xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision 729362425c09cf6b362366aabc6fb547eee8035a)
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 #include <opt_mac.h>
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/mac.h>
54 #include <sys/malloc.h>
55 #include <sys/mount.h>
56 #include <sys/namei.h>
57 #include <sys/proc.h>
58 #include <sys/time.h>
59 #include <sys/unistd.h>
60 #include <sys/vnode.h>
61 
62 #include <fs/devfs/devfs.h>
63 
64 static int	devfs_access(struct vop_access_args *ap);
65 static int	devfs_getattr(struct vop_getattr_args *ap);
66 static int	devfs_ioctl(struct vop_ioctl_args *ap);
67 static int	devfs_lookupx(struct vop_lookup_args *ap);
68 static int	devfs_mknod(struct vop_mknod_args *ap);
69 static int	devfs_pathconf(struct vop_pathconf_args *ap);
70 static int	devfs_read(struct vop_read_args *ap);
71 static int	devfs_readdir(struct vop_readdir_args *ap);
72 static int	devfs_readlink(struct vop_readlink_args *ap);
73 static int	devfs_reclaim(struct vop_reclaim_args *ap);
74 static int	devfs_remove(struct vop_remove_args *ap);
75 static int	devfs_revoke(struct vop_revoke_args *ap);
76 static int	devfs_setattr(struct vop_setattr_args *ap);
77 #ifdef MAC
78 static int	devfs_setlabel(struct vop_setlabel_args *ap);
79 #endif
80 static int	devfs_symlink(struct vop_symlink_args *ap);
81 
82 static vop_t **devfs_vnodeop_p;
83 static vop_t **devfs_specop_p;
84 
85 /*
86  * Construct the fully qualified path name relative to the mountpoint
87  */
88 static char *
89 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
90 {
91 	int i;
92 	struct devfs_dirent *de, *dd;
93 	struct devfs_mount *dmp;
94 
95 	dmp = VFSTODEVFS(dvp->v_mount);
96 	dd = dvp->v_data;
97 	i = SPECNAMELEN;
98 	buf[i] = '\0';
99 	i -= cnp->cn_namelen;
100 	if (i < 0)
101 		 return (NULL);
102 	bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
103 	de = dd;
104 	while (de != dmp->dm_basedir) {
105 		i--;
106 		if (i < 0)
107 			 return (NULL);
108 		buf[i] = '/';
109 		i -= de->de_dirent->d_namlen;
110 		if (i < 0)
111 			 return (NULL);
112 		bcopy(de->de_dirent->d_name, buf + i,
113 		    de->de_dirent->d_namlen);
114 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
115 		de = TAILQ_NEXT(de, de_list);		/* ".." */
116 		de = de->de_dir;
117 	}
118 	return (buf + i);
119 }
120 
121 int
122 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct thread *td)
123 {
124 	int error;
125 	struct vnode *vp;
126 	dev_t dev;
127 
128 	if (td == NULL)
129 		td = curthread; /* XXX */
130 loop:
131 	vp = de->de_vnode;
132 	if (vp != NULL) {
133 		if (vget(vp, LK_EXCLUSIVE, td ? td : curthread))
134 			goto loop;
135 		*vpp = vp;
136 		return (0);
137 	}
138 	if (de->de_dirent->d_type == DT_CHR) {
139 		dev = *devfs_itod(de->de_inode);
140 		if (dev == NULL)
141 			return (ENOENT);
142 	} else {
143 		dev = NODEV;
144 	}
145 	error = getnewvnode("devfs", mp, devfs_vnodeop_p, &vp);
146 	if (error != 0) {
147 		printf("devfs_allocv: failed to allocate new vnode\n");
