1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2000-2004
5 * Poul-Henning Kamp. All rights reserved.
6 * Copyright (c) 1989, 1992-1993, 1995
7 * The Regents of the University of California. All rights reserved.
8 *
9 * This code is derived from software donated to Berkeley by
10 * Jan-Simon Pendry.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95
34 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43
35 *
36 * $FreeBSD$
37 */
38
39 /*
40 * TODO:
41 * mkdir: want it ?
42 */
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/conf.h>
47 #include <sys/dirent.h>
48 #include <sys/fcntl.h>
49 #include <sys/file.h>
50 #include <sys/filedesc.h>
51 #include <sys/filio.h>
52 #include <sys/jail.h>
53 #include <sys/kernel.h>
54 #include <sys/limits.h>
55 #include <sys/lock.h>
56 #include <sys/malloc.h>
57 #include <sys/mman.h>
58 #include <sys/mount.h>
59 #include <sys/namei.h>
60 #include <sys/priv.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 static struct vop_vector devfs_vnodeops;
71 static struct vop_vector devfs_specops;
72 static struct fileops devfs_ops_f;
73
74 #include <fs/devfs/devfs.h>
75 #include <fs/devfs/devfs_int.h>
76
77 #include <security/mac/mac_framework.h>
78
79 #include <vm/vm.h>
80 #include <vm/vm_extern.h>
81 #include <vm/vm_object.h>
82
83 static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data");
84
85 struct mtx devfs_de_interlock;
86 MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF);
87 struct sx clone_drain_lock;
88 SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock");
89 struct mtx cdevpriv_mtx;
90 MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF);
91
92 SYSCTL_DECL(_vfs_devfs);
93
94 static int devfs_dotimes;
95 SYSCTL_INT(_vfs_devfs, OID_AUTO, dotimes, CTLFLAG_RW,
96 &devfs_dotimes, 0, "Update timestamps on DEVFS with default precision");
97
98 /*
99 * Update devfs node timestamp. Note that updates are unlocked and
100 * stat(2) could see partially updated times.
101 */
102 static void
devfs_timestamp(struct timespec * tsp)103 devfs_timestamp(struct timespec *tsp)
104 {
105 time_t ts;
106
107 if (devfs_dotimes) {
108 vfs_timestamp(tsp);
109 } else {
110 ts = time_second;
111 if (tsp->tv_sec != ts) {
112 tsp->tv_sec = ts;
113 tsp->tv_nsec = 0;
114 }
115 }
116 }
117
118 static int
devfs_fp_check(struct file * fp,struct cdev ** devp,struct cdevsw ** dswp,int * ref)119 devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp,
120 int *ref)
121 {
122
123 *dswp = devvn_refthread(fp->f_vnode, devp, ref);
124 if (*devp != fp->f_data) {
125 if (*dswp != NULL)
126 dev_relthread(*devp, *ref);
127 return (ENXIO);
128 }
129 KASSERT((*devp)->si_refcount > 0,
130 ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
131 if (*dswp == NULL)
132 return (ENXIO);
133 curthread->td_fpop = fp;
134 return (0);
135 }
136
137 int
devfs_get_cdevpriv(void ** datap)138 devfs_get_cdevpriv(void **datap)
139 {
140 struct file *fp;
141 struct cdev_privdata *p;
142 int error;
143
144 fp = curthread->td_fpop;
145 if (fp == NULL)
146 return (EBADF);
147 p = fp->f_cdevpriv;
148 if (p != NULL) {
149 error = 0;
150 *datap = p->cdpd_data;
151 } else
152 error = ENOENT;
153 return (error);
154 }
155
156 int
devfs_set_cdevpriv(void * priv,d_priv_dtor_t * priv_dtr)157 devfs_set_cdevpriv(void *priv, d_priv_dtor_t *priv_dtr)
158 {
159 struct file *fp;
160 struct cdev_priv *cdp;
161 struct cdev_privdata *p;
162 int error;
163
164 fp = curthread->td_fpop;
165 if (fp == NULL)
166 return (ENOENT);
167 cdp = cdev2priv((struct cdev *)fp->f_data);
168 p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK);
169 p->cdpd_data = priv;
170 p->cdpd_dtr = priv_dtr;
171 p->cdpd_fp = fp;
172 mtx_lock(&cdevpriv_mtx);
173 if (fp->f_cdevpriv == NULL) {
174 LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list);
175 fp->f_cdevpriv = p;
176 mtx_unlock(&cdevpriv_mtx);
177 error = 0;
178 } else {
179 mtx_unlock(&cdevpriv_mtx);
180 free(p, M_CDEVPDATA);
181 error = EBUSY;
182 }
183 return (error);
184 }
185
186 void
devfs_destroy_cdevpriv(struct cdev_privdata * p)187 devfs_destroy_cdevpriv(struct cdev_privdata *p)
188 {
189
190 mtx_assert(&cdevpriv_mtx, MA_OWNED);
191 KASSERT(p->cdpd_fp->f_cdevpriv == p,
192 ("devfs_destoy_cdevpriv %p != %p", p->cdpd_fp->f_cdevpriv, p));
193 p->cdpd_fp->f_cdevpriv = NULL;
194 LIST_REMOVE(p, cdpd_list);
195 mtx_unlock(&cdevpriv_mtx);
196 (p->cdpd_dtr)(p->cdpd_data);
197 free(p, M_CDEVPDATA);
198 }
199
200 static void
devfs_fpdrop(struct file * fp)201 devfs_fpdrop(struct file *fp)
202 {
203 struct cdev_privdata *p;
204
205 mtx_lock(&cdevpriv_mtx);
206 if ((p = fp->f_cdevpriv) == NULL) {
207 mtx_unlock(&cdevpriv_mtx);
208 return;
209 }
210 devfs_destroy_cdevpriv(p);
211 }
212
213 void
devfs_clear_cdevpriv(void)214 devfs_clear_cdevpriv(void)
215 {
216 struct file *fp;
217
218 fp = curthread->td_fpop;
219 if (fp == NULL)
220 return;
221 devfs_fpdrop(fp);
222 }
223
224 /*
225 * On success devfs_populate_vp() returns with dmp->dm_lock held.
226 */
227 static int
devfs_populate_vp(struct vnode * vp)228 devfs_populate_vp(struct vnode *vp)
229 {
230 struct devfs_dirent *de;
231 struct devfs_mount *dmp;
232 int locked;
233
234 ASSERT_VOP_LOCKED(vp, "devfs_populate_vp");
235
236 dmp = VFSTODEVFS(vp->v_mount);
237 locked = VOP_ISLOCKED(vp);
238
239 sx_xlock(&dmp->dm_lock);
240 DEVFS_DMP_HOLD(dmp);
241
242 /* Can't call devfs_populate() with the vnode lock held. */
243 VOP_UNLOCK(vp, 0);
244 devfs_populate(dmp);
245
246 sx_xunlock(&dmp->dm_lock);
247 vn_lock(vp, locked | LK_RETRY);
248 sx_xlock(&dmp->dm_lock);
249 if (DEVFS_DMP_DROP(dmp)) {
250 sx_xunlock(&dmp->dm_lock);
251 devfs_unmount_final(dmp);
252 return (ERESTART);
253 }
254 if ((vp->v_iflag & VI_DOOMED) != 0) {
255 sx_xunlock(&dmp->dm_lock);
256 return (ERESTART);
257 }
258 de = vp->v_data;
259 KASSERT(de != NULL,
260 ("devfs_populate_vp: vp->v_data == NULL but vnode not doomed"));
261 if ((de->de_flags & DE_DOOMED) != 0) {
262 sx_xunlock(&dmp->dm_lock);
263 return (ERESTART);
264 }
265
266 return (0);
267 }
268
269 static int
devfs_vptocnp(struct vop_vptocnp_args * ap)270 devfs_vptocnp(struct vop_vptocnp_args *ap)
271 {
272 struct vnode *vp = ap->a_vp;
273 struct vnode **dvp = ap->a_vpp;
274 struct devfs_mount *dmp;
275 char *buf = ap->a_buf;
276 int *buflen = ap->a_buflen;
277 struct devfs_dirent *dd, *de;
278 int i, error;
279
280 dmp = VFSTODEVFS(vp->v_mount);
281
282 error = devfs_populate_vp(vp);
283 if (error != 0)
284 return (error);
285
286 i = *buflen;
287 dd = vp->v_data;
288
289 if (vp->v_type == VCHR) {
290 i -= strlen(dd->de_cdp->cdp_c.si_name);
291 if (i < 0) {
292 error = ENOMEM;
293 goto finished;
294 }
295 bcopy(dd->de_cdp->cdp_c.si_name, buf + i,
296 strlen(dd->de_cdp->cdp_c.si_name));
297 de = dd->de_dir;
298 } else if (vp->v_type == VDIR) {
299 if (dd == dmp->dm_rootdir) {
300 *dvp = vp;
301 vref(*dvp);
302 goto finished;
303 }
304 i -= dd->de_dirent->d_namlen;
305 if (i < 0) {
306 error = ENOMEM;
307 goto finished;
308 }
309 bcopy(dd->de_dirent->d_name, buf + i,
310 dd->de_dirent->d_namlen);
311 de = dd;
312 } else {
313 error = ENOENT;
314 goto finished;
315 }
316 *buflen = i;
317 de = devfs_parent_dirent(de);
318 if (de == NULL) {
319 error = ENOENT;
320 goto finished;
321 }
322 mtx_lock(&devfs_de_interlock);
323 *dvp = de->de_vnode;
324 if (*dvp != NULL) {
325 VI_LOCK(*dvp);
326 mtx_unlock(&devfs_de_interlock);
327 vholdl(*dvp);
328 VI_UNLOCK(*dvp);
329 vref(*dvp);
330 vdrop(*dvp);
331 } else {
332 mtx_unlock(&devfs_de_interlock);
333 error = ENOENT;
334 }
335 finished:
336 sx_xunlock(&dmp->dm_lock);
337 return (error);
338 }
339
340 /*
341 * Construct the fully qualified path name relative to the mountpoint.
