devfs_devs.c revision 313932 
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: stable/10/sys/fs/devfs/devfs_devs.c 313932 2017-02-19 03:17:11Z kib $
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 */
55struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
56
57struct unrhdr *devfs_inos;
58
59
60static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
61static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
62static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
63
64SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
65
66static unsigned devfs_generation;
67SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
68	&devfs_generation, 0, "DEVFS generation number");
69
70unsigned devfs_rule_depth = 1;
71SYSCTL_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 */
78static int
79sysctl_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
107SYSCTL_PROC(_kern, OID_AUTO, devname,
108    CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
109    NULL, 0, sysctl_devname, "", "devname(3) handler");
110
111SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
112    SYSCTL_NULL_INT_PTR, sizeof(struct cdev), "sizeof(struct cdev)");
113
114SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
115    SYSCTL_NULL_INT_PTR, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
116
117struct cdev *
118devfs_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_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
131	cdev = &cdp->cdp_c;
132	LIST_INIT(&cdev->si_children);
133	vfs_timestamp(&ts);
134	cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
135
136	return (cdev);
137}
138
139int
140devfs_dev_exists(const char *name)
141{
142	struct cdev_priv *cdp;
143
144	mtx_assert(&devmtx, MA_OWNED);
145
146	TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
147		if ((cdp->cdp_flags & CDP_ACTIVE) == 0)
148			continue;
149		if (devfs_pathpath(cdp->cdp_c.si_name, name) != 0)
150			return (1);
151		if (devfs_pathpath(name, cdp->cdp_c.si_name) != 0)
152			return (1);
153	}
154	if (devfs_dir_find(name) != 0)
155		return (1);
156
157	return (0);
158}
159
160void
161devfs_free(struct cdev *cdev)
162{
163	struct cdev_priv *cdp;
164
165	cdp = cdev2priv(cdev);
166	if (cdev->si_cred != NULL)
167		crfree(cdev->si_cred);
168	devfs_free_cdp_inode(cdp->cdp_inode);
169	if (cdp->cdp_maxdirent > 0)
170		free(cdp->cdp_dirents, M_DEVFS2);
171	free(cdp, M_CDEVP);
172}
173
174struct devfs_dirent *
175devfs_find(struct devfs_dirent *dd, const char *name, int namelen, int type)
176{
177	struct devfs_dirent *de;
178
179	TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
180		if (namelen != de->de_dirent->d_namlen)
181			continue;
182		if (type != 0 && type != de->de_dirent->d_type)
183			continue;
184
185		/*
186		 * The race with finding non-active name is not
187		 * completely closed by the check, but it is similar
188		 * to the devfs_allocv() in making it unlikely enough.
189		 */
190		if (de->de_dirent->d_type == DT_CHR &&
191		    (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
192			continue;
193
194		if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
195			continue;
196		break;
197	}
198	KASSERT(de == NULL || (de->de_flags & DE_DOOMED) == 0,
199	    ("devfs_find: returning a doomed entry"));
200	return (de);
201}
202
203struct devfs_dirent *
204devfs_newdirent(char *name, int namelen)
205{
206	int i;
207	struct devfs_dirent *de;
208	struct dirent d;
209
210	d.d_namlen = namelen;
211	i = sizeof(*de) + GENERIC_DIRSIZ(&d);
212	de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
213	de->de_dirent = (struct dirent *)(de + 1);
214	de->de_dirent->d_namlen = namelen;
215	de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
216	bcopy(name, de->de_dirent->d_name, namelen);
217	de->de_dirent->d_name[namelen] = '\0';
218	vfs_timestamp(&de->de_ctime);
219	de->de_mtime = de->de_atime = de->de_ctime;
220	de->de_links = 1;
221	de->de_holdcnt = 1;
222#ifdef MAC
223	mac_devfs_init(de);
224#endif
225	return (de);
226}
227
228struct devfs_dirent *
229devfs_parent_dirent(struct devfs_dirent *de)
230{
231
232	if (de->de_dirent->d_type != DT_DIR)
233		return (de->de_dir);
234
235	if (de->de_flags & (DE_DOT | DE_DOTDOT))
236		return (NULL);
237
238	de = TAILQ_FIRST(&de->de_dlist);	/* "." */
239	if (de == NULL)
240		return (NULL);
241	de = TAILQ_NEXT(de, de_list);		/* ".." */
242	if (de == NULL)
243		return (NULL);
244
245	return (de->de_dir);
246}
247
248struct devfs_dirent *
249devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen,
250    struct devfs_dirent *dotdot, u_int inode)
251{
252	struct devfs_dirent *dd;
253	struct devfs_dirent *de;
254
255	/* Create the new directory */
256	dd = devfs_newdirent(name, namelen);
257	TAILQ_INIT(&dd->de_dlist);
258	dd->de_dirent->d_type = DT_DIR;
259	dd->de_mode = 0555;
260	dd->de_links = 2;
261	dd->de_dir = dd;
262	if (inode != 0)
263		dd->de_inode = inode;
264	else
265		dd->de_inode = alloc_unr(devfs_inos);
266
267	/*
268	 * "." and ".." are always the two first entries in the
269	 * de_dlist list.