148 		return (error);
149 	}
150 
151 	if (de->de_dirent->d_type == DT_CHR) {
152 		vp->v_type = VCHR;
153 		vp = addaliasu(vp, dev->si_udev);
154 		vp->v_op = devfs_specop_p;
155 	} else if (de->de_dirent->d_type == DT_DIR) {
156 		vp->v_type = VDIR;
157 	} else if (de->de_dirent->d_type == DT_LNK) {
158 		vp->v_type = VLNK;
159 	} else {
160 		vp->v_type = VBAD;
161 	}
162 	vp->v_data = de;
163 	de->de_vnode = vp;
164 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
165 #ifdef MAC
166 	mac_associate_vnode_devfs(mp, de, vp);
167 #endif
168 	*vpp = vp;
169 	return (0);
170 }
171 
172 static int
173 devfs_access(ap)
174 	struct vop_access_args /* {
175 		struct vnode *a_vp;
176 		int  a_mode;
177 		struct ucred *a_cred;
178 		struct thread *a_td;
179 	} */ *ap;
180 {
181 	struct vnode *vp = ap->a_vp;
182 	struct devfs_dirent *de;
183 	int error;
184 
185 	de = vp->v_data;
186 	if (vp->v_type == VDIR)
187 		de = de->de_dir;
188 
189 	error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
190 	    ap->a_mode, ap->a_cred, NULL);
191 	if (!error)
192 		return (error);
193 	if (error != EACCES)
194 		return (error);
195 	/* We do, however, allow access to the controlling terminal */
196 	if (!(ap->a_td->td_proc->p_flag & P_CONTROLT))
197 		return (error);
198 	if (ap->a_td->td_proc->p_session->s_ttyvp == de->de_vnode)
199 		return (0);
200 	return (error);
201 }
202 
203 static int
204 devfs_getattr(ap)
205 	struct vop_getattr_args /* {
206 		struct vnode *a_vp;
207 		struct vattr *a_vap;
208 		struct ucred *a_cred;
209 		struct thread *a_td;
210 	} */ *ap;
211 {
212 	struct vnode *vp = ap->a_vp;
213 	struct vattr *vap = ap->a_vap;
214 	int error = 0;
215 	struct devfs_dirent *de;
216 	dev_t dev;
217 
218 	de = vp->v_data;
219 	if (vp->v_type == VDIR)
220 		de = de->de_dir;
221 	bzero((caddr_t) vap, sizeof(*vap));
222 	vattr_null(vap);
223 	vap->va_uid = de->de_uid;
224 	vap->va_gid = de->de_gid;
225 	vap->va_mode = de->de_mode;
226 	if (vp->v_type == VLNK)
227 		vap->va_size = de->de_dirent->d_namlen;
228 	else if (vp->v_type == VDIR)
229 		vap->va_size = vap->va_bytes = DEV_BSIZE;
230 	else
231 		vap->va_size = 0;
232 	if (vp->v_type != VDIR)
233 		vap->va_bytes = 0;
234 	vap->va_blocksize = DEV_BSIZE;
235 	vap->va_type = vp->v_type;
236 
237 #define fix(aa)							\
238 	do {							\
239 		if ((aa).tv_sec == 0) {				\
240 			(aa).tv_sec = boottime.tv_sec;		\
241 			(aa).tv_nsec = boottime.tv_usec * 1000; \
242 		}						\
243 	} while (0)
244 
245 	if (vp->v_type != VCHR)  {
246 		fix(de->de_atime);
247 		vap->va_atime = de->de_atime;
248 		fix(de->de_mtime);
249 		vap->va_mtime = de->de_mtime;
250 		fix(de->de_ctime);
251 		vap->va_ctime = de->de_ctime;
252 	} else {
253 		dev = vp->v_rdev;
254 		fix(dev->si_atime);
255 		vap->va_atime = dev->si_atime;
256 		fix(dev->si_mtime);
257 		vap->va_mtime = dev->si_mtime;
258 		fix(dev->si_ctime);
259 		vap->va_ctime = dev->si_ctime;
260 		vap->va_rdev = dev->si_udev;
