdev;
215 	int error, cloned, i, flags, nameiop;
216 	char specname[SPECNAMELEN + 1], *pname;
217 
218 	cnp = ap->a_cnp;
219 	vpp = ap->a_vpp;
220 	dvp = ap->a_dvp;
221 	pname = cnp->cn_nameptr;
222 	p = cnp->cn_proc;
223 	flags = cnp->cn_flags;
224 	nameiop = cnp->cn_nameiop;
225 	dmp = VFSTODEVFS(dvp->v_mount);
226 	cloned = 0;
227 	dd = dvp->v_data;
228 
229 	*vpp = NULLVP;
230 
231 	if (nameiop == RENAME)
232 		return (EOPNOTSUPP);
233 
234 	if (dvp->v_type != VDIR)
235 		return (ENOTDIR);
236 
237 	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
238 		return (EIO);
239 
240 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_proc);
241 	if (error)
242 		return (error);
243 
244 	if (cnp->cn_namelen == 1 && *pname == '.') {
245 		if (nameiop != LOOKUP)
246 			return (EINVAL);
247 		*vpp = dvp;
248 		VREF(dvp);
249 		return (0);
250 	}
251 
252 	if (flags & ISDOTDOT) {
253 		if (nameiop != LOOKUP)
254 			return (EINVAL);
255 		VOP_UNLOCK(dvp, 0, p);
256 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
257 		de = TAILQ_NEXT(de, de_list);		/* ".." */
258 		de = de->de_dir;
259 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
260 		if (error) {
261 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
262 			return (error);
263 		}
264 		if ((flags & LOCKPARENT) && (flags & ISLASTCN))
265 			error = vn_lock(dvp, LK_EXCLUSIVE, p);
266 		if (error)
267 			vput(*vpp);
268 		return (error);
269 	}
270 
271 	devfs_populate(dmp);
272 	dd = dvp->v_data;
273 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
274 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
275 			continue;
276 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
277 		    de->de_dirent->d_namlen) != 0)
278 			continue;
279 		goto found;
280 	}
281 
282 	/*
283 	 * OK, we didn't have an entry for the name we were asked for
284 	 * so we try to see if anybody can create it on demand.
285 	 * We need to construct the full "devname" for this device
286 	 * relative to "basedir" or the clone functions would not
287 	 * be able to tell "/dev/foo" from "/dev/bar/foo"
288 	 */
289 	i = SPECNAMELEN;
290 	specname[i] = '\0';
291 	i -= cnp->cn_namelen;
292 	if (i < 0)
293 		 goto notfound;
294 	bcopy(cnp->cn_nameptr, specname + i, cnp->cn_namelen);
295 	de = dd;
296 	while (de != dmp->dm_basedir) {
297 		i--;
298 		if (i < 0)
299 			 goto notfound;
300 		specname[i] = '/';
301 		i -= de->de_dirent->d_namlen;
302 		if (i < 0)
303 			 goto notfound;
304 		bcopy(de->de_dirent->d_name, specname + i,
305 		    de->de_dirent->d_namlen);
306 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
307 		de = TAILQ_NEXT(de, de_list);		/* ".." */
308 		de = de->de_dir;
309 	}
310 
311 #if 0
312 	printf("Finished specname: %d \"%s\"\n", i, specname + i);
313 #endif
314 	cdev = NODEV;
315 	EVENTHANDLER_INVOKE(dev_clone, specname + i,
316 	    strlen(specname + i), &cdev);
317 #if 0
318 	printf("cloned %s -> %p %s\n", specname + i, cdev,
319 	    cdev == NODEV ? "NODEV" : cdev->si_name);
320 #endif
321 	if (cdev == NODEV)
322 		goto notfound;
323 
324 	devfs_populate(dmp);
325 	dd = dvp->v_data;
326 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
327 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
328 			continue;
329 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
330 		    de->de_dirent->d_namlen) != 0)
331 			continue;
332 		goto found;
333 	}
334 
335 notfound:
336 
337 	if ((nameiop == CREATE || nameiop == RENAME) &&
338 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
339 		cnp->cn_flags |= SAVENAME;
340 		if (!(flags & LOCKPARENT))
341 			VOP_UNLOCK(dvp, 0, p);
