xref: /freebsd/sys/fs/devfs/devfs_vnops.c (revision e168b357aa7fe7ae2bb9b56373a3aada3ebf56d7)
1 /*-
2  * Copyright (c) 2000-2004
3  *	Poul-Henning Kamp.  All rights reserved.
4  * Copyright (c) 1989, 1992-1993, 1995
5  *	The Regents of the University of California.  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/fcntl.h>
52 #include <sys/file.h>
53 #include <sys/filedesc.h>
54 #include <sys/filio.h>
55 #include <sys/kernel.h>
56 #include <sys/lock.h>
57 #include <sys/mac.h>
58 #include <sys/malloc.h>
59 #include <sys/mount.h>
60 #include <sys/namei.h>
61 #include <sys/proc.h>
62 #include <sys/stat.h>
63 #include <sys/sx.h>
64 #include <sys/sysctl.h>
65 #include <sys/time.h>
66 #include <sys/ttycom.h>
67 #include <sys/unistd.h>
68 #include <sys/vnode.h>
69 
70 #include <fs/devfs/devfs.h>
71 
72 static fo_rdwr_t	devfs_read_f;
73 static fo_rdwr_t	devfs_write_f;
74 static fo_ioctl_t	devfs_ioctl_f;
75 static fo_poll_t	devfs_poll_f;
76 static fo_kqfilter_t	devfs_kqfilter_f;
77 static fo_stat_t	devfs_stat_f;
78 static fo_close_t	devfs_close_f;
79 
80 static struct fileops devfs_ops_f = {
81 	.fo_read =	devfs_read_f,
82 	.fo_write =	devfs_write_f,
83 	.fo_ioctl =	devfs_ioctl_f,
84 	.fo_poll =	devfs_poll_f,
85 	.fo_kqfilter =	devfs_kqfilter_f,
86 	.fo_stat =	devfs_stat_f,
87 	.fo_close =	devfs_close_f,
88 	.fo_flags =	DFLAG_PASSABLE | DFLAG_SEEKABLE
89 };
90 
91 static vop_access_t	devfs_access;
92 static vop_advlock_t	devfs_advlock;
93 static vop_close_t	devfs_close;
94 static vop_fsync_t	devfs_fsync;
95 static vop_getattr_t	devfs_getattr;
96 static vop_lookup_t	devfs_lookup;
97 static vop_lookup_t	devfs_lookupx;
98 static vop_mknod_t	devfs_mknod;
99 static vop_open_t	devfs_open;
100 static vop_pathconf_t	devfs_pathconf;
101 static vop_print_t	devfs_print;
102 static vop_readdir_t	devfs_readdir;
103 static vop_readlink_t	devfs_readlink;
104 static vop_reclaim_t	devfs_reclaim;
105 static vop_remove_t	devfs_remove;
106 static vop_revoke_t	devfs_revoke;
107 static vop_ioctl_t	devfs_rioctl;
108 static vop_read_t	devfs_rread;
109 static vop_setattr_t	devfs_setattr;
110 #ifdef MAC
111 static vop_setlabel_t	devfs_setlabel;
112 #endif
113 static vop_symlink_t	devfs_symlink;
114 
115 static struct vop_vector devfs_vnodeops = {
116 	.vop_default =		&default_vnodeops,
117 
118 	.vop_access =		devfs_access,
119 	.vop_getattr =		devfs_getattr,
120 	.vop_ioctl =		devfs_rioctl,
121 	.vop_lookup =		devfs_lookup,
122 	.vop_mknod =		devfs_mknod,
123 	.vop_pathconf =		devfs_pathconf,
124 	.vop_read =		devfs_rread,
125 	.vop_readdir =		devfs_readdir,
126 	.vop_readlink =		devfs_readlink,
127 	.vop_reclaim =		devfs_reclaim,
128 	.vop_remove =		devfs_remove,
129 	.vop_revoke =		devfs_revoke,
130 	.vop_setattr =		devfs_setattr,
131 #ifdef MAC
132 	.vop_setlabel =		devfs_setlabel,
133 #endif
134 	.vop_symlink =		devfs_symlink,
135 };
136 
137 static struct vop_vector devfs_specops = {
138 	.vop_default =		&default_vnodeops,
139 
140 	.vop_access =		devfs_access,
141 	.vop_advlock =		devfs_advlock,
142 	.vop_bmap =		VOP_PANIC,
143 	.vop_close =		devfs_close,
144 	.vop_create =		VOP_PANIC,
145 	.vop_fsync =		devfs_fsync,
146 	.vop_getattr =		devfs_getattr,
147 	.vop_lease =		VOP_NULL,
148 	.vop_link =		VOP_PANIC,
149 	.vop_mkdir =		VOP_PANIC,
150 	.vop_mknod =		VOP_PANIC,
151 	.vop_open =		devfs_open,
152 	.vop_pathconf =		devfs_pathconf,
153 	.vop_print =		devfs_print,
154 	.vop_read =		VOP_PANIC,
155 	.vop_readdir =		VOP_PANIC,
156 	.vop_readlink =		VOP_PANIC,
157 	.vop_reallocblks =	VOP_PANIC,
158 	.vop_reclaim =		devfs_reclaim,
159 	.vop_remove =		devfs_remove,
160 	.vop_rename =		VOP_PANIC,
161 	.vop_revoke =		devfs_revoke,
162 	.vop_rmdir =		VOP_PANIC,
163 	.vop_setattr =		devfs_setattr,
164 #ifdef MAC
165 	.vop_setlabel =		devfs_setlabel,
166 #endif
167 	.vop_strategy =		VOP_PANIC,
168 	.vop_symlink =		VOP_PANIC,
169 	.vop_write =		VOP_PANIC,
170 };
171 
172 static u_int
173 devfs_random(void)
174 {
175 	static u_int devfs_seed;
176 
177 	while (devfs_seed == 0) {
178 		/*
179 		 * Make sure people don't make stupid assumptions
180 		 * about device major/minor numbers in userspace.
181 		 * We do this late to get entropy and for the same
182 		 * reason we force a reseed, but it may not be
183 		 * late enough for entropy to be available.