342 * If a NULL cnp is provided, no '/' is appended to the resulting path.
343 */
344 char *
devfs_fqpn(char * buf,struct devfs_mount * dmp,struct devfs_dirent * dd,struct componentname * cnp)345 devfs_fqpn(char *buf, struct devfs_mount *dmp, struct devfs_dirent *dd,
346 struct componentname *cnp)
347 {
348 int i;
349 struct devfs_dirent *de;
350
351 sx_assert(&dmp->dm_lock, SA_LOCKED);
352
353 i = SPECNAMELEN;
354 buf[i] = '\0';
355 if (cnp != NULL)
356 i -= cnp->cn_namelen;
357 if (i < 0)
358 return (NULL);
359 if (cnp != NULL)
360 bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
361 de = dd;
362 while (de != dmp->dm_rootdir) {
363 if (cnp != NULL || i < SPECNAMELEN) {
364 i--;
365 if (i < 0)
366 return (NULL);
367 buf[i] = '/';
368 }
369 i -= de->de_dirent->d_namlen;
370 if (i < 0)
371 return (NULL);
372 bcopy(de->de_dirent->d_name, buf + i,
373 de->de_dirent->d_namlen);
374 de = devfs_parent_dirent(de);
375 if (de == NULL)
376 return (NULL);
377 }
378 return (buf + i);
379 }
380
381 static int
devfs_allocv_drop_refs(int drop_dm_lock,struct devfs_mount * dmp,struct devfs_dirent * de)382 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
383 struct devfs_dirent *de)
384 {
385 int not_found;
386
387 not_found = 0;
388 if (de->de_flags & DE_DOOMED)
389 not_found = 1;
390 if (DEVFS_DE_DROP(de)) {
391 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
392 devfs_dirent_free(de);
393 }
394 if (DEVFS_DMP_DROP(dmp)) {
395 KASSERT(not_found == 1,
396 ("DEVFS mount struct freed before dirent"));
397 not_found = 2;
398 sx_xunlock(&dmp->dm_lock);
399 devfs_unmount_final(dmp);
400 }
401 if (not_found == 1 || (drop_dm_lock && not_found != 2))
402 sx_unlock(&dmp->dm_lock);
403 return (not_found);
404 }
405
406 static void
devfs_insmntque_dtr(struct vnode * vp,void * arg)407 devfs_insmntque_dtr(struct vnode *vp, void *arg)
408 {
409 struct devfs_dirent *de;
410
411 de = (struct devfs_dirent *)arg;
412 mtx_lock(&devfs_de_interlock);
413 vp->v_data = NULL;
414 de->de_vnode = NULL;
415 mtx_unlock(&devfs_de_interlock);
416 vgone(vp);
417 vput(vp);
418 }
419
420 /*
421 * devfs_allocv shall be entered with dmp->dm_lock held, and it drops
422 * it on return.
423 */
424 int
devfs_allocv(struct devfs_dirent * de,struct mount * mp,int lockmode,struct vnode ** vpp)425 devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode,
426 struct vnode **vpp)
427 {
428 int error;
429 struct vnode *vp;
430 struct cdev *dev;
431 struct devfs_mount *dmp;
432 struct cdevsw *dsw;
433
434 dmp = VFSTODEVFS(mp);
435 if (de->de_flags & DE_DOOMED) {
436 sx_xunlock(&dmp->dm_lock);
437 return (ENOENT);
438 }
439 loop:
440 DEVFS_DE_HOLD(de);
441 DEVFS_DMP_HOLD(dmp);
442 mtx_lock(&devfs_de_interlock);
443 vp = de->de_vnode;
444 if (vp != NULL) {
445 VI_LOCK(vp);
446 mtx_unlock(&devfs_de_interlock);
447 sx_xunlock(&dmp->dm_lock);
448 vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread);
449 sx_xlock(&dmp->dm_lock);
450 if (devfs_allocv_drop_refs(0, dmp, de)) {
451 vput(vp);
452 return (ENOENT);
453 }
454 else if ((vp->v_iflag & VI_DOOMED) != 0) {
455 mtx_lock(&devfs_de_interlock);
456 if (de->de_vnode == vp) {
457 de->de_vnode = NULL;
458 vp->v_data = NULL;
459 }
460 mtx_unlock(&devfs_de_interlock);
461 vput(vp);
462 goto loop;
463 }
464 sx_xunlock(&dmp->dm_lock);
465 *vpp = vp;
466 return (0);
467 }
468 mtx_unlock(&devfs_de_interlock);
469 if (de->de_dirent->d_type == DT_CHR) {
470 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
471 devfs_allocv_drop_refs(1, dmp, de);
472 return (ENOENT);
473 }
474 dev = &de->de_cdp->cdp_c;
475 } else {
476 dev = NULL;
477 }
478 error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
479 if (error != 0) {
480 devfs_allocv_drop_refs(1, dmp, de);
481 printf("devfs_allocv: failed to allocate new vnode\n");
482 return (error);
483 }
484
485 if (de->de_dirent->d_type == DT_CHR) {
486 vp->v_type = VCHR;
487 VI_LOCK(vp);
488 dev_lock();
489 dev_refl(dev);
490 /* XXX: v_rdev should be protect by vnode lock */
491 vp->v_rdev = dev;
492 KASSERT(vp->v_usecount == 1,
493 ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
494 dev->si_usecount += vp->v_usecount;
495 /* Special casing of ttys for deadfs. Probably redundant. */
496 dsw = dev->si_devsw;
497 if (dsw != NULL && (dsw->d_flags & D_TTY) != 0)
498 vp->v_vflag |= VV_ISTTY;
499 dev_unlock();
500 VI_UNLOCK(vp);
501 if ((dev->si_flags & SI_ETERNAL) != 0)
502 vp->v_vflag |= VV_ETERNALDEV;
503 vp->v_op = &devfs_specops;
504 } else if (de->de_dirent->d_type == DT_DIR) {
505 vp->v_type = VDIR;
506 } else if (de->de_dirent->d_type == DT_LNK) {
507 vp->v_type = VLNK;
508 } else {
509 vp->v_type = VBAD;
510 }
511 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
512 VN_LOCK_ASHARE(vp);
513 mtx_lock(&devfs_de_interlock);
514 vp->v_data = de;
515 de->de_vnode = vp;
516 mtx_unlock(&devfs_de_interlock);
517 error = insmntque1(vp, mp, devfs_insmntque_dtr, de);
518 if (error != 0) {
519 (void) devfs_allocv_drop_refs(1, dmp, de);
520 return (error);
521 }
522 if (devfs_allocv_drop_refs(0, dmp, de)) {
523 vput(vp);
524 return (ENOENT);
525 }
526 #ifdef MAC
527 mac_devfs_vnode_associate(mp, de, vp);
528 #endif
529 sx_xunlock(&dmp->dm_lock);
530 *vpp = vp;
531 return (0);
532 }
533
534 static int
devfs_access(struct vop_access_args * ap)535 devfs_access(struct vop_access_args *ap)
536 {
537 struct vnode *vp = ap->a_vp;
538 struct devfs_dirent *de;
539 struct proc *p;
540 int error;
541
542 de = vp->v_data;
543 if (vp->v_type == VDIR)
544 de = de->de_dir;
545
546 error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
547 ap->a_accmode, ap->a_cred, NULL);
548 if (error == 0)
549 return (0);
550 if (error != EACCES)
551 return (error);
552 p = ap->a_td->td_proc;
553 /* We do, however, allow access to the controlling terminal */
554 PROC_LOCK(p);
555 if (!(p->p_flag & P_CONTROLT)) {
556 PROC_UNLOCK(p);
557 return (error);
558 }
559 if (p->p_session->s_ttydp == de->de_cdp)
560 error = 0;
561 PROC_UNLOCK(p);
562 return (error);
563 }
564
565 _Static_assert(((FMASK | FCNTLFLAGS) & (FLASTCLOSE | FREVOKE)) == 0,
566 "devfs-only flag reuse failed");
567
568 static int
devfs_close(struct vop_close_args * ap)569 devfs_close(struct vop_close_args *ap)
570 {
571 struct vnode *vp = ap->a_vp, *oldvp;
572 struct thread *td = ap->a_td;
573 struct proc *p;
574 struct cdev *dev = vp->v_rdev;
575 struct cdevsw *dsw;
576 int dflags, error, ref, vp_locked;
577
578 /*
579 * XXX: Don't call d_close() if we were called because of
580 * XXX: insmntque1() failure.
