1 /*-
2 * Copyright (c) 2000,2004
3 * Poul-Henning Kamp. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Neither the name of the University nor the names of its contributors
11 * may be used to endorse or promote products derived from this software
12 * without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
27 *
28 * $FreeBSD$
29 */
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/conf.h>
34 #include <sys/dirent.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/proc.h>
40 #include <sys/sx.h>
41 #include <sys/sysctl.h>
42 #include <sys/vnode.h>
43
44 #include <sys/kdb.h>
45
46 #include <fs/devfs/devfs.h>
47 #include <fs/devfs/devfs_int.h>
48
49 #include <security/mac/mac_framework.h>
50
51 /*
52 * The one true (but secret) list of active devices in the system.
53 * Locked by dev_lock()/devmtx
54 */
55 struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
56
57 struct unrhdr *devfs_inos;
58
59
60 static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
61 static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
62 static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
63
64 static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
65
66 static unsigned devfs_generation;
67 SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
68 &devfs_generation, 0, "DEVFS generation number");
69
70 unsigned devfs_rule_depth = 1;
71 SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW,
72 &devfs_rule_depth, 0, "Max depth of ruleset include");
73
74 /*
75 * Helper sysctl for devname(3). We're given a dev_t and return the
76 * name, if any, registered by the device driver.
77 */
78 static int
79 sysctl_devname(SYSCTL_HANDLER_ARGS)
80 {
81 int error;
82 dev_t ud;
83 struct cdev_priv *cdp;
84 struct cdev *dev;
85
86 error = SYSCTL_IN(req, &ud, sizeof (ud));
87 if (error)
88 return (error);
89 if (ud == NODEV)
90 return (EINVAL);
91 dev = NULL;
92 dev_lock();
93 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
94 if (cdp->cdp_inode == ud) {
95 dev = &cdp->cdp_c;
96 dev_refl(dev);
97 break;
98 }
99 dev_unlock();
100 if (dev == NULL)
101 return (ENOENT);
102 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
103 dev_rel(dev);
104 return (error);
105 }
106
107 SYSCTL_PROC(_kern, OID_AUTO, devname,
108 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
109 NULL, 0, sysctl_devname, "", "devname(3) handler");
110
111 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
112 SYSCTL_NULL_INT_PTR, sizeof(struct cdev), "sizeof(struct cdev)");
113
114 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
115 SYSCTL_NULL_INT_PTR, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
116
117 struct cdev *
118 devfs_alloc(int flags)
119 {
120 struct cdev_priv *cdp;
121 struct cdev *cdev;
122 struct timespec ts;
123
124 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO |
125 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
126 if (cdp == NULL)
127 return (NULL);
128
129 cdp->cdp_dirents = &cdp->cdp_dirent0;
130 cdp->cdp_dirent0 = NULL;
131 cdp->cdp_maxdirent = 0;
132 cdp->cdp_inode = 0;
133
134 cdev = &cdp->cdp_c;
135
136 cdev->si_name = cdev->__si_namebuf;
137 LIST_INIT(&cdev->si_children);
138 vfs_timestamp(&ts);
139 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
140 cdev->si_cred = NULL;
141
142 return (cdev);
143 }
144
145 int
146 devfs_dev_exists(const char *name)
147 {
148 struct cdev_priv *cdp;
149
150 mtx_assert(&devmtx, MA_OWNED);
151
152 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
153 if ((cdp->cdp_flags & CDP_ACTIVE) == 0)
154 continue;
155 if (devfs_pathpath(cdp->cdp_c.si_name, name) != 0)
156 return (1);
157 if (devfs_pathpath(name, cdp->cdp_c.si_name) != 0)
158 return (1);
