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
31 #include <sys/param.h>
32 #include <sys/systm.h>
34 #include <sys/dirent.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
38 #include <sys/malloc.h>
41 #include <sys/sysctl.h>
42 #include <sys/vnode.h>
46 #include <fs/devfs/devfs.h>
47 #include <fs/devfs/devfs_int.h>
49 #include <security/mac/mac_framework.h>
52 * The one true (but secret) list of active devices in the system.
53 * Locked by dev_lock()/devmtx
55 struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
57 struct unrhdr *devfs_inos;
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");
64 SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
66 static unsigned devfs_generation;
67 SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
68 &devfs_generation, 0, "DEVFS generation number");
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");
75 * Helper sysctl for devname(3). We're given a dev_t and return the
76 * name, if any, registered by the device driver.
79 sysctl_devname(SYSCTL_HANDLER_ARGS)
83 struct cdev_priv *cdp;
86 error = SYSCTL_IN(req, &ud, sizeof (ud));
93 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
94 if (cdp->cdp_inode == ud) {
102 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
107 SYSCTL_PROC(_kern, OID_AUTO, devname,
108 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
109 NULL, 0, sysctl_devname, "", "devname(3) handler");
111 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
112 SYSCTL_NULL_INT_PTR, sizeof(struct cdev), "sizeof(struct cdev)");
114 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
115 SYSCTL_NULL_INT_PTR, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
118 devfs_alloc(int flags)
120 struct cdev_priv *cdp;
124 cdp = malloc(sizeof *cdp, M_CDEVP, M_ZERO |
125 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
129 cdp->cdp_dirents = &cdp->cdp_dirent0;
130 cdp->cdp_dirent0 = NULL;
131 cdp->cdp_maxdirent = 0;
136 LIST_INIT(&cdev->si_children);
138 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
139 cdev->si_cred = NULL;
145 devfs_dev_exists(const char *name)
147 struct cdev_priv *cdp;
149 mtx_assert(&devmtx, MA_OWNED);
151 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
152 if ((cdp->cdp_flags & CDP_ACTIVE) == 0)
154 if (devfs_pathpath(cdp->cdp_c.si_name, name) != 0)
156 if (devfs_pathpath(name, cdp->cdp_c.si_name) != 0)
159 if (devfs_dir_find(name) != 0)
166 devfs_free(struct cdev *cdev)
168 struct cdev_priv *cdp;
170 cdp = cdev2priv(cdev);
171 if (cdev->si_cred != NULL)
172 crfree(cdev->si_cred);
173 devfs_free_cdp_inode(cdp->cdp_inode);
174 if (cdp->cdp_maxdirent > 0)
175 free(cdp->cdp_dirents, M_DEVFS2);
179 struct devfs_dirent *
180 devfs_find(struct devfs_dirent *dd, const char *name, int namelen, int type)
182 struct devfs_dirent *de;
184 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
185 if (namelen != de->de_dirent->d_namlen)
187 if (type != 0 && type != de->de_dirent->d_type)
191 * The race with finding non-active name is not
192 * completely closed by the check, but it is similar
193 * to the devfs_allocv() in making it unlikely enough.