581 */
582 if (vp->v_data == NULL)
583 return (0);
584
585 /*
586 * Hack: a tty device that is a controlling terminal
587 * has a reference from the session structure.
588 * We cannot easily tell that a character device is
589 * a controlling terminal, unless it is the closing
590 * process' controlling terminal. In that case,
591 * if the reference count is 2 (this last descriptor
592 * plus the session), release the reference from the session.
593 */
594 if (td != NULL) {
595 p = td->td_proc;
596 PROC_LOCK(p);
597 if (vp == p->p_session->s_ttyvp) {
598 PROC_UNLOCK(p);
599 oldvp = NULL;
600 sx_xlock(&proctree_lock);
601 if (vp == p->p_session->s_ttyvp) {
602 SESS_LOCK(p->p_session);
603 VI_LOCK(vp);
604 if (count_dev(dev) == 2 &&
605 (vp->v_iflag & VI_DOOMED) == 0) {
606 p->p_session->s_ttyvp = NULL;
607 p->p_session->s_ttydp = NULL;
608 oldvp = vp;
609 }
610 VI_UNLOCK(vp);
611 SESS_UNLOCK(p->p_session);
612 }
613 sx_xunlock(&proctree_lock);
614 if (oldvp != NULL)
615 vrele(oldvp);
616 } else
617 PROC_UNLOCK(p);
618 }
619 /*
620 * We do not want to really close the device if it
621 * is still in use unless we are trying to close it
622 * forcibly. Since every use (buffer, vnode, swap, cmap)
623 * holds a reference to the vnode, and because we mark
624 * any other vnodes that alias this device, when the
625 * sum of the reference counts on all the aliased
626 * vnodes descends to one, we are on last close.
627 */
628 dsw = dev_refthread(dev, &ref);
629 if (dsw == NULL)
630 return (ENXIO);
631 dflags = 0;
632 VI_LOCK(vp);
633 if (vp->v_iflag & VI_DOOMED) {
634 /* Forced close. */
635 dflags |= FREVOKE | FNONBLOCK;
636 } else if (dsw->d_flags & D_TRACKCLOSE) {
637 /* Keep device updated on status. */
638 } else if (count_dev(dev) > 1) {
639 VI_UNLOCK(vp);
640 dev_relthread(dev, ref);
641 return (0);
642 }
643 if (count_dev(dev) == 1)
644 dflags |= FLASTCLOSE;
645 vholdl(vp);
646 VI_UNLOCK(vp);
647 vp_locked = VOP_ISLOCKED(vp);
648 VOP_UNLOCK(vp, 0);
649 KASSERT(dev->si_refcount > 0,
650 ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
651 error = dsw->d_close(dev, ap->a_fflag | dflags, S_IFCHR, td);
652 dev_relthread(dev, ref);
653 vn_lock(vp, vp_locked | LK_RETRY);
654 vdrop(vp);
655 return (error);
656 }
657
658 static int
devfs_close_f(struct file * fp,struct thread * td)659 devfs_close_f(struct file *fp, struct thread *td)
660 {
661 int error;
662 struct file *fpop;
663
664 /*
665 * NB: td may be NULL if this descriptor is closed due to
666 * garbage collection from a closed UNIX domain socket.
667 */
668 fpop = curthread->td_fpop;
669 curthread->td_fpop = fp;
670 error = vnops.fo_close(fp, td);
671 curthread->td_fpop = fpop;
672
673 /*
674 * The f_cdevpriv cannot be assigned non-NULL value while we
675 * are destroying the file.
676 */
677 if (fp->f_cdevpriv != NULL)
678 devfs_fpdrop(fp);
679 return (error);
680 }
681
682 static int
devfs_getattr(struct vop_getattr_args * ap)683 devfs_getattr(struct vop_getattr_args *ap)
684 {
685 struct vnode *vp = ap->a_vp;
686 struct vattr *vap = ap->a_vap;
687 struct devfs_dirent *de;
688 struct devfs_mount *dmp;
689 struct cdev *dev;
690 struct timeval boottime;
691 int error;
692
693 error = devfs_populate_vp(vp);
694 if (error != 0)
695 return (error);
696
697 dmp = VFSTODEVFS(vp->v_mount);
698 sx_xunlock(&dmp->dm_lock);
699
700 de = vp->v_data;
701 KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
702 if (vp->v_type == VDIR) {
703 de = de->de_dir;
704 KASSERT(de != NULL,
705 ("Null dir dirent in devfs_getattr vp=%p", vp));
706 }
707 vap->va_uid = de->de_uid;
708 vap->va_gid = de->de_gid;
709 vap->va_mode = de->de_mode;
710 if (vp->v_type == VLNK)
711 vap->va_size = strlen(de->de_symlink);
712 else if (vp->v_type == VDIR)
713 vap->va_size = vap->va_bytes = DEV_BSIZE;
714 else
715 vap->va_size = 0;
716 if (vp->v_type != VDIR)
717 vap->va_bytes = 0;
718 vap->va_blocksize = DEV_BSIZE;
719 vap->va_type = vp->v_type;
720
721 getboottime(&boottime);
722 #define fix(aa) \
723 do { \
724 if ((aa).tv_sec <= 3600) { \
725 (aa).tv_sec = boottime.tv_sec; \
726 (aa).tv_nsec = boottime.tv_usec * 1000; \
727 } \
728 } while (0)
729
730 if (vp->v_type != VCHR) {
731 fix(de->de_atime);
732 vap->va_atime = de->de_atime;
733 fix(de->de_mtime);
734 vap->va_mtime = de->de_mtime;
735 fix(de->de_ctime);
736 vap->va_ctime = de->de_ctime;
737 } else {
738 dev = vp->v_rdev;
739 fix(dev->si_atime);
740 vap->va_atime = dev->si_atime;
741 fix(dev->si_mtime);
742 vap->va_mtime = dev->si_mtime;
743 fix(dev->si_ctime);
744 vap->va_ctime = dev->si_ctime;
745
746 vap->va_rdev = cdev2priv(dev)->cdp_inode;
747 }
748 vap->va_gen = 0;
749 vap->va_flags = 0;
750 vap->va_filerev = 0;
751 vap->va_nlink = de->de_links;
752 vap->va_fileid = de->de_inode;
753
754 return (error);
755 }
756
757 /* ARGSUSED */
758 static int
devfs_ioctl_f(struct file * fp,u_long com,void * data,struct ucred * cred,struct thread * td)759 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
760 {
761 struct file *fpop;
762 int error;
763
764 fpop = td->td_fpop;
765 td->td_fpop = fp;
766 error = vnops.fo_ioctl(fp, com, data, cred, td);
767 td->td_fpop = fpop;
768 return (error);
769 }
770
771 static int
devfs_ioctl(struct vop_ioctl_args * ap)772 devfs_ioctl(struct vop_ioctl_args *ap)
773 {
774 struct fiodgname_arg *fgn;
775 struct vnode *vpold, *vp;
776 struct cdevsw *dsw;
777 struct thread *td;
778 struct cdev *dev;
779 int error, ref, i;
780 const char *p;
781 u_long com;
782
783 vp = ap->a_vp;
784 com = ap->a_command;
785 td = ap->a_td;
786
787 dsw = devvn_refthread(vp, &dev, &ref);
788 if (dsw == NULL)
789 return (ENXIO);
790 KASSERT(dev->si_refcount > 0,
791 ("devfs: un-referenced struct cdev *(%s)", devtoname(dev)));
792
793 if (com == FIODTYPE) {
794 *(int *)ap->a_data = dsw->d_flags & D_TYPEMASK;
795 error = 0;
796 goto out;
797 } else if (com == FIODGNAME) {
798 fgn = ap->a_data;
799 p = devtoname(dev);
800 i = strlen(p) + 1;
801 if (i > fgn->len)
802 error = EINVAL;
803 else
804 error = copyout(p, fgn->buf, i);
805 goto out;
806 }
807
808 error = dsw->d_ioctl(dev, com, ap->a_data, ap->a_fflag, td);
809
810 out:
811 dev_relthread(dev, ref);
812 if (error == ENOIOCTL)
813 error = ENOTTY;
814
815 if (error == 0 && com == TIOCSCTTY) {
816 /* Do nothing if reassigning same control tty */
