2 * Copyright (c) 2000,2004
3 * Poul-Henning Kamp. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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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
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)");
115 devfs_alloc(int flags)
117 struct cdev_priv *cdp;
121 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO |
122 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
126 cdp->cdp_dirents = &cdp->cdp_dirent0;
127 cdp->cdp_dirent0 = NULL;
128 cdp->cdp_maxdirent = 0;
133 cdev->si_name = cdev->__si_namebuf;
134 LIST_INIT(&cdev->si_children);
136 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
137 cdev->si_cred = NULL;
143 devfs_free(struct cdev *cdev)
145 struct cdev_priv *cdp;
147 cdp = cdev2priv(cdev);
148 if (cdev->si_cred != NULL)
149 crfree(cdev->si_cred);
150 if (cdp->cdp_inode > 0)
151 free_unr(devfs_inos, cdp->cdp_inode);
152 if (cdp->cdp_maxdirent > 0)
153 free(cdp->cdp_dirents, M_DEVFS2);
157 struct devfs_dirent *
158 devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
160 struct devfs_dirent *de;
162 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
163 if (namelen != de->de_dirent->d_namlen)
165 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
172 struct devfs_dirent *
173 devfs_newdirent(char *name, int namelen)
176 struct devfs_dirent *de;
179 d.d_namlen = namelen;
180 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
181 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
182 de->de_dirent = (struct dirent *)(de + 1);
183 de->de_dirent->d_namlen = namelen;
184 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
185 bcopy(name, de->de_dirent->d_name, namelen);
186 de->de_dirent->d_name[namelen] = '\0';
187 vfs_timestamp(&de->de_ctime);
188 de->de_mtime = de->de_atime = de->de_ctime;
197 struct devfs_dirent *
198 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
200 struct devfs_dirent *dd;
201 struct devfs_dirent *de;
203 /* Create the new directory */
204 dd = devfs_newdirent(name, namelen);
205 TAILQ_INIT(&dd->de_dlist);
206 dd->de_dirent->d_type = DT_DIR;
211 dd->de_inode = inode;
213 dd->de_inode = alloc_unr(devfs_inos);
215 /* Create the "." entry in the new directory */
216 de = devfs_newdirent(".", 1);
217 de->de_dirent->d_type = DT_DIR;
218 de->de_flags |= DE_DOT;
219 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
222 /* Create the ".." entry in the new directory */
223 de = devfs_newdirent("..", 2);
224 de->de_dirent->d_type = DT_DIR;
225 de->de_flags |= DE_DOTDOT;
226 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
227 if (dotdot == NULL) {
231 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
236 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
242 devfs_dirent_free(struct devfs_dirent *de)
248 * The caller needs to hold the dm for the duration of the call since
249 * dm->dm_lock may be temporary dropped.
252 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
256 KASSERT((de->de_flags & DE_DOOMED) == 0,
257 ("devfs_delete doomed dirent"));
258 de->de_flags |= DE_DOOMED;
259 mtx_lock(&devfs_de_interlock);
263 mtx_unlock(&devfs_de_interlock);
265 sx_unlock(&dm->dm_lock);
267 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
274 sx_xlock(&dm->dm_lock);
276 mtx_unlock(&devfs_de_interlock);
277 if (de->de_symlink) {
278 free(de->de_symlink, M_DEVFS);
279 de->de_symlink = NULL;
282 mac_devfs_destroy(de);
284 if (de->de_inode > DEVFS_ROOTINO) {
285 free_unr(devfs_inos, de->de_inode);
288 if (DEVFS_DE_DROP(de))
289 devfs_dirent_free(de);
294 * Recursively removes the entire tree.
295 * The caller needs to hold the dm for the duration of the call.
299 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
301 struct devfs_dirent *de;
303 sx_assert(&dm->dm_lock, SX_XLOCKED);
305 de = TAILQ_FIRST(&dd->de_dlist);
308 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
309 if (de->de_flags & (DE_DOT|DE_DOTDOT))
310 devfs_delete(dm, de, 0);
311 else if (de->de_dirent->d_type == DT_DIR)
314 devfs_delete(dm, de, 0);
316 devfs_delete(dm, dd, 0);
320 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
321 * by the mount points dm_idx.
322 * This function extends the array when necessary, taking into account that
323 * the default array is 1 element and not malloc'ed.