261 	}
262 	vap->va_gen = 0;
263 	vap->va_flags = 0;
264 	vap->va_nlink = de->de_links;
265 	vap->va_fileid = de->de_inode;
266 
267 	return (error);
268 }
269 
270 static int
271 devfs_ioctl(ap)
272 	struct vop_ioctl_args /* {
273 		struct vnode *a_vp;
274 		u_long  a_command;
275 		caddr_t  a_data;
276 		int  a_fflag;
277 		struct ucred *a_cred;
278 		struct thread *a_td;
279 	} */ *ap;
280 {
281 	int error;
282 
283 	error = devfs_rules_ioctl(ap->a_vp->v_mount, ap->a_command, ap->a_data,
284 	    ap->a_td);
285 	return (error);
286 }
287 
288 static int
289 devfs_lookupx(ap)
290 	struct vop_lookup_args /* {
291 		struct vnode * a_dvp;
292 		struct vnode ** a_vpp;
293 		struct componentname * a_cnp;
294 	} */ *ap;
295 {
296 	struct componentname *cnp;
297 	struct vnode *dvp, **vpp;
298 	struct thread *td;
299 	struct devfs_dirent *de, *dd;
300 	struct devfs_mount *dmp;
301 	dev_t cdev, *cpdev;
302 	int error, cloned, flags, nameiop;
303 	char specname[SPECNAMELEN + 1], *pname;
304 
305 	cnp = ap->a_cnp;
306 	vpp = ap->a_vpp;
307 	dvp = ap->a_dvp;
308 	pname = cnp->cn_nameptr;
309 	td = cnp->cn_thread;
310 	flags = cnp->cn_flags;
311 	nameiop = cnp->cn_nameiop;
312 	dmp = VFSTODEVFS(dvp->v_mount);
313 	cloned = 0;
314 	dd = dvp->v_data;
315 
316 	*vpp = NULLVP;
317 	cnp->cn_flags &= ~PDIRUNLOCK;
318 
319 	if ((flags & ISLASTCN) && nameiop == RENAME)
320 		return (EOPNOTSUPP);
321 
322 	if (dvp->v_type != VDIR)
323 		return (ENOTDIR);
324 
325 	if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
326 		return (EIO);
327 
328 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
329 	if (error)
330 		return (error);
331 
332 	if (cnp->cn_namelen == 1 && *pname == '.') {
333 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
334 			return (EINVAL);
335 		*vpp = dvp;
336 		VREF(dvp);
337 		return (0);
338 	}
339 
340 	if (flags & ISDOTDOT) {
341 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
342 			return (EINVAL);
343 		VOP_UNLOCK(dvp, 0, td);
344 		cnp->cn_flags |= PDIRUNLOCK;
345 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
346 		de = TAILQ_NEXT(de, de_list);		/* ".." */
347 		de = de->de_dir;
348 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
349 		if (error || ((flags & LOCKPARENT) && (flags & ISLASTCN))) {
350 			vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
351 			cnp->cn_flags &= ~PDIRUNLOCK;
352 		}
353 		return (error);
354 	}
355 
356 	devfs_populate(dmp);
357 	dd = dvp->v_data;
358 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
359 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
360 			continue;
361 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
362 		    de->de_dirent->d_namlen) != 0)
363 			continue;
364 		if (de->de_flags & DE_WHITEOUT)
365 			goto notfound;
366 		goto found;
367 	}
368 
369 	if (nameiop == DELETE)
370 		goto notfound;
371 
372 	/*
373 	 * OK, we didn't have an entry for the name we were asked for
374 	 * so we try to see if anybody can create it on demand.
