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: releng/11.0/sys/fs/devfs/devfs_vnops.c 301928 2016-06-15 15:55:14Z kib $
35 */
36
37 /*
38 * TODO:
39 * mkdir: want it ?
40 */
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/conf.h>
45 #include <sys/dirent.h>
46 #include <sys/fcntl.h>
47 #include <sys/file.h>
48 #include <sys/filedesc.h>
49 #include <sys/filio.h>
50 #include <sys/jail.h>
51 #include <sys/kernel.h>
52 #include <sys/lock.h>
53 #include <sys/malloc.h>
54 #include <sys/mman.h>
55 #include <sys/mount.h>
56 #include <sys/namei.h>
57 #include <sys/priv.h>
58 #include <sys/proc.h>
59 #include <sys/stat.h>
60 #include <sys/sx.h>
61 #include <sys/sysctl.h>
62 #include <sys/time.h>
63 #include <sys/ttycom.h>
64 #include <sys/unistd.h>
65 #include <sys/vnode.h>
66
67 static struct vop_vector devfs_vnodeops;
68 static struct vop_vector devfs_specops;
69 static struct fileops devfs_ops_f;
70
71 #include <fs/devfs/devfs.h>
72 #include <fs/devfs/devfs_int.h>
73
74 #include <security/mac/mac_framework.h>
75
76 #include <vm/vm.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_object.h>
79
80 static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data");
81
82 struct mtx devfs_de_interlock;
83 MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF);
84 struct sx clone_drain_lock;
85 SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock");
86 struct mtx cdevpriv_mtx;
87 MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF);
88
89 SYSCTL_DECL(_vfs_devfs);
90
91 static int devfs_dotimes;
92 SYSCTL_INT(_vfs_devfs, OID_AUTO, dotimes, CTLFLAG_RW,
93 &devfs_dotimes, 0, "Update timestamps on DEVFS with default precision");
94
95 /*
96 * Update devfs node timestamp. Note that updates are unlocked and
97 * stat(2) could see partially updated times.
98 */
99 static void
100 devfs_timestamp(struct timespec *tsp)
101 {
102 time_t ts;
103
104 if (devfs_dotimes) {
105 vfs_timestamp(tsp);
106 } else {
107 ts = time_second;
108 if (tsp->tv_sec != ts) {
109 tsp->tv_sec = ts;
110 tsp->tv_nsec = 0;
111 }
112 }
113 }
114
115 static int
116 devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp,
117 int *ref)
118 {
119
120 *dswp = devvn_refthread(fp->f_vnode, devp, ref);
121 if (*devp != fp->f_data) {
122 if (*dswp != NULL)
123 dev_relthread(*devp, *ref);
124 return (ENXIO);
125 }
126 KASSERT((*devp)->si_refcount > 0,
127 ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
128 if (*dswp == NULL)
129 return (ENXIO);
130 curthread->td_fpop = fp;
131 return (0);
132 }
133
134 int
135 devfs_get_cdevpriv(void **datap)
136 {
137 struct file *fp;
138 struct cdev_privdata *p;
139 int error;
140
141 fp = curthread->td_fpop;
142 if (fp == NULL)
143 return (EBADF);
144 p = fp->f_cdevpriv;
145 if (p != NULL) {
146 error = 0;
147 *datap = p->cdpd_data;
148 } else
149 error = ENOENT;
150 return (error);
151 }
152
153 int
154 devfs_set_cdevpriv(void *priv, d_priv_dtor_t *priv_dtr)
155 {
156 struct file *fp;
157 struct cdev_priv *cdp;
158 struct cdev_privdata *p;
159 int error;
160
161 fp = curthread->td_fpop;
162 if (fp == NULL)
163 return (ENOENT);
164 cdp = cdev2priv((struct cdev *)fp->f_data);
165 p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK);
166 p->cdpd_data = priv;
167 p->cdpd_dtr = priv_dtr;
168 p->cdpd_fp = fp;
169 mtx_lock(&cdevpriv_mtx);
170 if (fp->f_cdevpriv == NULL) {
171 LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list);
172 fp->f_cdevpriv = p;
173 mtx_unlock(&cdevpriv_mtx);
174 error = 0;
175 } else {
176 mtx_unlock(&cdevpriv_mtx);
177 free(p, M_CDEVPDATA);
178 error = EBUSY;
179 }
180 return (error);
181 }
182
183 void
184 devfs_destroy_cdevpriv(struct cdev_privdata *p)
185 {
186
187 mtx_assert(&cdevpriv_mtx, MA_OWNED);
188 KASSERT(p->cdpd_fp->f_cdevpriv == p,
189 ("devfs_destoy_cdevpriv %p != %p", p->cdpd_fp->f_cdevpriv, p));
190 p->cdpd_fp->f_cdevpriv = NULL;
191 LIST_REMOVE(p, cdpd_list);
192 mtx_unlock(&cdevpriv_mtx);
193 (p->cdpd_dtr)(p->cdpd_data);
194 free(p, M_CDEVPDATA);
195 }
196
197 static void
198 devfs_fpdrop(struct file *fp)
199 {
200 struct cdev_privdata *p;
201
202 mtx_lock(&cdevpriv_mtx);
203 if ((p = fp->f_cdevpriv) == NULL) {
204 mtx_unlock(&cdevpriv_mtx);
205 return;
206 }
207 devfs_destroy_cdevpriv(p);
208 }
209
210 void
211 devfs_clear_cdevpriv(void)
212 {
213 struct file *fp;
214
215 fp = curthread->td_fpop;
216 if (fp == NULL)
217 return;
218 devfs_fpdrop(fp);
219 }
220
221 /*
222 * On success devfs_populate_vp() returns with dmp->dm_lock held.
223 */
224 static int
225 devfs_populate_vp(struct vnode *vp)
226 {
227 struct devfs_dirent *de;
228 struct devfs_mount *dmp;
229 int locked;
230
231 ASSERT_VOP_LOCKED(vp, "devfs_populate_vp");
232
233 dmp = VFSTODEVFS(vp->v_mount);
234 locked = VOP_ISLOCKED(vp);
235
236 sx_xlock(&dmp->dm_lock);
237 DEVFS_DMP_HOLD(dmp);
238
239 /* Can't call devfs_populate() with the vnode lock held. */
240 VOP_UNLOCK(vp, 0);
241 devfs_populate(dmp);
242
243 sx_xunlock(&dmp->dm_lock);
244 vn_lock(vp, locked | LK_RETRY);
245 sx_xlock(&dmp->dm_lock);
246 if (DEVFS_DMP_DROP(dmp)) {
247 sx_xunlock(&dmp->dm_lock);
248 devfs_unmount_final(dmp);
249 return (ERESTART);
250 }
251 if ((vp->v_iflag & VI_DOOMED) != 0) {
252 sx_xunlock(&dmp->dm_lock);
253 return (ERESTART);
254 }
255 de = vp->v_data;
256 KASSERT(de != NULL,
257 ("devfs_populate_vp: vp->v_data == NULL but vnode not doomed"));
258 if ((de->de_flags & DE_DOOMED) != 0) {
259 sx_xunlock(&dmp->dm_lock);
260 return (ERESTART);
261 }
262
263 return (0);
264 }
265
266 static int
267 devfs_vptocnp(struct vop_vptocnp_args *ap)
268 {
269 struct vnode *vp = ap->a_vp;
270 struct vnode **dvp = ap->a_vpp;
271 struct devfs_mount *dmp;
272 char *buf = ap->a_buf;
273 int *buflen = ap->a_buflen;
274 struct devfs_dirent *dd, *de;
275 int i, error;
276
277 dmp = VFSTODEVFS(vp->v_mount);
278
279 error = devfs_populate_vp(vp);
280 if (error != 0)
281 return (error);
282
283 i = *buflen;
284 dd = vp->v_data;
285
286 if (vp->v_type == VCHR) {
287 i -= strlen(dd->de_cdp->cdp_c.si_name);
288 if (i < 0) {
289 error = ENOMEM;
290 goto finished;
291 }
292 bcopy(dd->de_cdp->cdp_c.si_name, buf + i,
293 strlen(dd->de_cdp->cdp_c.si_name));
294 de = dd->de_dir;
295 } else if (vp->v_type == VDIR) {
296 if (dd == dmp->dm_rootdir) {
297 *dvp = vp;
298 vref(*dvp);
299 goto finished;
300 }
301 i -= dd->de_dirent->d_namlen;
302 if (i < 0) {
303 error = ENOMEM;
304 goto finished;
305 }
306 bcopy(dd->de_dirent->d_name, buf + i,
307 dd->de_dirent->d_namlen);
308 de = dd;
309 } else {
310 error = ENOENT;
311 goto finished;
312 }
313 *buflen = i;
314 de = devfs_parent_dirent(de);
315 if (de == NULL) {
316 error = ENOENT;
317 goto finished;
318 }
319 mtx_lock(&devfs_de_interlock);
320 *dvp = de->de_vnode;
321 if (*dvp != NULL) {
322 VI_LOCK(*dvp);
323 mtx_unlock(&devfs_de_interlock);
324 vholdl(*dvp);
325 VI_UNLOCK(*dvp);
326 vref(*dvp);
327 vdrop(*dvp);
328 } else {
329 mtx_unlock(&devfs_de_interlock);
330 error = ENOENT;
331 }
332 finished:
333 sx_xunlock(&dmp->dm_lock);
334 return (error);
335 }
336
337 /*
338 * Construct the fully qualified path name relative to the mountpoint.