270	 *
271	 * Create the "." entry in the new directory.
272	 */
273	de = devfs_newdirent(".", 1);
274	de->de_dirent->d_type = DT_DIR;
275	de->de_flags |= DE_DOT;
276	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
277	de->de_dir = dd;
278
279	/* Create the ".." entry in the new directory. */
280	de = devfs_newdirent("..", 2);
281	de->de_dirent->d_type = DT_DIR;
282	de->de_flags |= DE_DOTDOT;
283	TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
284	if (dotdot == NULL) {
285		de->de_dir = dd;
286	} else {
287		de->de_dir = dotdot;
288		sx_assert(&dmp->dm_lock, SX_XLOCKED);
289		TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
290		dotdot->de_links++;
291		devfs_rules_apply(dmp, dd);
292	}
293
294#ifdef MAC
295	mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
296#endif
297	return (dd);
298}
299
300void
301devfs_dirent_free(struct devfs_dirent *de)
302{
303	struct vnode *vp;
304
305	vp = de->de_vnode;
306	mtx_lock(&devfs_de_interlock);
307	if (vp != NULL && vp->v_data == de)
308		vp->v_data = NULL;
309	mtx_unlock(&devfs_de_interlock);
310	free(de, M_DEVFS3);
311}
312
313/*
314 * Removes a directory if it is empty. Also empty parent directories are
315 * removed recursively.
316 */
317static void
318devfs_rmdir_empty(struct devfs_mount *dm, struct devfs_dirent *de)
319{
320	struct devfs_dirent *dd, *de_dot, *de_dotdot;
321
322	sx_assert(&dm->dm_lock, SX_XLOCKED);
323
324	for (;;) {
325		KASSERT(de->de_dirent->d_type == DT_DIR,
326		    ("devfs_rmdir_empty: de is not a directory"));
327
328		if ((de->de_flags & DE_DOOMED) != 0 || de == dm->dm_rootdir)
329			return;
330
331		de_dot = TAILQ_FIRST(&de->de_dlist);
332		KASSERT(de_dot != NULL, ("devfs_rmdir_empty: . missing"));
333		de_dotdot = TAILQ_NEXT(de_dot, de_list);
334		KASSERT(de_dotdot != NULL, ("devfs_rmdir_empty: .. missing"));
335		/* Return if the directory is not empty. */
336		if (TAILQ_NEXT(de_dotdot, de_list) != NULL)
337			return;
338
339		dd = devfs_parent_dirent(de);
340		KASSERT(dd != NULL, ("devfs_rmdir_empty: NULL dd"));
341		TAILQ_REMOVE(&de->de_dlist, de_dot, de_list);
342		TAILQ_REMOVE(&de->de_dlist, de_dotdot, de_list);
343		TAILQ_REMOVE(&dd->de_dlist, de, de_list);
344		DEVFS_DE_HOLD(dd);
345		devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
346		devfs_delete(dm, de_dot, DEVFS_DEL_NORECURSE);
347		devfs_delete(dm, de_dotdot, DEVFS_DEL_NORECURSE);
348		if (DEVFS_DE_DROP(dd)) {
349			devfs_dirent_free(dd);
350			return;
351		}
352
353		de = dd;
354	}
355}
356
357/*
358 * The caller needs to hold the dm for the duration of the call since
359 * dm->dm_lock may be temporary dropped.