375 	 */
376 	pname = devfs_fqpn(specname, dvp, cnp);
377 	if (pname == NULL)
378 		goto notfound;
379 
380 	cdev = NODEV;
381 	EVENTHANDLER_INVOKE(dev_clone, pname, strlen(pname), &cdev);
382 	if (cdev == NODEV)
383 		goto notfound;
384 
385 	devfs_populate(dmp);
386 	dd = dvp->v_data;
387 
388 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
389 		cpdev = devfs_itod(de->de_inode);
390 		if (cpdev != NULL && cdev == *cpdev)
391 			goto found;
392 		continue;
393 	}
394 
395 notfound:
396 
397 	if ((nameiop == CREATE || nameiop == RENAME) &&
398 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
399 		cnp->cn_flags |= SAVENAME;
400 		if (!(flags & LOCKPARENT)) {
401 			VOP_UNLOCK(dvp, 0, td);
402 			cnp->cn_flags |= PDIRUNLOCK;
403 		}
404 		return (EJUSTRETURN);
405 	}
406 	return (ENOENT);
407 
408 
409 found:
410 
411 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
412 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
413 		if (error)
414 			return (error);
415 		if (*vpp == dvp) {
416 			VREF(dvp);
417 			*vpp = dvp;
418 			return (0);
419 		}
420 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
421 		if (error)
422 			return (error);
423 		if (!(flags & LOCKPARENT)) {
424 			VOP_UNLOCK(dvp, 0, td);
425 			cnp->cn_flags |= PDIRUNLOCK;
426 		}
427 		return (0);
428 	}
429 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
430 	if (error)
431 		return (error);
432 	if (!(flags & LOCKPARENT) || !(flags & ISLASTCN)) {
433 		VOP_UNLOCK(dvp, 0, td);
434 		cnp->cn_flags |= PDIRUNLOCK;
435 	}
436 	return (0);
437 }
438 
439 static int
440 devfs_lookup(struct vop_lookup_args *ap)
441 {
442 	int j;
443 	struct devfs_mount *dmp;
444 
445 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
446 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
447 	j = devfs_lookupx(ap);
448 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
449 	return (j);
450 }
451 
452 static int
453 devfs_mknod(struct vop_mknod_args *ap)
454 /*
455 struct vop_mknod_args {
456 	struct vnodeop_desc *a_desc;
457 	struct vnode *a_dvp;
458 	struct vnode **a_vpp;
459 	struct componentname *a_cnp;
460 	struct vattr *a_vap;
461 };
462 */
463 {
464 	struct componentname *cnp;
465 	struct vnode *dvp, **vpp;
466 	struct thread *td;
467 	struct devfs_dirent *dd, *de;
468 	struct devfs_mount *dmp;
469 	int cloned, flags, nameiop;
470 	int error;
471 
472 	dvp = ap->a_dvp;
473 	dmp = VFSTODEVFS(dvp->v_mount);
474 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
475 
476 	cnp = ap->a_cnp;
477 	vpp = ap->a_vpp;
478 	td = cnp->cn_thread;
479 	flags = cnp->cn_flags;
480 	nameiop = cnp->cn_nameiop;
481 	cloned = 0;
482 	dd = dvp->v_data;
483 
484 	error = ENOENT;
485 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
486 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
487 			continue;
488 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
489 		    de->de_dirent->d_namlen) != 0)
490 			continue;
491 		if (de->de_flags & DE_WHITEOUT)
492 			break;
493 		goto notfound;
494 	}
495 	if (de == NULL)
496 		goto notfound;
497 	de->de_flags &= ~DE_WHITEOUT;
498 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
499 notfound:
500 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
501 	return (error);
502 }
503 
504 
505 static int
506 devfs_pathconf(ap)
507 	struct vop_pathconf_args /* {
508 		struct vnode *a_vp;
509 		int a_name;
510 		int *a_retval;
511 	} */ *ap;
512 {
513 
514 	switch (ap->a_name) {
515 	case _PC_NAME_MAX:
516 		*ap->a_retval = NAME_MAX;
517 		return (0);
518 	case _PC_PATH_MAX:
519 		*ap->a_retval = PATH_MAX;
520 		return (0);
521 	case _PC_MAC_PRESENT:
522 #ifdef MAC
523 		/*
524 		 * If MAC is enabled, devfs automatically supports
525 		 * trivial non-persistant label storage.