339 * If a NULL cnp is provided, no '/' is appended to the resulting path.
340 */
341 char *
342 devfs_fqpn(char *buf, struct devfs_mount *dmp, struct devfs_dirent *dd,
343 struct componentname *cnp)
344 {
345 int i;
346 struct devfs_dirent *de;
347
348 sx_assert(&dmp->dm_lock, SA_LOCKED);
349
350 i = SPECNAMELEN;
351 buf[i] = '\0';
352 if (cnp != NULL)
353 i -= cnp->cn_namelen;
354 if (i < 0)
355 return (NULL);
356 if (cnp != NULL)
357 bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
358 de = dd;
359 while (de != dmp->dm_rootdir) {
360 if (cnp != NULL || i < SPECNAMELEN) {
361 i--;
362 if (i < 0)
363 return (NULL);
364 buf[i] = '/';
365 }
366 i -= de->de_dirent->d_namlen;
367 if (i < 0)
368 return (NULL);
369 bcopy(de->de_dirent->d_name, buf + i,
370 de->de_dirent->d_namlen);
371 de = devfs_parent_dirent(de);
372 if (de == NULL)
373 return (NULL);
374 }
375 return (buf + i);
376 }
377
378 static int
379 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
380 struct devfs_dirent *de)
381 {
382 int not_found;
383
384 not_found = 0;
385 if (de->de_flags & DE_DOOMED)
386 not_found = 1;
387 if (DEVFS_DE_DROP(de)) {
388 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
389 devfs_dirent_free(de);
390 }
391 if (DEVFS_DMP_DROP(dmp)) {
392 KASSERT(not_found == 1,
393 ("DEVFS mount struct freed before dirent"));
394 not_found = 2;
395 sx_xunlock(&dmp->dm_lock);
396 devfs_unmount_final(dmp);
397 }
398 if (not_found == 1 || (drop_dm_lock && not_found != 2))
399 sx_unlock(&dmp->dm_lock);
400 return (not_found);
401 }
402
403 static void
404 devfs_insmntque_dtr(struct vnode *vp, void *arg)
405 {
406 struct devfs_dirent *de;
407
408 de = (struct devfs_dirent *)arg;
409 mtx_lock(&devfs_de_interlock);
410 vp->v_data = NULL;
411 de->de_vnode = NULL;
412 mtx_unlock(&devfs_de_interlock);
413 vgone(vp);
414 vput(vp);
415 }
416
417 /*
418 * devfs_allocv shall be entered with dmp->dm_lock held, and it drops
419 * it on return.
420 */
421 int
422 devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode,
423 struct vnode **vpp)
424 {
425 int error;
426 struct vnode *vp;
427 struct cdev *dev;
428 struct devfs_mount *dmp;
429 struct cdevsw *dsw;
430
431 dmp = VFSTODEVFS(mp);
432 if (de->de_flags & DE_DOOMED) {
433 sx_xunlock(&dmp->dm_lock);
434 return (ENOENT);
435 }
436 loop:
437 DEVFS_DE_HOLD(de);
438 DEVFS_DMP_HOLD(dmp);
439 mtx_lock(&devfs_de_interlock);
440 vp = de->de_vnode;
441 if (vp != NULL) {
442 VI_LOCK(vp);
443 mtx_unlock(&devfs_de_interlock);
444 sx_xunlock(&dmp->dm_lock);
445 vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread);
446 sx_xlock(&dmp->dm_lock);
447 if (devfs_allocv_drop_refs(0, dmp, de)) {
448 vput(vp);
449 return (ENOENT);
450 }
451 else if ((vp->v_iflag & VI_DOOMED) != 0) {
452 mtx_lock(&devfs_de_interlock);
453 if (de->de_vnode == vp) {
454 de->de_vnode = NULL;
455 vp->v_data = NULL;
456 }
457 mtx_unlock(&devfs_de_interlock);
458 vput(vp);
459 goto loop;
460 }
461 sx_xunlock(&dmp->dm_lock);
462 *vpp = vp;
463 return (0);
464 }
465 mtx_unlock(&devfs_de_interlock);
466 if (de->de_dirent->d_type == DT_CHR) {
467 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
468 devfs_allocv_drop_refs(1, dmp, de);
469 return (ENOENT);
470 }
471 dev = &de->de_cdp->cdp_c;
472 } else {
473 dev = NULL;
474 }
475 error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
476 if (error != 0) {
477 devfs_allocv_drop_refs(1, dmp, de);
478 printf("devfs_allocv: failed to allocate new vnode\n");
479 return (error);
480 }
481
482 if (de->de_dirent->d_type == DT_CHR) {
483 vp->v_type = VCHR;
484 VI_LOCK(vp);
485 dev_lock();
486 dev_refl(dev);
487 /* XXX: v_rdev should be protect by vnode lock */
488 vp->v_rdev = dev;
489 KASSERT(vp->v_usecount == 1,
490 ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
491 dev->si_usecount += vp->v_usecount;
492 /* Special casing of ttys for deadfs. Probably redundant. */
493 dsw = dev->si_devsw;
494 if (dsw != NULL && (dsw->d_flags & D_TTY) != 0)
495 vp->v_vflag |= VV_ISTTY;
496 dev_unlock();
497 VI_UNLOCK(vp);
498 if ((dev->si_flags & SI_ETERNAL) != 0)
499 vp->v_vflag |= VV_ETERNALDEV;
500 vp->v_op = &devfs_specops;
501 } else if (de->de_dirent->d_type == DT_DIR) {
502 vp->v_type = VDIR;
503 } else if (de->de_dirent->d_type == DT_LNK) {
504 vp->v_type = VLNK;
505 } else {
506 vp->v_type = VBAD;
507 }
508 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
509 VN_LOCK_ASHARE(vp);
510 mtx_lock(&devfs_de_interlock);
511 vp->v_data = de;
512 de->de_vnode = vp;
513 mtx_unlock(&devfs_de_interlock);
514 error = insmntque1(vp, mp, devfs_insmntque_dtr, de);
515 if (error != 0) {
516 (void) devfs_allocv_drop_refs(1, dmp, de);
517 return (error);
518 }
519 if (devfs_allocv_drop_refs(0, dmp, de)) {
520 vput(vp);
521 return (ENOENT);
522 }
523 #ifdef MAC
524 mac_devfs_vnode_associate(mp, de, vp);
525 #endif
526 sx_xunlock(&dmp->dm_lock);
527 *vpp = vp;
528 return (0);
529 }
530
531 static int
532 devfs_access(struct vop_access_args *ap)
533 {
534 struct vnode *vp = ap->a_vp;
535 struct devfs_dirent *de;
536 struct proc *p;
537 int error;
538
539 de = vp->v_data;
540 if (vp->v_type == VDIR)
541 de = de->de_dir;
542
543 error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
544 ap->a_accmode, ap->a_cred, NULL);
545 if (error == 0)
546 return (0);
547 if (error != EACCES)
548 return (error);
549 p = ap->a_td->td_proc;
550 /* We do, however, allow access to the controlling terminal */
551 PROC_LOCK(p);
552 if (!(p->p_flag & P_CONTROLT)) {
553 PROC_UNLOCK(p);
554 return (error);
555 }
556 if (p->p_session->s_ttydp == de->de_cdp)
557 error = 0;
558 PROC_UNLOCK(p);
559 return (error);
560 }
561
562 _Static_assert(((FMASK | FCNTLFLAGS) & (FLASTCLOSE | FREVOKE)) == 0,
563 "devfs-only flag reuse failed");
564
565 static int
566 devfs_close(struct vop_close_args *ap)
567 {
568 struct vnode *vp = ap->a_vp, *oldvp;
569 struct thread *td = ap->a_td;
570 struct proc *p;
571 struct cdev *dev = vp->v_rdev;
572 struct cdevsw *dsw;
573 int dflags, error, ref, vp_locked;
574
575 /*
576 * XXX: Don't call d_close() if we were called because of
577 * XXX: insmntque1() failure.