342 		return (EJUSTRETURN);
343 	}
344 	return (ENOENT);
345 
346 
347 found:
348 
349 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
350 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, p);
351 		if (error)
352 			return (error);
353 		if (*vpp == dvp) {
354 			VREF(dvp);
355 			*vpp = dvp;
356 			return (0);
357 		}
358 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
359 		if (error)
360 			return (error);
361 		if (!(flags & LOCKPARENT))
362 			VOP_UNLOCK(dvp, 0, p);
363 		return (0);
364 	}
365 	error = devfs_allocv(de, dvp->v_mount, vpp, p);
366 	if (error)
367 		return (error);
368 	if (!(flags & LOCKPARENT) || !(flags & ISLASTCN))
369 		VOP_UNLOCK(dvp, 0, p);
370 	return (0);
371 }
372 
373 static int
374 devfs_lookup(struct vop_lookup_args *ap)
375 {
376 	int j;
377 	struct devfs_mount *dmp;
378 
379 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
380 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
381 	j = devfs_lookupx(ap);
382 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
383 	return (j);
384 }
385 
386 /* ARGSUSED */
387 static int
388 devfs_print(ap)
389 	struct vop_print_args /* {
390 		struct vnode *a_vp;
391 	} */ *ap;
392 {
393 
394 	printf("tag VT_DEVFS, devfs vnode\n");
395 	return (0);
396 }
397 
398 static int
399 devfs_read(ap)
400 	struct vop_read_args /* {
401 		struct vnode *a_vp;
402 		struct uio *a_uio;
403 		int a_ioflag;
404 		struct ucred *a_cred;
405 	} */ *ap;
406 {
407 
408 	if (ap->a_vp->v_type != VDIR)
409 		return (EINVAL);
410 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
411 }
412 
413 static int
414 devfs_readdir(ap)
415 	struct vop_readdir_args /* {
416 		struct vnode *a_vp;
417 		struct uio *a_uio;
418 		struct ucred *a_cred;
419 		int *a_eofflag;
420 		int *a_ncookies;
421 		u_long **a_cookies;
422 	} */ *ap;
423 {
424 	int error;
425 	struct uio *uio;
426 	struct dirent *dp;
427 	struct devfs_dirent *dd;
428 	struct devfs_dirent *de;
429 	struct devfs_mount *dmp;
430 	off_t off;
431 
432 	if (ap->a_vp->v_type != VDIR)
433 		return (ENOTDIR);
434 
435 	if (ap->a_ncookies)
436 		return (EOPNOTSUPP);
437 
438 	uio = ap->a_uio;
439 	if (uio->uio_offset < 0)
440 		return (EINVAL);
441 
442 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
443 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
444 	devfs_populate(dmp);
445 	error = 0;
446 	de = ap->a_vp->v_data;
447 	dd = TAILQ_FIRST(&de->de_dlist);
448 	off = 0;
449 	while (dd != NULL) {
450 		if (dd->de_dirent->d_type == DT_DIR)
451 			de = dd->de_dir;
452 		else
453 			de = dd;
454 		dp = dd->de_dirent;
455 		if (dp->d_reclen > uio->uio_resid)
456 			break;
457 		dp->d_fileno = de->de_inode;
458 		if (off >= uio->uio_offset) {
459 			error = uiomove((caddr_t)dp, dp->d_reclen, uio);
460 			if (error)
461 				break;
462 		}
463 		off += dp->d_reclen;
464 		dd = TAILQ_NEXT(dd, de_list);
465 	}
466 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
467 	uio->uio_offset = off;
468 	return (error);
469 }
470 
471 static int
472 devfs_readlink(ap)
473 	struct vop_readlink_args /* {
474 		struct vnode *a_vp;
475 		struct uio *a_uio;
476 		struct ucred *a_cead;
477 	} */ *ap;
478 {
479 	int error;
480 	struct devfs_dirent *de;
481 
482 	de = ap->a_vp->v_data;
483 	error = uiomove(de->de_symlink, strlen(de->de_symlink) + 1, ap->a_uio);
484 	return (error);
485 }
486 
487 static int
488 devfs_reclaim(ap)
489 	struct vop_reclaim_args /* {
490 		struct vnode *a_vp;
491 	} */ *ap;
492 {
493 	struct vnode *vp = ap->a_vp;
494 	struct devfs_dirent *de;
495 	int i;
496 
497 	de = vp->v_data;
498 	if (de != NULL)
499 		de->de_vnode = NULL;
