devfs_devs.c

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    1 /*-
    2  * Copyright (c) 2000,2004
    3  *      Poul-Henning Kamp.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    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.
   13  *
   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
   24  * SUCH DAMAGE.
   25  *
   26  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
   27  *
   28  * $FreeBSD$
   29  */
   30 
   31 #include <sys/param.h>
   32 #include <sys/systm.h>
   33 #include <sys/conf.h>
   34 #include <sys/dirent.h>
   35 #include <sys/kernel.h>
   36 #include <sys/limits.h>
   37 #include <sys/lock.h>
   38 #include <sys/malloc.h>
   39 #include <sys/proc.h>
   40 #include <sys/sx.h>
   41 #include <sys/sysctl.h>
   42 #include <sys/vnode.h>
   43 
   44 #include <sys/kdb.h>
   45 
   46 #include <fs/devfs/devfs.h>
   47 #include <fs/devfs/devfs_int.h>
   48 
   49 #include <security/mac/mac_framework.h>
   50 
   51 /*
   52  * The one true (but secret) list of active devices in the system.
   53  * Locked by dev_lock()/devmtx
   54  */
   55 struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
   56 
   57 struct unrhdr *devfs_inos;
   58 
   59 
   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");
   63 
   64 SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
   65 
   66 static unsigned devfs_generation;
   67 SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
   68         &devfs_generation, 0, "DEVFS generation number");
   69 
   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");
   73 
   74 /*
   75  * Helper sysctl for devname(3).  We're given a dev_t and return the
   76  * name, if any, registered by the device driver.
   77  */
   78 static int
   79 sysctl_devname(SYSCTL_HANDLER_ARGS)
   80 {
   81         int error;
   82         dev_t ud;
   83         struct cdev_priv *cdp;
   84         struct cdev *dev;
   85 
   86         error = SYSCTL_IN(req, &ud, sizeof (ud));
   87         if (error)
   88                 return (error);
   89         if (ud == NODEV)
   90                 return (EINVAL);
   91         dev = NULL;
   92         dev_lock();
   93         TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
   94                 if (cdp->cdp_inode == ud) {
   95                         dev = &cdp->cdp_c;
   96                         dev_refl(dev);
   97                         break;
   98                 }
   99         dev_unlock();
  100         if (dev == NULL)
  101                 return (ENOENT);
  102         error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
  103         dev_rel(dev);
  104         return (error);
  105 }
  106 
  107 SYSCTL_PROC(_kern, OID_AUTO, devname,
  108     CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
  109     NULL, 0, sysctl_devname, "", "devname(3) handler");
  110 
  111 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
  112     SYSCTL_NULL_INT_PTR, sizeof(struct cdev), "sizeof(struct cdev)");
  113 
  114 SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
  115     SYSCTL_NULL_INT_PTR, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
  116 
  117 struct cdev *
  118 devfs_alloc(int flags)
  119 {
  120         struct cdev_priv *cdp;
  121         struct cdev *cdev;
  122         struct timespec ts;
  123 
  124         cdp = malloc(sizeof *cdp, M_CDEVP, M_ZERO |
  125             ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
  126         if (cdp == NULL)
  127                 return (NULL);
  128 
  129         cdp->cdp_dirents = &cdp->cdp_dirent0;
  130 
  131         cdev = &cdp->cdp_c;
  132         LIST_INIT(&cdev->si_children);
  133         vfs_timestamp(&ts);
  134         cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
  135 
  136         return (cdev);
  137 }
  138 
  139 int
  140 devfs_dev_exists(const char *name)
  141 {
  142         struct cdev_priv *cdp;
  143 
  144         mtx_assert(&devmtx, MA_OWNED);
  145 
  146         TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
  147                 if ((cdp->cdp_flags & CDP_ACTIVE) == 0)
  148                         continue;
  149                 if (devfs_pathpath(cdp->cdp_c.si_name, name) != 0)
  150                         return (1);
  151                 if (devfs_pathpath(name, cdp->cdp_c.si_name) != 0)
  152                         return (1);
  153         }
  154         if (devfs_dir_find(name) != 0)
  155                 return (1);
  156 
  157         return (0);
  158 }
  159 
  160 void
  161 devfs_free(struct cdev *cdev)
  162 {
  163         struct cdev_priv *cdp;
  164 
  165         cdp = cdev2priv(cdev);
  166         if (cdev->si_cred != NULL)
  167                 crfree(cdev->si_cred);
  168         devfs_free_cdp_inode(cdp->cdp_inode);
  169         if (cdp->cdp_maxdirent > 0) 
  170                 free(cdp->cdp_dirents, M_DEVFS2);
  171         free(cdp, M_CDEVP);
  172 }
  173 
  174 struct devfs_dirent *
  175 devfs_find(struct devfs_dirent *dd, const char *name, int namelen, int type)
  176 {
  177         struct devfs_dirent *de;
  178 
  179         TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
  180                 if (namelen != de->de_dirent->d_namlen)
  181                         continue;
  182                 if (type != 0 && type != de->de_dirent->d_type)
  183                         continue;
  184 
  185                 /*
  186                  * The race with finding non-active name is not
  187                  * completely closed by the check, but it is similar
  188                  * to the devfs_allocv() in making it unlikely enough.