578 */
579 if (vp->v_data == NULL)
580 return (0);
581
582 /*
583 * Hack: a tty device that is a controlling terminal
584 * has a reference from the session structure.
585 * We cannot easily tell that a character device is
586 * a controlling terminal, unless it is the closing
587 * process' controlling terminal. In that case,
588 * if the reference count is 2 (this last descriptor
589 * plus the session), release the reference from the session.
590 */
591 if (td != NULL) {
592 p = td->td_proc;
593 PROC_LOCK(p);
594 if (vp == p->p_session->s_ttyvp) {
595 PROC_UNLOCK(p);
596 oldvp = NULL;
597 sx_xlock(&proctree_lock);
598 if (vp == p->p_session->s_ttyvp) {
599 SESS_LOCK(p->p_session);
600 VI_LOCK(vp);
601 if (count_dev(dev) == 2 &&
602 (vp->v_iflag & VI_DOOMED) == 0) {
603 p->p_session->s_ttyvp = NULL;
604 p->p_session->s_ttydp = NULL;
605 oldvp = vp;
606 }
607 VI_UNLOCK(vp);
608 SESS_UNLOCK(p->p_session);
609 }
610 sx_xunlock(&proctree_lock);
611 if (oldvp != NULL)
612 vrele(oldvp);
613 } else
614 PROC_UNLOCK(p);
615 }
616 /*
617 * We do not want to really close the device if it
618 * is still in use unless we are trying to close it
619 * forcibly. Since every use (buffer, vnode, swap, cmap)
620 * holds a reference to the vnode, and because we mark
621 * any other vnodes that alias this device, when the
622 * sum of the reference counts on all the aliased
623 * vnodes descends to one, we are on last close.
624 */
625 dsw = dev_refthread(dev, &ref);
626 if (dsw == NULL)
627 return (ENXIO);
628 dflags = 0;
629 VI_LOCK(vp);
630 if (vp->v_iflag & VI_DOOMED) {
631 /* Forced close. */
632 dflags |= FREVOKE | FNONBLOCK;
633 } else if (dsw->d_flags & D_TRACKCLOSE) {
634 /* Keep device updated on status. */
635 } else if (count_dev(dev) > 1) {
636 VI_UNLOCK(vp);
637 dev_relthread(dev, ref);
638 return (0);
639 }
640 if (count_dev(dev) == 1)
641 dflags |= FLASTCLOSE;
642 vholdl(vp);
643 VI_UNLOCK(vp);
644 vp_locked = VOP_ISLOCKED(vp);
645 VOP_UNLOCK(vp, 0);
646 KASSERT(dev->si_refcount > 0,
647 ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
648 error = dsw->d_close(dev, ap->a_fflag | dflags, S_IFCHR, td);
649 dev_relthread(dev, ref);
650 vn_lock(vp, vp_locked | LK_RETRY);
651 vdrop(vp);
652 return (error);
653 }
654
655 static int
656 devfs_close_f(struct file *fp, struct thread *td)
657 {
658 int error;
659 struct file *fpop;
660
661 /*
662 * NB: td may be NULL if this descriptor is closed due to
663 * garbage collection from a closed UNIX domain socket.
664 */
665 fpop = curthread->td_fpop;
666 curthread->td_fpop = fp;
667 error = vnops.fo_close(fp, td);
668 curthread->td_fpop = fpop;
669
670 /*
671 * The f_cdevpriv cannot be assigned non-NULL value while we
672 * are destroying the file.
673 */
674 if (fp->f_cdevpriv != NULL)
675 devfs_fpdrop(fp);
676 return (error);
677 }
678
679 static int
680 devfs_fsync(struct vop_fsync_args *ap)
681 {
682 int error;
683 struct bufobj *bo;
684 struct devfs_dirent *de;
685
686 if (!vn_isdisk(ap->a_vp, &error)) {
687 bo = &ap->a_vp->v_bufobj;
688 de = ap->a_vp->v_data;
689 if (error == ENXIO && bo->bo_dirty.bv_cnt > 0) {
690 printf("Device %s went missing before all of the data "
691 "could be written to it; expect data loss.\n",
692 de->de_dirent->d_name);
693
694 error = vop_stdfsync(ap);
695 if (bo->bo_dirty.bv_cnt != 0 || error != 0)
696 panic("devfs_fsync: vop_stdfsync failed.");
697 }
698
699 return (0);
700 }
701
702 return (vop_stdfsync(ap));
703 }
704
705 static int
706 devfs_getattr(struct vop_getattr_args *ap)
707 {
708 struct vnode *vp = ap->a_vp;
709 struct vattr *vap = ap->a_vap;
710 int error;
711 struct devfs_dirent *de;
712 struct devfs_mount *dmp;
713 struct cdev *dev;
714
715 error = devfs_populate_vp(vp);
716 if (error != 0)
717 return (error);
718
719 dmp = VFSTODEVFS(vp->v_mount);
720 sx_xunlock(&dmp->dm_lock);
721
722 de = vp->v_data;
723 KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
724 if (vp->v_type == VDIR) {
725 de = de->de_dir;
726 KASSERT(de != NULL,
727 ("Null dir dirent in devfs_getattr vp=%p", vp));
728 }
729 vap->va_uid = de->de_uid;
730 vap->va_gid = de->de_gid;
731 vap->va_mode = de->de_mode;
732 if (vp->v_type == VLNK)
733 vap->va_size = strlen(de->de_symlink);
734 else if (vp->v_type == VDIR)
735 vap->va_size = vap->va_bytes = DEV_BSIZE;
736 else
737 vap->va_size = 0;
738 if (vp->v_type != VDIR)
739 vap->va_bytes = 0;
740 vap->va_blocksize = DEV_BSIZE;
741 vap->va_type = vp->v_type;
742
743 #define fix(aa) \
744 do { \
745 if ((aa).tv_sec <= 3600) { \
746 (aa).tv_sec = boottime.tv_sec; \
747 (aa).tv_nsec = boottime.tv_usec * 1000; \
748 } \
749 } while (0)
750
751 if (vp->v_type != VCHR) {
752 fix(de->de_atime);
753 vap->va_atime = de->de_atime;
754 fix(de->de_mtime);
755 vap->va_mtime = de->de_mtime;
756 fix(de->de_ctime);
757 vap->va_ctime = de->de_ctime;
758 } else {
759 dev = vp->v_rdev;
760 fix(dev->si_atime);
761 vap->va_atime = dev->si_atime;
762 fix(dev->si_mtime);
763 vap->va_mtime = dev->si_mtime;