360 */
361void
362devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int flags)
363{
364	struct devfs_dirent *dd;
365	struct vnode *vp;
366
367	KASSERT((de->de_flags & DE_DOOMED) == 0,
368		("devfs_delete doomed dirent"));
369	de->de_flags |= DE_DOOMED;
370
371	if ((flags & DEVFS_DEL_NORECURSE) == 0) {
372		dd = devfs_parent_dirent(de);
373		if (dd != NULL)
374			DEVFS_DE_HOLD(dd);
375		if (de->de_flags & DE_USER) {
376			KASSERT(dd != NULL, ("devfs_delete: NULL dd"));
377			devfs_dir_unref_de(dm, dd);
378		}
379	} else
380		dd = NULL;
381
382	mtx_lock(&devfs_de_interlock);
383	vp = de->de_vnode;
384	if (vp != NULL) {
385		VI_LOCK(vp);
386		mtx_unlock(&devfs_de_interlock);
387		vholdl(vp);
388		sx_unlock(&dm->dm_lock);
389		if ((flags & DEVFS_DEL_VNLOCKED) == 0)
390			vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
391		else
392			VI_UNLOCK(vp);
393		vgone(vp);
394		if ((flags & DEVFS_DEL_VNLOCKED) == 0)
395			VOP_UNLOCK(vp, 0);
396		vdrop(vp);
397		sx_xlock(&dm->dm_lock);
398	} else
399		mtx_unlock(&devfs_de_interlock);
400	if (de->de_symlink) {
401		free(de->de_symlink, M_DEVFS);
402		de->de_symlink = NULL;
403	}
404#ifdef MAC
405	mac_devfs_destroy(de);
406#endif
407	if (de->de_inode > DEVFS_ROOTINO) {
408		devfs_free_cdp_inode(de->de_inode);
409		de->de_inode = 0;
410	}
411	if (DEVFS_DE_DROP(de))
412		devfs_dirent_free(de);
413
414	if (dd != NULL) {
415		if (DEVFS_DE_DROP(dd))
416			devfs_dirent_free(dd);
417		else
418			devfs_rmdir_empty(dm, dd);
419	}
420}
421
422/*
423 * Called on unmount.
424 * Recursively removes the entire tree.
425 * The caller needs to hold the dm for the duration of the call.
426 */
427
428static void
429devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
430{
431	struct devfs_dirent *de;
432
433	sx_assert(&dm->dm_lock, SX_XLOCKED);
434
435	DEVFS_DE_HOLD(dd);
436	for (;;) {
437		/*
438		 * Use TAILQ_LAST() to remove "." and ".." last.
439		 * We might need ".." to resolve a path in
440		 * devfs_dir_unref_de().
441		 */
442		de = TAILQ_LAST(&dd->de_dlist, devfs_dlist_head);
443		if (de == NULL)
444			break;
445		TAILQ_REMOVE(&dd->de_dlist, de, de_list);
446		if (de->de_flags & DE_USER)
447			devfs_dir_unref_de(dm, dd);
448		if (de->de_flags & (DE_DOT | DE_DOTDOT))
449			devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
450		else if (de->de_dirent->d_type == DT_DIR)
451			devfs_purge(dm, de);
452		else
453			devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
454	}
455	if (DEVFS_DE_DROP(dd))
456		devfs_dirent_free(dd);
457	else if ((dd->de_flags & DE_DOOMED) == 0)
458		devfs_delete(dm, dd, DEVFS_DEL_NORECURSE);
459}
460
461/*
462 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
463 * by the mount points dm_idx.