184 		 */
185 		arc4rand(&devfs_seed, sizeof devfs_seed, 1);
186 		devfs_seed &= 0xf0f;
187 	}
188 	return (devfs_seed);
189 }
190 
191 static int
192 devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp)
193 {
194 
195 	*devp = fp->f_vnode->v_rdev;
196 	if (*devp != fp->f_data)
197 		return (ENXIO);
198 	KASSERT((*devp)->si_refcount > 0,
199 	    ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
200 	*dswp = dev_refthread(*devp);
201 	if (*dswp == NULL)
202 		return (ENXIO);
203 	return (0);
204 }
205 
206 /*
207  * Construct the fully qualified path name relative to the mountpoint
208  */
209 static char *
210 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
211 {
212 	int i;
213 	struct devfs_dirent *de, *dd;
214 	struct devfs_mount *dmp;
215 
216 	dmp = VFSTODEVFS(dvp->v_mount);
217 	dd = dvp->v_data;
218 	i = SPECNAMELEN;
219 	buf[i] = '\0';
220 	i -= cnp->cn_namelen;
221 	if (i < 0)
222 		 return (NULL);
223 	bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
224 	de = dd;
225 	while (de != dmp->dm_basedir) {
226 		i--;
227 		if (i < 0)
228 			 return (NULL);
229 		buf[i] = '/';
230 		i -= de->de_dirent->d_namlen;
231 		if (i < 0)
232 			 return (NULL);
233 		bcopy(de->de_dirent->d_name, buf + i,
234 		    de->de_dirent->d_namlen);
235 		de = TAILQ_FIRST(&de->de_dlist);	/* "." */
236 		de = TAILQ_NEXT(de, de_list);		/* ".." */
237 		de = de->de_dir;
238 	}
239 	return (buf + i);
240 }
241 
242 int
243 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct thread *td)
244 {
245 	int error;
246 	struct vnode *vp;
247 	struct cdev *dev;
248 
249 	KASSERT(td == curthread, ("devfs_allocv: td != curthread"));
250 loop:
251 	vp = de->de_vnode;
252 	if (vp != NULL) {
253 		if (vget(vp, LK_EXCLUSIVE, td))
254 			goto loop;
255 		*vpp = vp;
256 		return (0);
257 	}
258 	if (de->de_dirent->d_type == DT_CHR) {
259 		dev = *devfs_itod(de->de_inode);
260 		if (dev == NULL)
261 			return (ENOENT);
262 	} else {
263 		dev = NULL;
264 	}
265 	error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
266 	if (error != 0) {
267 		printf("devfs_allocv: failed to allocate new vnode\n");
268 		return (error);
269 	}
270 
271 	if (de->de_dirent->d_type == DT_CHR) {
272 		vp->v_type = VCHR;
273 		VI_LOCK(vp);
274 		dev_lock();
275 		dev_refl(dev);
276 		vp->v_rdev = dev;
277 		LIST_INSERT_HEAD(&dev->si_alist, de, de_alias);
278 		dev->si_usecount += vp->v_usecount;
279 		dev_unlock();
280 		VI_UNLOCK(vp);
281 		vp->v_op = &devfs_specops;
282 	} else if (de->de_dirent->d_type == DT_DIR) {
283 		vp->v_type = VDIR;
284 	} else if (de->de_dirent->d_type == DT_LNK) {
285 		vp->v_type = VLNK;
286 	} else {
287 		vp->v_type = VBAD;
288 	}
289 	vp->v_data = de;
290 	de->de_vnode = vp;
291 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
292 #ifdef MAC
293 	mac_associate_vnode_devfs(mp, de, vp);
294 #endif
295 	*vpp = vp;
296 	return (0);
297 }
298 
299 static int
300 devfs_access(ap)
301 	struct vop_access_args /* {
302 		struct vnode *a_vp;
303 		int  a_mode;
304 		struct ucred *a_cred;
305 		struct thread *a_td;
306 	} */ *ap;
307 {
308 	struct vnode *vp = ap->a_vp;
309 	struct devfs_dirent *de;
310 	int error;
311 
312 	de = vp->v_data;
313 	if (vp->v_type == VDIR)
314 		de = de->de_dir;
315 
316 	error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
317 	    ap->a_mode, ap->a_cred, NULL);
318 	if (!error)
319 		return (error);
320 	if (error != EACCES)
321 		return (error);
322 	/* We do, however, allow access to the controlling terminal */
323 	if (!(ap->a_td->td_proc->p_flag & P_CONTROLT))
324 		return (error);
325 	if (ap->a_td->td_proc->p_session->s_ttyvp == de->de_vnode)
326 		return (0);
327 	return (error);
328 }
329 
330 /*
331  * Special device advisory byte-level locks.
332  */
333 /* ARGSUSED */
334 static int
335 devfs_advlock(ap)
336 	struct vop_advlock_args /* {
337 		struct vnode *a_vp;
338 		caddr_t  a_id;
339 		int  a_op;
340 		struct flock *a_fl;
341 		int  a_flags;
342 	} */ *ap;
343 {
344 
345 	return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
346 }
347 
348 /*
349  * Device close routine
350  */
351 /* ARGSUSED */
352 static int
353 devfs_close(ap)
354 	struct vop_close_args /* {
355 		struct vnode *a_vp;
356 		int  a_fflag;
357 		struct ucred *a_cred;
358 		struct thread *a_td;
359 	} */ *ap;
360 {
361 	struct vnode *vp = ap->a_vp, *oldvp;
362 	struct thread *td = ap->a_td;
363 	struct cdev *dev = vp->v_rdev;
364 	struct cdevsw *dsw;
365 	int error;
366 
367 	/*
368 	 * Hack: a tty device that is a controlling terminal
369 	 * has a reference from the session structure.
370 	 * We cannot easily tell that a character device is
371 	 * a controlling terminal, unless it is the closing
372 	 * process' controlling terminal.  In that case,
373 	 * if the reference count is 2 (this last descriptor
374 	 * plus the session), release the reference from the session.
375 	 */
376 
377 	/*
378 	 * This needs to be rewritten to take the vp interlock into
379 	 * consideration.