764 fix(dev->si_ctime);
765 vap->va_ctime = dev->si_ctime;
766
767 vap->va_rdev = cdev2priv(dev)->cdp_inode;
768 }
769 vap->va_gen = 0;
770 vap->va_flags = 0;
771 vap->va_filerev = 0;
772 vap->va_nlink = de->de_links;
773 vap->va_fileid = de->de_inode;
774
775 return (error);
776 }
777
778 /* ARGSUSED */
779 static int
780 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
781 {
782 struct cdev *dev;
783 struct cdevsw *dsw;
784 struct vnode *vp;
785 struct vnode *vpold;
786 int error, i, ref;
787 const char *p;
788 struct fiodgname_arg *fgn;
789 struct file *fpop;
790
791 fpop = td->td_fpop;
792 error = devfs_fp_check(fp, &dev, &dsw, &ref);
793 if (error != 0) {
794 error = vnops.fo_ioctl(fp, com, data, cred, td);
795 return (error);
796 }
797
798 if (com == FIODTYPE) {
799 *(int *)data = dsw->d_flags & D_TYPEMASK;
800 td->td_fpop = fpop;
801 dev_relthread(dev, ref);
802 return (0);
803 } else if (com == FIODGNAME) {
804 fgn = data;
805 p = devtoname(dev);
806 i = strlen(p) + 1;
807 if (i > fgn->len)
808 error = EINVAL;
809 else
810 error = copyout(p, fgn->buf, i);
811 td->td_fpop = fpop;
812 dev_relthread(dev, ref);
813 return (error);
814 }
815 error = dsw->d_ioctl(dev, com, data, fp->f_flag, td);
816 td->td_fpop = NULL;
817 dev_relthread(dev, ref);
818 if (error == ENOIOCTL)
819 error = ENOTTY;
820 if (error == 0 && com == TIOCSCTTY) {
821 vp = fp->f_vnode;
822
823 /* Do nothing if reassigning same control tty */
824 sx_slock(&proctree_lock);
825 if (td->td_proc->p_session->s_ttyvp == vp) {
826 sx_sunlock(&proctree_lock);
827 return (0);
828 }
829
830 vpold = td->td_proc->p_session->s_ttyvp;
831 VREF(vp);
832 SESS_LOCK(td->td_proc->p_session);
833 td->td_proc->p_session->s_ttyvp = vp;
834 td->td_proc->p_session->s_ttydp = cdev2priv(dev);
835 SESS_UNLOCK(td->td_proc->p_session);
836
837 sx_sunlock(&proctree_lock);
838
839 /* Get rid of reference to old control tty */
840 if (vpold)
841 vrele(vpold);
842 }
843 return (error);
844 }
845
846 /* ARGSUSED */
847 static int
848 devfs_kqfilter_f(struct file *fp, struct knote *kn)
849 {
850 struct cdev *dev;
851 struct cdevsw *dsw;
852 int error, ref;
853 struct file *fpop;
854 struct thread *td;
855
856 td = curthread;
857 fpop = td->td_fpop;
858 error = devfs_fp_check(fp, &dev, &dsw, &ref);
859 if (error)
860 return (error);
861 error = dsw->d_kqfilter(dev, kn);
862 td->td_fpop = fpop;
863 dev_relthread(dev, ref);
864 return (error);
865 }
866
867 static inline int
868 devfs_prison_check(struct devfs_dirent *de, struct thread *td)
869 {
870 struct cdev_priv *cdp;
871 struct ucred *dcr;
872 struct proc *p;
873 int error;
874
875 cdp = de->de_cdp;
876 if (cdp == NULL)
877 return (0);
878 dcr = cdp->cdp_c.si_cred;
879 if (dcr == NULL)
880 return (0);
881
882 error = prison_check(td->td_ucred, dcr);
883 if (error == 0)
884 return (0);
885 /* We do, however, allow access to the controlling terminal */
886 p = td->td_proc;
887 PROC_LOCK(p);
888 if (!(p->p_flag & P_CONTROLT)) {
889 PROC_UNLOCK(p);
890 return (error);
891 }
892 if (p->p_session->s_ttydp == cdp)
893 error = 0;
894 PROC_UNLOCK(p);
895 return (error);
896 }
897
898 static int
899 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
900 {
901 struct componentname *cnp;
902 struct vnode *dvp, **vpp;
903 struct thread *td;
904 struct devfs_dirent *de, *dd;
905 struct devfs_dirent **dde;
906 struct devfs_mount *dmp;
907 struct cdev *cdev;
908 int error, flags, nameiop, dvplocked;
909 char specname[SPECNAMELEN + 1], *pname;
910
911 cnp = ap->a_cnp;
912 vpp = ap->a_vpp;
913 dvp = ap->a_dvp;
914 pname = cnp->cn_nameptr;
915 td = cnp->cn_thread;
916 flags = cnp->cn_flags;
917 nameiop = cnp->cn_nameiop;
918 dmp = VFSTODEVFS(dvp->v_mount);
919 dd = dvp->v_data;
920 *vpp = NULLVP;
921
922 if ((flags & ISLASTCN) && nameiop == RENAME)
923 return (EOPNOTSUPP);
924
925 if (dvp->v_type != VDIR)
926 return (ENOTDIR);
927
928 if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
929 return (EIO);
930
931 error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
932 if (error)
933 return (error);
934
935 if (cnp->cn_namelen == 1 && *pname == '.') {
936 if ((flags & ISLASTCN) && nameiop != LOOKUP)
937 return (EINVAL);
938 *vpp = dvp;
939 VREF(dvp);
940 return (0);
941 }
942
943 if (flags & ISDOTDOT) {
944 if ((flags & ISLASTCN) && nameiop != LOOKUP)
945 return (EINVAL);
946 de = devfs_parent_dirent(dd);
947 if (de == NULL)
948 return (ENOENT);
949 dvplocked = VOP_ISLOCKED(dvp);
950 VOP_UNLOCK(dvp, 0);
951 error = devfs_allocv(de, dvp->v_mount,
952 cnp->cn_lkflags & LK_TYPE_MASK, vpp);
953 *dm_unlock = 0;
954 vn_lock(dvp, dvplocked | LK_RETRY);
955 return (error);
956 }
957
958 dd = dvp->v_data;
959 de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen, 0);
960 while (de == NULL) { /* While(...) so we can use break */
961
962 if (nameiop == DELETE)
963 return (ENOENT);
964
965 /*
966 * OK, we didn't have an entry for the name we were asked for
967 * so we try to see if anybody can create it on demand.