464 * This function extends the array when necessary, taking into account that
465 * the default array is 1 element and not malloc'ed.
466 */
467static void
468devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
469{
470	struct devfs_dirent **dep;
471	int siz;
472
473	siz = (dm->dm_idx + 1) * sizeof *dep;
474	dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
475	dev_lock();
476	if (dm->dm_idx <= cdp->cdp_maxdirent) {
477		/* We got raced */
478		dev_unlock();
479		free(dep, M_DEVFS2);
480		return;
481	}
482	memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
483	if (cdp->cdp_maxdirent > 0)
484		free(cdp->cdp_dirents, M_DEVFS2);
485	cdp->cdp_dirents = dep;
486	/*
487	 * XXX: if malloc told us how much we actually got this could
488	 * XXX: be optimized.
489	 */
490	cdp->cdp_maxdirent = dm->dm_idx;
491	dev_unlock();
492}
493
494/*
495 * The caller needs to hold the dm for the duration of the call.
496 */
497static int
498devfs_populate_loop(struct devfs_mount *dm, int cleanup)
499{
500	struct cdev_priv *cdp;
501	struct devfs_dirent *de;
502	struct devfs_dirent *dd;
503	struct cdev *pdev;
504	int de_flags, j;
505	char *q, *s;
506
507	sx_assert(&dm->dm_lock, SX_XLOCKED);
508	dev_lock();
509	TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
510
511		KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
512
513		/*
514		 * If we are unmounting, or the device has been destroyed,
515		 * clean up our dirent.
516		 */
517		if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
518		    dm->dm_idx <= cdp->cdp_maxdirent &&
519		    cdp->cdp_dirents[dm->dm_idx] != NULL) {
520			de = cdp->cdp_dirents[dm->dm_idx];
521			cdp->cdp_dirents[dm->dm_idx] = NULL;
522			KASSERT(cdp == de->de_cdp,
523			    ("%s %d %s %p %p", __func__, __LINE__,
524			    cdp->cdp_c.si_name, cdp, de->de_cdp));
525			KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
526			dev_unlock();
527
528			TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
529			de->de_cdp = NULL;
530			de->de_inode = 0;
531			devfs_delete(dm, de, 0);
532			dev_lock();
533			cdp->cdp_inuse--;
534			dev_unlock();
535			return (1);
536		}
537		/*
538	 	 * GC any lingering devices
539		 */
540		if (!(cdp->cdp_flags & CDP_ACTIVE)) {
541			if (cdp->cdp_inuse > 0)
542				continue;
543			TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
544			dev_unlock();
545			dev_rel(&cdp->cdp_c);
546			return (1);
547		}
548		/*
549		 * Don't create any new dirents if we are unmounting
550		 */
551		if (cleanup)
552			continue;
553		KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
554
555		if (dm->dm_idx <= cdp->cdp_maxdirent &&
556		    cdp->cdp_dirents[dm->dm_idx] != NULL) {
557			de = cdp->cdp_dirents[dm->dm_idx];
558			KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
559			continue;
560		}
561
562
563		cdp->cdp_inuse++;
564		dev_unlock();
565
566		if (dm->dm_idx > cdp->cdp_maxdirent)
567		        devfs_metoo(cdp, dm);
568
569		dd = dm->dm_rootdir;
570		s = cdp->cdp_c.si_name;
571		for (;;) {
572			for (q = s; *q != '/' && *q != '\0'; q++)
573				continue;
574			if (*q != '/')
575				break;
576			de = devfs_find(dd, s, q - s, 0);
577			if (de == NULL)
578				de = devfs_vmkdir(dm, s, q - s, dd, 0);
579			else if (de->de_dirent->d_type == DT_LNK) {
580				de = devfs_find(dd, s, q - s, DT_DIR);
581				if (de == NULL)
582					de = devfs_vmkdir(dm, s, q - s, dd, 0);
583				de->de_flags |= DE_COVERED;
