xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision d1ba25f456132eabc6f1244e4bbbf3d19e8f3a31)
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/proc.h>
46 #include <sys/mount.h>
47 #include <sys/namei.h>
48 #include <sys/dirent.h>
49 
50 #include <fs/devfs/devfs.h>
51 
52 static int	devfs_access __P((struct vop_access_args *ap));
53 static int	devfs_badop __P((void));
54 static int	devfs_getattr __P((struct vop_getattr_args *ap));
55 static int	devfs_lookupx __P((struct vop_lookup_args *ap));
56 static int	devfs_print __P((struct vop_print_args *ap));
57 static int	devfs_read __P((struct vop_read_args *ap));
58 static int	devfs_readdir __P((struct vop_readdir_args *ap));
59 static int	devfs_readlink __P((struct vop_readlink_args *ap));
60 static int	devfs_reclaim __P((struct vop_reclaim_args *ap));
61 static int	devfs_remove __P((struct vop_remove_args *ap));
62 static int	devfs_revoke __P((struct vop_revoke_args *ap));
63 static int	devfs_setattr __P((struct vop_setattr_args *ap));
64 static int	devfs_symlink __P((struct vop_symlink_args *ap));
65 
66 int
67 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct proc *p)
68 {
69 	int error;
70 	struct vnode *vp;
71 	dev_t dev;
72 
73 	if (p == NULL)
74 		p = curproc; /* XXX */
75 loop:
76 	vp = de->de_vnode;
77 	if (vp != NULL) {
78 		if (vget(vp, LK_EXCLUSIVE, p ? p : curproc))
79 			goto loop;
80 		*vpp = vp;
81 		return (0);
82 	}
83 	if (de->de_dirent->d_type == DT_CHR) {
84 		dev = *devfs_itod(de->de_inode);
85 		if (dev == NULL)
86 			return (ENOENT);
87 	} else {
88 		dev = NODEV;
89 	}
90 	error = getnewvnode(VT_DEVFS, mp, devfs_vnodeop_p, &vp);
91 	if (error != 0) {
92 		printf("devfs_allocv: failed to allocate new vnode\n");
93 		return (error);
94 	}
95 
96 	if (de->de_dirent->d_type == DT_CHR) {
97 		vp->v_type = VCHR;
98 		vp = addaliasu(vp, dev->si_udev);
99 		vp->v_op = devfs_specop_p;
100 	} else if (de->de_dirent->d_type == DT_DIR) {
101 		vp->v_type = VDIR;
102 	} else if (de->de_dirent->d_type == DT_LNK) {
103 		vp->v_type = VLNK;
104 	} else {
105 		vp->v_type = VBAD;
106 	}
107 	vp->v_data = de;
108 	de->de_vnode = vp;
109 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
110 	*vpp = vp;
111 	return (0);
112 }
113 
114 static int
115 devfs_access(ap)
116 	struct vop_access_args /* {
117 		struct vnode *a_vp;
118 		int  a_mode;
119 		struct ucred *a_cred;
120 		struct proc *a_p;
121 	} */ *ap;
122 {
123 	struct vnode *vp = ap->a_vp;
124 	struct devfs_dirent *de;
125 
126 	de = vp->v_data;
127 	if (vp->v_type == VDIR)
128 		de = de->de_dir;
129 
130 	return (vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
131 	    ap->a_mode, ap->a_cred, NULL));
132 }
133 
134 static int
135 devfs_getattr(ap)
136 	struct vop_getattr_args /* {
137 		struct vnode *a_vp;
138 		struct vattr *a_vap;
139 		struct ucred *a_cred;
140 		struct proc *a_p;
141 	} */ *ap;
142 {
143 	struct vnode *vp = ap->a_vp;
144 	struct vattr *vap = ap->a_vap;
145 	int error = 0;
146 	struct devfs_dirent *de;
147 	dev_t dev;
148 
149 	de = vp->v_data;
150 	if (vp->v_type == VDIR)
151 		de = de->de_dir;
