2 * Copyright (c) 2000,2004
3 * Poul-Henning Kamp. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
33 #include <sys/param.h>
34 #include <sys/systm.h>
36 #include <sys/dirent.h>
37 #include <sys/kernel.h>
38 #include <sys/limits.h>
40 #include <sys/malloc.h>
43 #include <sys/sysctl.h>
44 #include <sys/vnode.h>
48 #include <fs/devfs/devfs.h>
49 #include <fs/devfs/devfs_int.h>
51 #include <security/mac/mac_framework.h>
54 * The one true (but secret) list of active devices in the system.
55 * Locked by dev_lock()/devmtx
57 struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
59 struct unrhdr *devfs_inos;
62 static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
63 static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
64 static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
66 static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
68 static unsigned devfs_generation;
69 SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
70 &devfs_generation, 0, "DEVFS generation number");
72 unsigned devfs_rule_depth = 1;
73 SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW,
74 &devfs_rule_depth, 0, "Max depth of ruleset include");
77 * Helper sysctl for devname(3). We're given a struct cdev * and return
78 * the name, if any, registered by the device driver.
81 sysctl_devname(SYSCTL_HANDLER_ARGS)
85 struct cdev_priv *cdp;
87 error = SYSCTL_IN(req, &ud, sizeof (ud));
96 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
97 if (cdp->cdp_inode == ud)
102 return(SYSCTL_OUT(req, cdp->cdp_c.si_name, strlen(cdp->cdp_c.si_name) + 1));
106 SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY,
107 NULL, 0, sysctl_devname, "", "devname(3) handler");
109 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
110 0, sizeof(struct cdev), "sizeof(struct cdev)");
112 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
113 0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
118 struct cdev_priv *cdp;
121 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO | M_WAITOK);
123 cdp->cdp_dirents = &cdp->cdp_dirent0;
124 cdp->cdp_dirent0 = NULL;
125 cdp->cdp_maxdirent = 0;
130 cdev->si_name = cdev->__si_namebuf;
131 LIST_INIT(&cdev->si_children);
136 devfs_free(struct cdev *cdev)
138 struct cdev_priv *cdp;
141 if (cdev->si_cred != NULL)
142 crfree(cdev->si_cred);
143 if (cdp->cdp_inode > 0)
144 free_unr(devfs_inos, cdp->cdp_inode);
145 if (cdp->cdp_maxdirent > 0)
146 free(cdp->cdp_dirents, M_DEVFS2);
150 struct devfs_dirent *
151 devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
153 struct devfs_dirent *de;
155 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
156 if (namelen != de->de_dirent->d_namlen)
158 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
165 struct devfs_dirent *
166 devfs_newdirent(char *name, int namelen)
169 struct devfs_dirent *de;
172 d.d_namlen = namelen;
173 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
174 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
175 de->de_dirent = (struct dirent *)(de + 1);
176 de->de_dirent->d_namlen = namelen;
177 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
178 bcopy(name, de->de_dirent->d_name, namelen);
179 de->de_dirent->d_name[namelen] = '\0';
180 vfs_timestamp(&de->de_ctime);
181 de->de_mtime = de->de_atime = de->de_ctime;
190 struct devfs_dirent *
191 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
193 struct devfs_dirent *dd;
194 struct devfs_dirent *de;
196 /* Create the new directory */
197 dd = devfs_newdirent(name, namelen);
198 TAILQ_INIT(&dd->de_dlist);
199 dd->de_dirent->d_type = DT_DIR;
204 dd->de_inode = inode;
206 dd->de_inode = alloc_unr(devfs_inos);
208 /* Create the "." entry in the new directory */
209 de = devfs_newdirent(".", 1);
210 de->de_dirent->d_type = DT_DIR;
211 de->de_flags |= DE_DOT;
212 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
215 /* Create the ".." entry in the new directory */
216 de = devfs_newdirent("..", 2);
217 de->de_dirent->d_type = DT_DIR;
218 de->de_flags |= DE_DOTDOT;
219 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
220 if (dotdot == NULL) {
224 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
229 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
235 devfs_dirent_free(struct devfs_dirent *de)
241 * The caller needs to hold the dm for the duration of the call since
242 * dm->dm_lock may be temporary dropped.
245 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
249 KASSERT((de->de_flags & DE_DOOMED) == 0,
250 ("devfs_delete doomed dirent"));
251 de->de_flags |= DE_DOOMED;
252 mtx_lock(&devfs_de_interlock);
256 mtx_unlock(&devfs_de_interlock);
258 sx_unlock(&dm->dm_lock);
260 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
267 sx_xlock(&dm->dm_lock);
269 mtx_unlock(&devfs_de_interlock);
270 if (de->de_symlink) {
271 free(de->de_symlink, M_DEVFS);
272 de->de_symlink = NULL;
275 mac_devfs_destroy(de);
277 if (de->de_inode > DEVFS_ROOTINO) {
278 free_unr(devfs_inos, de->de_inode);
281 if (DEVFS_DE_DROP(de))
282 devfs_dirent_free(de);
287 * Recursively removes the entire tree.
288 * The caller needs to hold the dm for the duration of the call.