968 */
969 pname = devfs_fqpn(specname, dmp, dd, cnp);
970 if (pname == NULL)
971 break;
972
973 cdev = NULL;
974 DEVFS_DMP_HOLD(dmp);
975 sx_xunlock(&dmp->dm_lock);
976 sx_slock(&clone_drain_lock);
977 EVENTHANDLER_INVOKE(dev_clone,
978 td->td_ucred, pname, strlen(pname), &cdev);
979 sx_sunlock(&clone_drain_lock);
980
981 if (cdev == NULL)
982 sx_xlock(&dmp->dm_lock);
983 else if (devfs_populate_vp(dvp) != 0) {
984 *dm_unlock = 0;
985 sx_xlock(&dmp->dm_lock);
986 if (DEVFS_DMP_DROP(dmp)) {
987 sx_xunlock(&dmp->dm_lock);
988 devfs_unmount_final(dmp);
989 } else
990 sx_xunlock(&dmp->dm_lock);
991 dev_rel(cdev);
992 return (ENOENT);
993 }
994 if (DEVFS_DMP_DROP(dmp)) {
995 *dm_unlock = 0;
996 sx_xunlock(&dmp->dm_lock);
997 devfs_unmount_final(dmp);
998 if (cdev != NULL)
999 dev_rel(cdev);
1000 return (ENOENT);
1001 }
1002
1003 if (cdev == NULL)
1004 break;
1005
1006 dev_lock();
1007 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
1008 if (dde != NULL && *dde != NULL)
1009 de = *dde;
1010 dev_unlock();
1011 dev_rel(cdev);
1012 break;
1013 }
1014
1015 if (de == NULL || de->de_flags & DE_WHITEOUT) {
1016 if ((nameiop == CREATE || nameiop == RENAME) &&
1017 (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
1018 cnp->cn_flags |= SAVENAME;
1019 return (EJUSTRETURN);
1020 }
1021 return (ENOENT);
1022 }
1023
1024 if (devfs_prison_check(de, td))
1025 return (ENOENT);
1026
1027 if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
1028 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
1029 if (error)
1030 return (error);
1031 if (*vpp == dvp) {
1032 VREF(dvp);
1033 *vpp = dvp;
1034 return (0);
1035 }
1036 }
1037 error = devfs_allocv(de, dvp->v_mount, cnp->cn_lkflags & LK_TYPE_MASK,
1038 vpp);
1039 *dm_unlock = 0;
1040 return (error);
1041 }
1042
1043 static int
1044 devfs_lookup(struct vop_lookup_args *ap)
1045 {
1046 int j;
1047 struct devfs_mount *dmp;
1048 int dm_unlock;
1049
1050 if (devfs_populate_vp(ap->a_dvp) != 0)
1051 return (ENOTDIR);
1052
1053 dmp = VFSTODEVFS(ap->a_dvp->v_mount);
1054 dm_unlock = 1;
1055 j = devfs_lookupx(ap, &dm_unlock);
1056 if (dm_unlock == 1)
1057 sx_xunlock(&dmp->dm_lock);
1058 return (j);
1059 }
1060
1061 static int
1062 devfs_mknod(struct vop_mknod_args *ap)
1063 {
1064 struct componentname *cnp;
1065 struct vnode *dvp, **vpp;
1066 struct devfs_dirent *dd, *de;
1067 struct devfs_mount *dmp;
1068 int error;
1069
1070 /*
1071 * The only type of node we should be creating here is a
1072 * character device, for anything else return EOPNOTSUPP.
1073 */
1074 if (ap->a_vap->va_type != VCHR)
1075 return (EOPNOTSUPP);
1076 dvp = ap->a_dvp;
1077 dmp = VFSTODEVFS(dvp->v_mount);
1078
1079 cnp = ap->a_cnp;
1080 vpp = ap->a_vpp;
1081 dd = dvp->v_data;
1082
1083 error = ENOENT;
1084 sx_xlock(&dmp->dm_lock);
1085 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
1086 if (cnp->cn_namelen != de->de_dirent->d_namlen)
1087 continue;
1088 if (de->de_dirent->d_type == DT_CHR &&
1089 (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
1090 continue;
1091 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
1092 de->de_dirent->d_namlen) != 0)
1093 continue;
1094 if (de->de_flags & DE_WHITEOUT)
1095 break;
1096 goto notfound;
1097 }
1098 if (de == NULL)
1099 goto notfound;
1100 de->de_flags &= ~DE_WHITEOUT;
1101 error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp);
1102 return (error);
1103 notfound:
1104 sx_xunlock(&dmp->dm_lock);
1105 return (error);
1106 }
1107
1108 /* ARGSUSED */
1109 static int
1110 devfs_open(struct vop_open_args *ap)
1111 {
1112 struct thread *td = ap->a_td;
1113 struct vnode *vp = ap->a_vp;
1114 struct cdev *dev = vp->v_rdev;
1115 struct file *fp = ap->a_fp;
1116 int error, ref, vlocked;
1117 struct cdevsw *dsw;
1118 struct file *fpop;
1119 struct mtx *mtxp;
1120
1121 if (vp->v_type == VBLK)
1122 return (ENXIO);
1123
1124 if (dev == NULL)
1125 return (ENXIO);
1126
1127 /* Make this field valid before any I/O in d_open. */
1128 if (dev->si_iosize_max == 0)
1129 dev->si_iosize_max = DFLTPHYS;
1130
1131 dsw = dev_refthread(dev, &ref);
1132 if (dsw == NULL)
1133 return (ENXIO);
1134 if (fp == NULL && dsw->d_fdopen != NULL) {
1135 dev_relthread(dev, ref);
1136 return (ENXIO);
1137 }
1138
1139 vlocked = VOP_ISLOCKED(vp);
1140 VOP_UNLOCK(vp, 0);
1141
1142 fpop = td->td_fpop;
1143 td->td_fpop = fp;
1144 if (fp != NULL) {
1145 fp->f_data = dev;
1146 fp->f_vnode = vp;
1147 }
1148 if (dsw->d_fdopen != NULL)
1149 error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
1150 else
1151 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
1152 /* Clean up any cdevpriv upon error. */
1153 if (error != 0)
1154 devfs_clear_cdevpriv();
1155 td->td_fpop = fpop;
1156
1157 vn_lock(vp, vlocked | LK_RETRY);
1158 dev_relthread(dev, ref);
1159 if (error != 0) {
1160 if (error == ERESTART)
1161 error = EINTR;
1162 return (error);
1163 }
1164
1165 #if 0 /* /dev/console */
1166 KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp"));
1167 #else
1168 if (fp == NULL)
1169 return (error);
1170 #endif
1171 if (fp->f_ops == &badfileops)
1172 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
1173 mtxp = mtx_pool_find(mtxpool_sleep, fp);
1174
1175 /*
1176 * Hint to the dofilewrite() to not force the buffer draining
1177 * on the writer to the file. Most likely, the write would
1178 * not need normal buffers.
1179 */
1180 mtx_lock(mtxp);
1181 fp->f_vnread_flags |= FDEVFS_VNODE;
1182 mtx_unlock(mtxp);
1183 return (error);
1184 }
1185
1186 static int
1187 devfs_pathconf(struct vop_pathconf_args *ap)
1188 {
1189
1190 switch (ap->a_name) {
1191 case _PC_MAC_PRESENT:
1192 #ifdef MAC
1193 /*
1194 * If MAC is enabled, devfs automatically supports
1195 * trivial non-persistant label storage.
1196 */
1197 *ap->a_retval = 1;
1198 #else
1199 *ap->a_retval = 0;
1200 #endif
1201 return (0);
1202 default:
1203 return (vop_stdpathconf(ap));
1204 }
1205 /* NOTREACHED */
1206 }
1207
1208 /* ARGSUSED */
1209 static int
1210 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
1211 {
1212 struct cdev *dev;
1213 struct cdevsw *dsw;
1214 int error, ref;
1215 struct file *fpop;
1216
1217 fpop = td->td_fpop;
1218 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1219 if (error != 0) {
1220 error = vnops.fo_poll(fp, events, cred, td);
1221 return (error);
1222 }
1223 error = dsw->d_poll(dev, events, td);
1224 td->td_fpop = fpop;
1225 dev_relthread(dev, ref);
1226 return(error);
1227 }
1228
1229 /*
1230 * Print out the contents of a special device vnode.