500 	if (de != NULL && de->de_flags & DE_ORPHAN) {
501 		if (de->de_symlink)
502 			FREE(de->de_symlink, M_DEVFS);
503 		FREE(de, M_DEVFS);
504 	}
505 	vp->v_data = NULL;
506 	if (vp->v_rdev != NODEV && vp->v_rdev != NULL) {
507 		i = vcount(vp);
508 		if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0)
509 			destroy_dev(vp->v_rdev);
510 	}
511 	return (0);
512 }
513 
514 static int
515 devfs_remove(ap)
516 	struct vop_remove_args /* {
517 		struct vnode *a_dvp;
518 		struct vnode *a_vp;
519 		struct componentname *a_cnp;
520 	} */ *ap;
521 {
522 	struct vnode *vp = ap->a_vp;
523 	struct devfs_dirent *dd;
524 	struct devfs_dirent *de, **dep;
525 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
526 
527 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
528 	dd = ap->a_dvp->v_data;
529 	de = vp->v_data;
530 	TAILQ_REMOVE(&dd->de_dlist, de, de_list);
531 	dep = devfs_itode(dmp, de->de_inode);
532 	if (dep != NULL)
533 		*dep = DE_DELETED;
534 	de->de_flags |= DE_ORPHAN;
535 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
536 	return (0);
537 }
538 
539 /*
540  * Revoke is called on a tty when a terminal session ends.  The vnode
541  * is orphaned by setting v_op to deadfs so we need to let go of it
542  * as well so that we create a new one next time around.
543  */
544 static int
545 devfs_revoke(ap)
546 	struct vop_revoke_args /* {
547 		struct vnode *a_vp;
548 		int a_flags;
549 	} */ *ap;
550 {
551 	struct vnode *vp = ap->a_vp;
552 	struct devfs_dirent *de;
553 
554 	de = vp->v_data;
555 	de->de_vnode = NULL;
556 	vop_revoke(ap);
557 	return (0);
558 }
559 
560 static int
561 devfs_setattr(ap)
562 	struct vop_setattr_args /* {
563 		struct vnode *a_vp;
564 		struct vattr *a_vap;
565 		struct ucred *a_cred;
566 		struct proc *a_p;
567 	} */ *ap;
568 {
569 	struct devfs_dirent *de;
570 	struct vattr *vap;
571 	int c, error;
572 	uid_t uid;
573 	gid_t gid;
574 
575 	vap = ap->a_vap;
576 	if ((vap->va_type != VNON) ||
577 	    (vap->va_nlink != VNOVAL) ||
578 	    (vap->va_fsid != VNOVAL) ||
579 	    (vap->va_fileid != VNOVAL) ||
580 	    (vap->va_blocksize != VNOVAL) ||
581 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
582 	    (vap->va_rdev != VNOVAL) ||
583 	    ((int)vap->va_bytes != VNOVAL) ||
584 	    (vap->va_gen != VNOVAL)) {
585 		return (EINVAL);
586 	}
587 
588 	de = ap->a_vp->v_data;
589 	if (ap->a_vp->v_type == VDIR)
590 		de = de->de_dir;
591 
592 	error = c = 0;
593 	if (vap->va_uid == (uid_t)VNOVAL)
594 		uid = de->de_uid;
595 	else
596 		uid = vap->va_uid;
597 	if (vap->va_gid == (gid_t)VNOVAL)
598 		gid = de->de_gid;
599 	else
600 		gid = vap->va_gid;
601 	if (uid != de->de_uid || gid != de->de_gid) {
602 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
603 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
604 		    (error = suser(ap->a_p)) != 0)
605 			return (error);
606 		de->de_uid = uid;
607 		de->de_gid = gid;
608 		c = 1;
609 	}
610 	if (vap->va_mode != (mode_t)VNOVAL) {
611 		if ((ap->a_cred->cr_uid != de->de_uid) &&
612 		    (error = suser(ap->a_p)))
613 			return (error);
614 		de->de_mode = vap->va_mode;
615 		c = 1;
616 	}
617 	if (vap->va_atime.tv_sec != VNOVAL) {
618 		if ((ap->a_cred->cr_uid != de->de_uid) &&
619 		    (error = suser(ap->a_p)))
620 			return (error);
621 		de->de_atime = vap->va_atime;
622 		c = 1;
623 	}
624 	if (vap->va_mtime.tv_sec != VNOVAL) {
625 		if ((ap->a_cred->cr_uid != de->de_uid) &&
626 		    (error = suser(ap->a_p)))
627 			return (error);
628 		de->de_mtime = vap->va_mtime;
629 		c = 1;
630 	}
631 
632 	if (c)
633 		getnanotime(&de->de_ctime);
634 	return (0);
635 }