  189                  */
  190                 if (de->de_dirent->d_type == DT_CHR &&
  191                     (de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
  192                         continue;
  193 
  194                 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
  195                         continue;
  196                 break;
  197         }
  198         KASSERT(de == NULL || (de->de_flags & DE_DOOMED) == 0,
  199             ("devfs_find: returning a doomed entry"));
  200         return (de);
  201 }
  202 
  203 struct devfs_dirent *
  204 devfs_newdirent(char *name, int namelen)
  205 {
  206         int i;
  207         struct devfs_dirent *de;
  208         struct dirent d;
  209 
  210         d.d_namlen = namelen;
  211         i = sizeof(*de) + GENERIC_DIRSIZ(&d);
  212         de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
  213         de->de_dirent = (struct dirent *)(de + 1);
  214         de->de_dirent->d_namlen = namelen;
  215         de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
  216         bcopy(name, de->de_dirent->d_name, namelen);
  217         de->de_dirent->d_name[namelen] = '\0';
  218         vfs_timestamp(&de->de_ctime);
  219         de->de_mtime = de->de_atime = de->de_ctime;
  220         de->de_links = 1;
  221         de->de_holdcnt = 1;
  222 #ifdef MAC
  223         mac_devfs_init(de);
  224 #endif
  225         return (de);
  226 }
  227 
  228 struct devfs_dirent *
  229 devfs_parent_dirent(struct devfs_dirent *de)
  230 {
  231 
  232         if (de->de_dirent->d_type != DT_DIR)
  233                 return (de->de_dir);
  234 
  235         if (de->de_flags & (DE_DOT | DE_DOTDOT))
  236                 return (NULL);
  237 
  238         de = TAILQ_FIRST(&de->de_dlist);        /* "." */
  239         if (de == NULL)
  240                 return (NULL);
  241         de = TAILQ_NEXT(de, de_list);           /* ".." */
  242         if (de == NULL)
  243                 return (NULL);
  244 
  245         return (de->de_dir);
  246 }
  247 
  248 struct devfs_dirent *
  249 devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen,
  250     struct devfs_dirent *dotdot, u_int inode)
  251 {
  252         struct devfs_dirent *dd;
  253         struct devfs_dirent *de;
  254 
  255         /* Create the new directory */
  256         dd = devfs_newdirent(name, namelen);
  257         TAILQ_INIT(&dd->de_dlist);
  258         dd->de_dirent->d_type = DT_DIR;
  259         dd->de_mode = 0555;
  260         dd->de_links = 2;
  261         dd->de_dir = dd;
  262         if (inode != 0)
  263                 dd->de_inode = inode;
  264         else
  265                 dd->de_inode = alloc_unr(devfs_inos);
  266 
  267         /*
  268          * "." and ".." are always the two first entries in the
  269          * de_dlist list.
  270          *
  271          * Create the "." entry in the new directory.