152 	bzero((caddr_t) vap, sizeof(*vap));
153 	vattr_null(vap);
154 	vap->va_uid = de->de_uid;
155 	vap->va_gid = de->de_gid;
156 	vap->va_mode = de->de_mode;
157 	vap->va_size = 0;
158 	vap->va_blocksize = DEV_BSIZE;
159 	vap->va_type = vp->v_type;
160 	if (vp->v_type != VCHR)  {
161 		vap->va_atime = de->de_atime;
162 		vap->va_mtime = de->de_mtime;
163 		vap->va_ctime = de->de_ctime;
164 	} else {
165 		dev = vp->v_rdev;
166 		vap->va_atime = dev->si_atime;
167 		vap->va_mtime = dev->si_mtime;
168 		vap->va_ctime = dev->si_ctime;
169 		vap->va_rdev = dev->si_udev;
170 	}
171 	vap->va_gen = 0;
172 	vap->va_flags = 0;
173 	vap->va_bytes = 0;
174 	vap->va_nlink = de->de_links;
175 	vap->va_fileid = de->de_inode;
176 
177 #ifdef DEBUG
178 	if (error)
179 		printf("devfs_getattr: return error %d\n", error);
180 #endif
181 	return (error);
182 }
183 
184 static int
185 devfs_lookupx(ap)
186 	struct vop_lookup_args /* {
187 		struct vnode * a_dvp;
188 		struct vnode ** a_vpp;
189 		struct componentname * a_cnp;
190 	} */ *ap;
191 {
192 	struct componentname *cnp;
193 	struct vnode *dvp, **vpp;
194 	struct proc *p;
195 	struct devfs_dirent *de, *dd;
196 	struct devfs_mount *dmp;
197 	dev_t cdev;
198 	int error, cloned, i, flags, nameiop;
199 	char specname[SPECNAMELEN + 1], *pname;
200 
201 	cnp = ap->a_cnp;
202 	vpp = ap->a_vpp;
203 	dvp = ap->a_dvp;
204 	pname = cnp->cn_nameptr;
205 	p = cnp->cn_proc;
206 	flags = cnp->cn_flags;
207 	nameiop = cnp->cn_nameiop;
208 	dmp = VFSTODEVFS(dvp->v_mount);
209 	cloned = 0;
210 	dd = dvp->v_data;
211 
212 	*vpp = NULLVP;
213 
214 	if (nameiop == RENAME)
215 		return (EOPNOTSUPP);
216 
217 	if (dvp->v_type != VDIR)
218 		return (ENOTDIR);
219 
220 	if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
221 		return (EIO);
222 
223 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_proc);
224 	if (error)
225 		return (error);
226 
227 	if (cnp->cn_namelen == 1 && *pname == '.') {
228 		if (nameiop != LOOKUP)
229 			return (EINVAL);
230 		*vpp = dvp;
231 		VREF(dvp);
232 		return (0);
233 	}
234 
235 	if (flags & ISDOTDOT) {
236 		if (nameiop != LOOKUP)
237 			return (EINVAL);
238 		VOP_UNLOCK(dvp, 0, p);
239 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
240 		de = TAILQ_NEXT(de, de_list);		/* ".." */
241 		de = de->de_dir;
242 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
243 		if (error) {
244 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
245 			return (error);
246 		}
247 		if ((flags & LOCKPARENT) && (flags & ISLASTCN))
248 			error = vn_lock(dvp, LK_EXCLUSIVE, p);
249 		if (error)
250 			vput(*vpp);
251 		return (error);
252 	}
253 
254 	devfs_populate(dmp);
255 	dd = dvp->v_data;
256 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
257 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
258 			continue;
259 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
260 		    de->de_dirent->d_namlen) != 0)
261 			continue;
262 		goto found;
263 	}
264 
265 	/*
266 	 * OK, we didn't have an entry for the name we were asked for
267 	 * so we try to see if anybody can create it on demand.