159 }
160 if (devfs_dir_find(name) != 0)
161 return (1);
162
163 return (0);
164 }
165
166 void
167 devfs_free(struct cdev *cdev)
168 {
169 struct cdev_priv *cdp;
170
171 cdp = cdev2priv(cdev);
172 if (cdev->si_cred != NULL)
173 crfree(cdev->si_cred);
174 devfs_free_cdp_inode(cdp->cdp_inode);
175 if (cdp->cdp_maxdirent > 0)
176 free(cdp->cdp_dirents, M_DEVFS2);
177 free(cdp, M_CDEVP);
178 }
179
180 struct devfs_dirent *
181 devfs_find(struct devfs_dirent *dd, const char *name, int namelen, int type)
182 {
183 struct devfs_dirent *de;
184
185 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
186 if (namelen != de->de_dirent->d_namlen)
187 continue;
188 if (type != 0 && type != de->de_dirent->d_type)
189 continue;
190 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
191 continue;
192 break;
193 }
194 KASSERT(de == NULL || (de->de_flags & DE_DOOMED) == 0,
195 ("devfs_find: returning a doomed entry"));
196 return (de);
197 }
198
199 struct devfs_dirent *
200 devfs_newdirent(char *name, int namelen)
201 {
202 int i;
203 struct devfs_dirent *de;
204 struct dirent d;
205
206 d.d_namlen = namelen;
207 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
208 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
209 de->de_dirent = (struct dirent *)(de + 1);
210 de->de_dirent->d_namlen = namelen;
211 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
212 bcopy(name, de->de_dirent->d_name, namelen);
213 de->de_dirent->d_name[namelen] = '\0';
214 vfs_timestamp(&de->de_ctime);
215 de->de_mtime = de->de_atime = de->de_ctime;
216 de->de_links = 1;
217 de->de_holdcnt = 1;
218 #ifdef MAC
219 mac_devfs_init(de);
220 #endif
221 return (de);
222 }
223
224 struct devfs_dirent *
225 devfs_parent_dirent(struct devfs_dirent *de)
226 {
227
228 if (de->de_dirent->d_type != DT_DIR)
229 return (de->de_dir);
230
231 if (de->de_flags & (DE_DOT | DE_DOTDOT))
232 return (NULL);
233
234 de = TAILQ_FIRST(&de->de_dlist); /* "." */
235 if (de == NULL)
236 return (NULL);
237 de = TAILQ_NEXT(de, de_list); /* ".." */
238 if (de == NULL)
239 return (NULL);
240
241 return (de->de_dir);
242 }
243
244 struct devfs_dirent *
245 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
246 {
247 struct devfs_dirent *dd;
248 struct devfs_dirent *de;
249
250 /* Create the new directory */
251 dd = devfs_newdirent(name, namelen);
252 TAILQ_INIT(&dd->de_dlist);
253 dd->de_dirent->d_type = DT_DIR;
254 dd->de_mode = 0555;
255 dd->de_links = 2;
256 dd->de_dir = dd;
257 if (inode != 0)
258 dd->de_inode = inode;
259 else
260 dd->de_inode = alloc_unr(devfs_inos);
261
262 /*
263 * "." and ".." are always the two first entries in the
264 * de_dlist list.
265 *
266 * Create the "." entry in the new directory.
267 */
268 de = devfs_newdirent(".", 1);
269 de->de_dirent->d_type = DT_DIR;
270 de->de_flags |= DE_DOT;
271 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
272 de->de_dir = dd;
273
274 /* Create the ".." entry in the new directory. */
275 de = devfs_newdirent("..", 2);
276 de->de_dirent->d_type = DT_DIR;
277 de->de_flags |= DE_DOTDOT;
278 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
279 if (dotdot == NULL) {
280 de->de_dir = dd;
281 } else {
282 de->de_dir = dotdot;
283 sx_assert(&dmp->dm_lock, SX_XLOCKED);
284 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
285 dotdot->de_links++;
286 devfs_rules_apply(dmp, dd);
287 }
288
289 #ifdef MAC
290 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
291 #endif
292 return (dd);
293 }
294
295 void
296 devfs_dirent_free(struct devfs_dirent *de)
297 {
298 free(de, M_DEVFS3);
299 }
300
301 /*
302 * Removes a directory if it is empty. Also empty parent directories are
303 * removed recursively.