292 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
294 struct devfs_dirent *de;
296 sx_assert(&dm->dm_lock, SX_XLOCKED);
298 de = TAILQ_FIRST(&dd->de_dlist);
301 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
302 if (de->de_flags & (DE_DOT|DE_DOTDOT))
303 devfs_delete(dm, de, 0);
304 else if (de->de_dirent->d_type == DT_DIR)
307 devfs_delete(dm, de, 0);
309 devfs_delete(dm, dd, 0);
313 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
314 * by the mount points dm_idx.
315 * This function extends the array when necessary, taking into account that
316 * the default array is 1 element and not malloc'ed.
319 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
321 struct devfs_dirent **dep;
324 siz = (dm->dm_idx + 1) * sizeof *dep;
325 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
327 if (dm->dm_idx <= cdp->cdp_maxdirent) {
333 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
334 if (cdp->cdp_maxdirent > 0)
335 free(cdp->cdp_dirents, M_DEVFS2);
336 cdp->cdp_dirents = dep;
338 * XXX: if malloc told us how much we actually got this could
341 cdp->cdp_maxdirent = dm->dm_idx;
346 * The caller needs to hold the dm for the duration of the call.
349 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
351 struct cdev_priv *cdp;
352 struct devfs_dirent *de;
353 struct devfs_dirent *dd;
358 sx_assert(&dm->dm_lock, SX_XLOCKED);
360 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
362 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
365 * If we are unmounting, or the device has been destroyed,
366 * clean up our dirent.
368 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
369 dm->dm_idx <= cdp->cdp_maxdirent &&
370 cdp->cdp_dirents[dm->dm_idx] != NULL) {
371 de = cdp->cdp_dirents[dm->dm_idx];
372 cdp->cdp_dirents[dm->dm_idx] = NULL;
373 KASSERT(cdp == de->de_cdp,
374 ("%s %d %s %p %p", __func__, __LINE__,
375 cdp->cdp_c.si_name, cdp, de->de_cdp));
376 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
379 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
382 devfs_delete(dm, de, 0);
389 * GC any lingering devices
391 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
392 if (cdp->cdp_inuse > 0)
394 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
396 dev_rel(&cdp->cdp_c);
400 * Don't create any new dirents if we are unmounting
404 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
406 if (dm->dm_idx <= cdp->cdp_maxdirent &&
407 cdp->cdp_dirents[dm->dm_idx] != NULL) {
408 de = cdp->cdp_dirents[dm->dm_idx];
409 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
417 if (dm->dm_idx > cdp->cdp_maxdirent)
418 devfs_metoo(cdp, dm);
421 s = cdp->cdp_c.si_name;
423 for (q = s; *q != '/' && *q != '\0'; q++)
427 de = devfs_find(dd, s, q - s);
429 de = devfs_vmkdir(dm, s, q - s, dd, 0);
434 de = devfs_newdirent(s, q - s);
435 if (cdp->cdp_c.si_flags & SI_ALIAS) {
439 de->de_dirent->d_type = DT_LNK;
440 pdev = cdp->cdp_c.si_parent;
441 j = strlen(pdev->si_name) + 1;
442 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
443 bcopy(pdev->si_name, de->de_symlink, j);
445 de->de_uid = cdp->cdp_c.si_uid;
446 de->de_gid = cdp->cdp_c.si_gid;
447 de->de_mode = cdp->cdp_c.si_mode;
448 de->de_dirent->d_type = DT_CHR;
450 de->de_inode = cdp->cdp_inode;
453 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
457 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
458 devfs_rules_apply(dm, de);
460 /* XXX: could check that cdp is still active here */
461 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
462 ("%s %d\n", __func__, __LINE__));
463 cdp->cdp_dirents[dm->dm_idx] = de;
464 KASSERT(de->de_cdp != (void *)0xdeadc0de,
465 ("%s %d\n", __func__, __LINE__));
474 * The caller needs to hold the dm for the duration of the call.
477 devfs_populate(struct devfs_mount *dm)
480 sx_assert(&dm->dm_lock, SX_XLOCKED);
481 if (dm->dm_generation == devfs_generation)
483 while (devfs_populate_loop(dm, 0))
485 dm->dm_generation = devfs_generation;
489 * The caller needs to hold the dm for the duration of the call.
492 devfs_cleanup(struct devfs_mount *dm)
495 sx_assert(&dm->dm_lock, SX_XLOCKED);
496 while (devfs_populate_loop(dm, 1))
498 devfs_purge(dm, dm->dm_rootdir);
502 * devfs_create() and devfs_destroy() are called from kern_conf.c and
503 * in both cases the devlock() mutex is held, so no further locking
504 * is necesary and no sleeping allowed.
508 devfs_create(struct cdev *dev)
510 struct cdev_priv *cdp;
512 mtx_assert(&devmtx, MA_OWNED);
514 cdp->cdp_flags |= CDP_ACTIVE;
515 cdp->cdp_inode = alloc_unrl(devfs_inos);
517 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
522 devfs_destroy(struct cdev *dev)
524 struct cdev_priv *cdp;
526 mtx_assert(&devmtx, MA_OWNED);
528 cdp->cdp_flags &= ~CDP_ACTIVE;
533 devfs_devs_init(void *junk __unused)
536 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
539 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);