526 		 */
527 		*ap->a_retval = 1;
528 #else
529 		*ap->a_retval = 0;
530 #endif
531 		return (0);
532 	default:
533 		return (vop_stdpathconf(ap));
534 	}
535 	/* NOTREACHED */
536 }
537 
538 static int
539 devfs_read(ap)
540 	struct vop_read_args /* {
541 		struct vnode *a_vp;
542 		struct uio *a_uio;
543 		int a_ioflag;
544 		struct ucred *a_cred;
545 	} */ *ap;
546 {
547 
548 	if (ap->a_vp->v_type != VDIR)
549 		return (EINVAL);
550 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
551 }
552 
553 static int
554 devfs_readdir(ap)
555 	struct vop_readdir_args /* {
556 		struct vnode *a_vp;
557 		struct uio *a_uio;
558 		struct ucred *a_cred;
559 		int *a_eofflag;
560 		int *a_ncookies;
561 		u_long **a_cookies;
562 	} */ *ap;
563 {
564 	int error;
565 	struct uio *uio;
566 	struct dirent *dp;
567 	struct devfs_dirent *dd;
568 	struct devfs_dirent *de;
569 	struct devfs_mount *dmp;
570 	off_t off, oldoff;
571 	int ncookies = 0;
572 	u_long *cookiebuf, *cookiep;
573 	struct dirent *dps, *dpe;
574 
575 	if (ap->a_vp->v_type != VDIR)
576 		return (ENOTDIR);
577 
578 	uio = ap->a_uio;
579 	if (uio->uio_offset < 0)
580 		return (EINVAL);
581 
582 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
583 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
584 	devfs_populate(dmp);
585 	error = 0;
586 	de = ap->a_vp->v_data;
587 	off = 0;
588 	oldoff = uio->uio_offset;
589 	TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
590 		if (dd->de_flags & DE_WHITEOUT)
591 			continue;
592 		if (dd->de_dirent->d_type == DT_DIR)
593 			de = dd->de_dir;
594 		else
595 			de = dd;
596 		dp = dd->de_dirent;
597 		if (dp->d_reclen > uio->uio_resid)
598 			break;
599 		dp->d_fileno = de->de_inode;
600 		if (off >= uio->uio_offset) {
601 			ncookies++;
602 			error = uiomove(dp, dp->d_reclen, uio);
603 			if (error)
604 				break;
605 		}
606 		off += dp->d_reclen;
607 	}
608 	if( !error && ap->a_ncookies != NULL && ap->a_cookies != NULL ) {
609 		MALLOC(cookiebuf, u_long *, ncookies * sizeof(u_long),
610 		       M_TEMP, M_WAITOK);
611 		cookiep = cookiebuf;
612 		dps = (struct dirent *)((char *)uio->uio_iov->iov_base -
613 		    (uio->uio_offset - oldoff));
614 		dpe = (struct dirent *) uio->uio_iov->iov_base;
615 		for( dp = dps;
616 			dp < dpe;
617 			dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
618 				oldoff += dp->d_reclen;
619 				*cookiep++ = (u_long) oldoff;
620 		}
621 		*ap->a_ncookies = ncookies;
622 		*ap->a_cookies = cookiebuf;
623 	}
624 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
625 	uio->uio_offset = off;
626 	return (error);
627 }
628 
629 static int
630 devfs_readlink(ap)
631 	struct vop_readlink_args /* {
632 		struct vnode *a_vp;
633 		struct uio *a_uio;
634 		struct ucred *a_cead;
635 	} */ *ap;
636 {
637 	int error;
638 	struct devfs_dirent *de;
639 
640 	de = ap->a_vp->v_data;
641 	error = uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio);
642 	return (error);
643 }
644 
645 static int
646 devfs_reclaim(ap)
647 	struct vop_reclaim_args /* {
648 		struct vnode *a_vp;
649 	} */ *ap;
650 {
651 	struct vnode *vp = ap->a_vp;
652 	struct devfs_dirent *de;
653 	int i;
654 
655 	de = vp->v_data;
656 	if (de != NULL)
657 		de->de_vnode = NULL;
658 	vp->v_data = NULL;
659 	if (vp->v_rdev != NODEV && vp->v_rdev != NULL) {
660 		i = vcount(vp);
661 		if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0 &&
662 		    (vp->v_rdev->si_flags & SI_NAMED))
663 			destroy_dev(vp->v_rdev);
664 	}
665 	return (0);
666 }
667 
668 static int
669 devfs_remove(ap)
670 	struct vop_remove_args /* {
671 		struct vnode *a_dvp;
672 		struct vnode *a_vp;
673 		struct componentname *a_cnp;
674 	} */ *ap;
675 {
676 	struct vnode *vp = ap->a_vp;
677 	struct devfs_dirent *dd;
678 	struct devfs_dirent *de;
679 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
680 
681 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
682 	dd = ap->a_dvp->v_data;
683 	de = vp->v_data;
684 	if (de->de_dirent->d_type == DT_LNK) {
685 		TAILQ_REMOVE(&dd->de_dlist, de, de_list);
686 		if (de->de_vnode)
687 			de->de_vnode->v_data = NULL;
688 #ifdef MAC
689 		mac_destroy_devfsdirent(de);
690 #endif
691 		FREE(de, M_DEVFS);
692 	} else {
693 		de->de_flags |= DE_WHITEOUT;
694 	}
695 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
696 	return (0);
697 }
698 
699 /*
700  * Revoke is called on a tty when a terminal session ends.  The vnode
701  * is orphaned by setting v_op to deadfs so we need to let go of it
702  * as well so that we create a new one next time around.