817 sx_slock(&proctree_lock);
818 if (td->td_proc->p_session->s_ttyvp == vp) {
819 sx_sunlock(&proctree_lock);
820 return (0);
821 }
822
823 vpold = td->td_proc->p_session->s_ttyvp;
824 VREF(vp);
825 SESS_LOCK(td->td_proc->p_session);
826 td->td_proc->p_session->s_ttyvp = vp;
827 td->td_proc->p_session->s_ttydp = cdev2priv(dev);
828 SESS_UNLOCK(td->td_proc->p_session);
829
830 sx_sunlock(&proctree_lock);
831
832 /* Get rid of reference to old control tty */
833 if (vpold)
834 vrele(vpold);
835 }
836 return (error);
837 }
838
839 /* ARGSUSED */
840 static int
devfs_kqfilter_f(struct file * fp,struct knote * kn)841 devfs_kqfilter_f(struct file *fp, struct knote *kn)
842 {
843 struct cdev *dev;
844 struct cdevsw *dsw;
845 int error, ref;
846 struct file *fpop;
847 struct thread *td;
848
849 td = curthread;
850 fpop = td->td_fpop;
851 error = devfs_fp_check(fp, &dev, &dsw, &ref);
852 if (error)
853 return (error);
854 error = dsw->d_kqfilter(dev, kn);
855 td->td_fpop = fpop;
856 dev_relthread(dev, ref);
857 return (error);
858 }
859
860 static inline int
devfs_prison_check(struct devfs_dirent * de,struct thread * td)861 devfs_prison_check(struct devfs_dirent *de, struct thread *td)
862 {
863 struct cdev_priv *cdp;
864 struct ucred *dcr;
865 struct proc *p;
866 int error;
867
868 cdp = de->de_cdp;
869 if (cdp == NULL)
870 return (0);
871 dcr = cdp->cdp_c.si_cred;
872 if (dcr == NULL)
873 return (0);
874
875 error = prison_check(td->td_ucred, dcr);
876 if (error == 0)
877 return (0);
878 /* We do, however, allow access to the controlling terminal */
879 p = td->td_proc;
880 PROC_LOCK(p);
881 if (!(p->p_flag & P_CONTROLT)) {
882 PROC_UNLOCK(p);
883 return (error);
884 }
885 if (p->p_session->s_ttydp == cdp)
886 error = 0;
887 PROC_UNLOCK(p);
888 return (error);
889 }
890
891 static int
devfs_lookupx(struct vop_lookup_args * ap,int * dm_unlock)892 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
893 {
894 struct componentname *cnp;
895 struct vnode *dvp, **vpp;
896 struct thread *td;
897 struct devfs_dirent *de, *dd;
898 struct devfs_dirent **dde;
899 struct devfs_mount *dmp;
900 struct mount *mp;
901 struct cdev *cdev;
902 int error, flags, nameiop, dvplocked;
903 char specname[SPECNAMELEN + 1], *pname;
904
905 cnp = ap->a_cnp;
906 vpp = ap->a_vpp;
907 dvp = ap->a_dvp;
908 pname = cnp->cn_nameptr;
909 td = cnp->cn_thread;
910 flags = cnp->cn_flags;
911 nameiop = cnp->cn_nameiop;
912 mp = dvp->v_mount;
913 dmp = VFSTODEVFS(mp);
914 dd = dvp->v_data;
915 *vpp = NULLVP;
916
917 if ((flags & ISLASTCN) && nameiop == RENAME)
918 return (EOPNOTSUPP);
919
920 if (dvp->v_type != VDIR)
921 return (ENOTDIR);
922
923 if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
924 return (EIO);
925
926 error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
927 if (error)
928 return (error);
929
930 if (cnp->cn_namelen == 1 && *pname == '.') {
931 if ((flags & ISLASTCN) && nameiop != LOOKUP)
932 return (EINVAL);
933 *vpp = dvp;
934 VREF(dvp);
935 return (0);
936 }
937
938 if (flags & ISDOTDOT) {
939 if ((flags & ISLASTCN) && nameiop != LOOKUP)
940 return (EINVAL);
941 de = devfs_parent_dirent(dd);
942 if (de == NULL)
943 return (ENOENT);
944 dvplocked = VOP_ISLOCKED(dvp);
945 VOP_UNLOCK(dvp, 0);
946 error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK,
947 vpp);
948 *dm_unlock = 0;
949 vn_lock(dvp, dvplocked | LK_RETRY);
950 return (error);
951 }
952
953 dd = dvp->v_data;
954 de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen, 0);
955 while (de == NULL) { /* While(...) so we can use break */
956
957 if (nameiop == DELETE)
958 return (ENOENT);
959
960 /*
961 * OK, we didn't have an entry for the name we were asked for
962 * so we try to see if anybody can create it on demand.
963 */
964 pname = devfs_fqpn(specname, dmp, dd, cnp);
965 if (pname == NULL)
966 break;
967
968 cdev = NULL;
969 DEVFS_DMP_HOLD(dmp);
970 sx_xunlock(&dmp->dm_lock);
971 sx_slock(&clone_drain_lock);
972 EVENTHANDLER_INVOKE(dev_clone,
973 td->td_ucred, pname, strlen(pname), &cdev);
974 sx_sunlock(&clone_drain_lock);
975
976 if (cdev == NULL)
977 sx_xlock(&dmp->dm_lock);
978 else if (devfs_populate_vp(dvp) != 0) {
979 *dm_unlock = 0;
980 sx_xlock(&dmp->dm_lock);
981 if (DEVFS_DMP_DROP(dmp)) {
982 sx_xunlock(&dmp->dm_lock);
983 devfs_unmount_final(dmp);
984 } else
985 sx_xunlock(&dmp->dm_lock);
986 dev_rel(cdev);
987 return (ENOENT);
988 }
989 if (DEVFS_DMP_DROP(dmp)) {
990 *dm_unlock = 0;
991 sx_xunlock(&dmp->dm_lock);
992 devfs_unmount_final(dmp);
993 if (cdev != NULL)
994 dev_rel(cdev);
995 return (ENOENT);
996 }
997
998 if (cdev == NULL)
999 break;
1000
1001 dev_lock();
1002 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
1003 if (dde != NULL && *dde != NULL)
1004 de = *dde;
1005 dev_unlock();
1006 dev_rel(cdev);
1007 break;
1008 }
1009
1010 if (de == NULL || de->de_flags & DE_WHITEOUT) {
1011 if ((nameiop == CREATE || nameiop == RENAME) &&
1012 (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
1013 cnp->cn_flags |= SAVENAME;
1014 return (EJUSTRETURN);
1015 }
1016 return (ENOENT);
1017 }
1018
1019 if (devfs_prison_check(de, td))
1020 return (ENOENT);
1021
1022 if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
1023 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
1024 if (error)
1025 return (error);
1026 if (*vpp == dvp) {
1027 VREF(dvp);
1028 *vpp = dvp;
1029 return (0);
1030 }
1031 }
1032 error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK, vpp);
1033 *dm_unlock = 0;
1034 return (error);
1035 }
1036
1037 static int
devfs_lookup(struct vop_lookup_args * ap)1038 devfs_lookup(struct vop_lookup_args *ap)
1039 {
1040 int j;
1041 struct devfs_mount *dmp;
1042 int dm_unlock;
1043
1044 if (devfs_populate_vp(ap->a_dvp) != 0)
1045 return (ENOTDIR);
1046
1047 dmp = VFSTODEVFS(ap->a_dvp->v_mount);
1048 dm_unlock = 1;
1049 j = devfs_lookupx(ap, &dm_unlock);
1050 if (dm_unlock == 1)
1051 sx_xunlock(&dmp->dm_lock);
1052 return (j);
1053 }
1054
1055 static int
devfs_mknod(struct vop_mknod_args * ap)1056 devfs_mknod(struct vop_mknod_args *ap)
1057 {
1058 struct componentname *cnp;
1059 struct vnode *dvp, **vpp;
1060 struct devfs_dirent *dd, *de;
1061 struct devfs_mount *dmp;
1062 int error;
1063
1064 /*
1065 * The only type of node we should be creating here is a
1066 * character device, for anything else return EOPNOTSUPP.
