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
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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;
122 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO | M_WAITOK);
124 cdp->cdp_dirents = &cdp->cdp_dirent0;
125 cdp->cdp_dirent0 = NULL;
126 cdp->cdp_maxdirent = 0;
130 cdev->si_name = cdev->__si_namebuf;
131 LIST_INIT(&cdev->si_children);
133 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
139 devfs_free(struct cdev *cdev)
141 struct cdev_priv *cdp;
143 cdp = cdev2priv(cdev);
144 if (cdev->si_cred != NULL)
145 crfree(cdev->si_cred);
146 if (cdp->cdp_inode > 0)
147 free_unr(devfs_inos, cdp->cdp_inode);
148 if (cdp->cdp_maxdirent > 0)
149 free(cdp->cdp_dirents, M_DEVFS2);
153 struct devfs_dirent *
154 devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
156 struct devfs_dirent *de;
158 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
159 if (namelen != de->de_dirent->d_namlen)
161 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
168 struct devfs_dirent *
169 devfs_newdirent(char *name, int namelen)
172 struct devfs_dirent *de;
175 d.d_namlen = namelen;
176 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
177 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
178 de->de_dirent = (struct dirent *)(de + 1);
179 de->de_dirent->d_namlen = namelen;
180 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
181 bcopy(name, de->de_dirent->d_name, namelen);
182 de->de_dirent->d_name[namelen] = '\0';
183 vfs_timestamp(&de->de_ctime);
184 de->de_mtime = de->de_atime = de->de_ctime;
193 struct devfs_dirent *
194 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
196 struct devfs_dirent *dd;
197 struct devfs_dirent *de;
199 /* Create the new directory */
200 dd = devfs_newdirent(name, namelen);
201 TAILQ_INIT(&dd->de_dlist);
202 dd->de_dirent->d_type = DT_DIR;
207 dd->de_inode = inode;
209 dd->de_inode = alloc_unr(devfs_inos);
211 /* Create the "." entry in the new directory */
212 de = devfs_newdirent(".", 1);
213 de->de_dirent->d_type = DT_DIR;
214 de->de_flags |= DE_DOT;
215 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
218 /* Create the ".." entry in the new directory */
219 de = devfs_newdirent("..", 2);
220 de->de_dirent->d_type = DT_DIR;
221 de->de_flags |= DE_DOTDOT;
222 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
223 if (dotdot == NULL) {
227 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
232 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
238 devfs_dirent_free(struct devfs_dirent *de)
244 * The caller needs to hold the dm for the duration of the call since
245 * dm->dm_lock may be temporary dropped.
248 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
252 KASSERT((de->de_flags & DE_DOOMED) == 0,
253 ("devfs_delete doomed dirent"));
254 de->de_flags |= DE_DOOMED;
255 mtx_lock(&devfs_de_interlock);
259 mtx_unlock(&devfs_de_interlock);
261 sx_unlock(&dm->dm_lock);
263 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
270 sx_xlock(&dm->dm_lock);
272 mtx_unlock(&devfs_de_interlock);
273 if (de->de_symlink) {
274 free(de->de_symlink, M_DEVFS);
275 de->de_symlink = NULL;
278 mac_devfs_destroy(de);
280 if (de->de_inode > DEVFS_ROOTINO) {
281 free_unr(devfs_inos, de->de_inode);
284 if (DEVFS_DE_DROP(de))
285 devfs_dirent_free(de);
290 * Recursively removes the entire tree.
291 * The caller needs to hold the dm for the duration of the call.
295 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
297 struct devfs_dirent *de;
299 sx_assert(&dm->dm_lock, SX_XLOCKED);
301 de = TAILQ_FIRST(&dd->de_dlist);
304 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
305 if (de->de_flags & (DE_DOT|DE_DOTDOT))
306 devfs_delete(dm, de, 0);
307 else if (de->de_dirent->d_type == DT_DIR)
310 devfs_delete(dm, de, 0);
312 devfs_delete(dm, dd, 0);
316 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
317 * by the mount points dm_idx.
318 * This function extends the array when necessary, taking into account that
319 * the default array is 1 element and not malloc'ed.
322 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
324 struct devfs_dirent **dep;
327 siz = (dm->dm_idx + 1) * sizeof *dep;
328 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
330 if (dm->dm_idx <= cdp->cdp_maxdirent) {
336 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
337 if (cdp->cdp_maxdirent > 0)
338 free(cdp->cdp_dirents, M_DEVFS2);
339 cdp->cdp_dirents = dep;
341 * XXX: if malloc told us how much we actually got this could
344 cdp->cdp_maxdirent = dm->dm_idx;
349 * The caller needs to hold the dm for the duration of the call.