304 */
305 static void
306 devfs_rmdir_empty(struct devfs_mount *dm, struct devfs_dirent *de)
307 {
308 struct devfs_dirent *dd, *de_dot, *de_dotdot;
309
310 sx_assert(&dm->dm_lock, SX_XLOCKED);
311
312 for (;;) {
313 KASSERT(de->de_dirent->d_type == DT_DIR,
314 ("devfs_rmdir_empty: de is not a directory"));
315
316 if ((de->de_flags & DE_DOOMED) != 0 || de == dm->dm_rootdir)
317 return;
318
319 de_dot = TAILQ_FIRST(&de->de_dlist);
320 KASSERT(de_dot != NULL, ("devfs_rmdir_empty: . missing"));
321 de_dotdot = TAILQ_NEXT(de_dot, de_list);
322 KASSERT(de_dotdot != NULL, ("devfs_rmdir_empty: .. missing"));
323 /* Return if the directory is not empty. */
324 if (TAILQ_NEXT(de_dotdot, de_list) != NULL)
325 return;
326
327 dd = devfs_parent_dirent(de);
328 KASSERT(dd != NULL, ("devfs_rmdir_empty: NULL dd"));
329 TAILQ_REMOVE(&de->de_dlist, de_dot, de_list);
330 TAILQ_REMOVE(&de->de_dlist, de_dotdot, de_list);
331 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
332 DEVFS_DE_HOLD(dd);
333 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
334 devfs_delete(dm, de_dot, DEVFS_DEL_NORECURSE);
335 devfs_delete(dm, de_dotdot, DEVFS_DEL_NORECURSE);
336 if (DEVFS_DE_DROP(dd)) {
337 devfs_dirent_free(dd);
338 return;
339 }
340
341 de = dd;
342 }
343 }
344
345 /*
346 * The caller needs to hold the dm for the duration of the call since
347 * dm->dm_lock may be temporary dropped.
348 */
349 void
350 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int flags)
351 {
352 struct devfs_dirent *dd;
353 struct vnode *vp;
354
355 KASSERT((de->de_flags & DE_DOOMED) == 0,
356 ("devfs_delete doomed dirent"));
357 de->de_flags |= DE_DOOMED;
358
359 if ((flags & DEVFS_DEL_NORECURSE) == 0) {
360 dd = devfs_parent_dirent(de);
361 if (dd != NULL)
362 DEVFS_DE_HOLD(dd);
363 if (de->de_flags & DE_USER) {
364 KASSERT(dd != NULL, ("devfs_delete: NULL dd"));
365 devfs_dir_unref_de(dm, dd);
366 }
367 } else
368 dd = NULL;
369
370 mtx_lock(&devfs_de_interlock);
371 vp = de->de_vnode;
372 if (vp != NULL) {
373 VI_LOCK(vp);
374 mtx_unlock(&devfs_de_interlock);
375 vholdl(vp);
376 sx_unlock(&dm->dm_lock);
377 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
378 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
379 else
380 VI_UNLOCK(vp);
381 vgone(vp);
382 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
383 VOP_UNLOCK(vp, 0);
384 vdrop(vp);
385 sx_xlock(&dm->dm_lock);
386 } else
387 mtx_unlock(&devfs_de_interlock);
388 if (de->de_symlink) {
389 free(de->de_symlink, M_DEVFS);
390 de->de_symlink = NULL;
391 }
392 #ifdef MAC
393 mac_devfs_destroy(de);
394 #endif
395 if (de->de_inode > DEVFS_ROOTINO) {
396 devfs_free_cdp_inode(de->de_inode);
397 de->de_inode = 0;
398 }
399 if (DEVFS_DE_DROP(de))
400 devfs_dirent_free(de);
401
402 if (dd != NULL) {
403 if (DEVFS_DE_DROP(dd))
404 devfs_dirent_free(dd);
405 else
406 devfs_rmdir_empty(dm, dd);
407 }
408 }
409
410 /*
411 * Called on unmount.
412 * Recursively removes the entire tree.
413 * The caller needs to hold the dm for the duration of the call.
414 */
415
416 static void
417 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
418 {
419 struct devfs_dirent *de;
420
421 sx_assert(&dm->dm_lock, SX_XLOCKED);
422
423 DEVFS_DE_HOLD(dd);
424 for (;;) {
425 /*
426 * Use TAILQ_LAST() to remove "." and ".." last.
427 * We might need ".." to resolve a path in
428 * devfs_dir_unref_de().