1067 */
1068 if (ap->a_vap->va_type != VCHR)
1069 return (EOPNOTSUPP);
1070 dvp = ap->a_dvp;
1071 dmp = VFSTODEVFS(dvp->v_mount);
1072
1073 cnp = ap->a_cnp;
1074 vpp = ap->a_vpp;
1075 dd = dvp->v_data;
1076
1077 error = ENOENT;
1078 sx_xlock(&dmp->dm_lock);
1079 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
1080 if (cnp->cn_namelen != de->de_dirent->d_namlen)
1081 continue;
1082 if (de->de_dirent->d_type == DT_CHR &&
1083 (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
1084 continue;
1085 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
1086 de->de_dirent->d_namlen) != 0)
1087 continue;
1088 if (de->de_flags & DE_WHITEOUT)
1089 break;
1090 goto notfound;
1091 }
1092 if (de == NULL)
1093 goto notfound;
1094 de->de_flags &= ~DE_WHITEOUT;
1095 error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp);
1096 return (error);
1097 notfound:
1098 sx_xunlock(&dmp->dm_lock);
1099 return (error);
1100 }
1101
1102 /* ARGSUSED */
1103 static int
devfs_open(struct vop_open_args * ap)1104 devfs_open(struct vop_open_args *ap)
1105 {
1106 struct thread *td = ap->a_td;
1107 struct vnode *vp = ap->a_vp;
1108 struct cdev *dev = vp->v_rdev;
1109 struct file *fp = ap->a_fp;
1110 int error, ref, vlocked;
1111 struct cdevsw *dsw;
1112 struct file *fpop;
1113 struct mtx *mtxp;
1114
1115 if (vp->v_type == VBLK)
1116 return (ENXIO);
1117
1118 if (dev == NULL)
1119 return (ENXIO);
1120
1121 /* Make this field valid before any I/O in d_open. */
1122 if (dev->si_iosize_max == 0)
1123 dev->si_iosize_max = DFLTPHYS;
1124
1125 dsw = dev_refthread(dev, &ref);
1126 if (dsw == NULL)
1127 return (ENXIO);
1128 if (fp == NULL && dsw->d_fdopen != NULL) {
1129 dev_relthread(dev, ref);
1130 return (ENXIO);
1131 }
1132
1133 vlocked = VOP_ISLOCKED(vp);
1134 VOP_UNLOCK(vp, 0);
1135
1136 fpop = td->td_fpop;
1137 td->td_fpop = fp;
1138 if (fp != NULL) {
1139 fp->f_data = dev;
1140 fp->f_vnode = vp;
1141 }
1142 if (dsw->d_fdopen != NULL)
1143 error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
1144 else
1145 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
1146 /* Clean up any cdevpriv upon error. */
1147 if (error != 0)
1148 devfs_clear_cdevpriv();
1149 td->td_fpop = fpop;
1150
1151 vn_lock(vp, vlocked | LK_RETRY);
1152 dev_relthread(dev, ref);
1153 if (error != 0) {
1154 if (error == ERESTART)
1155 error = EINTR;
1156 return (error);
1157 }
1158
1159 #if 0 /* /dev/console */
1160 KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp"));
1161 #else
1162 if (fp == NULL)
1163 return (error);
1164 #endif
1165 if (fp->f_ops == &badfileops)
1166 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
1167 mtxp = mtx_pool_find(mtxpool_sleep, fp);
1168
1169 /*
1170 * Hint to the dofilewrite() to not force the buffer draining
1171 * on the writer to the file. Most likely, the write would
1172 * not need normal buffers.
1173 */
1174 mtx_lock(mtxp);
1175 fp->f_vnread_flags |= FDEVFS_VNODE;
1176 mtx_unlock(mtxp);
1177 return (error);
1178 }
1179
1180 static int
devfs_pathconf(struct vop_pathconf_args * ap)1181 devfs_pathconf(struct vop_pathconf_args *ap)
1182 {
1183
1184 switch (ap->a_name) {
1185 case _PC_FILESIZEBITS:
1186 *ap->a_retval = 64;
1187 return (0);
1188 case _PC_NAME_MAX:
1189 *ap->a_retval = NAME_MAX;
1190 return (0);
1191 case _PC_LINK_MAX:
1192 *ap->a_retval = INT_MAX;
1193 return (0);
1194 case _PC_SYMLINK_MAX:
1195 *ap->a_retval = MAXPATHLEN;
1196 return (0);
1197 case _PC_MAX_CANON:
1198 if (ap->a_vp->v_vflag & VV_ISTTY) {
1199 *ap->a_retval = MAX_CANON;
1200 return (0);
1201 }
1202 return (EINVAL);
1203 case _PC_MAX_INPUT:
1204 if (ap->a_vp->v_vflag & VV_ISTTY) {
1205 *ap->a_retval = MAX_INPUT;
1206 return (0);
1207 }
1208 return (EINVAL);
1209 case _PC_VDISABLE:
1210 if (ap->a_vp->v_vflag & VV_ISTTY) {
1211 *ap->a_retval = _POSIX_VDISABLE;
1212 return (0);
1213 }
1214 return (EINVAL);
1215 case _PC_MAC_PRESENT:
1216 #ifdef MAC
1217 /*
1218 * If MAC is enabled, devfs automatically supports
1219 * trivial non-persistant label storage.
1220 */
1221 *ap->a_retval = 1;
1222 #else
1223 *ap->a_retval = 0;
1224 #endif
1225 return (0);
1226 case _PC_CHOWN_RESTRICTED:
1227 *ap->a_retval = 1;
1228 return (0);
1229 default:
1230 return (vop_stdpathconf(ap));
1231 }
1232 /* NOTREACHED */
1233 }
1234
1235 /* ARGSUSED */
1236 static int
devfs_poll_f(struct file * fp,int events,struct ucred * cred,struct thread * td)1237 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
1238 {
1239 struct cdev *dev;
1240 struct cdevsw *dsw;
1241 int error, ref;
1242 struct file *fpop;
1243
1244 fpop = td->td_fpop;
1245 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1246 if (error != 0) {
1247 error = vnops.fo_poll(fp, events, cred, td);
1248 return (error);
1249 }
1250 error = dsw->d_poll(dev, events, td);
1251 td->td_fpop = fpop;
1252 dev_relthread(dev, ref);
1253 return(error);
1254 }
1255
1256 /*
1257 * Print out the contents of a special device vnode.