380 	 */
381 
382 	oldvp = NULL;
383 	sx_xlock(&proctree_lock);
384 	if (td && vp == td->td_proc->p_session->s_ttyvp) {
385 		SESS_LOCK(td->td_proc->p_session);
386 		VI_LOCK(vp);
387 		if (count_dev(dev) == 2 && (vp->v_iflag & VI_DOOMED) == 0) {
388 			td->td_proc->p_session->s_ttyvp = NULL;
389 			oldvp = vp;
390 		}
391 		VI_UNLOCK(vp);
392 		SESS_UNLOCK(td->td_proc->p_session);
393 	}
394 	sx_xunlock(&proctree_lock);
395 	if (oldvp != NULL)
396 		vrele(oldvp);
397 	/*
398 	 * We do not want to really close the device if it
399 	 * is still in use unless we are trying to close it
400 	 * forcibly. Since every use (buffer, vnode, swap, cmap)
401 	 * holds a reference to the vnode, and because we mark
402 	 * any other vnodes that alias this device, when the
403 	 * sum of the reference counts on all the aliased
404 	 * vnodes descends to one, we are on last close.
405 	 */
406 	dsw = dev_refthread(dev);
407 	if (dsw == NULL)
408 		return (ENXIO);
409 	VI_LOCK(vp);
410 	if (vp->v_iflag & VI_DOOMED) {
411 		/* Forced close. */
412 	} else if (dsw->d_flags & D_TRACKCLOSE) {
413 		/* Keep device updated on status. */
414 	} else if (count_dev(dev) > 1) {
415 		VI_UNLOCK(vp);
416 		dev_relthread(dev);
417 		return (0);
418 	}
419 	VI_UNLOCK(vp);
420 	KASSERT(dev->si_refcount > 0,
421 	    ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
422 	if (!(dsw->d_flags & D_NEEDGIANT)) {
423 		DROP_GIANT();
424 		error = dsw->d_close(dev, ap->a_fflag, S_IFCHR, td);
425 		PICKUP_GIANT();
426 	} else {
427 		mtx_lock(&Giant);
428 		error = dsw->d_close(dev, ap->a_fflag, S_IFCHR, td);
429 		mtx_unlock(&Giant);
430 	}
431 	dev_relthread(dev);
432 	return (error);
433 }
434 
435 static int
436 devfs_close_f(struct file *fp, struct thread *td)
437 {
438 
439 	return (vnops.fo_close(fp, td));
440 }
441 
442 /*
443  * Synch buffers associated with a block device
444  */
445 /* ARGSUSED */
446 static int
447 devfs_fsync(ap)
448 	struct vop_fsync_args /* {
449 		struct vnode *a_vp;
450 		struct ucred *a_cred;
451 		int  a_waitfor;
452 		struct thread *a_td;
453 	} */ *ap;
454 {
455 	if (!vn_isdisk(ap->a_vp, NULL))
456 		return (0);
457 
458 	return (vop_stdfsync(ap));
459 }
460 
461 static int
462 devfs_getattr(ap)
463 	struct vop_getattr_args /* {
464 		struct vnode *a_vp;
465 		struct vattr *a_vap;
466 		struct ucred *a_cred;
467 		struct thread *a_td;
468 	} */ *ap;
469 {
470 	struct vnode *vp = ap->a_vp;
471 	struct vattr *vap = ap->a_vap;
472 	int error = 0;
473 	struct devfs_dirent *de;
474 	struct cdev *dev;
475 
476 	de = vp->v_data;
477 	KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
478 	if (vp->v_type == VDIR) {
479 		de = de->de_dir;
480 		KASSERT(de != NULL,
481 		    ("Null dir dirent in devfs_getattr vp=%p", vp));
482 	}
483 	bzero((caddr_t) vap, sizeof(*vap));
484 	vattr_null(vap);
485 	vap->va_uid = de->de_uid;
486 	vap->va_gid = de->de_gid;
487 	vap->va_mode = de->de_mode;
488 	if (vp->v_type == VLNK)
489 		vap->va_size = strlen(de->de_symlink);
490 	else if (vp->v_type == VDIR)
491 		vap->va_size = vap->va_bytes = DEV_BSIZE;
492 	else
493 		vap->va_size = 0;
494 	if (vp->v_type != VDIR)
495 		vap->va_bytes = 0;
496 	vap->va_blocksize = DEV_BSIZE;
497 	vap->va_type = vp->v_type;
498 
499 #define fix(aa)							\
500 	do {							\
501 		if ((aa).tv_sec == 0) {				\
502 			(aa).tv_sec = boottime.tv_sec;		\
503 			(aa).tv_nsec = boottime.tv_usec * 1000; \
504 		}						\
505 	} while (0)
506 
507 	if (vp->v_type != VCHR)  {
508 		fix(de->de_atime);
509 		vap->va_atime = de->de_atime;
510 		fix(de->de_mtime);
511 		vap->va_mtime = de->de_mtime;
512 		fix(de->de_ctime);
513 		vap->va_ctime = de->de_ctime;
514 	} else {
515 		dev = vp->v_rdev;
516 		fix(dev->si_atime);
517 		vap->va_atime = dev->si_atime;
518 		fix(dev->si_mtime);
519 		vap->va_mtime = dev->si_mtime;
520 		fix(dev->si_ctime);
521 		vap->va_ctime = dev->si_ctime;
522 
523 		vap->va_rdev = dev->si_inode ^ devfs_random();
524 	}
525 	vap->va_gen = 0;
526 	vap->va_flags = 0;
527 	vap->va_nlink = de->de_links;
528 	vap->va_fileid = de->de_inode;
529 
530 	return (error);
531 }
532 
533 /*
534  * Device ioctl operation.