195 if (de->de_dirent->d_type == DT_CHR &&
196 (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
199 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
203 KASSERT(de == NULL || (de->de_flags & DE_DOOMED) == 0,
204 ("devfs_find: returning a doomed entry"));
208 struct devfs_dirent *
209 devfs_newdirent(char *name, int namelen)
212 struct devfs_dirent *de;
215 d.d_namlen = namelen;
216 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
217 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
218 de->de_dirent = (struct dirent *)(de + 1);
219 de->de_dirent->d_namlen = namelen;
220 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
221 bcopy(name, de->de_dirent->d_name, namelen);
222 de->de_dirent->d_name[namelen] = '\0';
223 vfs_timestamp(&de->de_ctime);
224 de->de_mtime = de->de_atime = de->de_ctime;
233 struct devfs_dirent *
234 devfs_parent_dirent(struct devfs_dirent *de)
237 if (de->de_dirent->d_type != DT_DIR)
240 if (de->de_flags & (DE_DOT | DE_DOTDOT))
243 de = TAILQ_FIRST(&de->de_dlist); /* "." */
246 de = TAILQ_NEXT(de, de_list); /* ".." */
253 struct devfs_dirent *
254 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
256 struct devfs_dirent *dd;
257 struct devfs_dirent *de;
259 /* Create the new directory */
260 dd = devfs_newdirent(name, namelen);
261 TAILQ_INIT(&dd->de_dlist);
262 dd->de_dirent->d_type = DT_DIR;
267 dd->de_inode = inode;
269 dd->de_inode = alloc_unr(devfs_inos);
272 * "." and ".." are always the two first entries in the
275 * Create the "." entry in the new directory.
277 de = devfs_newdirent(".", 1);
278 de->de_dirent->d_type = DT_DIR;
279 de->de_flags |= DE_DOT;
280 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
283 /* Create the ".." entry in the new directory. */
284 de = devfs_newdirent("..", 2);
285 de->de_dirent->d_type = DT_DIR;
286 de->de_flags |= DE_DOTDOT;
287 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
288 if (dotdot == NULL) {
292 sx_assert(&dmp->dm_lock, SX_XLOCKED);
293 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
295 devfs_rules_apply(dmp, dd);
299 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
305 devfs_dirent_free(struct devfs_dirent *de)
310 mtx_lock(&devfs_de_interlock);
311 if (vp != NULL && vp->v_data == de)
313 mtx_unlock(&devfs_de_interlock);
318 * Removes a directory if it is empty. Also empty parent directories are
319 * removed recursively.
322 devfs_rmdir_empty(struct devfs_mount *dm, struct devfs_dirent *de)
324 struct devfs_dirent *dd, *de_dot, *de_dotdot;
326 sx_assert(&dm->dm_lock, SX_XLOCKED);
329 KASSERT(de->de_dirent->d_type == DT_DIR,
330 ("devfs_rmdir_empty: de is not a directory"));
332 if ((de->de_flags & DE_DOOMED) != 0 || de == dm->dm_rootdir)
335 de_dot = TAILQ_FIRST(&de->de_dlist);
336 KASSERT(de_dot != NULL, ("devfs_rmdir_empty: . missing"));
337 de_dotdot = TAILQ_NEXT(de_dot, de_list);
338 KASSERT(de_dotdot != NULL, ("devfs_rmdir_empty: .. missing"));
339 /* Return if the directory is not empty. */
340 if (TAILQ_NEXT(de_dotdot, de_list) != NULL)
343 dd = devfs_parent_dirent(de);
344 KASSERT(dd != NULL, ("devfs_rmdir_empty: NULL dd"));
345 TAILQ_REMOVE(&de->de_dlist, de_dot, de_list);
346 TAILQ_REMOVE(&de->de_dlist, de_dotdot, de_list);
347 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
349 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
350 devfs_delete(dm, de_dot, DEVFS_DEL_NORECURSE);
351 devfs_delete(dm, de_dotdot, DEVFS_DEL_NORECURSE);
352 if (DEVFS_DE_DROP(dd)) {
353 devfs_dirent_free(dd);
362 * The caller needs to hold the dm for the duration of the call since
363 * dm->dm_lock may be temporary dropped.