1258 */
1259 static int
devfs_print(struct vop_print_args * ap)1260 devfs_print(struct vop_print_args *ap)
1261 {
1262
1263 printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
1264 return (0);
1265 }
1266
1267 static int
devfs_read_f(struct file * fp,struct uio * uio,struct ucred * cred,int flags,struct thread * td)1268 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred,
1269 int flags, struct thread *td)
1270 {
1271 struct cdev *dev;
1272 int ioflag, error, ref;
1273 ssize_t resid;
1274 struct cdevsw *dsw;
1275 struct file *fpop;
1276
1277 if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1278 return (EINVAL);
1279 fpop = td->td_fpop;
1280 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1281 if (error != 0) {
1282 error = vnops.fo_read(fp, uio, cred, flags, td);
1283 return (error);
1284 }
1285 resid = uio->uio_resid;
1286 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
1287 if (ioflag & O_DIRECT)
1288 ioflag |= IO_DIRECT;
1289
1290 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
1291 error = dsw->d_read(dev, uio, ioflag);
1292 if (uio->uio_resid != resid || (error == 0 && resid != 0))
1293 devfs_timestamp(&dev->si_atime);
1294 td->td_fpop = fpop;
1295 dev_relthread(dev, ref);
1296
1297 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF);
1298 return (error);
1299 }
1300
1301 static int
devfs_readdir(struct vop_readdir_args * ap)1302 devfs_readdir(struct vop_readdir_args *ap)
1303 {
1304 int error;
1305 struct uio *uio;
1306 struct dirent *dp;
1307 struct devfs_dirent *dd;
1308 struct devfs_dirent *de;
1309 struct devfs_mount *dmp;
1310 off_t off;
1311 int *tmp_ncookies = NULL;
1312
1313 if (ap->a_vp->v_type != VDIR)
1314 return (ENOTDIR);
1315
1316 uio = ap->a_uio;
1317 if (uio->uio_offset < 0)
1318 return (EINVAL);
1319
1320 /*
1321 * XXX: This is a temporary hack to get around this filesystem not
1322 * supporting cookies. We store the location of the ncookies pointer
1323 * in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
1324 * and set the number of cookies to 0. We then set the pointer to
1325 * NULL so that vfs_read_dirent doesn't try to call realloc() on
1326 * ap->a_cookies. Later in this function, we restore the ap->a_ncookies
1327 * pointer to its original location before returning to the caller.
1328 */
1329 if (ap->a_ncookies != NULL) {
1330 tmp_ncookies = ap->a_ncookies;
1331 *ap->a_ncookies = 0;
1332 ap->a_ncookies = NULL;
1333 }
1334
1335 dmp = VFSTODEVFS(ap->a_vp->v_mount);
1336 if (devfs_populate_vp(ap->a_vp) != 0) {
1337 if (tmp_ncookies != NULL)
1338 ap->a_ncookies = tmp_ncookies;
1339 return (EIO);
1340 }
1341 error = 0;
1342 de = ap->a_vp->v_data;
1343 off = 0;
1344 TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
1345 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
1346 if (dd->de_flags & (DE_COVERED | DE_WHITEOUT))
1347 continue;
1348 if (devfs_prison_check(dd, uio->uio_td))
1349 continue;
1350 if (dd->de_dirent->d_type == DT_DIR)
1351 de = dd->de_dir;
1352 else
1353 de = dd;
1354 dp = dd->de_dirent;
1355 MPASS(dp->d_reclen == GENERIC_DIRSIZ(dp));
1356 if (dp->d_reclen > uio->uio_resid)
1357 break;
1358 dp->d_fileno = de->de_inode;
1359 /* NOTE: d_off is the offset for the *next* entry. */
1360 dp->d_off = off + dp->d_reclen;
1361 if (off >= uio->uio_offset) {
1362 error = vfs_read_dirent(ap, dp, off);
1363 if (error)
1364 break;
1365 }
1366 off += dp->d_reclen;
1367 }
1368 sx_xunlock(&dmp->dm_lock);
1369 uio->uio_offset = off;
1370
1371 /*
1372 * Restore ap->a_ncookies if it wasn't originally NULL in the first
1373 * place.
1374 */
1375 if (tmp_ncookies != NULL)
1376 ap->a_ncookies = tmp_ncookies;
1377
1378 return (error);
1379 }
1380
1381 static int
devfs_readlink(struct vop_readlink_args * ap)1382 devfs_readlink(struct vop_readlink_args *ap)
1383 {
1384 struct devfs_dirent *de;
1385
1386 de = ap->a_vp->v_data;
1387 return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
1388 }
1389
1390 static int
devfs_reclaim(struct vop_reclaim_args * ap)1391 devfs_reclaim(struct vop_reclaim_args *ap)
1392 {
1393 struct vnode *vp;
1394 struct devfs_dirent *de;
1395
1396 vp = ap->a_vp;
1397 mtx_lock(&devfs_de_interlock);
1398 de = vp->v_data;
1399 if (de != NULL) {
1400 de->de_vnode = NULL;
1401 vp->v_data = NULL;
1402 }
1403 mtx_unlock(&devfs_de_interlock);
1404 vnode_destroy_vobject(vp);
1405 return (0);
1406 }
1407
1408 static int
devfs_reclaim_vchr(struct vop_reclaim_args * ap)1409 devfs_reclaim_vchr(struct vop_reclaim_args *ap)
1410 {
1411 struct vnode *vp;
1412 struct cdev *dev;
1413
1414 vp = ap->a_vp;
1415 MPASS(vp->v_type == VCHR);
1416
1417 devfs_reclaim(ap);
1418
1419 VI_LOCK(vp);
1420 dev_lock();
1421 dev = vp->v_rdev;
1422 vp->v_rdev = NULL;
1423 if (dev != NULL)
1424 dev->si_usecount -= vp->v_usecount;
1425 dev_unlock();
1426 VI_UNLOCK(vp);
1427 if (dev != NULL)
1428 dev_rel(dev);
1429 return (0);
1430 }
1431
1432 static int
devfs_remove(struct vop_remove_args * ap)1433 devfs_remove(struct vop_remove_args *ap)
1434 {
1435 struct vnode *dvp = ap->a_dvp;
1436 struct vnode *vp = ap->a_vp;
1437 struct devfs_dirent *dd;
1438 struct devfs_dirent *de, *de_covered;
1439 struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
1440
1441 ASSERT_VOP_ELOCKED(dvp, "devfs_remove");
1442 ASSERT_VOP_ELOCKED(vp, "devfs_remove");
1443
1444 sx_xlock(&dmp->dm_lock);
1445 dd = ap->a_dvp->v_data;
1446 de = vp->v_data;
1447 if (de->de_cdp == NULL) {
1448 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
1449 if (de->de_dirent->d_type == DT_LNK) {
1450 de_covered = devfs_find(dd, de->de_dirent->d_name,
1451 de->de_dirent->d_namlen, 0);
1452 if (de_covered != NULL)
1453 de_covered->de_flags &= ~DE_COVERED;
1454 }
1455 /* We need to unlock dvp because devfs_delete() may lock it. */
1456 VOP_UNLOCK(vp, 0);
1457 if (dvp != vp)
1458 VOP_UNLOCK(dvp, 0);
1459 devfs_delete(dmp, de, 0);
1460 sx_xunlock(&dmp->dm_lock);
1461 if (dvp != vp)
1462 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1463 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1464 } else {
1465 de->de_flags |= DE_WHITEOUT;
1466 sx_xunlock(&dmp->dm_lock);
1467 }
1468 return (0);
1469 }
1470
1471 /*
1472 * Revoke is called on a tty when a terminal session ends. The vnode
1473 * is orphaned by setting v_op to deadfs so we need to let go of it
1474 * as well so that we create a new one next time around.