535  */
536 /* ARGSUSED */
537 static int
538 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
539 {
540 	struct cdev *dev;
541 	struct cdevsw *dsw;
542 	struct vnode *vp;
543 	struct vnode *vpold;
544 	int error, i;
545 	const char *p;
546 	struct fiodgname_arg *fgn;
547 
548 	error = devfs_fp_check(fp, &dev, &dsw);
549 	if (error)
550 		return (error);
551 
552 	if (com == FIODTYPE) {
553 		*(int *)data = dsw->d_flags & D_TYPEMASK;
554 		dev_relthread(dev);
555 		return (0);
556 	} else if (com == FIODGNAME) {
557 		fgn = data;
558 		p = devtoname(dev);
559 		i = strlen(p) + 1;
560 		if (i > fgn->len)
561 			return (EINVAL);
562 		return (copyout(p, fgn->buf, i));
563 	}
564 	if (dsw->d_flags & D_NEEDGIANT)
565 		mtx_lock(&Giant);
566 	error = dsw->d_ioctl(dev, com, data, fp->f_flag, td);
567 	if (dsw->d_flags & D_NEEDGIANT)
568 		mtx_unlock(&Giant);
569 	dev_relthread(dev);
570 	if (error == ENOIOCTL)
571 		error = ENOTTY;
572 	if (error == 0 && com == TIOCSCTTY) {
573 		vp = fp->f_vnode;
574 
575 		/* Do nothing if reassigning same control tty */
576 		sx_slock(&proctree_lock);
577 		if (td->td_proc->p_session->s_ttyvp == vp) {
578 			sx_sunlock(&proctree_lock);
579 			return (0);
580 		}
581 
582 		mtx_lock(&Giant);
583 
584 		vpold = td->td_proc->p_session->s_ttyvp;
585 		VREF(vp);
586 		SESS_LOCK(td->td_proc->p_session);
587 		td->td_proc->p_session->s_ttyvp = vp;
588 		SESS_UNLOCK(td->td_proc->p_session);
589 
590 		sx_sunlock(&proctree_lock);
591 
592 		/* Get rid of reference to old control tty */
593 		if (vpold)
594 			vrele(vpold);
595 		mtx_unlock(&Giant);
596 	}
597 	return (error);
598 }
599 
600 
601 /* ARGSUSED */
602 static int
603 devfs_kqfilter_f(struct file *fp, struct knote *kn)
604 {
605 	struct cdev *dev;
606 	struct cdevsw *dsw;
607 	int error;
608 
609 	error = devfs_fp_check(fp, &dev, &dsw);
610 	if (error)
611 		return (error);
612 	if (dsw->d_flags & D_NEEDGIANT)
613 		mtx_lock(&Giant);
614 	error = dsw->d_kqfilter(dev, kn);
615 	if (dsw->d_flags & D_NEEDGIANT)
616 		mtx_unlock(&Giant);
617 	dev_relthread(dev);
618 	return (error);
619 }
620 
621 static int
622 devfs_lookupx(ap)
623 	struct vop_lookup_args /* {
624 		struct vnode * a_dvp;
625 		struct vnode ** a_vpp;
626 		struct componentname * a_cnp;
627 	} */ *ap;
628 {
629 	struct componentname *cnp;
630 	struct vnode *dvp, **vpp;
631 	struct thread *td;
632 	struct devfs_dirent *de, *dd;
633 	struct devfs_dirent **dde;
634 	struct devfs_mount *dmp;
635 	struct cdev *cdev;
636 	int error, flags, nameiop;
637 	char specname[SPECNAMELEN + 1], *pname;
638 
639 	cnp = ap->a_cnp;
640 	vpp = ap->a_vpp;
641 	dvp = ap->a_dvp;
642 	pname = cnp->cn_nameptr;
643 	td = cnp->cn_thread;
644 	flags = cnp->cn_flags;
645 	nameiop = cnp->cn_nameiop;
646 	dmp = VFSTODEVFS(dvp->v_mount);
647 	dd = dvp->v_data;
648 	*vpp = NULLVP;
649 
650 	if ((flags & ISLASTCN) && nameiop == RENAME)
651 		return (EOPNOTSUPP);
652 
653 	if (dvp->v_type != VDIR)
654 		return (ENOTDIR);
655 
656 	if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
657 		return (EIO);
658 
659 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
660 	if (error)
661 		return (error);
662 
663 	if (cnp->cn_namelen == 1 && *pname == '.') {
664 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
665 			return (EINVAL);
666 		*vpp = dvp;
667 		VREF(dvp);
668 		return (0);
669 	}
670 
671 	if (flags & ISDOTDOT) {
672 		if ((flags & ISLASTCN) && nameiop != LOOKUP)
673 			return (EINVAL);
674 		VOP_UNLOCK(dvp, 0, td);
675 		de = TAILQ_FIRST(&dd->de_dlist);	/* "." */
676 		de = TAILQ_NEXT(de, de_list);		/* ".." */
677 		de = de->de_dir;
678 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
679 		vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
680 		return (error);
681 	}
682 
683 	devfs_populate(dmp);
684 	dd = dvp->v_data;
685 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
686 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
687 			continue;
688 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
689 		    de->de_dirent->d_namlen) != 0)
690 			continue;
691 		if (de->de_flags & DE_WHITEOUT)
692 			goto notfound;
693 		goto found;
694 	}
695 
696 	if (nameiop == DELETE)
697 		goto notfound;
698 
699 	/*
700 	 * OK, we didn't have an entry for the name we were asked for
701 	 * so we try to see if anybody can create it on demand.
702 	 */
703 	pname = devfs_fqpn(specname, dvp, cnp);
704 	if (pname == NULL)
705 		goto notfound;
706 
707 	cdev = NULL;
708 	EVENTHANDLER_INVOKE(dev_clone, td->td_ucred, pname, strlen(pname),
709 	    &cdev);
710 	if (cdev == NULL)
711 		goto notfound;
712 
713 	devfs_populate(dmp);
714 
715 	dde = devfs_itode(dmp, cdev->si_inode);
716 	dev_rel(cdev);
717 
718 	if (dde == NULL || *dde == NULL || *dde == DE_DELETED)
719 		goto notfound;
720 
721 	if ((*dde)->de_flags & DE_WHITEOUT)
722 		goto notfound;
723 
724 	de = *dde;
725 	goto found;
726 
727 notfound:
728 
729 	if ((nameiop == CREATE || nameiop == RENAME) &&
730 	    (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
731 		cnp->cn_flags |= SAVENAME;
732 		return (EJUSTRETURN);
733 	}
734 	return (ENOENT);
735 
736 
737 found:
738 
739 	if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
740 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
741 		if (error)
742 			return (error);
743 		if (*vpp == dvp) {
744 			VREF(dvp);
745 			*vpp = dvp;
746 			return (0);
747 		}
748 		error = devfs_allocv(de, dvp->v_mount, vpp, td);
749 		if (error)
750 			return (error);
751 		return (0);
752 	}
753 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
754 	return (error);
755 }
756 
757 static int
758 devfs_lookup(struct vop_lookup_args *ap)
759 {
760 	int j;
761 	struct devfs_mount *dmp;
762 
763 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
764 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
765 	j = devfs_lookupx(ap);
766 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
767 	return (j);
768 }
769 
770 static int
771 devfs_mknod(struct vop_mknod_args *ap)
772 	/*
773 	struct vop_mknod_args {
774 		struct vnodeop_desc *a_desc;
775 		struct vnode *a_dvp;
776 		struct vnode **a_vpp;
777 		struct componentname *a_cnp;
778 		struct vattr *a_vap;
779 	}; */
780 {
781 	struct componentname *cnp;
782 	struct vnode *dvp, **vpp;
783 	struct thread *td;
784 	struct devfs_dirent *dd, *de;
785 	struct devfs_mount *dmp;
786 	int error;
787 
788 	/*
789 	 * The only type of node we should be creating here is a
790 	 * character device, for anything else return EOPNOTSUPP.