326 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
328 struct devfs_dirent **dep;
331 siz = (dm->dm_idx + 1) * sizeof *dep;
332 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
334 if (dm->dm_idx <= cdp->cdp_maxdirent) {
340 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
341 if (cdp->cdp_maxdirent > 0)
342 free(cdp->cdp_dirents, M_DEVFS2);
343 cdp->cdp_dirents = dep;
345 * XXX: if malloc told us how much we actually got this could
348 cdp->cdp_maxdirent = dm->dm_idx;
353 * The caller needs to hold the dm for the duration of the call.
356 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
358 struct cdev_priv *cdp;
359 struct devfs_dirent *de;
360 struct devfs_dirent *dd;
365 sx_assert(&dm->dm_lock, SX_XLOCKED);
367 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
369 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
372 * If we are unmounting, or the device has been destroyed,
373 * clean up our dirent.
375 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
376 dm->dm_idx <= cdp->cdp_maxdirent &&
377 cdp->cdp_dirents[dm->dm_idx] != NULL) {
378 de = cdp->cdp_dirents[dm->dm_idx];
379 cdp->cdp_dirents[dm->dm_idx] = NULL;
380 KASSERT(cdp == de->de_cdp,
381 ("%s %d %s %p %p", __func__, __LINE__,
382 cdp->cdp_c.si_name, cdp, de->de_cdp));
383 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
386 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
389 devfs_delete(dm, de, 0);
396 * GC any lingering devices
398 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
399 if (cdp->cdp_inuse > 0)
401 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
403 dev_rel(&cdp->cdp_c);
407 * Don't create any new dirents if we are unmounting
411 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
413 if (dm->dm_idx <= cdp->cdp_maxdirent &&
414 cdp->cdp_dirents[dm->dm_idx] != NULL) {
415 de = cdp->cdp_dirents[dm->dm_idx];
416 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
424 if (dm->dm_idx > cdp->cdp_maxdirent)
425 devfs_metoo(cdp, dm);
428 s = cdp->cdp_c.si_name;
430 for (q = s; *q != '/' && *q != '\0'; q++)
434 de = devfs_find(dd, s, q - s);
436 de = devfs_vmkdir(dm, s, q - s, dd, 0);
441 de = devfs_newdirent(s, q - s);
442 if (cdp->cdp_c.si_flags & SI_ALIAS) {
446 de->de_dirent->d_type = DT_LNK;
447 pdev = cdp->cdp_c.si_parent;
448 j = strlen(pdev->si_name) + 1;
449 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
450 bcopy(pdev->si_name, de->de_symlink, j);
452 de->de_uid = cdp->cdp_c.si_uid;
453 de->de_gid = cdp->cdp_c.si_gid;
454 de->de_mode = cdp->cdp_c.si_mode;
455 de->de_dirent->d_type = DT_CHR;
457 de->de_inode = cdp->cdp_inode;
460 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
464 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
465 devfs_rules_apply(dm, de);
467 /* XXX: could check that cdp is still active here */
468 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
469 ("%s %d\n", __func__, __LINE__));
470 cdp->cdp_dirents[dm->dm_idx] = de;
471 KASSERT(de->de_cdp != (void *)0xdeadc0de,
472 ("%s %d\n", __func__, __LINE__));
481 * The caller needs to hold the dm for the duration of the call.
484 devfs_populate(struct devfs_mount *dm)
487 sx_assert(&dm->dm_lock, SX_XLOCKED);
488 if (dm->dm_generation == devfs_generation)
490 while (devfs_populate_loop(dm, 0))
492 dm->dm_generation = devfs_generation;
496 * The caller needs to hold the dm for the duration of the call.
499 devfs_cleanup(struct devfs_mount *dm)
502 sx_assert(&dm->dm_lock, SX_XLOCKED);
503 while (devfs_populate_loop(dm, 1))
505 devfs_purge(dm, dm->dm_rootdir);
509 * devfs_create() and devfs_destroy() are called from kern_conf.c and
510 * in both cases the devlock() mutex is held, so no further locking
511 * is necesary and no sleeping allowed.
515 devfs_create(struct cdev *dev)
517 struct cdev_priv *cdp;
519 mtx_assert(&devmtx, MA_OWNED);
520 cdp = cdev2priv(dev);
521 cdp->cdp_flags |= CDP_ACTIVE;
522 cdp->cdp_inode = alloc_unrl(devfs_inos);
524 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
529 devfs_destroy(struct cdev *dev)
531 struct cdev_priv *cdp;
533 mtx_assert(&devmtx, MA_OWNED);
534 cdp = cdev2priv(dev);
535 cdp->cdp_flags &= ~CDP_ACTIVE;
540 devfs_devs_init(void *junk __unused)
543 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
546 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);