584			}
585			s = q + 1;
586			dd = de;
587			KASSERT(dd->de_dirent->d_type == DT_DIR &&
588			    (dd->de_flags & (DE_DOT | DE_DOTDOT)) == 0,
589			    ("%s: invalid directory (si_name=%s)",
590			    __func__, cdp->cdp_c.si_name));
591
592		}
593		de_flags = 0;
594		de = devfs_find(dd, s, q - s, DT_LNK);
595		if (de != NULL)
596			de_flags |= DE_COVERED;
597
598		de = devfs_newdirent(s, q - s);
599		if (cdp->cdp_c.si_flags & SI_ALIAS) {
600			de->de_uid = 0;
601			de->de_gid = 0;
602			de->de_mode = 0755;
603			de->de_dirent->d_type = DT_LNK;
604			pdev = cdp->cdp_c.si_parent;
605			j = strlen(pdev->si_name) + 1;
606			de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
607			bcopy(pdev->si_name, de->de_symlink, j);
608		} else {
609			de->de_uid = cdp->cdp_c.si_uid;
610			de->de_gid = cdp->cdp_c.si_gid;
611			de->de_mode = cdp->cdp_c.si_mode;
612			de->de_dirent->d_type = DT_CHR;
613		}
614		de->de_flags |= de_flags;
615		de->de_inode = cdp->cdp_inode;
616		de->de_cdp = cdp;
617#ifdef MAC
618		mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
619		    &cdp->cdp_c, de);
620#endif
621		de->de_dir = dd;
622		TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
623		devfs_rules_apply(dm, de);
624		dev_lock();
625		/* XXX: could check that cdp is still active here */
626		KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
627		    ("%s %d\n", __func__, __LINE__));
628		cdp->cdp_dirents[dm->dm_idx] = de;
629		KASSERT(de->de_cdp != (void *)0xdeadc0de,
630		    ("%s %d\n", __func__, __LINE__));
631		dev_unlock();
632		return (1);
633	}
634	dev_unlock();
635	return (0);
636}
637
638/*
639 * The caller needs to hold the dm for the duration of the call.
640 */
641void
642devfs_populate(struct devfs_mount *dm)
643{
644	unsigned gen;
645
646	sx_assert(&dm->dm_lock, SX_XLOCKED);
647	gen = devfs_generation;
648	if (dm->dm_generation == gen)
649		return;
650	while (devfs_populate_loop(dm, 0))
651		continue;
652	dm->dm_generation = gen;
653}
654
655/*
656 * The caller needs to hold the dm for the duration of the call.
657 */
658void
659devfs_cleanup(struct devfs_mount *dm)
660{
661
662	sx_assert(&dm->dm_lock, SX_XLOCKED);
663	while (devfs_populate_loop(dm, 1))
664		continue;
665	devfs_purge(dm, dm->dm_rootdir);
666}
667
668/*
669 * devfs_create() and devfs_destroy() are called from kern_conf.c and
670 * in both cases the devlock() mutex is held, so no further locking
671 * is necessary and no sleeping allowed.
672 */
673
674void
675devfs_create(struct cdev *dev)
676{
677	struct cdev_priv *cdp;
678
679	mtx_assert(&devmtx, MA_OWNED);
680	cdp = cdev2priv(dev);
681	cdp->cdp_flags |= CDP_ACTIVE;
682	cdp->cdp_inode = alloc_unrl(devfs_inos);
683	dev_refl(dev);
684	TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
685	devfs_generation++;
686}
687
688void
689devfs_destroy(struct cdev *dev)
690{
691	struct cdev_priv *cdp;
692
693	mtx_assert(&devmtx, MA_OWNED);
694	cdp = cdev2priv(dev);
695	cdp->cdp_flags &= ~CDP_ACTIVE;
696	devfs_generation++;
697}
698
699ino_t
700devfs_alloc_cdp_inode(void)
701{
702
703	return (alloc_unr(devfs_inos));
704}
705
706void
707devfs_free_cdp_inode(ino_t ino)
708{
709
710	if (ino > 0)
711		free_unr(devfs_inos, ino);
712}
713
714static void
715devfs_devs_init(void *junk __unused)
716{
717
718	devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
719}
720
721SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);
722