1231 */
1232 static int
1233 devfs_print(struct vop_print_args *ap)
1234 {
1235
1236 printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
1237 return (0);
1238 }
1239
1240 static int
1241 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred,
1242 int flags, struct thread *td)
1243 {
1244 struct cdev *dev;
1245 int ioflag, error, ref;
1246 ssize_t resid;
1247 struct cdevsw *dsw;
1248 struct file *fpop;
1249
1250 if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1251 return (EINVAL);
1252 fpop = td->td_fpop;
1253 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1254 if (error != 0) {
1255 error = vnops.fo_read(fp, uio, cred, flags, td);
1256 return (error);
1257 }
1258 resid = uio->uio_resid;
1259 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
1260 if (ioflag & O_DIRECT)
1261 ioflag |= IO_DIRECT;
1262
1263 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
1264 error = dsw->d_read(dev, uio, ioflag);
1265 if (uio->uio_resid != resid || (error == 0 && resid != 0))
1266 devfs_timestamp(&dev->si_atime);
1267 td->td_fpop = fpop;
1268 dev_relthread(dev, ref);
1269
1270 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF);
1271 return (error);
1272 }
1273
1274 static int
1275 devfs_readdir(struct vop_readdir_args *ap)
1276 {
1277 int error;
1278 struct uio *uio;
1279 struct dirent *dp;
1280 struct devfs_dirent *dd;
1281 struct devfs_dirent *de;
1282 struct devfs_mount *dmp;
1283 off_t off;
1284 int *tmp_ncookies = NULL;
1285
1286 if (ap->a_vp->v_type != VDIR)
1287 return (ENOTDIR);
1288
1289 uio = ap->a_uio;
1290 if (uio->uio_offset < 0)
1291 return (EINVAL);
1292
1293 /*
1294 * XXX: This is a temporary hack to get around this filesystem not
1295 * supporting cookies. We store the location of the ncookies pointer
1296 * in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
1297 * and set the number of cookies to 0. We then set the pointer to
1298 * NULL so that vfs_read_dirent doesn't try to call realloc() on
1299 * ap->a_cookies. Later in this function, we restore the ap->a_ncookies
1300 * pointer to its original location before returning to the caller.
1301 */
1302 if (ap->a_ncookies != NULL) {
1303 tmp_ncookies = ap->a_ncookies;
1304 *ap->a_ncookies = 0;
1305 ap->a_ncookies = NULL;
1306 }
1307
1308 dmp = VFSTODEVFS(ap->a_vp->v_mount);
1309 if (devfs_populate_vp(ap->a_vp) != 0) {
1310 if (tmp_ncookies != NULL)
1311 ap->a_ncookies = tmp_ncookies;
1312 return (EIO);
1313 }
1314 error = 0;
1315 de = ap->a_vp->v_data;
1316 off = 0;
1317 TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
1318 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
1319 if (dd->de_flags & (DE_COVERED | DE_WHITEOUT))
1320 continue;
1321 if (devfs_prison_check(dd, uio->uio_td))
1322 continue;
1323 if (dd->de_dirent->d_type == DT_DIR)
1324 de = dd->de_dir;
1325 else
1326 de = dd;
1327 dp = dd->de_dirent;
1328 if (dp->d_reclen > uio->uio_resid)
1329 break;
1330 dp->d_fileno = de->de_inode;
1331 if (off >= uio->uio_offset) {
1332 error = vfs_read_dirent(ap, dp, off);
1333 if (error)
1334 break;
1335 }
1336 off += dp->d_reclen;
1337 }
1338 sx_xunlock(&dmp->dm_lock);
1339 uio->uio_offset = off;
1340
1341 /*
1342 * Restore ap->a_ncookies if it wasn't originally NULL in the first
1343 * place.
1344 */
1345 if (tmp_ncookies != NULL)
1346 ap->a_ncookies = tmp_ncookies;
1347
1348 return (error);
1349 }
1350
1351 static int
1352 devfs_readlink(struct vop_readlink_args *ap)
1353 {
1354 struct devfs_dirent *de;
1355
1356 de = ap->a_vp->v_data;
1357 return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
1358 }
1359
1360 static int
1361 devfs_reclaim(struct vop_reclaim_args *ap)
1362 {
1363 struct vnode *vp;
1364 struct devfs_dirent *de;
1365
1366 vp = ap->a_vp;
1367 mtx_lock(&devfs_de_interlock);
1368 de = vp->v_data;
1369 if (de != NULL) {
1370 de->de_vnode = NULL;
1371 vp->v_data = NULL;
1372 }
1373 mtx_unlock(&devfs_de_interlock);
1374 vnode_destroy_vobject(vp);
1375 return (0);
1376 }
1377
1378 static int
1379 devfs_reclaim_vchr(struct vop_reclaim_args *ap)
1380 {
1381 struct vnode *vp;
1382 struct cdev *dev;
1383
1384 vp = ap->a_vp;
1385 MPASS(vp->v_type == VCHR);
1386
1387 devfs_reclaim(ap);
1388
1389 VI_LOCK(vp);
1390 dev_lock();
1391 dev = vp->v_rdev;
1392 vp->v_rdev = NULL;
1393 if (dev != NULL)
1394 dev->si_usecount -= vp->v_usecount;
1395 dev_unlock();
1396 VI_UNLOCK(vp);
1397 if (dev != NULL)
1398 dev_rel(dev);
1399 return (0);
1400 }
1401
1402 static int
1403 devfs_remove(struct vop_remove_args *ap)
1404 {
1405 struct vnode *dvp = ap->a_dvp;
1406 struct vnode *vp = ap->a_vp;
1407 struct devfs_dirent *dd;
1408 struct devfs_dirent *de, *de_covered;
1409 struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
1410
1411 ASSERT_VOP_ELOCKED(dvp, "devfs_remove");
1412 ASSERT_VOP_ELOCKED(vp, "devfs_remove");
1413
1414 sx_xlock(&dmp->dm_lock);
1415 dd = ap->a_dvp->v_data;
1416 de = vp->v_data;
1417 if (de->de_cdp == NULL) {
1418 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
1419 if (de->de_dirent->d_type == DT_LNK) {
1420 de_covered = devfs_find(dd, de->de_dirent->d_name,
1421 de->de_dirent->d_namlen, 0);
1422 if (de_covered != NULL)
1423 de_covered->de_flags &= ~DE_COVERED;
1424 }
1425 /* We need to unlock dvp because devfs_delete() may lock it. */
1426 VOP_UNLOCK(vp, 0);
1427 if (dvp != vp)
1428 VOP_UNLOCK(dvp, 0);
1429 devfs_delete(dmp, de, 0);
1430 sx_xunlock(&dmp->dm_lock);
1431 if (dvp != vp)
1432 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1433 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1434 } else {
1435 de->de_flags |= DE_WHITEOUT;
1436 sx_xunlock(&dmp->dm_lock);
1437 }
1438 return (0);
1439 }
1440
1441 /*
1442 * Revoke is called on a tty when a terminal session ends. The vnode
1443 * is orphaned by setting v_op to deadfs so we need to let go of it
1444 * as well so that we create a new one next time around.