703  */
704 static int
705 devfs_revoke(ap)
706 	struct vop_revoke_args /* {
707 		struct vnode *a_vp;
708 		int a_flags;
709 	} */ *ap;
710 {
711 	struct vnode *vp = ap->a_vp;
712 	struct devfs_dirent *de;
713 
714 	de = vp->v_data;
715 	de->de_vnode = NULL;
716 	vop_revoke(ap);
717 	return (0);
718 }
719 
720 static int
721 devfs_setattr(ap)
722 	struct vop_setattr_args /* {
723 		struct vnode *a_vp;
724 		struct vattr *a_vap;
725 		struct ucred *a_cred;
726 		struct proc *a_p;
727 	} */ *ap;
728 {
729 	struct devfs_dirent *de;
730 	struct vattr *vap;
731 	struct vnode *vp;
732 	int c, error;
733 	uid_t uid;
734 	gid_t gid;
735 
736 	vap = ap->a_vap;
737 	vp = ap->a_vp;
738 	if ((vap->va_type != VNON) ||
739 	    (vap->va_nlink != VNOVAL) ||
740 	    (vap->va_fsid != VNOVAL) ||
741 	    (vap->va_fileid != VNOVAL) ||
742 	    (vap->va_blocksize != VNOVAL) ||
743 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
744 	    (vap->va_rdev != VNOVAL) ||
745 	    ((int)vap->va_bytes != VNOVAL) ||
746 	    (vap->va_gen != VNOVAL)) {
747 		return (EINVAL);
748 	}
749 
750 	de = vp->v_data;
751 	if (vp->v_type == VDIR)
752 		de = de->de_dir;
753 
754 	error = c = 0;
755 	if (vap->va_uid == (uid_t)VNOVAL)
756 		uid = de->de_uid;
757 	else
758 		uid = vap->va_uid;
759 	if (vap->va_gid == (gid_t)VNOVAL)
760 		gid = de->de_gid;
761 	else
762 		gid = vap->va_gid;
763 	if (uid != de->de_uid || gid != de->de_gid) {
764 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
765 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
766 		    (error = suser_cred(ap->a_td->td_ucred, PRISON_ROOT)) != 0)
767 			return (error);
768 		de->de_uid = uid;
769 		de->de_gid = gid;
770 		c = 1;
771 	}
772 
773 	if (vap->va_mode != (mode_t)VNOVAL) {
774 		if ((ap->a_cred->cr_uid != de->de_uid) &&
775 		    (error = suser_cred(ap->a_td->td_ucred, PRISON_ROOT)))
776 			return (error);
777 		de->de_mode = vap->va_mode;
778 		c = 1;
779 	}
780 
781 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
782 		/* See the comment in ufs_vnops::ufs_setattr(). */
783 		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)) &&
784 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
785 		    (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, ap->a_td))))
786 			return (error);
787 		if (vap->va_atime.tv_sec != VNOVAL) {
788 			if (vp->v_type == VCHR)
789 				vp->v_rdev->si_atime = vap->va_atime;
790 			else
791 				de->de_atime = vap->va_atime;
792 		}
793 		if (vap->va_mtime.tv_sec != VNOVAL) {
794 			if (vp->v_type == VCHR)
795 				vp->v_rdev->si_mtime = vap->va_mtime;
796 			else
797 				de->de_mtime = vap->va_mtime;
798 		}
799 		c = 1;
800 	}
801 
802 	if (c) {
803 		if (vp->v_type == VCHR)
804 			vfs_timestamp(&vp->v_rdev->si_ctime);
805 		else
806 			vfs_timestamp(&de->de_mtime);
807 	}
808 	return (0);
809 }
810 
811 #ifdef MAC
812 static int
813 devfs_setlabel(ap)
814 	struct vop_setlabel_args /* {
815 		struct vnode *a_vp;
816 		struct mac *a_label;
817 		struct ucred *a_cred;
818 		struct thread *a_td;
819 	} */ *ap;
820 {
821 	struct vnode *vp;
822 	struct devfs_dirent *de;
823 
824 	vp = ap->a_vp;
825 	de = vp->v_data;
826 
827 	mac_relabel_vnode(ap->a_cred, vp, ap->a_label);