366 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int flags)
368 struct devfs_dirent *dd;
371 KASSERT((de->de_flags & DE_DOOMED) == 0,
372 ("devfs_delete doomed dirent"));
373 de->de_flags |= DE_DOOMED;
375 if ((flags & DEVFS_DEL_NORECURSE) == 0) {
376 dd = devfs_parent_dirent(de);
379 if (de->de_flags & DE_USER) {
380 KASSERT(dd != NULL, ("devfs_delete: NULL dd"));
381 devfs_dir_unref_de(dm, dd);
386 mtx_lock(&devfs_de_interlock);
390 mtx_unlock(&devfs_de_interlock);
392 sx_unlock(&dm->dm_lock);
393 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
394 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
398 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
401 sx_xlock(&dm->dm_lock);
403 mtx_unlock(&devfs_de_interlock);
404 if (de->de_symlink) {
405 free(de->de_symlink, M_DEVFS);
406 de->de_symlink = NULL;
409 mac_devfs_destroy(de);
411 if (de->de_inode > DEVFS_ROOTINO) {
412 devfs_free_cdp_inode(de->de_inode);
415 if (DEVFS_DE_DROP(de))
416 devfs_dirent_free(de);
419 if (DEVFS_DE_DROP(dd))
420 devfs_dirent_free(dd);
422 devfs_rmdir_empty(dm, dd);
428 * Recursively removes the entire tree.
429 * The caller needs to hold the dm for the duration of the call.
433 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
435 struct devfs_dirent *de;
437 sx_assert(&dm->dm_lock, SX_XLOCKED);
442 * Use TAILQ_LAST() to remove "." and ".." last.
443 * We might need ".." to resolve a path in
444 * devfs_dir_unref_de().
446 de = TAILQ_LAST(&dd->de_dlist, devfs_dlist_head);
449 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
450 if (de->de_flags & DE_USER)
451 devfs_dir_unref_de(dm, dd);
452 if (de->de_flags & (DE_DOT | DE_DOTDOT))
453 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
454 else if (de->de_dirent->d_type == DT_DIR)
457 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
459 if (DEVFS_DE_DROP(dd))
460 devfs_dirent_free(dd);
461 else if ((dd->de_flags & DE_DOOMED) == 0)
462 devfs_delete(dm, dd, DEVFS_DEL_NORECURSE);
466 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
467 * by the mount points dm_idx.
468 * This function extends the array when necessary, taking into account that
469 * the default array is 1 element and not malloc'ed.
472 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
474 struct devfs_dirent **dep;
477 siz = (dm->dm_idx + 1) * sizeof *dep;
478 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
480 if (dm->dm_idx <= cdp->cdp_maxdirent) {
486 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
487 if (cdp->cdp_maxdirent > 0)
488 free(cdp->cdp_dirents, M_DEVFS2);
489 cdp->cdp_dirents = dep;
491 * XXX: if malloc told us how much we actually got this could
494 cdp->cdp_maxdirent = dm->dm_idx;
499 * The caller needs to hold the dm for the duration of the call.
502 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
504 struct cdev_priv *cdp;
505 struct devfs_dirent *de;
506 struct devfs_dirent *dd;
511 sx_assert(&dm->dm_lock, SX_XLOCKED);
513 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
515 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
518 * If we are unmounting, or the device has been destroyed,
519 * clean up our dirent.