  272          */
  273         de = devfs_newdirent(".", 1);
  274         de->de_dirent->d_type = DT_DIR;
  275         de->de_flags |= DE_DOT;
  276         TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
  277         de->de_dir = dd;
  278 
  279         /* Create the ".." entry in the new directory. */
  280         de = devfs_newdirent("..", 2);
  281         de->de_dirent->d_type = DT_DIR;
  282         de->de_flags |= DE_DOTDOT;
  283         TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
  284         if (dotdot == NULL) {
  285                 de->de_dir = dd;
  286         } else {
  287                 de->de_dir = dotdot;
  288                 sx_assert(&dmp->dm_lock, SX_XLOCKED);
  289                 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
  290                 dotdot->de_links++;
  291                 devfs_rules_apply(dmp, dd);
  292         }
  293 
  294 #ifdef MAC
  295         mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
  296 #endif
  297         return (dd);
  298 }
  299 
  300 void
  301 devfs_dirent_free(struct devfs_dirent *de)
  302 {
  303         struct vnode *vp;
  304 
  305         vp = de->de_vnode;
  306         mtx_lock(&devfs_de_interlock);
  307         if (vp != NULL && vp->v_data == de)
  308                 vp->v_data = NULL;
  309         mtx_unlock(&devfs_de_interlock);
  310         free(de, M_DEVFS3);
  311 }
  312 
  313 /*
  314  * Removes a directory if it is empty. Also empty parent directories are
  315  * removed recursively.
  316  */
  317 static void
  318 devfs_rmdir_empty(struct devfs_mount *dm, struct devfs_dirent *de)
  319 {
  320         struct devfs_dirent *dd, *de_dot, *de_dotdot;
  321 
  322         sx_assert(&dm->dm_lock, SX_XLOCKED);
  323 
  324         for (;;) {
  325                 KASSERT(de->de_dirent->d_type == DT_DIR,
  326                     ("devfs_rmdir_empty: de is not a directory"));
  327 
  328                 if ((de->de_flags & DE_DOOMED) != 0 || de == dm->dm_rootdir)
  329                         return;
  330 
  331                 de_dot = TAILQ_FIRST(&de->de_dlist);
  332                 KASSERT(de_dot != NULL, ("devfs_rmdir_empty: . missing"));
  333                 de_dotdot = TAILQ_NEXT(de_dot, de_list);
  334                 KASSERT(de_dotdot != NULL, ("devfs_rmdir_empty: .. missing"));
  335                 /* Return if the directory is not empty. */
  336                 if (TAILQ_NEXT(de_dotdot, de_list) != NULL)
  337                         return;
  338 
  339                 dd = devfs_parent_dirent(de);
  340                 KASSERT(dd != NULL, ("devfs_rmdir_empty: NULL dd"));
  341                 TAILQ_REMOVE(&de->de_dlist, de_dot, de_list);
  342                 TAILQ_REMOVE(&de->de_dlist, de_dotdot, de_list);
  343                 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
  344                 DEVFS_DE_HOLD(dd);
  345                 devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
  346                 devfs_delete(dm, de_dot, DEVFS_DEL_NORECURSE);
  347                 devfs_delete(dm, de_dotdot, DEVFS_DEL_NORECURSE);
  348                 if (DEVFS_DE_DROP(dd)) {
  349                         devfs_dirent_free(dd);
  350                         return;
  351                 }
  352 
  353                 de = dd;
  354         }
  355 }
  356 
  357 /*
  358  * The caller needs to hold the dm for the duration of the call since
  359  * dm->dm_lock may be temporary dropped.