429 */
430 de = TAILQ_LAST(&dd->de_dlist, devfs_dlist_head);
431 if (de == NULL)
432 break;
433 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
434 if (de->de_flags & DE_USER)
435 devfs_dir_unref_de(dm, dd);
436 if (de->de_flags & (DE_DOT | DE_DOTDOT))
437 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
438 else if (de->de_dirent->d_type == DT_DIR)
439 devfs_purge(dm, de);
440 else
441 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
442 }
443 if (DEVFS_DE_DROP(dd))
444 devfs_dirent_free(dd);
445 else if ((dd->de_flags & DE_DOOMED) == 0)
446 devfs_delete(dm, dd, DEVFS_DEL_NORECURSE);
447 }
448
449 /*
450 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
451 * by the mount points dm_idx.
452 * This function extends the array when necessary, taking into account that
453 * the default array is 1 element and not malloc'ed.
454 */
455 static void
456 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
457 {
458 struct devfs_dirent **dep;
459 int siz;
460
461 siz = (dm->dm_idx + 1) * sizeof *dep;
462 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
463 dev_lock();
464 if (dm->dm_idx <= cdp->cdp_maxdirent) {
465 /* We got raced */
466 dev_unlock();
467 free(dep, M_DEVFS2);
468 return;
469 }
470 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
471 if (cdp->cdp_maxdirent > 0)
472 free(cdp->cdp_dirents, M_DEVFS2);
473 cdp->cdp_dirents = dep;
474 /*
475 * XXX: if malloc told us how much we actually got this could
476 * XXX: be optimized.
477 */
478 cdp->cdp_maxdirent = dm->dm_idx;
479 dev_unlock();
480 }
481
482 /*
483 * The caller needs to hold the dm for the duration of the call.
484 */
485 static int
486 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
487 {
488 struct cdev_priv *cdp;
489 struct devfs_dirent *de;
490 struct devfs_dirent *dd;
491 struct cdev *pdev;
492 int de_flags, j;
493 char *q, *s;
494
495 sx_assert(&dm->dm_lock, SX_XLOCKED);
496 dev_lock();
497 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
498
499 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
500
501 /*
502 * If we are unmounting, or the device has been destroyed,
503 * clean up our dirent.
504 */
505 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
506 dm->dm_idx <= cdp->cdp_maxdirent &&
507 cdp->cdp_dirents[dm->dm_idx] != NULL) {
508 de = cdp->cdp_dirents[dm->dm_idx];
509 cdp->cdp_dirents[dm->dm_idx] = NULL;
510 KASSERT(cdp == de->de_cdp,
511 ("%s %d %s %p %p", __func__, __LINE__,
512 cdp->cdp_c.si_name, cdp, de->de_cdp));
513 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
514 dev_unlock();
515
516 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
517 de->de_cdp = NULL;
518 de->de_inode = 0;
519 devfs_delete(dm, de, 0);
520 dev_lock();
521 cdp->cdp_inuse--;
522 dev_unlock();
523 return (1);
524 }
525 /*
526 * GC any lingering devices
527 */
528 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
529 if (cdp->cdp_inuse > 0)
530 continue;
531 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
532 dev_unlock();
533 dev_rel(&cdp->cdp_c);
534 return (1);
535 }
536 /*
537 * Don't create any new dirents if we are unmounting
538 */
539 if (cleanup)
540 continue;
541 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
542
543 if (dm->dm_idx <= cdp->cdp_maxdirent &&
544 cdp->cdp_dirents[dm->dm_idx] != NULL) {
545 de = cdp->cdp_dirents[dm->dm_idx];
546 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
547 continue;
548 }
549
550
551 cdp->cdp_inuse++;
552 dev_unlock();
553
554 if (dm->dm_idx > cdp->cdp_maxdirent)
555 devfs_metoo(cdp, dm);
556
557 dd = dm->dm_rootdir;
558 s = cdp->cdp_c.si_name;
559 for (;;) {
560 for (q = s; *q != '/' && *q != '\0'; q++)
561 continue;
562 if (*q != '/')