521 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
522 dm->dm_idx <= cdp->cdp_maxdirent &&
523 cdp->cdp_dirents[dm->dm_idx] != NULL) {
524 de = cdp->cdp_dirents[dm->dm_idx];
525 cdp->cdp_dirents[dm->dm_idx] = NULL;
526 KASSERT(cdp == de->de_cdp,
527 ("%s %d %s %p %p", __func__, __LINE__,
528 cdp->cdp_c.si_name, cdp, de->de_cdp));
529 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
532 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
535 devfs_delete(dm, de, 0);
542 * GC any lingering devices
544 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
545 if (cdp->cdp_inuse > 0)
547 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
549 dev_rel(&cdp->cdp_c);
553 * Don't create any new dirents if we are unmounting
557 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
559 if (dm->dm_idx <= cdp->cdp_maxdirent &&
560 cdp->cdp_dirents[dm->dm_idx] != NULL) {
561 de = cdp->cdp_dirents[dm->dm_idx];
562 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
570 if (dm->dm_idx > cdp->cdp_maxdirent)
571 devfs_metoo(cdp, dm);
574 s = cdp->cdp_c.si_name;
576 for (q = s; *q != '/' && *q != '\0'; q++)
580 de = devfs_find(dd, s, q - s, 0);
582 de = devfs_vmkdir(dm, s, q - s, dd, 0);
583 else if (de->de_dirent->d_type == DT_LNK) {
584 de = devfs_find(dd, s, q - s, DT_DIR);
586 de = devfs_vmkdir(dm, s, q - s, dd, 0);
587 de->de_flags |= DE_COVERED;
591 KASSERT(dd->de_dirent->d_type == DT_DIR &&
592 (dd->de_flags & (DE_DOT | DE_DOTDOT)) == 0,
593 ("%s: invalid directory (si_name=%s)",
594 __func__, cdp->cdp_c.si_name));
598 de = devfs_find(dd, s, q - s, DT_LNK);
600 de_flags |= DE_COVERED;
602 de = devfs_newdirent(s, q - s);
603 if (cdp->cdp_c.si_flags & SI_ALIAS) {
607 de->de_dirent->d_type = DT_LNK;
608 pdev = cdp->cdp_c.si_parent;
609 j = strlen(pdev->si_name) + 1;
610 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
611 bcopy(pdev->si_name, de->de_symlink, j);
613 de->de_uid = cdp->cdp_c.si_uid;
614 de->de_gid = cdp->cdp_c.si_gid;
615 de->de_mode = cdp->cdp_c.si_mode;
616 de->de_dirent->d_type = DT_CHR;
618 de->de_flags |= de_flags;
619 de->de_inode = cdp->cdp_inode;
622 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
626 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
627 devfs_rules_apply(dm, de);
629 /* XXX: could check that cdp is still active here */
630 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
631 ("%s %d\n", __func__, __LINE__));
632 cdp->cdp_dirents[dm->dm_idx] = de;
633 KASSERT(de->de_cdp != (void *)0xdeadc0de,
634 ("%s %d\n", __func__, __LINE__));
643 * The caller needs to hold the dm for the duration of the call.
646 devfs_populate(struct devfs_mount *dm)
650 sx_assert(&dm->dm_lock, SX_XLOCKED);
651 gen = devfs_generation;
652 if (dm->dm_generation == gen)
654 while (devfs_populate_loop(dm, 0))
656 dm->dm_generation = gen;
660 * The caller needs to hold the dm for the duration of the call.
663 devfs_cleanup(struct devfs_mount *dm)
666 sx_assert(&dm->dm_lock, SX_XLOCKED);
667 while (devfs_populate_loop(dm, 1))
669 devfs_purge(dm, dm->dm_rootdir);
673 * devfs_create() and devfs_destroy() are called from kern_conf.c and
674 * in both cases the devlock() mutex is held, so no further locking
675 * is necessary and no sleeping allowed.
679 devfs_create(struct cdev *dev)
681 struct cdev_priv *cdp;
683 mtx_assert(&devmtx, MA_OWNED);
684 cdp = cdev2priv(dev);
685 cdp->cdp_flags |= CDP_ACTIVE;
686 cdp->cdp_inode = alloc_unrl(devfs_inos);
688 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
693 devfs_destroy(struct cdev *dev)
695 struct cdev_priv *cdp;
697 mtx_assert(&devmtx, MA_OWNED);
698 cdp = cdev2priv(dev);
699 cdp->cdp_flags &= ~CDP_ACTIVE;
704 devfs_alloc_cdp_inode(void)
707 return (alloc_unr(devfs_inos));
711 devfs_free_cdp_inode(ino_t ino)
715 free_unr(devfs_inos, ino);
719 devfs_devs_init(void *junk __unused)
722 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
725 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);