791 	 */
792 	if (ap->a_vap->va_type != VCHR)
793 		return (EOPNOTSUPP);
794 	dvp = ap->a_dvp;
795 	dmp = VFSTODEVFS(dvp->v_mount);
796 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
797 
798 	cnp = ap->a_cnp;
799 	vpp = ap->a_vpp;
800 	td = cnp->cn_thread;
801 	dd = dvp->v_data;
802 
803 	error = ENOENT;
804 	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
805 		if (cnp->cn_namelen != de->de_dirent->d_namlen)
806 			continue;
807 		if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
808 		    de->de_dirent->d_namlen) != 0)
809 			continue;
810 		if (de->de_flags & DE_WHITEOUT)
811 			break;
812 		goto notfound;
813 	}
814 	if (de == NULL)
815 		goto notfound;
816 	de->de_flags &= ~DE_WHITEOUT;
817 	error = devfs_allocv(de, dvp->v_mount, vpp, td);
818 notfound:
819 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
820 	return (error);
821 }
822 
823 /*
824  * Open a special file.
825  */
826 /* ARGSUSED */
827 static int
828 devfs_open(ap)
829 	struct vop_open_args /* {
830 		struct vnode *a_vp;
831 		int  a_mode;
832 		struct ucred *a_cred;
833 		struct thread *a_td;
834 		int a_fdidx;
835 	} */ *ap;
836 {
837 	struct thread *td = ap->a_td;
838 	struct vnode *vp = ap->a_vp;
839 	struct cdev *dev = vp->v_rdev;
840 	struct file *fp;
841 	int error;
842 	struct cdevsw *dsw;
843 
844 	if (vp->v_type == VBLK)
845 		return (ENXIO);
846 
847 	if (dev == NULL)
848 		return (ENXIO);
849 
850 	/* Make this field valid before any I/O in d_open. */
851 	if (dev->si_iosize_max == 0)
852 		dev->si_iosize_max = DFLTPHYS;
853 
854 	if (vn_isdisk(vp, NULL) &&
855 	    ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
856 		/*
857 		* When running in very secure mode, do not allow
858 		* opens for writing of any disks.
859 		* XXX: should be in geom_dev.c, but we lack the cred there.
860 		*/
861 		error = securelevel_ge(td->td_ucred, 2);
862 		if (error)
863 			return (error);
864 	}
865 
866 	dsw = dev_refthread(dev);
867 	if (dsw == NULL)
868 		return (ENXIO);
869 
870 	/* XXX: Special casing of ttys for deadfs.  Probably redundant. */
871 	if (dsw->d_flags & D_TTY)
872 		vp->v_vflag |= VV_ISTTY;
873 
874 	VOP_UNLOCK(vp, 0, td);
875 
876 	if(!(dsw->d_flags & D_NEEDGIANT)) {
877 		DROP_GIANT();
878 		if (dsw->d_fdopen != NULL)
879 			error = dsw->d_fdopen(dev, ap->a_mode, td, ap->a_fdidx);
880 		else
881 			error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
882 		PICKUP_GIANT();
883 	} else {
884 		mtx_lock(&Giant);
885 		if (dsw->d_fdopen != NULL)
886 			error = dsw->d_fdopen(dev, ap->a_mode, td, ap->a_fdidx);
887 		else
888 			error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
889 		mtx_unlock(&Giant);
890 	}
891 
892 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
893 
894 	dev_relthread(dev);
895 
896 	if (error)
897 		return (error);
898 
899 #if 0	/* /dev/console */
900 	KASSERT(ap->a_fdidx >= 0,
901 	     ("Could not vnode bypass device on fd %d", ap->a_fdidx));
902 #else
903 	if(ap->a_fdidx < 0)
904 		return (error);
905 #endif
906 	/*
907 	 * This is a pretty disgustingly long chain, but I am not
908 	 * sure there is any better way.  Passing the fdidx into
909 	 * VOP_OPEN() offers us more information than just passing
910 	 * the file *.
911 	 */
912 	fp = ap->a_td->td_proc->p_fd->fd_ofiles[ap->a_fdidx];
913 	KASSERT(fp->f_ops == &badfileops,
914 	     ("Could not vnode bypass device on fdops %p", fp->f_ops));
915 	fp->f_ops = &devfs_ops_f;
916 	fp->f_data = dev;
917 	return (error);
918 }
919 
920 static int
921 devfs_pathconf(ap)
922 	struct vop_pathconf_args /* {
923 		struct vnode *a_vp;
924 		int a_name;
925 		int *a_retval;
926 	} */ *ap;
927 {
928 
929 	switch (ap->a_name) {
930 	case _PC_NAME_MAX:
931 		*ap->a_retval = NAME_MAX;
932 		return (0);
933 	case _PC_PATH_MAX:
934 		*ap->a_retval = PATH_MAX;
935 		return (0);
936 	case _PC_MAC_PRESENT:
937 #ifdef MAC
938 		/*
939 		 * If MAC is enabled, devfs automatically supports
940 		 * trivial non-persistant label storage.