1445 *
1446 */
1447 static int
1448 devfs_revoke(struct vop_revoke_args *ap)
1449 {
1450 struct vnode *vp = ap->a_vp, *vp2;
1451 struct cdev *dev;
1452 struct cdev_priv *cdp;
1453 struct devfs_dirent *de;
1454 u_int i;
1455
1456 KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
1457
1458 dev = vp->v_rdev;
1459 cdp = cdev2priv(dev);
1460
1461 dev_lock();
1462 cdp->cdp_inuse++;
1463 dev_unlock();
1464
1465 vhold(vp);
1466 vgone(vp);
1467 vdrop(vp);
1468
1469 VOP_UNLOCK(vp,0);
1470 loop:
1471 for (;;) {
1472 mtx_lock(&devfs_de_interlock);
1473 dev_lock();
1474 vp2 = NULL;
1475 for (i = 0; i <= cdp->cdp_maxdirent; i++) {
1476 de = cdp->cdp_dirents[i];
1477 if (de == NULL)
1478 continue;
1479
1480 vp2 = de->de_vnode;
1481 if (vp2 != NULL) {
1482 dev_unlock();
1483 VI_LOCK(vp2);
1484 mtx_unlock(&devfs_de_interlock);
1485 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
1486 curthread))
1487 goto loop;
1488 vhold(vp2);
1489 vgone(vp2);
1490 vdrop(vp2);
1491 vput(vp2);
1492 break;
1493 }
1494 }
1495 if (vp2 != NULL) {
1496 continue;
1497 }
1498 dev_unlock();
1499 mtx_unlock(&devfs_de_interlock);
1500 break;
1501 }
1502 dev_lock();
1503 cdp->cdp_inuse--;
1504 if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
1505 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
1506 dev_unlock();
1507 dev_rel(&cdp->cdp_c);
1508 } else
1509 dev_unlock();
1510
1511 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1512 return (0);
1513 }
1514
1515 static int
1516 devfs_rioctl(struct vop_ioctl_args *ap)
1517 {
1518 struct vnode *vp;
1519 struct devfs_mount *dmp;
1520 int error;
1521
1522 vp = ap->a_vp;
1523 vn_lock(vp, LK_SHARED | LK_RETRY);
1524 if (vp->v_iflag & VI_DOOMED) {
1525 VOP_UNLOCK(vp, 0);
1526 return (EBADF);
1527 }
1528 dmp = VFSTODEVFS(vp->v_mount);
1529 sx_xlock(&dmp->dm_lock);
1530 VOP_UNLOCK(vp, 0);
1531 DEVFS_DMP_HOLD(dmp);
1532 devfs_populate(dmp);
1533 if (DEVFS_DMP_DROP(dmp)) {
1534 sx_xunlock(&dmp->dm_lock);
1535 devfs_unmount_final(dmp);
1536 return (ENOENT);
1537 }
1538 error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
1539 sx_xunlock(&dmp->dm_lock);
1540 return (error);
1541 }
1542
1543 static int
1544 devfs_rread(struct vop_read_args *ap)
1545 {
1546
1547 if (ap->a_vp->v_type != VDIR)
1548 return (EINVAL);
1549 return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
1550 }
1551
1552 static int
1553 devfs_setattr(struct vop_setattr_args *ap)
1554 {
1555 struct devfs_dirent *de;
1556 struct vattr *vap;
1557 struct vnode *vp;
1558 struct thread *td;
1559 int c, error;
1560 uid_t uid;
1561 gid_t gid;
1562
1563 vap = ap->a_vap;
1564 vp = ap->a_vp;
1565 td = curthread;
1566 if ((vap->va_type != VNON) ||
1567 (vap->va_nlink != VNOVAL) ||
1568 (vap->va_fsid != VNOVAL) ||
1569 (vap->va_fileid != VNOVAL) ||
1570 (vap->va_blocksize != VNOVAL) ||
1571 (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
1572 (vap->va_rdev != VNOVAL) ||
1573 ((int)vap->va_bytes != VNOVAL) ||
1574 (vap->va_gen != VNOVAL)) {
1575 return (EINVAL);
1576 }
1577
1578 error = devfs_populate_vp(vp);
1579 if (error != 0)
1580 return (error);
1581
1582 de = vp->v_data;
1583 if (vp->v_type == VDIR)
1584 de = de->de_dir;
1585
1586 c = 0;
1587 if (vap->va_uid == (uid_t)VNOVAL)
1588 uid = de->de_uid;
1589 else
1590 uid = vap->va_uid;
1591 if (vap->va_gid == (gid_t)VNOVAL)
1592 gid = de->de_gid;
1593 else
1594 gid = vap->va_gid;
1595 if (uid != de->de_uid || gid != de->de_gid) {
1596 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
1597 (gid != de->de_gid && !groupmember(gid, ap->a_cred))) {
1598 error = priv_check(td, PRIV_VFS_CHOWN);
1599 if (error != 0)
1600 goto ret;
1601 }
1602 de->de_uid = uid;
1603 de->de_gid = gid;
1604 c = 1;
1605 }
1606
1607 if (vap->va_mode != (mode_t)VNOVAL) {
1608 if (ap->a_cred->cr_uid != de->de_uid) {
1609 error = priv_check(td, PRIV_VFS_ADMIN);
1610 if (error != 0)
1611 goto ret;
1612 }
1613 de->de_mode = vap->va_mode;
1614 c = 1;
1615 }
1616
1617 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
1618 error = vn_utimes_perm(vp, vap, ap->a_cred, td);
1619 if (error != 0)
1620 goto ret;
1621 if (vap->va_atime.tv_sec != VNOVAL) {
1622 if (vp->v_type == VCHR)
1623 vp->v_rdev->si_atime = vap->va_atime;
1624 else
1625 de->de_atime = vap->va_atime;
1626 }
1627 if (vap->va_mtime.tv_sec != VNOVAL) {
1628 if (vp->v_type == VCHR)
1629 vp->v_rdev->si_mtime = vap->va_mtime;
1630 else
1631 de->de_mtime = vap->va_mtime;
1632 }
1633 c = 1;
1634 }
1635
1636 if (c) {
1637 if (vp->v_type == VCHR)
1638 vfs_timestamp(&vp->v_rdev->si_ctime);
1639 else
1640 vfs_timestamp(&de->de_mtime);
1641 }
1642
1643 ret:
1644 sx_xunlock(&VFSTODEVFS(vp->v_mount)->dm_lock);
1645 return (error);
1646 }
1647
1648 #ifdef MAC
1649 static int
1650 devfs_setlabel(struct vop_setlabel_args *ap)
1651 {
1652 struct vnode *vp;
1653 struct devfs_dirent *de;
1654
1655 vp = ap->a_vp;
1656 de = vp->v_data;
1657
1658 mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
1659 mac_devfs_update(vp->v_mount, de, vp);
1660
1661 return (0);
1662 }
1663 #endif
1664
1665 static int
1666 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
1667 {
1668
1669 return (vnops.fo_stat(fp, sb, cred, td));
1670 }
1671
1672 static int
1673 devfs_symlink(struct vop_symlink_args *ap)
1674 {
1675 int i, error;
1676 struct devfs_dirent *dd;
1677 struct devfs_dirent *de, *de_covered, *de_dotdot;
1678 struct devfs_mount *dmp;
1679
1680 error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
1681 if (error)
1682 return(error);
1683 dmp = VFSTODEVFS(ap->a_dvp->v_mount);
1684 if (devfs_populate_vp(ap->a_dvp) != 0)
1685 return (ENOENT);
1686
1687 dd = ap->a_dvp->v_data;
1688 de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
1689 de->de_flags = DE_USER;
1690 de->de_uid = 0;
1691 de->de_gid = 0;
1692 de->de_mode = 0755;
1693 de->de_inode = alloc_unr(devfs_inos);
1694 de->de_dir = dd;
1695 de->de_dirent->d_type = DT_LNK;
1696 i = strlen(ap->a_target) + 1;
1697 de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
1698 bcopy(ap->a_target, de->de_symlink, i);
1699 #ifdef MAC
1700 mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
1701 #endif
1702 de_covered = devfs_find(dd, de->de_dirent->d_name,
1703 de->de_dirent->d_namlen, 0);
1704 if (de_covered != NULL) {
1705 if ((de_covered->de_flags & DE_USER) != 0) {
1706 devfs_delete(dmp, de, DEVFS_DEL_NORECURSE);
1707 sx_xunlock(&dmp->dm_lock);
1708 return (EEXIST);
1709 }
1710 KASSERT((de_covered->de_flags & DE_COVERED) == 0,
1711 ("devfs_symlink: entry %p already covered", de_covered));
1712 de_covered->de_flags |= DE_COVERED;
1713 }
1714
1715 de_dotdot = TAILQ_FIRST(&dd->de_dlist); /* "." */
1716 de_dotdot = TAILQ_NEXT(de_dotdot, de_list); /* ".." */
1717 TAILQ_INSERT_AFTER(&dd->de_dlist, de_dotdot, de, de_list);
1718 devfs_dir_ref_de(dmp, dd);
1719 devfs_rules_apply(dmp, de);
1720
1721 return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
1722 }
1723
1724 static int
1725 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
1726 {
1727
1728 return (vnops.fo_truncate(fp, length, cred, td));
1729 }
1730
1731 static int
1732 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred,
1733 int flags, struct thread *td)
1734 {
1735 struct cdev *dev;
1736 int error, ioflag, ref;
1737 ssize_t resid;
1738 struct cdevsw *dsw;
1739 struct file *fpop;
1740
1741 if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1742 return (EINVAL);
1743 fpop = td->td_fpop;
1744 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1745 if (error != 0) {
1746 error = vnops.fo_write(fp, uio, cred, flags, td);
1747 return (error);
1748 }
1749 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
1750 ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
1751 if (ioflag & O_DIRECT)
1752 ioflag |= IO_DIRECT;
1753 foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
1754
1755 resid = uio->uio_resid;
1756
1757 error = dsw->d_write(dev, uio, ioflag);
1758 if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
1759 devfs_timestamp(&dev->si_ctime);
1760 dev->si_mtime = dev->si_ctime;
1761 }
1762 td->td_fpop = fpop;
1763 dev_relthread(dev, ref);
1764
1765 foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF);
1766 return (error);
1767 }
1768
1769 static int
1770 devfs_mmap_f(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
1771 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
1772 struct thread *td)
1773 {
1774 struct cdev *dev;
1775 struct cdevsw *dsw;
1776 struct mount *mp;
1777 struct vnode *vp;
1778 struct file *fpop;
1779 vm_object_t object;
1780 vm_prot_t maxprot;
1781 int error, ref;
1782
1783 vp = fp->f_vnode;
1784
1785 /*
1786 * Ensure that file and memory protections are
1787 * compatible.