1475 *
1476 */
1477 static int
devfs_revoke(struct vop_revoke_args * ap)1478 devfs_revoke(struct vop_revoke_args *ap)
1479 {
1480 struct vnode *vp = ap->a_vp, *vp2;
1481 struct cdev *dev;
1482 struct cdev_priv *cdp;
1483 struct devfs_dirent *de;
1484 u_int i;
1485
1486 KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
1487
1488 dev = vp->v_rdev;
1489 cdp = cdev2priv(dev);
1490
1491 dev_lock();
1492 cdp->cdp_inuse++;
1493 dev_unlock();
1494
1495 vhold(vp);
1496 vgone(vp);
1497 vdrop(vp);
1498
1499 VOP_UNLOCK(vp,0);
1500 loop:
1501 for (;;) {
1502 mtx_lock(&devfs_de_interlock);
1503 dev_lock();
1504 vp2 = NULL;
1505 for (i = 0; i <= cdp->cdp_maxdirent; i++) {
1506 de = cdp->cdp_dirents[i];
1507 if (de == NULL)
1508 continue;
1509
1510 vp2 = de->de_vnode;
1511 if (vp2 != NULL) {
1512 dev_unlock();
1513 VI_LOCK(vp2);
1514 mtx_unlock(&devfs_de_interlock);
1515 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
1516 curthread))
1517 goto loop;
1518 vhold(vp2);
1519 vgone(vp2);
1520 vdrop(vp2);
1521 vput(vp2);
1522 break;
1523 }
1524 }
1525 if (vp2 != NULL) {
1526 continue;
1527 }
1528 dev_unlock();
1529 mtx_unlock(&devfs_de_interlock);
1530 break;
1531 }
1532 dev_lock();
1533 cdp->cdp_inuse--;
1534 if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
1535 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
1536 dev_unlock();
1537 dev_rel(&cdp->cdp_c);
1538 } else
1539 dev_unlock();
1540
1541 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1542 return (0);
1543 }
1544
1545 static int
devfs_rioctl(struct vop_ioctl_args * ap)1546 devfs_rioctl(struct vop_ioctl_args *ap)
1547 {
1548 struct vnode *vp;
1549 struct devfs_mount *dmp;
1550 int error;
1551
1552 vp = ap->a_vp;
1553 vn_lock(vp, LK_SHARED | LK_RETRY);
1554 if (vp->v_iflag & VI_DOOMED) {
1555 VOP_UNLOCK(vp, 0);
1556 return (EBADF);
1557 }
1558 dmp = VFSTODEVFS(vp->v_mount);
1559 sx_xlock(&dmp->dm_lock);
1560 VOP_UNLOCK(vp, 0);
1561 DEVFS_DMP_HOLD(dmp);
1562 devfs_populate(dmp);
1563 if (DEVFS_DMP_DROP(dmp)) {
1564 sx_xunlock(&dmp->dm_lock);
1565 devfs_unmount_final(dmp);
1566 return (ENOENT);
1567 }
1568 error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
1569 sx_xunlock(&dmp->dm_lock);
1570 return (error);
1571 }
1572
1573 static int
devfs_rread(struct vop_read_args * ap)1574 devfs_rread(struct vop_read_args *ap)
1575 {
1576
1577 if (ap->a_vp->v_type != VDIR)
1578 return (EINVAL);
1579 return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
1580 }
1581
1582 static int
devfs_setattr(struct vop_setattr_args * ap)1583 devfs_setattr(struct vop_setattr_args *ap)
1584 {
1585 struct devfs_dirent *de;
1586 struct vattr *vap;
1587 struct vnode *vp;
1588 struct thread *td;
1589 int c, error;
1590 uid_t uid;
1591 gid_t gid;
1592
1593 vap = ap->a_vap;
1594 vp = ap->a_vp;
1595 td = curthread;
1596 if ((vap->va_type != VNON) ||
1597 (vap->va_nlink != VNOVAL) ||
1598 (vap->va_fsid != VNOVAL) ||
1599 (vap->va_fileid != VNOVAL) ||
1600 (vap->va_blocksize != VNOVAL) ||
1601 (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
1602 (vap->va_rdev != VNOVAL) ||
1603 ((int)vap->va_bytes != VNOVAL) ||
1604 (vap->va_gen != VNOVAL)) {
1605 return (EINVAL);
1606 }
1607
1608 error = devfs_populate_vp(vp);
1609 if (error != 0)
1610 return (error);
1611
1612 de = vp->v_data;
1613 if (vp->v_type == VDIR)
1614 de = de->de_dir;
1615
1616 c = 0;
1617 if (vap->va_uid == (uid_t)VNOVAL)
1618 uid = de->de_uid;
1619 else
1620 uid = vap->va_uid;
1621 if (vap->va_gid == (gid_t)VNOVAL)
1622 gid = de->de_gid;
1623 else
1624 gid = vap->va_gid;
1625 if (uid != de->de_uid || gid != de->de_gid) {
1626 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
1627 (gid != de->de_gid && !groupmember(gid, ap->a_cred))) {
1628 error = priv_check(td, PRIV_VFS_CHOWN);
1629 if (error != 0)
1630 goto ret;
1631 }
1632 de->de_uid = uid;
1633 de->de_gid = gid;
1634 c = 1;
1635 }
1636
1637 if (vap->va_mode != (mode_t)VNOVAL) {
1638 if (ap->a_cred->cr_uid != de->de_uid) {
1639 error = priv_check(td, PRIV_VFS_ADMIN);
1640 if (error != 0)
1641 goto ret;
1642 }
1643 de->de_mode = vap->va_mode;
1644 c = 1;
1645 }
1646
1647 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
1648 error = vn_utimes_perm(vp, vap, ap->a_cred, td);
1649 if (error != 0)
1650 goto ret;
1651 if (vap->va_atime.tv_sec != VNOVAL) {
1652 if (vp->v_type == VCHR)
1653 vp->v_rdev->si_atime = vap->va_atime;
1654 else
1655 de->de_atime = vap->va_atime;
1656 }
1657 if (vap->va_mtime.tv_sec != VNOVAL) {
1658 if (vp->v_type == VCHR)
1659 vp->v_rdev->si_mtime = vap->va_mtime;
1660 else
1661 de->de_mtime = vap->va_mtime;
1662 }
1663 c = 1;
1664 }
1665
1666 if (c) {
1667 if (vp->v_type == VCHR)
1668 vfs_timestamp(&vp->v_rdev->si_ctime);
1669 else
1670 vfs_timestamp(&de->de_mtime);
1671 }
1672
1673 ret:
1674 sx_xunlock(&VFSTODEVFS(vp->v_mount)->dm_lock);
1675 return (error);
1676 }
1677
1678 #ifdef MAC
1679 static int
devfs_setlabel(struct vop_setlabel_args * ap)1680 devfs_setlabel(struct vop_setlabel_args *ap)
1681 {
1682 struct vnode *vp;
1683 struct devfs_dirent *de;
1684
1685 vp = ap->a_vp;
1686 de = vp->v_data;
1687
1688 mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
1689 mac_devfs_update(vp->v_mount, de, vp);
1690
1691 return (0);
1692 }
1693 #endif
1694
1695 static int
devfs_stat_f(struct file * fp,struct stat * sb,struct ucred * cred,struct thread * td)1696 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
1697 {
1698
1699 return (vnops.fo_stat(fp, sb, cred, td));
1700 }
1701
1702 static int
devfs_symlink(struct vop_symlink_args * ap)1703 devfs_symlink(struct vop_symlink_args *ap)
1704 {
1705 int i, error;
1706 struct devfs_dirent *dd;
1707 struct devfs_dirent *de, *de_covered, *de_dotdot;
1708 struct devfs_mount *dmp;
1709
1710 error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
1711 if (error)
1712 return(error);
1713 dmp = VFSTODEVFS(ap->a_dvp->v_mount);
1714 if (devfs_populate_vp(ap->a_dvp) != 0)
1715 return (ENOENT);
1716
1717 dd = ap->a_dvp->v_data;
1718 de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
1719 de->de_flags = DE_USER;
1720 de->de_uid = 0;
1721 de->de_gid = 0;
1722 de->de_mode = 0755;
1723 de->de_inode = alloc_unr(devfs_inos);
1724 de->de_dir = dd;
1725 de->de_dirent->d_type = DT_LNK;
1726 i = strlen(ap->a_target) + 1;
1727 de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
1728 bcopy(ap->a_target, de->de_symlink, i);
1729 #ifdef MAC
1730 mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
1731 #endif
1732 de_covered = devfs_find(dd, de->de_dirent->d_name,
1733 de->de_dirent->d_namlen, 0);
1734 if (de_covered != NULL) {
1735 if ((de_covered->de_flags & DE_USER) != 0) {
1736 devfs_delete(dmp, de, DEVFS_DEL_NORECURSE);
1737 sx_xunlock(&dmp->dm_lock);
1738 return (EEXIST);
1739 }
1740 KASSERT((de_covered->de_flags & DE_COVERED) == 0,
1741 ("devfs_symlink: entry %p already covered", de_covered));
1742 de_covered->de_flags |= DE_COVERED;
1743 }
1744
1745 de_dotdot = TAILQ_FIRST(&dd->de_dlist); /* "." */
1746 de_dotdot = TAILQ_NEXT(de_dotdot, de_list); /* ".." */
1747 TAILQ_INSERT_AFTER(&dd->de_dlist, de_dotdot, de, de_list);
1748 devfs_dir_ref_de(dmp, dd);
1749 devfs_rules_apply(dmp, de);
1750
1751 return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
1752 }
1753
1754 static int
devfs_truncate_f(struct file * fp,off_t length,struct ucred * cred,struct thread * td)1755 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
1756 {
1757
1758 return (vnops.fo_truncate(fp, length, cred, td));
1759 }
1760
1761 static int
devfs_write_f(struct file * fp,struct uio * uio,struct ucred * cred,int flags,struct thread * td)1762 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred,
1763 int flags, struct thread *td)
1764 {
1765 struct cdev *dev;
1766 int error, ioflag, ref;
1767 ssize_t resid;
1768 struct cdevsw *dsw;
1769 struct file *fpop;
1770
1771 if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1772 return (EINVAL);
1773 fpop = td->td_fpop;
1774 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1775 if (error != 0) {
1776 error = vnops.fo_write(fp, uio, cred, flags, td);
1777 return (error);
1778 }
1779 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
1780 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
1781 if (ioflag & O_DIRECT)
1782 ioflag |= IO_DIRECT;
1783 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
1784
1785 resid = uio->uio_resid;
1786
1787 error = dsw->d_write(dev, uio, ioflag);
1788 if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
1789 devfs_timestamp(&dev->si_ctime);
1790 dev->si_mtime = dev->si_ctime;
1791 }
1792 td->td_fpop = fpop;
1793 dev_relthread(dev, ref);
1794
1795 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF);
1796 return (error);
1797 }
1798
1799 static int
devfs_mmap_f(struct file * fp,vm_map_t map,vm_offset_t * addr,vm_size_t size,vm_prot_t prot,vm_prot_t cap_maxprot,int flags,vm_ooffset_t foff,struct thread * td)1800 devfs_mmap_f(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
1801 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
1802 struct thread *td)
1803 {
1804 struct cdev *dev;
1805 struct cdevsw *dsw;
1806 struct mount *mp;
1807 struct vnode *vp;
1808 struct file *fpop;
1809 vm_object_t object;
1810 vm_prot_t maxprot;
1811 int error, ref;
1812
1813 vp = fp->f_vnode;
1814
1815 /*
1816 * Ensure that file and memory protections are
1817 * compatible.