  360  */
  361 void
  362 devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int flags)
  363 {
  364         struct devfs_dirent *dd;
  365         struct vnode *vp;
  366 
  367         KASSERT((de->de_flags & DE_DOOMED) == 0,
  368                 ("devfs_delete doomed dirent"));
  369         de->de_flags |= DE_DOOMED;
  370 
  371         if ((flags & DEVFS_DEL_NORECURSE) == 0) {
  372                 dd = devfs_parent_dirent(de);
  373                 if (dd != NULL)
  374                         DEVFS_DE_HOLD(dd);
  375                 if (de->de_flags & DE_USER) {
  376                         KASSERT(dd != NULL, ("devfs_delete: NULL dd"));
  377                         devfs_dir_unref_de(dm, dd);
  378                 }
  379         } else
  380                 dd = NULL;
  381 
  382         mtx_lock(&devfs_de_interlock);
  383         vp = de->de_vnode;
  384         if (vp != NULL) {
  385                 VI_LOCK(vp);
  386                 mtx_unlock(&devfs_de_interlock);
  387                 vholdl(vp);
  388                 sx_unlock(&dm->dm_lock);
  389                 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
  390                         vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
  391                 else
  392                         VI_UNLOCK(vp);
  393                 vgone(vp);
  394                 if ((flags & DEVFS_DEL_VNLOCKED) == 0)
  395                         VOP_UNLOCK(vp, 0);
  396                 vdrop(vp);
  397                 sx_xlock(&dm->dm_lock);
  398         } else
  399                 mtx_unlock(&devfs_de_interlock);
  400         if (de->de_symlink) {
  401                 free(de->de_symlink, M_DEVFS);
  402                 de->de_symlink = NULL;
  403         }
  404 #ifdef MAC
  405         mac_devfs_destroy(de);
  406 #endif
  407         if (de->de_inode > DEVFS_ROOTINO) {
  408                 devfs_free_cdp_inode(de->de_inode);
  409                 de->de_inode = 0;
  410         }
  411         if (DEVFS_DE_DROP(de))
  412                 devfs_dirent_free(de);
  413 
  414         if (dd != NULL) {
  415                 if (DEVFS_DE_DROP(dd))
  416                         devfs_dirent_free(dd);
  417                 else
  418                         devfs_rmdir_empty(dm, dd);
  419         }
  420 }
  421 
  422 /*
  423  * Called on unmount.
  424  * Recursively removes the entire tree.
  425  * The caller needs to hold the dm for the duration of the call.
  426  */
  427 
  428 static void
  429 devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
  430 {
  431         struct devfs_dirent *de;
  432 
  433         sx_assert(&dm->dm_lock, SX_XLOCKED);
  434 
  435         DEVFS_DE_HOLD(dd);
  436         for (;;) {
  437                 /*
  438                  * Use TAILQ_LAST() to remove "." and ".." last.
  439                  * We might need ".." to resolve a path in
  440                  * devfs_dir_unref_de().
  441                  */
  442                 de = TAILQ_LAST(&dd->de_dlist, devfs_dlist_head);
  443                 if (de == NULL)
  444                         break;
  445                 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
  446                 if (de->de_flags & DE_USER)
  447                         devfs_dir_unref_de(dm, dd);
  448                 if (de->de_flags & (DE_DOT | DE_DOTDOT))
  449                         devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
  450                 else if (de->de_dirent->d_type == DT_DIR)
  451                         devfs_purge(dm, de);
  452                 else
  453                         devfs_delete(dm, de, DEVFS_DEL_NORECURSE);
  454         }
  455         if (DEVFS_DE_DROP(dd))
  456                 devfs_dirent_free(dd);
  457         else if ((dd->de_flags & DE_DOOMED) == 0)
  458                 devfs_delete(dm, dd, DEVFS_DEL_NORECURSE);
  459 }
  460 
  461 /*
  462  * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
  463  * by the mount points dm_idx.
  464  * This function extends the array when necessary, taking into account that
  465  * the default array is 1 element and not malloc'ed.
  466  */
  467 static void
  468 devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
  469 {
  470         struct devfs_dirent **dep;
  471         int siz;
  472 
  473         siz = (dm->dm_idx + 1) * sizeof *dep;
  474         dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
  475         dev_lock();
  476         if (dm->dm_idx <= cdp->cdp_maxdirent) {
  477                 /* We got raced */
  478                 dev_unlock();
  479                 free(dep, M_DEVFS2);
  480                 return;
  481         } 
  482         memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
  483         if (cdp->cdp_maxdirent > 0)
  484                 free(cdp->cdp_dirents, M_DEVFS2);
  485         cdp->cdp_dirents = dep;
  486         /*
  487          * XXX: if malloc told us how much we actually got this could
  488          * XXX: be optimized.
  489          */
  490         cdp->cdp_maxdirent = dm->dm_idx;
  491         dev_unlock();
  492 }
  493 
  494 /*
  495  * The caller needs to hold the dm for the duration of the call.