352 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
354 struct cdev_priv *cdp;
355 struct devfs_dirent *de;
356 struct devfs_dirent *dd;
361 sx_assert(&dm->dm_lock, SX_XLOCKED);
363 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
365 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
368 * If we are unmounting, or the device has been destroyed,
369 * clean up our dirent.
371 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
372 dm->dm_idx <= cdp->cdp_maxdirent &&
373 cdp->cdp_dirents[dm->dm_idx] != NULL) {
374 de = cdp->cdp_dirents[dm->dm_idx];
375 cdp->cdp_dirents[dm->dm_idx] = NULL;
376 KASSERT(cdp == de->de_cdp,
377 ("%s %d %s %p %p", __func__, __LINE__,
378 cdp->cdp_c.si_name, cdp, de->de_cdp));
379 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
382 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
385 devfs_delete(dm, de, 0);
392 * GC any lingering devices
394 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
395 if (cdp->cdp_inuse > 0)
397 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
399 dev_rel(&cdp->cdp_c);
403 * Don't create any new dirents if we are unmounting
407 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
409 if (dm->dm_idx <= cdp->cdp_maxdirent &&
410 cdp->cdp_dirents[dm->dm_idx] != NULL) {
411 de = cdp->cdp_dirents[dm->dm_idx];
412 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
420 if (dm->dm_idx > cdp->cdp_maxdirent)
421 devfs_metoo(cdp, dm);
424 s = cdp->cdp_c.si_name;
426 for (q = s; *q != '/' && *q != '\0'; q++)
430 de = devfs_find(dd, s, q - s);
432 de = devfs_vmkdir(dm, s, q - s, dd, 0);
437 de = devfs_newdirent(s, q - s);
438 if (cdp->cdp_c.si_flags & SI_ALIAS) {
442 de->de_dirent->d_type = DT_LNK;
443 pdev = cdp->cdp_c.si_parent;
444 j = strlen(pdev->si_name) + 1;
445 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
446 bcopy(pdev->si_name, de->de_symlink, j);
448 de->de_uid = cdp->cdp_c.si_uid;
449 de->de_gid = cdp->cdp_c.si_gid;
450 de->de_mode = cdp->cdp_c.si_mode;
451 de->de_dirent->d_type = DT_CHR;
453 de->de_inode = cdp->cdp_inode;
456 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
460 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
461 devfs_rules_apply(dm, de);
463 /* XXX: could check that cdp is still active here */
464 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
465 ("%s %d\n", __func__, __LINE__));
466 cdp->cdp_dirents[dm->dm_idx] = de;
467 KASSERT(de->de_cdp != (void *)0xdeadc0de,
468 ("%s %d\n", __func__, __LINE__));
477 * The caller needs to hold the dm for the duration of the call.
480 devfs_populate(struct devfs_mount *dm)
483 sx_assert(&dm->dm_lock, SX_XLOCKED);
484 if (dm->dm_generation == devfs_generation)
486 while (devfs_populate_loop(dm, 0))
488 dm->dm_generation = devfs_generation;
492 * The caller needs to hold the dm for the duration of the call.
495 devfs_cleanup(struct devfs_mount *dm)
498 sx_assert(&dm->dm_lock, SX_XLOCKED);
499 while (devfs_populate_loop(dm, 1))
501 devfs_purge(dm, dm->dm_rootdir);
505 * devfs_create() and devfs_destroy() are called from kern_conf.c and
506 * in both cases the devlock() mutex is held, so no further locking
507 * is necesary and no sleeping allowed.
511 devfs_create(struct cdev *dev)
513 struct cdev_priv *cdp;
515 mtx_assert(&devmtx, MA_OWNED);
516 cdp = cdev2priv(dev);
517 cdp->cdp_flags |= CDP_ACTIVE;
518 cdp->cdp_inode = alloc_unrl(devfs_inos);
520 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
525 devfs_destroy(struct cdev *dev)
527 struct cdev_priv *cdp;
529 mtx_assert(&devmtx, MA_OWNED);
530 cdp = cdev2priv(dev);
531 cdp->cdp_flags &= ~CDP_ACTIVE;
536 devfs_devs_init(void *junk __unused)
539 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
542 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);