1818 */
1819 mp = vp->v_mount;
1820 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
1821 maxprot = VM_PROT_NONE;
1822 if ((prot & VM_PROT_EXECUTE) != 0)
1823 return (EACCES);
1824 } else
1825 maxprot = VM_PROT_EXECUTE;
1826 if ((fp->f_flag & FREAD) != 0)
1827 maxprot |= VM_PROT_READ;
1828 else if ((prot & VM_PROT_READ) != 0)
1829 return (EACCES);
1830
1831 /*
1832 * If we are sharing potential changes via MAP_SHARED and we
1833 * are trying to get write permission although we opened it
1834 * without asking for it, bail out.
1835 *
1836 * Note that most character devices always share mappings.
1837 * The one exception is that D_MMAP_ANON devices
1838 * (i.e. /dev/zero) permit private writable mappings.
1839 *
1840 * Rely on vm_mmap_cdev() to fail invalid MAP_PRIVATE requests
1841 * as well as updating maxprot to permit writing for
1842 * D_MMAP_ANON devices rather than doing that here.
1843 */
1844 if ((flags & MAP_SHARED) != 0) {
1845 if ((fp->f_flag & FWRITE) != 0)
1846 maxprot |= VM_PROT_WRITE;
1847 else if ((prot & VM_PROT_WRITE) != 0)
1848 return (EACCES);
1849 }
1850 maxprot &= cap_maxprot;
1851
1852 fpop = td->td_fpop;
1853 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1854 if (error != 0)
1855 return (error);
1856
1857 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, dev, dsw, &foff,
1858 &object);
1859 td->td_fpop = fpop;
1860 dev_relthread(dev, ref);
1861 if (error != 0)
1862 return (error);
1863
1864 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1865 foff, FALSE, td);
1866 if (error != 0)
1867 vm_object_deallocate(object);
1868 return (error);
1869 }
1870
1871 dev_t
dev2udev(struct cdev * x)1872 dev2udev(struct cdev *x)
1873 {
1874 if (x == NULL)
1875 return (NODEV);
1876 return (cdev2priv(x)->cdp_inode);
1877 }
1878
1879 static struct fileops devfs_ops_f = {
1880 .fo_read = devfs_read_f,
1881 .fo_write = devfs_write_f,
1882 .fo_truncate = devfs_truncate_f,
1883 .fo_ioctl = devfs_ioctl_f,
1884 .fo_poll = devfs_poll_f,
1885 .fo_kqfilter = devfs_kqfilter_f,
1886 .fo_stat = devfs_stat_f,
1887 .fo_close = devfs_close_f,
1888 .fo_chmod = vn_chmod,
1889 .fo_chown = vn_chown,
1890 .fo_sendfile = vn_sendfile,
1891 .fo_seek = vn_seek,
1892 .fo_fill_kinfo = vn_fill_kinfo,
1893 .fo_mmap = devfs_mmap_f,
1894 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
1895 };
1896
1897 /* Vops for non-CHR vnodes in /dev. */
1898 static struct vop_vector devfs_vnodeops = {
1899 .vop_default = &default_vnodeops,
1900
1901 .vop_access = devfs_access,
1902 .vop_getattr = devfs_getattr,
1903 .vop_ioctl = devfs_rioctl,
1904 .vop_lookup = devfs_lookup,
1905 .vop_mknod = devfs_mknod,
1906 .vop_pathconf = devfs_pathconf,
1907 .vop_read = devfs_rread,
1908 .vop_readdir = devfs_readdir,
1909 .vop_readlink = devfs_readlink,
1910 .vop_reclaim = devfs_reclaim,
1911 .vop_remove = devfs_remove,
1912 .vop_revoke = devfs_revoke,
1913 .vop_setattr = devfs_setattr,
1914 #ifdef MAC
1915 .vop_setlabel = devfs_setlabel,
1916 #endif
1917 .vop_symlink = devfs_symlink,
1918 .vop_vptocnp = devfs_vptocnp,
1919 };
1920
1921 /* Vops for VCHR vnodes in /dev. */
1922 static struct vop_vector devfs_specops = {
1923 .vop_default = &default_vnodeops,
1924
1925 .vop_access = devfs_access,
1926 .vop_bmap = VOP_PANIC,
1927 .vop_close = devfs_close,
1928 .vop_create = VOP_PANIC,
1929 .vop_fsync = vop_stdfsync,
1930 .vop_getattr = devfs_getattr,
1931 .vop_ioctl = devfs_ioctl,
1932 .vop_link = VOP_PANIC,
1933 .vop_mkdir = VOP_PANIC,
1934 .vop_mknod = VOP_PANIC,
1935 .vop_open = devfs_open,
1936 .vop_pathconf = devfs_pathconf,
1937 .vop_poll = dead_poll,
1938 .vop_print = devfs_print,
1939 .vop_read = dead_read,
1940 .vop_readdir = VOP_PANIC,
1941 .vop_readlink = VOP_PANIC,
1942 .vop_reallocblks = VOP_PANIC,
1943 .vop_reclaim = devfs_reclaim_vchr,
1944 .vop_remove = devfs_remove,
1945 .vop_rename = VOP_PANIC,
1946 .vop_revoke = devfs_revoke,
1947 .vop_rmdir = VOP_PANIC,
1948 .vop_setattr = devfs_setattr,
1949 #ifdef MAC
1950 .vop_setlabel = devfs_setlabel,
1951 #endif
1952 .vop_strategy = VOP_PANIC,
1953 .vop_symlink = VOP_PANIC,
1954 .vop_vptocnp = devfs_vptocnp,
1955 .vop_write = dead_write,
1956 };
1957
1958 /*
1959 * Our calling convention to the device drivers used to be that we passed
1960 * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_
1961 * flags instead since that's what open(), close() and ioctl() takes and
1962 * we don't really want vnode.h in device drivers.
1963 * We solved the source compatibility by redefining some vnode flags to
1964 * be the same as the fcntl ones and by sending down the bitwise OR of
1965 * the respective fcntl/vnode flags. These CTASSERTS make sure nobody
1966 * pulls the rug out under this.
1967 */
1968 CTASSERT(O_NONBLOCK == IO_NDELAY);
1969 CTASSERT(O_FSYNC == IO_SYNC);
1970