268 	 * We need to construct the full "devname" for this device
269 	 * relative to "basedir" or the clone functions would not
270 	 * be able to tell "/dev/foo" from "/dev/bar/foo"
271 	 */
272 	i = SPECNAMELEN;
273 	specname[i] = '\0';
274 	i -= cnp->cn_namelen;
275 	if (i < 0)
276 		 goto notfound;
277 	bcopy(cnp->cn_nameptr, specname + i, cnp->cn_namelen);
278 	de = dd;
279 	while (de != dmp->dm_basedir) {
280 		i--;
281 		if (i < 0)
282 			 goto notfound;
283 		specname[i] = '/';
284 		i -= de->de_dirent->d_namlen;
285 		if (i < 0)
286 			 goto notfound;
287 		bcopy(de->de_dirent->d_name, specname + i,
288 		    de->de_dirent->d_namlen);
289 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
290 		de = TAILQ_NEXT(de, de_list);		/* ".." */
291 		de = de->de_dir;
292 	}
293 
294 #if 0
295 	printf("Finished specname: %d \"%s\"\n", i, specname + i);
296 #endif
297 	cdev = NODEV;
298 	EVENTHANDLER_INVOKE(dev_clone, specname + i,
299 	    strlen(specname + i), &cdev);
300 #if 0
301 	printf("cloned %s -> %p %s\n", specname + i, cdev,
302 	    cdev == NODEV ? "NODEV" : cdev->si_name);
303 #endif
304 	if (cdev == NODEV)
305 		goto notfound;
306 
307 	devfs_populate(dmp);
308 	dd = dvp->v_data;
309 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
310 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
311 			continue;
312 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
313 		    de->de_dirent->d_namlen) != 0)
314 			continue;
315 		goto found;
316 	}
317 
318 notfound:
319 
320 	if ((nameiop == CREATE || nameiop == RENAME) &&
321 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
322 		cnp->cn_flags |= SAVENAME;
323 		if (!(flags & LOCKPARENT))
324 			VOP_UNLOCK(dvp, 0, p);
325 		return (EJUSTRETURN);
326 	}
327 	return (ENOENT);
328 
329 
330 found:
331 
332 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
333 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, p);
334 		if (error)
335 			return (error);
336 		if (*vpp == dvp) {
337 			VREF(dvp);
338 			*vpp = dvp;
339 			return (0);
340 		}
341 		error = devfs_allocv(de, dvp->v_mount, vpp, p);
342 		if (error)
343 			return (error);
344 		if (!(flags & LOCKPARENT))
345 			VOP_UNLOCK(dvp, 0, p);
346 		return (0);
347 	}
348 	error = devfs_allocv(de, dvp->v_mount, vpp, p);
349 	if (error)
350 		return (error);
351 	if (!(flags & LOCKPARENT) || !(flags & ISLASTCN))
352 		VOP_UNLOCK(dvp, 0, p);
353 	return (0);
354 }
355 
356 static int
357 devfs_lookup(struct vop_lookup_args *ap)
358 {
359 	int j;
360 	struct devfs_mount *dmp;
361 
362 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
363 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
364 	j = devfs_lookupx(ap);
365 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
366 	return (j);
367 }
368 
369 /* ARGSUSED */
370 static int
371 devfs_print(ap)
372 	struct vop_print_args /* {
373 		struct vnode *a_vp;
374 	} */ *ap;
375 {
376 
377 	printf("tag VT_DEVFS, devfs vnode\n");
378 	return (0);
379 }
380 
381 static int
382 devfs_read(ap)
383 	struct vop_read_args /* {
384 		struct vnode *a_vp;
385 		struct uio *a_uio;
386 		int a_ioflag;
387 		struct ucred *a_cred;
388 	} */ *ap;
389 {
390 
391 	if (ap->a_vp->v_type != VDIR)
392 		return (EINVAL);
393 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
394 }
395 
396 static int
397 devfs_readdir(ap)
398 	struct vop_readdir_args /* {
399 		struct vnode *a_vp;
400 		struct uio *a_uio;
401 		struct ucred *a_cred;
402 		int *a_eofflag;
403 		int *a_ncookies;
404 		u_long **a_cookies;
405 	} */ *ap;
406 {
407 	int error;
408 	struct uio *uio;
409 	struct dirent *dp;
410 	struct devfs_dirent *dd;
411 	struct devfs_dirent *de;
412 	struct devfs_mount *dmp;
413 	off_t off;
414 
415 	if (ap->a_vp->v_type != VDIR)
416 		return (ENOTDIR);
417 
418 	if (ap->a_ncookies)
419 		return (EOPNOTSUPP);
420 
421 	uio = ap->a_uio;
422 	if (uio->uio_offset < 0)
423 		return (EINVAL);
424 
425 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
426 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
427 	devfs_populate(dmp);
428 	error = 0;
429 	de = ap->a_vp->v_data;
430 	dd = TAILQ_FIRST(&de->de_dlist);
431 	off = 0;
432 	while (dd != NULL) {