1788 */
1789 mp = vp->v_mount;
1790 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0)
1791 maxprot = VM_PROT_NONE;
1792 else
1793 maxprot = VM_PROT_EXECUTE;
1794 if ((fp->f_flag & FREAD) != 0)
1795 maxprot |= VM_PROT_READ;
1796 else if ((prot & VM_PROT_READ) != 0)
1797 return (EACCES);
1798
1799 /*
1800 * If we are sharing potential changes via MAP_SHARED and we
1801 * are trying to get write permission although we opened it
1802 * without asking for it, bail out.
1803 *
1804 * Note that most character devices always share mappings.
1805 * The one exception is that D_MMAP_ANON devices
1806 * (i.e. /dev/zero) permit private writable mappings.
1807 *
1808 * Rely on vm_mmap_cdev() to fail invalid MAP_PRIVATE requests
1809 * as well as updating maxprot to permit writing for
1810 * D_MMAP_ANON devices rather than doing that here.
1811 */
1812 if ((flags & MAP_SHARED) != 0) {
1813 if ((fp->f_flag & FWRITE) != 0)
1814 maxprot |= VM_PROT_WRITE;
1815 else if ((prot & VM_PROT_WRITE) != 0)
1816 return (EACCES);
1817 }
1818 maxprot &= cap_maxprot;
1819
1820 fpop = td->td_fpop;
1821 error = devfs_fp_check(fp, &dev, &dsw, &ref);
1822 if (error != 0)
1823 return (error);
1824
1825 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, dev, dsw, &foff,
1826 &object);
1827 td->td_fpop = fpop;
1828 dev_relthread(dev, ref);
1829 if (error != 0)
1830 return (error);
1831
1832 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1833 foff, FALSE, td);
1834 if (error != 0)
1835 vm_object_deallocate(object);
1836 return (error);
1837 }
1838
1839 dev_t
1840 dev2udev(struct cdev *x)
1841 {
1842 if (x == NULL)
1843 return (NODEV);
1844 return (cdev2priv(x)->cdp_inode);
1845 }
1846
1847 static struct fileops devfs_ops_f = {
1848 .fo_read = devfs_read_f,
1849 .fo_write = devfs_write_f,
1850 .fo_truncate = devfs_truncate_f,
1851 .fo_ioctl = devfs_ioctl_f,
1852 .fo_poll = devfs_poll_f,
1853 .fo_kqfilter = devfs_kqfilter_f,
1854 .fo_stat = devfs_stat_f,
1855 .fo_close = devfs_close_f,
1856 .fo_chmod = vn_chmod,
1857 .fo_chown = vn_chown,
1858 .fo_sendfile = vn_sendfile,
1859 .fo_seek = vn_seek,
1860 .fo_fill_kinfo = vn_fill_kinfo,
1861 .fo_mmap = devfs_mmap_f,
1862 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
1863 };
1864
1865 static struct vop_vector devfs_vnodeops = {
1866 .vop_default = &default_vnodeops,
1867
1868 .vop_access = devfs_access,
1869 .vop_getattr = devfs_getattr,
1870 .vop_ioctl = devfs_rioctl,
1871 .vop_lookup = devfs_lookup,
1872 .vop_mknod = devfs_mknod,
1873 .vop_pathconf = devfs_pathconf,
1874 .vop_read = devfs_rread,
1875 .vop_readdir = devfs_readdir,
1876 .vop_readlink = devfs_readlink,
1877 .vop_reclaim = devfs_reclaim,
1878 .vop_remove = devfs_remove,
1879 .vop_revoke = devfs_revoke,
1880 .vop_setattr = devfs_setattr,
1881 #ifdef MAC
1882 .vop_setlabel = devfs_setlabel,
1883 #endif
1884 .vop_symlink = devfs_symlink,
1885 .vop_vptocnp = devfs_vptocnp,
1886 };
1887
1888 static struct vop_vector devfs_specops = {
1889 .vop_default = &default_vnodeops,
1890
1891 .vop_access = devfs_access,
1892 .vop_bmap = VOP_PANIC,
1893 .vop_close = devfs_close,
1894 .vop_create = VOP_PANIC,
1895 .vop_fsync = devfs_fsync,
1896 .vop_getattr = devfs_getattr,
1897 .vop_link = VOP_PANIC,
1898 .vop_mkdir = VOP_PANIC,
1899 .vop_mknod = VOP_PANIC,
1900 .vop_open = devfs_open,
1901 .vop_pathconf = devfs_pathconf,
1902 .vop_poll = dead_poll,
1903 .vop_print = devfs_print,
1904 .vop_read = dead_read,
1905 .vop_readdir = VOP_PANIC,
1906 .vop_readlink = VOP_PANIC,
1907 .vop_reallocblks = VOP_PANIC,
1908 .vop_reclaim = devfs_reclaim_vchr,
1909 .vop_remove = devfs_remove,
1910 .vop_rename = VOP_PANIC,
1911 .vop_revoke = devfs_revoke,
1912 .vop_rmdir = VOP_PANIC,
1913 .vop_setattr = devfs_setattr,
1914 #ifdef MAC
1915 .vop_setlabel = devfs_setlabel,
1916 #endif
1917 .vop_strategy = VOP_PANIC,
1918 .vop_symlink = VOP_PANIC,
1919 .vop_vptocnp = devfs_vptocnp,
1920 .vop_write = dead_write,
1921 };
1922
1923 /*
1924 * Our calling convention to the device drivers used to be that we passed
1925 * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_
1926 * flags instead since that's what open(), close() and ioctl() takes and
1927 * we don't really want vnode.h in device drivers.
1928 * We solved the source compatibility by redefining some vnode flags to
1929 * be the same as the fcntl ones and by sending down the bitwise OR of
1930 * the respective fcntl/vnode flags. These CTASSERTS make sure nobody
1931 * pulls the rug out under this.
1932 */
1933 CTASSERT(O_NONBLOCK == IO_NDELAY);
1934 CTASSERT(O_FSYNC == IO_SYNC);
Cache object: 8a93f9102112785f798f84419f168b61
|