  496  */
  497 static int
  498 devfs_populate_loop(struct devfs_mount *dm, int cleanup)
  499 {
  500         struct cdev_priv *cdp;
  501         struct devfs_dirent *de;
  502         struct devfs_dirent *dd;
  503         struct cdev *pdev;
  504         int de_flags, j;
  505         char *q, *s;
  506 
  507         sx_assert(&dm->dm_lock, SX_XLOCKED);
  508         dev_lock();
  509         TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
  510 
  511                 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
  512 
  513                 /*
  514                  * If we are unmounting, or the device has been destroyed,
  515                  * clean up our dirent.
  516                  */
  517                 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
  518                     dm->dm_idx <= cdp->cdp_maxdirent &&
  519                     cdp->cdp_dirents[dm->dm_idx] != NULL) {
  520                         de = cdp->cdp_dirents[dm->dm_idx];
  521                         cdp->cdp_dirents[dm->dm_idx] = NULL;
  522                         KASSERT(cdp == de->de_cdp,
  523                             ("%s %d %s %p %p", __func__, __LINE__,
  524                             cdp->cdp_c.si_name, cdp, de->de_cdp));
  525                         KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
  526                         dev_unlock();
  527 
  528                         TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
  529                         de->de_cdp = NULL;
  530                         de->de_inode = 0;
  531                         devfs_delete(dm, de, 0);
  532                         dev_lock();
  533                         cdp->cdp_inuse--;
  534                         dev_unlock();
  535                         return (1);
  536                 }
  537                 /*
  538                  * GC any lingering devices
  539                  */
  540                 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
  541                         if (cdp->cdp_inuse > 0)
  542                                 continue;
  543                         TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
  544                         dev_unlock();
  545                         dev_rel(&cdp->cdp_c);
  546                         return (1);
  547                 }
  548                 /*
  549                  * Don't create any new dirents if we are unmounting
  550                  */
  551                 if (cleanup)
  552                         continue;
  553                 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
  554 
  555                 if (dm->dm_idx <= cdp->cdp_maxdirent &&
  556                     cdp->cdp_dirents[dm->dm_idx] != NULL) {
  557                         de = cdp->cdp_dirents[dm->dm_idx];
  558                         KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
  559                         continue;
  560                 }
  561 
  562 
  563                 cdp->cdp_inuse++;
  564                 dev_unlock();
  565 
  566                 if (dm->dm_idx > cdp->cdp_maxdirent)
  567                         devfs_metoo(cdp, dm);
  568 
  569                 dd = dm->dm_rootdir;
  570                 s = cdp->cdp_c.si_name;
  571                 for (;;) {
  572                         for (q = s; *q != '/' && *q != '\0'; q++)
  573                                 continue;
  574                         if (*q != '/')
  575                                 break;
  576                         de = devfs_find(dd, s, q - s, 0);
  577                         if (de == NULL)
  578                                 de = devfs_vmkdir(dm, s, q - s, dd, 0);
  579                         else if (de->de_dirent->d_type == DT_LNK) {
  580                                 de = devfs_find(dd, s, q - s, DT_DIR);
  581                                 if (de == NULL)
  582                                         de = devfs_vmkdir(dm, s, q - s, dd, 0);
  583                                 de->de_flags |= DE_COVERED;
  584                         }
  585                         s = q + 1;
  586                         dd = de;
  587                         KASSERT(dd->de_dirent->d_type == DT_DIR &&
  588                             (dd->de_flags & (DE_DOT | DE_DOTDOT)) == 0,
  589                             ("%s: invalid directory (si_name=%s)",
  590                             __func__, cdp->cdp_c.si_name));
  591 
  592                 }
  593                 de_flags = 0;
