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 static 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 struct cdev * and return
76 * the name, if any, registered by the device driver.
79 sysctl_devname(SYSCTL_HANDLER_ARGS)
83 struct cdev_priv *cdp;
85 error = SYSCTL_IN(req, &ud, sizeof (ud));
94 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
95 if (cdp->cdp_inode == ud)
100 return(SYSCTL_OUT(req, cdp->cdp_c.si_name, strlen(cdp->cdp_c.si_name) + 1));
104 SYSCTL_PROC(_kern, OID_AUTO, devname,
105 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
106 NULL, 0, sysctl_devname, "", "devname(3) handler");
108 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
109 0, sizeof(struct cdev), "sizeof(struct cdev)");
111 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
112 0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
117 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;
129 cdev->si_name = cdev->__si_namebuf;
130 LIST_INIT(&cdev->si_children);
132 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
138 devfs_free(struct cdev *cdev)
140 struct cdev_priv *cdp;
142 cdp = cdev2priv(cdev);
143 if (cdev->si_cred != NULL)
144 crfree(cdev->si_cred);
145 if (cdp->cdp_inode > 0)
146 free_unr(devfs_inos, cdp->cdp_inode);
147 if (cdp->cdp_maxdirent > 0)
148 free(cdp->cdp_dirents, M_DEVFS2);
152 struct devfs_dirent *
153 devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
155 struct devfs_dirent *de;
157 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
158 if (namelen != de->de_dirent->d_namlen)
160 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
167 struct devfs_dirent *
168 devfs_newdirent(char *name, int namelen)
171 struct devfs_dirent *de;
174 d.d_namlen = namelen;
175 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
176 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
177 de->de_dirent = (struct dirent *)(de + 1);
178 de->de_dirent->d_namlen = namelen;
179 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
180 bcopy(name, de->de_dirent->d_name, namelen);
181 de->de_dirent->d_name[namelen] = '\0';
182 vfs_timestamp(&de->de_ctime);
183 de->de_mtime = de->de_atime = de->de_ctime;
192 struct devfs_dirent *
193 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
195 struct devfs_dirent *dd;
196 struct devfs_dirent *de;
198 /* Create the new directory */
199 dd = devfs_newdirent(name, namelen);
200 TAILQ_INIT(&dd->de_dlist);
201 dd->de_dirent->d_type = DT_DIR;
206 dd->de_inode = inode;
208 dd->de_inode = alloc_unr(devfs_inos);
210 /* Create the "." entry in the new directory */
211 de = devfs_newdirent(".", 1);
212 de->de_dirent->d_type = DT_DIR;
213 de->de_flags |= DE_DOT;
214 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
217 /* Create the ".." entry in the new directory */
218 de = devfs_newdirent("..", 2);
219 de->de_dirent->d_type = DT_DIR;
220 de->de_flags |= DE_DOTDOT;
221 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
222 if (dotdot == NULL) {
226 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
231 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
237 devfs_dirent_free(struct devfs_dirent *de)
243 * The caller needs to hold the dm for the duration of the call since
244 * dm->dm_lock may be temporary dropped.
247 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
251 KASSERT((de->de_flags & DE_DOOMED) == 0,
252 ("devfs_delete doomed dirent"));
253 de->de_flags |= DE_DOOMED;
254 mtx_lock(&devfs_de_interlock);
258 mtx_unlock(&devfs_de_interlock);
260 sx_unlock(&dm->dm_lock);
262 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
269 sx_xlock(&dm->dm_lock);
271 mtx_unlock(&devfs_de_interlock);
272 if (de->de_symlink) {
273 free(de->de_symlink, M_DEVFS);
274 de->de_symlink = NULL;
277 mac_devfs_destroy(de);
279 if (de->de_inode > DEVFS_ROOTINO) {
280 free_unr(devfs_inos, de->de_inode);
283 if (DEVFS_DE_DROP(de))
284 devfs_dirent_free(de);
289 * Recursively removes the entire tree.
290 * The caller needs to hold the dm for the duration of the call.
294 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
296 struct devfs_dirent *de;
298 sx_assert(&dm->dm_lock, SX_XLOCKED);
300 de = TAILQ_FIRST(&dd->de_dlist);
303 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
304 if (de->de_flags & (DE_DOT|DE_DOTDOT))
305 devfs_delete(dm, de, 0);
306 else if (de->de_dirent->d_type == DT_DIR)
309 devfs_delete(dm, de, 0);
311 devfs_delete(dm, dd, 0);
315 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
316 * by the mount points dm_idx.
317 * This function extends the array when necessary, taking into account that
318 * the default array is 1 element and not malloc'ed.