941 		 */
942 		*ap->a_retval = 1;
943 #else
944 		*ap->a_retval = 0;
945 #endif
946 		return (0);
947 	default:
948 		return (vop_stdpathconf(ap));
949 	}
950 	/* NOTREACHED */
951 }
952 
953 /* ARGSUSED */
954 static int
955 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
956 {
957 	struct cdev *dev;
958 	struct cdevsw *dsw;
959 	int error;
960 
961 	error = devfs_fp_check(fp, &dev, &dsw);
962 	if (error)
963 		return (error);
964 	if (dsw->d_flags & D_NEEDGIANT)
965 		mtx_lock(&Giant);
966 	error = dsw->d_poll(dev, events, td);
967 	if (dsw->d_flags & D_NEEDGIANT)
968 		mtx_unlock(&Giant);
969 	dev_relthread(dev);
970 	return(error);
971 }
972 
973 /*
974  * Print out the contents of a special device vnode.
975  */
976 static int
977 devfs_print(ap)
978 	struct vop_print_args /* {
979 		struct vnode *a_vp;
980 	} */ *ap;
981 {
982 
983 	printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
984 	return (0);
985 }
986 
987 /*
988  * Vnode op for read
989  */
990 /* ARGSUSED */
991 static int
992 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
993 {
994 	struct cdev *dev;
995 	int ioflag, error, resid;
996 	struct cdevsw *dsw;
997 
998 	error = devfs_fp_check(fp, &dev, &dsw);
999 	if (error)
1000 		return (error);
1001 	resid = uio->uio_resid;
1002 	ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
1003 	if (ioflag & O_DIRECT)
1004 		ioflag |= IO_DIRECT;
1005 
1006 	if ((flags & FOF_OFFSET) == 0)
1007 		uio->uio_offset = fp->f_offset;
1008 
1009 	if (dsw->d_flags & D_NEEDGIANT)
1010 		mtx_lock(&Giant);
1011 	error = dsw->d_read(dev, uio, ioflag);
1012 	if (dsw->d_flags & D_NEEDGIANT)
1013 		mtx_unlock(&Giant);
1014 	dev_relthread(dev);
1015 	if (uio->uio_resid != resid || (error == 0 && resid != 0))
1016 		vfs_timestamp(&dev->si_atime);
1017 
1018 	if ((flags & FOF_OFFSET) == 0)
1019 		fp->f_offset = uio->uio_offset;
1020 	fp->f_nextoff = uio->uio_offset;
1021 	return (error);
1022 }
1023 
1024 static int
1025 devfs_readdir(ap)
1026 	struct vop_readdir_args /* {
1027 		struct vnode *a_vp;
1028 		struct uio *a_uio;
1029 		struct ucred *a_cred;
1030 		int *a_eofflag;
1031 		int *a_ncookies;
1032 		u_long **a_cookies;
1033 	} */ *ap;
1034 {
1035 	int error;
1036 	struct uio *uio;
1037 	struct dirent *dp;
1038 	struct devfs_dirent *dd;
1039 	struct devfs_dirent *de;
1040 	struct devfs_mount *dmp;
1041 	off_t off, oldoff;
1042 	int ncookies = 0;
1043 	u_long *cookiebuf, *cookiep;
1044 	struct dirent *dps, *dpe;
1045 
1046 	if (ap->a_vp->v_type != VDIR)
1047 		return (ENOTDIR);
1048 
1049 	uio = ap->a_uio;
1050 	if (uio->uio_offset < 0)
1051 		return (EINVAL);
1052 
1053 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
1054 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
1055 	devfs_populate(dmp);
1056 	error = 0;
1057 	de = ap->a_vp->v_data;
1058 	off = 0;
1059 	oldoff = uio->uio_offset;
1060 	TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
1061 		if (dd->de_flags & DE_WHITEOUT)
1062 			continue;
1063 		if (dd->de_dirent->d_type == DT_DIR)
1064 			de = dd->de_dir;
1065 		else
1066 			de = dd;
1067 		dp = dd->de_dirent;
1068 		if (dp->d_reclen > uio->uio_resid)
1069 			break;
1070 		dp->d_fileno = de->de_inode;
1071 		if (off >= uio->uio_offset) {
1072 			ncookies++;
1073 			error = uiomove(dp, dp->d_reclen, uio);
1074 			if (error)
1075 				break;
1076 		}
1077 		off += dp->d_reclen;
1078 	}
1079 	if( !error && ap->a_ncookies != NULL && ap->a_cookies != NULL ) {
1080 		MALLOC(cookiebuf, u_long *, ncookies * sizeof(u_long),
1081 		       M_TEMP, M_WAITOK);
1082 		cookiep = cookiebuf;
1083 		dps = (struct dirent *)((char *)uio->uio_iov->iov_base -
1084 		    (uio->uio_offset - oldoff));
1085 		dpe = (struct dirent *) uio->uio_iov->iov_base;
1086 		for( dp = dps;
1087 			dp < dpe;
1088 			dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
1089 				oldoff += dp->d_reclen;
1090 				*cookiep++ = (u_long) oldoff;
1091 		}
1092 		*ap->a_ncookies = ncookies;
1093 		*ap->a_cookies = cookiebuf;
1094 	}
1095 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
1096 	uio->uio_offset = off;
1097 	return (error);
1098 }
1099 
1100 static int
1101 devfs_readlink(ap)
1102 	struct vop_readlink_args /* {
1103 		struct vnode *a_vp;
1104 		struct uio *a_uio;
1105 		struct ucred *a_cead;
1106 	} */ *ap;
1107 {
1108 	int error;
1109 	struct devfs_dirent *de;
1110 
1111 	de = ap->a_vp->v_data;
1112 	error = uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio);
1113 	return (error);
1114 }
1115 
1116 static int
1117 devfs_reclaim(ap)
1118 	struct vop_reclaim_args /* {
1119 		struct vnode *a_vp;
1120 	} */ *ap;
1121 {
1122 	struct vnode *vp = ap->a_vp;
1123 	struct devfs_dirent *de;
1124 	struct cdev *dev;
1125 
1126 	de = vp->v_data;
1127 	if (de != NULL)
1128 		de->de_vnode = NULL;
1129 	vp->v_data = NULL;
1130 	vnode_destroy_vobject(vp);
1131 
1132 	dev = vp->v_rdev;
1133 	vp->v_rdev = NULL;
1134 
1135 	if (dev == NULL)
1136 		return (0);
1137 
1138 	dev_lock();
1139 	if (de != NULL)
1140 		LIST_REMOVE(de, de_alias);
1141 	dev->si_usecount -= vp->v_usecount;
1142 	dev_unlock();
1143 	dev_rel(dev);
1144 	return (0);
1145 }
1146 
1147 static int
1148 devfs_remove(ap)
1149 	struct vop_remove_args /* {
1150 		struct vnode *a_dvp;
1151 		struct vnode *a_vp;
1152 		struct componentname *a_cnp;
1153 	} */ *ap;
1154 {
1155 	struct vnode *vp = ap->a_vp;
1156 	struct devfs_dirent *dd;
1157 	struct devfs_dirent *de;
1158 	struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
1159 
1160 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curthread);
1161 	dd = ap->a_dvp->v_data;
1162 	de = vp->v_data;
1163 	if (de->de_dirent->d_type == DT_LNK) {
1164 		TAILQ_REMOVE(&dd->de_dlist, de, de_list);
1165 		if (de->de_vnode)
1166 			de->de_vnode->v_data = NULL;
1167 #ifdef MAC
1168 		mac_destroy_devfsdirent(de);
1169 #endif
1170 		FREE(de, M_DEVFS);
1171 	} else {
1172 		de->de_flags |= DE_WHITEOUT;
1173 	}
1174 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
1175 	return (0);
1176 }
1177 
1178 /*
1179  * Revoke is called on a tty when a terminal session ends.  The vnode
1180  * is orphaned by setting v_op to deadfs so we need to let go of it
1181  * as well so that we create a new one next time around.