  594                 de = devfs_find(dd, s, q - s, DT_LNK);
  595                 if (de != NULL)
  596                         de_flags |= DE_COVERED;
  597 
  598                 de = devfs_newdirent(s, q - s);
  599                 if (cdp->cdp_c.si_flags & SI_ALIAS) {
  600                         de->de_uid = 0;
  601                         de->de_gid = 0;
  602                         de->de_mode = 0755;
  603                         de->de_dirent->d_type = DT_LNK;
  604                         pdev = cdp->cdp_c.si_parent;
  605                         j = strlen(pdev->si_name) + 1;
  606                         de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
  607                         bcopy(pdev->si_name, de->de_symlink, j);
  608                 } else {
  609                         de->de_uid = cdp->cdp_c.si_uid;
  610                         de->de_gid = cdp->cdp_c.si_gid;
  611                         de->de_mode = cdp->cdp_c.si_mode;
  612                         de->de_dirent->d_type = DT_CHR;
  613                 }
  614                 de->de_flags |= de_flags;
  615                 de->de_inode = cdp->cdp_inode;
  616                 de->de_cdp = cdp;
  617 #ifdef MAC
  618                 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
  619                     &cdp->cdp_c, de);
  620 #endif
  621                 de->de_dir = dd;
  622                 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
  623                 devfs_rules_apply(dm, de);
  624                 dev_lock();
  625                 /* XXX: could check that cdp is still active here */
  626                 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
  627                     ("%s %d\n", __func__, __LINE__));
  628                 cdp->cdp_dirents[dm->dm_idx] = de;
  629                 KASSERT(de->de_cdp != (void *)0xdeadc0de,
  630                     ("%s %d\n", __func__, __LINE__));
  631                 dev_unlock();
  632                 return (1);
  633         }
  634         dev_unlock();
  635         return (0);
  636 }
  637 
  638 /*
  639  * The caller needs to hold the dm for the duration of the call.
  640  */
  641 void
  642 devfs_populate(struct devfs_mount *dm)
  643 {
  644         unsigned gen;
  645 
  646         sx_assert(&dm->dm_lock, SX_XLOCKED);
  647         gen = devfs_generation;
  648         if (dm->dm_generation == gen)
  649                 return;
  650         while (devfs_populate_loop(dm, 0))
  651                 continue;
  652         dm->dm_generation = gen;
  653 }
  654 
  655 /*
  656  * The caller needs to hold the dm for the duration of the call.
  657  */
  658 void
  659 devfs_cleanup(struct devfs_mount *dm)
  660 {
  661 
  662         sx_assert(&dm->dm_lock, SX_XLOCKED);
  663         while (devfs_populate_loop(dm, 1))
  664                 continue;
  665         devfs_purge(dm, dm->dm_rootdir);
  666 }
  667 
  668 /*
  669  * devfs_create() and devfs_destroy() are called from kern_conf.c and
  670  * in both cases the devlock() mutex is held, so no further locking
  671  * is necessary and no sleeping allowed.
  672  */
  673 
  674 void
  675 devfs_create(struct cdev *dev)
  676 {
  677         struct cdev_priv *cdp;
  678 
  679         mtx_assert(&devmtx, MA_OWNED);
  680         cdp = cdev2priv(dev);
  681         cdp->cdp_flags |= CDP_ACTIVE;
  682         cdp->cdp_inode = alloc_unrl(devfs_inos);
  683         dev_refl(dev);
  684         TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
  685         devfs_generation++;
  686 }
  687 
  688 void
  689 devfs_destroy(struct cdev *dev)
  690 {
  691         struct cdev_priv *cdp;
  692 
  693         mtx_assert(&devmtx, MA_OWNED);
  694         cdp = cdev2priv(dev);
  695         cdp->cdp_flags &= ~CDP_ACTIVE;
  696         devfs_generation++;
  697 }
  698 
  699 ino_t
  700 devfs_alloc_cdp_inode(void)
  701 {
  702 
  703         return (alloc_unr(devfs_inos));
  704 }
  705 
  706 void
  707 devfs_free_cdp_inode(ino_t ino)
  708 {
  709 
  710         if (ino > 0)
  711                 free_unr(devfs_inos, ino);
  712 }
  713 
  714 static void
  715 devfs_devs_init(void *junk __unused)
  716 {
  717 
  718         devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
  719 }
  720 
  721 SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);
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FreeBSD/Linux Kernel Cross Reference sys/fs/devfs/devfs_devs.c

FreeBSD/Linux Kernel Cross Reference
sys/fs/devfs/devfs_devs.c