433 		if (dd->de_dirent->d_type == DT_DIR)
434 			de = dd->de_dir;
435 		else
436 			de = dd;
437 		dp = dd->de_dirent;
438 		if (dp->d_reclen > uio->uio_resid)
439 			break;
440 		dp->d_fileno = de->de_inode;
441 		if (off >= uio->uio_offset) {
442 			error = uiomove((caddr_t)dp, dp->d_reclen, uio);
443 			if (error)
444 				break;
445 		}
446 		off += dp->d_reclen;
447 		dd = TAILQ_NEXT(dd, de_list);
448 	}
449 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
450 	uio->uio_offset = off;
451 	return (error);
452 }
453 
454 static int
455 devfs_readlink(ap)
456 	struct vop_readlink_args /* {
457 		struct vnode *a_vp;
458 		struct uio *a_uio;
459 		struct ucred *a_cead;
460 	} */ *ap;
461 {
462 	int error;
463 	struct devfs_dirent *de;
464 
465 	de = ap->a_vp->v_data;
466 	error = uiomove(de->de_symlink, strlen(de->de_symlink) + 1, ap->a_uio);
467 	return (error);
468 }
469 
470 static int
471 devfs_reclaim(ap)
472 	struct vop_reclaim_args /* {
473 		struct vnode *a_vp;
474 	} */ *ap;
475 {
476 	struct vnode *vp = ap->a_vp;
477 	struct devfs_dirent *de;
478 	int i;
479 
480 	de = vp->v_data;
481 	if (de != NULL)
482 		de->de_vnode = NULL;
483 	if (de != NULL && de->de_flags & DE_ORPHAN) {
484 		if (de->de_symlink)
485 			FREE(de->de_symlink, M_DEVFS);
486 		FREE(de, M_DEVFS);
487 	}
488 	vp->v_data = NULL;
489 	if (vp->v_rdev != NODEV && vp->v_rdev != NULL) {
490 		i = vcount(vp);
491 		if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0) {
492 			destroy_dev(vp->v_rdev);
493 			printf("Reclaim <%s> %d %d Killed\n", vp->v_rdev->si_name, vp->v_rdev->si_flags, i);
494 		}
495 	}
496 	return (0);
497 }
498 
499 static int
500 devfs_remove(ap)
501 	struct vop_remove_args /* {
502 		struct vnode *a_dvp;
503 		struct vnode *a_vp;
504 		struct componentname *a_cnp;
505 	} */ *ap;
506 {
507 	struct vnode *vp = ap->a_vp;
508 	struct devfs_dirent *dd;
509 	struct devfs_dirent *de, **dep;
510 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
511 
512 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
513 	dd = ap->a_dvp->v_data;
514 	de = vp->v_data;
515 	TAILQ_REMOVE(&dd->de_dlist, de, de_list);
516 	dep = devfs_itode(dmp, de->de_inode);
517 	if (dep != NULL)
518 		*dep = DE_DELETED;
519 	de->de_flags |= DE_ORPHAN;
520 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
521 	return (0);
522 }
523 
524 /*
525  * Revoke is called on a tty when a terminal session ends.  The vnode
526  * is orphaned by setting v_op to deadfs so we need to let go of it
527  * as well so that we create a new one next time around.
528  */
529 static int
530 devfs_revoke(ap)
531 	struct vop_revoke_args /* {
532 		struct vnode *a_vp;
533 		int a_flags;
534 	} */ *ap;
535 {
536 	struct vnode *vp = ap->a_vp;
537 	struct devfs_dirent *de;
538 
539 	de = vp->v_data;
540 	de->de_vnode = NULL;
541 	vop_revoke(ap);
542 	return (0);
543 }
544 
545 static int
546 devfs_setattr(ap)
547 	struct vop_setattr_args /* {
548 		struct vnode *a_vp;
549 		struct vattr *a_vap;
550 		struct ucred *a_cred;
551 		struct proc *a_p;
552 	} */ *ap;
553 {
554 	struct devfs_dirent *de;
555 	struct vattr *vap;
556 	int c, error;
557 	uid_t uid;
558 	gid_t gid;
559 
560 	vap = ap->a_vap;
561 	if ((vap->va_type != VNON) ||
562 	    (vap->va_nlink != VNOVAL) ||
563 	    (vap->va_fsid != VNOVAL) ||
564 	    (vap->va_fileid != VNOVAL) ||
565 	    (vap->va_blocksize != VNOVAL) ||
566 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
567 	    (vap->va_rdev != VNOVAL) ||
568 	    ((int)vap->va_bytes != VNOVAL) ||
569 	    (vap->va_gen != VNOVAL)) {
570 		return (EINVAL);
571 	}
572 
573 	de = ap->a_vp->v_data;
574 	if (ap->a_vp->v_type == VDIR)
575 		de = de->de_dir;
576 
577 	error = c = 0;
578 	if (vap->va_uid == (uid_t)VNOVAL)
579 		uid = de->de_uid;
580 	else
581 		uid = vap->va_uid;
582 	if (vap->va_gid == (gid_t)VNOVAL)
583 		gid = de->de_gid;
584 	else
585 		gid = vap->va_gid;
586 	if (uid != de->de_uid || gid != de->de_gid) {
587 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
588 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
589 		    (error = suser(ap->a_p)) != 0)
590 			return (error);
591 		de->de_uid = uid;
592 		de->de_gid = gid;
593 		c = 1;
594 	}