1182  */
1183 static int
1184 devfs_revoke(ap)
1185 	struct vop_revoke_args /* {
1186 		struct vnode *a_vp;
1187 		int a_flags;
1188 	} */ *ap;
1189 {
1190 	struct vnode *vp = ap->a_vp;
1191 	struct cdev *dev;
1192 	struct devfs_dirent *de;
1193 
1194 	KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
1195 
1196 	dev = vp->v_rdev;
1197 	for (;;) {
1198 		dev_lock();
1199 		de = LIST_FIRST(&dev->si_alist);
1200 		dev_unlock();
1201 		if (de == NULL)
1202 			break;
1203 		vgone(de->de_vnode);
1204 	}
1205 	return (0);
1206 }
1207 
1208 static int
1209 devfs_rioctl(ap)
1210 	struct vop_ioctl_args /* {
1211 		struct vnode *a_vp;
1212 		u_long  a_command;
1213 		caddr_t  a_data;
1214 		int  a_fflag;
1215 		struct ucred *a_cred;
1216 		struct thread *a_td;
1217 	} */ *ap;
1218 {
1219 	int error;
1220 	struct devfs_mount *dmp;
1221 
1222 	dmp = VFSTODEVFS(ap->a_vp->v_mount);
1223 	lockmgr(&dmp->dm_lock, LK_SHARED, 0, curthread);
1224 	devfs_populate(dmp);
1225 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curthread);
1226 	error = devfs_rules_ioctl(ap->a_vp->v_mount, ap->a_command, ap->a_data,
1227 	    ap->a_td);
1228 	return (error);
1229 }
1230 
1231 static int
1232 devfs_rread(ap)
1233 	struct vop_read_args /* {
1234 		struct vnode *a_vp;
1235 		struct uio *a_uio;
1236 		int a_ioflag;
1237 		struct ucred *a_cred;
1238 	} */ *ap;
1239 {
1240 
1241 	if (ap->a_vp->v_type != VDIR)
1242 		return (EINVAL);
1243 	return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
1244 }
1245 
1246 static int
1247 devfs_setattr(ap)
1248 	struct vop_setattr_args /* {
1249 		struct vnode *a_vp;
1250 		struct vattr *a_vap;
1251 		struct ucred *a_cred;
1252 		struct proc *a_p;
1253 	} */ *ap;
1254 {
1255 	struct devfs_dirent *de;
1256 	struct vattr *vap;
1257 	struct vnode *vp;
1258 	int c, error;
1259 	uid_t uid;
1260 	gid_t gid;
1261 
1262 	vap = ap->a_vap;
1263 	vp = ap->a_vp;
1264 	if ((vap->va_type != VNON) ||
1265 	    (vap->va_nlink != VNOVAL) ||
1266 	    (vap->va_fsid != VNOVAL) ||
1267 	    (vap->va_fileid != VNOVAL) ||
1268 	    (vap->va_blocksize != VNOVAL) ||
1269 	    (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
1270 	    (vap->va_rdev != VNOVAL) ||
1271 	    ((int)vap->va_bytes != VNOVAL) ||
1272 	    (vap->va_gen != VNOVAL)) {
1273 		return (EINVAL);
1274 	}
1275 
1276 	de = vp->v_data;
1277 	if (vp->v_type == VDIR)
1278 		de = de->de_dir;
1279 
1280 	error = c = 0;
1281 	if (vap->va_uid == (uid_t)VNOVAL)
1282 		uid = de->de_uid;
1283 	else
1284 		uid = vap->va_uid;
1285 	if (vap->va_gid == (gid_t)VNOVAL)
1286 		gid = de->de_gid;
1287 	else
1288 		gid = vap->va_gid;
1289 	if (uid != de->de_uid || gid != de->de_gid) {
1290 		if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
1291 		    (gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
1292 		    (error = suser_cred(ap->a_td->td_ucred, SUSER_ALLOWJAIL)) != 0)
1293 			return (error);
1294 		de->de_uid = uid;
1295 		de->de_gid = gid;
1296 		c = 1;
1297 	}
1298 
1299 	if (vap->va_mode != (mode_t)VNOVAL) {
1300 		if ((ap->a_cred->cr_uid != de->de_uid) &&
1301 		    (error = suser_cred(ap->a_td->td_ucred, SUSER_ALLOWJAIL)))
1302 			return (error);
1303 		de->de_mode = vap->va_mode;
1304 		c = 1;
1305 	}
1306 
1307 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
1308 		/* See the comment in ufs_vnops::ufs_setattr(). */
1309 		if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, ap->a_td)) &&
1310 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
1311 		    (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, ap->a_td))))
1312 			return (error);
1313 		if (vap->va_atime.tv_sec != VNOVAL) {
1314 			if (vp->v_type == VCHR)
1315 				vp->v_rdev->si_atime = vap->va_atime;
1316 			else
1317 				de->de_atime = vap->va_atime;
1318 		}
1319 		if (vap->va_mtime.tv_sec != VNOVAL) {
1320 			if (vp->v_type == VCHR)
1321 				vp->v_rdev->si_mtime = vap->va_mtime;
1322 			else
1323 				de->de_mtime = vap->va_mtime;
1324 		}
1325 		c = 1;
1326 	}
1327 
1328 	if (c) {
1329 		if (vp->v_type == VCHR)
1330 			vfs_timestamp(&vp->v_rdev->si_ctime);
1331 		else
1332 			vfs_timestamp(&de->de_mtime);
1333 	}
1334 	return (0);
1335 }
1336 
1337 #ifdef MAC
1338 static int
1339 devfs_setlabel(ap)
1340 	struct vop_setlabel_args /* {
1341 		struct vnode *a_vp;
1342 		struct mac *a_label;
1343 		struct ucred *a_cred;
1344 		struct thread *a_td;
1345 	} */ *ap;
1346 {
1347 	struct vnode *vp;
1348 	struct devfs_dirent *de;
1349 