828 	mac_update_devfsdirent(vp->v_mount, de, vp);
829 
830 	return (0);
831 }
832 #endif
833 
834 static int
835 devfs_symlink(ap)
836 	struct vop_symlink_args /* {
837 		struct vnode *a_dvp;
838 		struct vnode **a_vpp;
839 		struct componentname *a_cnp;
840 		struct vattr *a_vap;
841 		char *a_target;
842 	} */ *ap;
843 {
844 	int i, error;
845 	struct devfs_dirent *dd;
846 	struct devfs_dirent *de;
847 	struct devfs_mount *dmp;
848 
849 	error = suser(ap->a_cnp->cn_thread);
850 	if (error)
851 		return(error);
852 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
853 	dd = ap->a_dvp->v_data;
854 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
855 	de->de_uid = 0;
856 	de->de_gid = 0;
857 	de->de_mode = 0755;
858 	de->de_inode = dmp->dm_inode++;
859 	de->de_dirent->d_type = DT_LNK;
860 	i = strlen(ap->a_target) + 1;
861 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
862 	bcopy(ap->a_target, de->de_symlink, i);
863 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
864 #ifdef MAC
865 	mac_create_devfs_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
866 #endif
867 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
868 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
869 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
870 	return (0);
871 }
872 
873 static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
874 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
875 	{ &vop_access_desc,		(vop_t *) devfs_access },
876 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
877 	{ &vop_ioctl_desc,		(vop_t *) devfs_ioctl },
878 	{ &vop_lookup_desc,		(vop_t *) devfs_lookup },
879 	{ &vop_mknod_desc,		(vop_t *) devfs_mknod },
880 	{ &vop_pathconf_desc,		(vop_t *) devfs_pathconf },
881 	{ &vop_read_desc,		(vop_t *) devfs_read },
882 	{ &vop_readdir_desc,		(vop_t *) devfs_readdir },
883 	{ &vop_readlink_desc,		(vop_t *) devfs_readlink },
884 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
885 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
886 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
887 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
888 #ifdef MAC
889 	{ &vop_setlabel_desc,		(vop_t *) devfs_setlabel },
890 #endif
891 	{ &vop_symlink_desc,		(vop_t *) devfs_symlink },
892 	{ NULL, NULL }
893 };
894 static struct vnodeopv_desc devfs_vnodeop_opv_desc =
895 	{ &devfs_vnodeop_p, devfs_vnodeop_entries };
896 
897 VNODEOP_SET(devfs_vnodeop_opv_desc);
898 
899 static struct vnodeopv_entry_desc devfs_specop_entries[] = {
900 	{ &vop_default_desc,		(vop_t *) spec_vnoperate },
901 	{ &vop_access_desc,		(vop_t *) devfs_access },
902 	{ &vop_getattr_desc,		(vop_t *) devfs_getattr },
903 	{ &vop_pathconf_desc,		(vop_t *) devfs_pathconf },
904 	{ &vop_reclaim_desc,		(vop_t *) devfs_reclaim },
905 	{ &vop_remove_desc,		(vop_t *) devfs_remove },
906 	{ &vop_revoke_desc,		(vop_t *) devfs_revoke },
907 	{ &vop_setattr_desc,		(vop_t *) devfs_setattr },
908 #ifdef MAC
909 	{ &vop_setlabel_desc,		(vop_t *) devfs_setlabel },
910 #endif
911 	{ NULL, NULL }
912 };
913 static struct vnodeopv_desc devfs_specop_opv_desc =
914 	{ &devfs_specop_p, devfs_specop_entries };
915 
916 VNODEOP_SET(devfs_specop_opv_desc);
917