321 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
323 struct devfs_dirent **dep;
326 siz = (dm->dm_idx + 1) * sizeof *dep;
327 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
329 if (dm->dm_idx <= cdp->cdp_maxdirent) {
335 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
336 if (cdp->cdp_maxdirent > 0)
337 free(cdp->cdp_dirents, M_DEVFS2);
338 cdp->cdp_dirents = dep;
340 * XXX: if malloc told us how much we actually got this could
343 cdp->cdp_maxdirent = dm->dm_idx;
348 * The caller needs to hold the dm for the duration of the call.
351 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
353 struct cdev_priv *cdp;
354 struct devfs_dirent *de;
355 struct devfs_dirent *dd;
360 sx_assert(&dm->dm_lock, SX_XLOCKED);
362 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
364 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
367 * If we are unmounting, or the device has been destroyed,
368 * clean up our dirent.
370 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
371 dm->dm_idx <= cdp->cdp_maxdirent &&
372 cdp->cdp_dirents[dm->dm_idx] != NULL) {
373 de = cdp->cdp_dirents[dm->dm_idx];
374 cdp->cdp_dirents[dm->dm_idx] = NULL;
375 KASSERT(cdp == de->de_cdp,
376 ("%s %d %s %p %p", __func__, __LINE__,
377 cdp->cdp_c.si_name, cdp, de->de_cdp));
378 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
381 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
384 devfs_delete(dm, de, 0);
391 * GC any lingering devices
393 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
394 if (cdp->cdp_inuse > 0)
396 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
398 dev_rel(&cdp->cdp_c);
402 * Don't create any new dirents if we are unmounting
406 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
408 if (dm->dm_idx <= cdp->cdp_maxdirent &&
409 cdp->cdp_dirents[dm->dm_idx] != NULL) {
410 de = cdp->cdp_dirents[dm->dm_idx];
411 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
419 if (dm->dm_idx > cdp->cdp_maxdirent)
420 devfs_metoo(cdp, dm);
423 s = cdp->cdp_c.si_name;
425 for (q = s; *q != '/' && *q != '\0'; q++)
429 de = devfs_find(dd, s, q - s);
431 de = devfs_vmkdir(dm, s, q - s, dd, 0);
436 de = devfs_newdirent(s, q - s);
437 if (cdp->cdp_c.si_flags & SI_ALIAS) {
441 de->de_dirent->d_type = DT_LNK;
442 pdev = cdp->cdp_c.si_parent;
443 j = strlen(pdev->si_name) + 1;
444 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
445 bcopy(pdev->si_name, de->de_symlink, j);
447 de->de_uid = cdp->cdp_c.si_uid;
448 de->de_gid = cdp->cdp_c.si_gid;
449 de->de_mode = cdp->cdp_c.si_mode;
450 de->de_dirent->d_type = DT_CHR;
452 de->de_inode = cdp->cdp_inode;
455 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
459 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
460 devfs_rules_apply(dm, de);
462 /* XXX: could check that cdp is still active here */
463 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
464 ("%s %d\n", __func__, __LINE__));
465 cdp->cdp_dirents[dm->dm_idx] = de;
466 KASSERT(de->de_cdp != (void *)0xdeadc0de,
467 ("%s %d\n", __func__, __LINE__));
476 * The caller needs to hold the dm for the duration of the call.
479 devfs_populate(struct devfs_mount *dm)
482 sx_assert(&dm->dm_lock, SX_XLOCKED);
483 if (dm->dm_generation == devfs_generation)
485 while (devfs_populate_loop(dm, 0))
487 dm->dm_generation = devfs_generation;
491 * The caller needs to hold the dm for the duration of the call.
494 devfs_cleanup(struct devfs_mount *dm)
497 sx_assert(&dm->dm_lock, SX_XLOCKED);
498 while (devfs_populate_loop(dm, 1))
500 devfs_purge(dm, dm->dm_rootdir);
504 * devfs_create() and devfs_destroy() are called from kern_conf.c and
505 * in both cases the devlock() mutex is held, so no further locking
506 * is necesary and no sleeping allowed.
510 devfs_create(struct cdev *dev)
512 struct cdev_priv *cdp;
514 mtx_assert(&devmtx, MA_OWNED);
515 cdp = cdev2priv(dev);
516 cdp->cdp_flags |= CDP_ACTIVE;
517 cdp->cdp_inode = alloc_unrl(devfs_inos);
519 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
524 devfs_destroy(struct cdev *dev)
526 struct cdev_priv *cdp;
528 mtx_assert(&devmtx, MA_OWNED);
529 cdp = cdev2priv(dev);
530 cdp->cdp_flags &= ~CDP_ACTIVE;
535 devfs_devs_init(void *junk __unused)
538 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
541 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);