595 	if (vap->va_mode != (mode_t)VNOVAL) {
596 		if ((ap->a_cred->cr_uid != de->de_uid) &&
597 		    (error = suser(ap->a_p)))
598 			return (error);
599 		de->de_mode = vap->va_mode;
600 		c = 1;
601 	}
602 	if (vap->va_atime.tv_sec != VNOVAL) {
603 		if ((ap->a_cred->cr_uid != de->de_uid) &&
604 		    (error = suser(ap->a_p)))
605 			return (error);
606 		de->de_atime = vap->va_atime;
607 		c = 1;
608 	}
609 	if (vap->va_mtime.tv_sec != VNOVAL) {
610 		if ((ap->a_cred->cr_uid != de->de_uid) &&
611 		    (error = suser(ap->a_p)))
612 			return (error);
613 		de->de_mtime = vap->va_mtime;
614 		c = 1;
615 	}
616 
617 	if (c)
618 		getnanotime(&de->de_ctime);
619 	return (0);
620 }
621 
622 static int
623 devfs_symlink(ap)
624 	struct vop_symlink_args /* {
625 		struct vnode *a_dvp;
626 		struct vnode **a_vpp;
627 		struct componentname *a_cnp;
628 		struct vattr *a_vap;
629 		char *a_target;
630 	} */ *ap;
631 {
632 	int i;
633 	struct devfs_dirent *dd;
634 	struct devfs_dirent *de;
635 	struct devfs_mount *dmp;
636 
637 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
638 	dd = ap->a_dvp->v_data;
639 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
640 	de->de_uid = 0;
641 	de->de_gid = 0;
642 	de->de_mode = 0642;
643 	de->de_inode = dmp->dm_inode++;
644 	de->de_dirent->d_type = DT_LNK;
645 	i = strlen(ap->a_target) + 1;
646 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
647 	bcopy(ap->a_target, de->de_symlink, i);
648 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
649 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
650 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
651 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
652 	return (0);
653 }
654 
655 /*
656  * DEVFS "should never get here" operation
657  */
658 static int
659 devfs_badop()
660 {
661 	return (EIO);
662 }
663 
664 vop_t	**devfs_vnodeop_p;
665 static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
666 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
667 	{ &vop_access_desc,		(vop_t *) devfs_access },
668 	{ &vop_bmap_desc,		(vop_t *) devfs_badop },
669 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
670 	{ &vop_lookup_desc,		(vop_t *) devfs_lookup },
671 	{ &vop_pathconf_desc,		(vop_t *) vop_stdpathconf },
672 	{ &vop_print_desc,		(vop_t *) devfs_print },
673 	{ &vop_read_desc,		(vop_t *) devfs_read },
674 	{ &vop_readdir_desc,		(vop_t *) devfs_readdir },
675 	{ &vop_readlink_desc,		(vop_t *) devfs_readlink },
676 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
677 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
678 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
679 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
680 	{ &vop_symlink_desc,		(vop_t *) devfs_symlink },
681 	{ NULL, NULL }
682 };
683 static struct vnodeopv_desc devfs_vnodeop_opv_desc =
684 	{ &devfs_vnodeop_p, devfs_vnodeop_entries };
685 
686 VNODEOP_SET(devfs_vnodeop_opv_desc);
687 
688 #if 0
689 int
690 foo(ap)
691 	struct vop_generic_args *ap;
692 {
693 	int i;
694 
695 	i = spec_vnoperate(ap);
696 	printf("foo(%s) = %d\n", ap->a_desc->vdesc_name, i);
697 	return (i);
698 }
699 #endif
700 
701 vop_t	**devfs_specop_p;
702 static struct vnodeopv_entry_desc devfs_specop_entries[] = {
703 #if 1
704 	{ &vop_default_desc,		(vop_t *) spec_vnoperate },
705 #else
706 	{ &vop_default_desc,		(vop_t *) foo },
707 	{ &vop_lock_desc,		(vop_t *) spec_vnoperate },
708 	{ &vop_unlock_desc,		(vop_t *) spec_vnoperate },
709 	{ &vop_lease_desc,		(vop_t *) spec_vnoperate },
710 	{ &vop_strategy_desc,		(vop_t *) spec_vnoperate },
711 	{ &vop_bmap_desc,		(vop_t *) spec_vnoperate },
712 #endif
713 	{ &vop_access_desc,		(vop_t *) devfs_access },
714 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
715 	{ &vop_print_desc,		(vop_t *) devfs_print },
716 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
717 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
718 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
719 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
720 	{ NULL, NULL }
721 };
722 static struct vnodeopv_desc devfs_specop_opv_desc =
723 	{ &devfs_specop_p, devfs_specop_entries };
724 
725 VNODEOP_SET(devfs_specop_opv_desc);
726