636 
637 static int
638 devfs_symlink(ap)
639 	struct vop_symlink_args /* {
640 		struct vnode *a_dvp;
641 		struct vnode **a_vpp;
642 		struct componentname *a_cnp;
643 		struct vattr *a_vap;
644 		char *a_target;
645 	} */ *ap;
646 {
647 	int i, error;
648 	struct devfs_dirent *dd;
649 	struct devfs_dirent *de;
650 	struct devfs_mount *dmp;
651 
652 	error = suser(ap->a_cnp->cn_proc);
653 	if (error)
654 		return(error);
655 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
656 	dd = ap->a_dvp->v_data;
657 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
658 	de->de_uid = 0;
659 	de->de_gid = 0;
660 	de->de_mode = 0755;
661 	de->de_inode = dmp->dm_inode++;
662 	de->de_dirent->d_type = DT_LNK;
663 	i = strlen(ap->a_target) + 1;
664 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
665 	bcopy(ap->a_target, de->de_symlink, i);
666 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
667 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
668 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
669 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
670 	return (0);
671 }
672 
673 /*
674  * DEVFS "should never get here" operation
675  */
676 static int
677 devfs_badop()
678 {
679 	return (EIO);
680 }
681 
682 static vop_t **devfs_vnodeop_p;
683 static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
684 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
685 	{ &vop_access_desc,		(vop_t *) devfs_access },
686 	{ &vop_bmap_desc,		(vop_t *) devfs_badop },
687 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
688 	{ &vop_lookup_desc,		(vop_t *) devfs_lookup },
689 	{ &vop_pathconf_desc,		(vop_t *) vop_stdpathconf },
690 	{ &vop_print_desc,		(vop_t *) devfs_print },
691 	{ &vop_read_desc,		(vop_t *) devfs_read },
692 	{ &vop_readdir_desc,		(vop_t *) devfs_readdir },
693 	{ &vop_readlink_desc,		(vop_t *) devfs_readlink },
694 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
695 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
696 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
697 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
698 	{ &vop_symlink_desc,		(vop_t *) devfs_symlink },
699 	{ NULL, NULL }
700 };
701 static struct vnodeopv_desc devfs_vnodeop_opv_desc =
702 	{ &devfs_vnodeop_p, devfs_vnodeop_entries };
703 
704 VNODEOP_SET(devfs_vnodeop_opv_desc);
705 
706 #if 0
707 int
708 foo(ap)
709 	struct vop_generic_args *ap;
710 {
711 	int i;
712 
713 	i = spec_vnoperate(ap);
714 	printf("foo(%s) = %d\n", ap->a_desc->vdesc_name, i);
715 	return (i);
716 }
717 #endif
718 
719 static vop_t **devfs_specop_p;
720 static struct vnodeopv_entry_desc devfs_specop_entries[] = {
721 #if 1
722 	{ &vop_default_desc,		(vop_t *) spec_vnoperate },
723 #else
724 	{ &vop_default_desc,		(vop_t *) foo },
725 	{ &vop_lock_desc,		(vop_t *) spec_vnoperate },
726 	{ &vop_unlock_desc,		(vop_t *) spec_vnoperate },
727 	{ &vop_lease_desc,		(vop_t *) spec_vnoperate },
728 	{ &vop_strategy_desc,		(vop_t *) spec_vnoperate },
729 	{ &vop_bmap_desc,		(vop_t *) spec_vnoperate },
730 #endif
731 	{ &vop_access_desc,		(vop_t *) devfs_access },
732 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
733 	{ &vop_print_desc,		(vop_t *) devfs_print },
734 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
735 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
736 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
737 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
738 	{ NULL, NULL }
739 };
740 static struct vnodeopv_desc devfs_specop_opv_desc =
741 	{ &devfs_specop_p, devfs_specop_entries };
742 
743 VNODEOP_SET(devfs_specop_opv_desc);
744