563 break;
564 de = devfs_find(dd, s, q - s, 0);
565 if (de == NULL)
566 de = devfs_vmkdir(dm, s, q - s, dd, 0);
567 else if (de->de_dirent->d_type == DT_LNK) {
568 de = devfs_find(dd, s, q - s, DT_DIR);
569 if (de == NULL)
570 de = devfs_vmkdir(dm, s, q - s, dd, 0);
571 de->de_flags |= DE_COVERED;
572 }
573 s = q + 1;
574 dd = de;
575 KASSERT(dd->de_dirent->d_type == DT_DIR &&
576 (dd->de_flags & (DE_DOT | DE_DOTDOT)) == 0,
577 ("%s: invalid directory (si_name=%s)",
578 __func__, cdp->cdp_c.si_name));
579
580 }
581 de_flags = 0;
582 de = devfs_find(dd, s, q - s, DT_LNK);
583 if (de != NULL)
584 de_flags |= DE_COVERED;
585
586 de = devfs_newdirent(s, q - s);
587 if (cdp->cdp_c.si_flags & SI_ALIAS) {
588 de->de_uid = 0;
589 de->de_gid = 0;
590 de->de_mode = 0755;
591 de->de_dirent->d_type = DT_LNK;
592 pdev = cdp->cdp_c.si_parent;
593 j = strlen(pdev->si_name) + 1;
594 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
595 bcopy(pdev->si_name, de->de_symlink, j);
596 } else {
597 de->de_uid = cdp->cdp_c.si_uid;
598 de->de_gid = cdp->cdp_c.si_gid;
599 de->de_mode = cdp->cdp_c.si_mode;
600 de->de_dirent->d_type = DT_CHR;
601 }
602 de->de_flags |= de_flags;
603 de->de_inode = cdp->cdp_inode;
604 de->de_cdp = cdp;
605 #ifdef MAC
606 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
607 &cdp->cdp_c, de);
608 #endif
609 de->de_dir = dd;
610 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
611 devfs_rules_apply(dm, de);
612 dev_lock();
613 /* XXX: could check that cdp is still active here */
614 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
615 ("%s %d\n", __func__, __LINE__));
616 cdp->cdp_dirents[dm->dm_idx] = de;
617 KASSERT(de->de_cdp != (void *)0xdeadc0de,
618 ("%s %d\n", __func__, __LINE__));
619 dev_unlock();
620 return (1);
621 }
622 dev_unlock();
623 return (0);
624 }
625
626 /*
627 * The caller needs to hold the dm for the duration of the call.
628 */
629 void
630 devfs_populate(struct devfs_mount *dm)
631 {
632 unsigned gen;
633
634 sx_assert(&dm->dm_lock, SX_XLOCKED);
635 gen = devfs_generation;
636 if (dm->dm_generation == gen)
637 return;
638 while (devfs_populate_loop(dm, 0))
639 continue;
640 dm->dm_generation = gen;
641 }
642
643 /*
644 * The caller needs to hold the dm for the duration of the call.
645 */
646 void
647 devfs_cleanup(struct devfs_mount *dm)
648 {
649
650 sx_assert(&dm->dm_lock, SX_XLOCKED);
651 while (devfs_populate_loop(dm, 1))
652 continue;
653 devfs_purge(dm, dm->dm_rootdir);
654 }
655
656 /*
657 * devfs_create() and devfs_destroy() are called from kern_conf.c and
658 * in both cases the devlock() mutex is held, so no further locking
659 * is necesary and no sleeping allowed.
660 */
661
662 void
663 devfs_create(struct cdev *dev)
664 {
665 struct cdev_priv *cdp;
666
667 mtx_assert(&devmtx, MA_OWNED);
668 cdp = cdev2priv(dev);
669 cdp->cdp_flags |= CDP_ACTIVE;
670 cdp->cdp_inode = alloc_unrl(devfs_inos);
671 dev_refl(dev);
672 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
673 devfs_generation++;
674 }
675
676 void
677 devfs_destroy(struct cdev *dev)
678 {
679 struct cdev_priv *cdp;
680
681 mtx_assert(&devmtx, MA_OWNED);
682 cdp = cdev2priv(dev);
683 cdp->cdp_flags &= ~CDP_ACTIVE;
684 devfs_generation++;
685 }
686
687 ino_t
688 devfs_alloc_cdp_inode(void)
689 {
690
691 return (alloc_unr(devfs_inos));
692 }
693
694 void
695 devfs_free_cdp_inode(ino_t ino)
696 {
697
698 if (ino > 0)
699 free_unr(devfs_inos, ino);
700 }
701
702 static void
703 devfs_devs_init(void *junk __unused)
704 {
705
706 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
707 }
708
709 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);
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