1350 	vp = ap->a_vp;
1351 	de = vp->v_data;
1352 
1353 	mac_relabel_vnode(ap->a_cred, vp, ap->a_label);
1354 	mac_update_devfsdirent(vp->v_mount, de, vp);
1355 
1356 	return (0);
1357 }
1358 #endif
1359 
1360 static int
1361 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
1362 {
1363 
1364 	return (vnops.fo_stat(fp, sb, cred, td));
1365 }
1366 
1367 static int
1368 devfs_symlink(ap)
1369 	struct vop_symlink_args /* {
1370 		struct vnode *a_dvp;
1371 		struct vnode **a_vpp;
1372 		struct componentname *a_cnp;
1373 		struct vattr *a_vap;
1374 		char *a_target;
1375 	} */ *ap;
1376 {
1377 	int i, error;
1378 	struct devfs_dirent *dd;
1379 	struct devfs_dirent *de;
1380 	struct devfs_mount *dmp;
1381 	struct thread *td;
1382 
1383 	td = ap->a_cnp->cn_thread;
1384 	KASSERT(td == curthread, ("devfs_symlink: td != curthread"));
1385 	error = suser(td);
1386 	if (error)
1387 		return(error);
1388 	dmp = VFSTODEVFS(ap->a_dvp->v_mount);
1389 	dd = ap->a_dvp->v_data;
1390 	de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
1391 	de->de_uid = 0;
1392 	de->de_gid = 0;
1393 	de->de_mode = 0755;
1394 	de->de_inode = dmp->dm_inode++;
1395 	de->de_dirent->d_type = DT_LNK;
1396 	i = strlen(ap->a_target) + 1;
1397 	MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
1398 	bcopy(ap->a_target, de->de_symlink, i);
1399 	lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, td);
1400 #ifdef MAC
1401 	mac_create_devfs_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
1402 #endif
1403 	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
1404 	devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, td);
1405 	lockmgr(&dmp->dm_lock, LK_RELEASE, 0, td);
1406 	return (0);
1407 }
1408 
1409 /*
1410  * Vnode op for write
1411  */
1412 /* ARGSUSED */
1413 static int
1414 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
1415 {
1416 	struct cdev *dev;
1417 	struct vnode *vp;
1418 	int error, ioflag, resid;
1419 	struct cdevsw *dsw;
1420 
1421 	error = devfs_fp_check(fp, &dev, &dsw);
1422 	if (error)
1423 		return (error);
1424 	KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
1425 	vp = fp->f_vnode;
1426 	ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
1427 	if (ioflag & O_DIRECT)
1428 		ioflag |= IO_DIRECT;
1429 	if ((flags & FOF_OFFSET) == 0)
1430 		uio->uio_offset = fp->f_offset;
1431 
1432 	resid = uio->uio_resid;
1433 
1434 	if (dsw->d_flags & D_NEEDGIANT)
1435 		mtx_lock(&Giant);
1436 	error = dsw->d_write(dev, uio, ioflag);
1437 	if (dsw->d_flags & D_NEEDGIANT)
1438 		mtx_unlock(&Giant);
1439 	dev_relthread(dev);
1440 	if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
1441 		vfs_timestamp(&dev->si_ctime);
1442 		dev->si_mtime = dev->si_ctime;
1443 	}
1444 
1445 	if ((flags & FOF_OFFSET) == 0)
1446 		fp->f_offset = uio->uio_offset;
1447 	fp->f_nextoff = uio->uio_offset;
1448 	return (error);
1449 }
1450 
1451 dev_t
1452 dev2udev(struct cdev *x)
1453 {
1454 	if (x == NULL)
1455 		return (NODEV);
1456 	return (x->si_inode ^ devfs_random());
1457 }
1458 
1459 /*
1460  * Helper sysctl for devname(3).  We're given a struct cdev * and return
1461  * the name, if any, registered by the device driver.
1462  */
1463 static int
1464 sysctl_devname(SYSCTL_HANDLER_ARGS)
1465 {
1466 	int error;
1467 	dev_t ud;
1468 	struct cdev *dev, **dp;
1469 
1470 	error = SYSCTL_IN(req, &ud, sizeof (ud));
1471 	if (error)
1472 		return (error);
1473 	if (ud == NODEV)
1474 		return(EINVAL);
1475 	dp = devfs_itod(ud ^ devfs_random());
1476 	if (dp == NULL)
1477 		return(ENOENT);
1478 	dev = *dp;
1479 	if (dev == NULL)
1480 		return(ENOENT);
1481 	return(SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1));
1482 	return (error);
1483 }
1484 
1485 SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY,
1486 	NULL, 0, sysctl_devname, "", "devname(3) handler");
1487 
1488 /*
1489  * Our calling convention to the device drivers used to be that we passed
1490  * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_
1491  * flags instead since that's what open(), close() and ioctl() takes and
1492  * we don't really want vnode.h in device drivers.
1493  * We solved the source compatibility by redefining some vnode flags to
1494  * be the same as the fcntl ones and by sending down the bitwise OR of
1495  * the respective fcntl/vnode flags.  These CTASSERTS make sure nobody
1496  * pulls the rug out under this.
1497  */
1498 CTASSERT(O_NONBLOCK == IO_NDELAY);
1499 CTASSERT(O_FSYNC == IO_SYNC);
1500