devfs_vnops.c

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    1 /*-
    2  * Copyright (c) 2000-2004
    3  *      Poul-Henning Kamp.  All rights reserved.
    4  * Copyright (c) 1989, 1992-1993, 1995
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * This code is derived from software donated to Berkeley by
    8  * Jan-Simon Pendry.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)kernfs_vnops.c      8.15 (Berkeley) 5/21/95
   32  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43
   33  *
   34  * $FreeBSD: releng/8.4/sys/fs/devfs/devfs_vnops.c 247083 2013-02-21 06:10:36Z kib $
   35  */
   36 
   37 /*
   38  * TODO:
   39  *      remove empty directories
   40  *      mkdir: want it ?
   41  */
   42 
   43 #include <sys/param.h>
   44 #include <sys/systm.h>
   45 #include <sys/conf.h>
   46 #include <sys/dirent.h>
   47 #include <sys/fcntl.h>
   48 #include <sys/file.h>
   49 #include <sys/filedesc.h>
   50 #include <sys/filio.h>
   51 #include <sys/jail.h>
   52 #include <sys/kernel.h>
   53 #include <sys/lock.h>
   54 #include <sys/malloc.h>
   55 #include <sys/mount.h>
   56 #include <sys/namei.h>
   57 #include <sys/priv.h>
   58 #include <sys/proc.h>
   59 #include <sys/stat.h>
   60 #include <sys/sx.h>
   61 #include <sys/time.h>
   62 #include <sys/ttycom.h>
   63 #include <sys/unistd.h>
   64 #include <sys/vnode.h>
   65 
   66 static struct vop_vector devfs_vnodeops;
   67 static struct vop_vector devfs_specops;
   68 static struct fileops devfs_ops_f;
   69 
   70 #include <fs/devfs/devfs.h>
   71 #include <fs/devfs/devfs_int.h>
   72 
   73 #include <security/mac/mac_framework.h>
   74 
   75 static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data");
   76 
   77 struct mtx      devfs_de_interlock;
   78 MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF);
   79 struct sx       clone_drain_lock;
   80 SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock");
   81 struct mtx      cdevpriv_mtx;
   82 MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF);
   83 
   84 static int
   85 devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp,
   86     int *ref)
   87 {
   88 
   89         *dswp = devvn_refthread(fp->f_vnode, devp, ref);
   90         if (*devp != fp->f_data) {
   91                 if (*dswp != NULL)
   92                         dev_relthread(*devp, *ref);
   93                 return (ENXIO);
   94         }
   95         KASSERT((*devp)->si_refcount > 0,
   96             ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
   97         if (*dswp == NULL)
   98                 return (ENXIO);
   99         curthread->td_fpop = fp;
  100         return (0);
  101 }
  102 
  103 int
  104 devfs_get_cdevpriv(void **datap)
  105 {
  106         struct file *fp;
  107         struct cdev_privdata *p;
  108         int error;
  109 
  110         fp = curthread->td_fpop;
  111         if (fp == NULL)
  112                 return (EBADF);
  113         p = fp->f_cdevpriv;
  114         if (p != NULL) {
  115                 error = 0;
  116                 *datap = p->cdpd_data;
  117         } else
  118                 error = ENOENT;
  119         return (error);
  120 }
  121 
  122 int
  123 devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t priv_dtr)
  124 {
  125         struct file *fp;
  126         struct cdev_priv *cdp;
  127         struct cdev_privdata *p;
  128         int error;
  129 
  130         fp = curthread->td_fpop;
  131         if (fp == NULL)
  132                 return (ENOENT);
  133         cdp = cdev2priv((struct cdev *)fp->f_data);
  134         p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK);
  135         p->cdpd_data = priv;
  136         p->cdpd_dtr = priv_dtr;
  137         p->cdpd_fp = fp;
  138         mtx_lock(&cdevpriv_mtx);
  139         if (fp->f_cdevpriv == NULL) {
  140                 LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list);
  141                 fp->f_cdevpriv = p;
  142                 mtx_unlock(&cdevpriv_mtx);
  143                 error = 0;
  144         } else {
  145                 mtx_unlock(&cdevpriv_mtx);
  146                 free(p, M_CDEVPDATA);
  147                 error = EBUSY;
  148         }
  149         return (error);
  150 }
  151 
  152 void
  153 devfs_destroy_cdevpriv(struct cdev_privdata *p)
  154 {
  155 
  156         mtx_assert(&cdevpriv_mtx, MA_OWNED);
  157         p->cdpd_fp->f_cdevpriv = NULL;
  158         LIST_REMOVE(p, cdpd_list);
  159         mtx_unlock(&cdevpriv_mtx);
  160         (p->cdpd_dtr)(p->cdpd_data);
  161         free(p, M_CDEVPDATA);
  162 }
  163 
  164 void
  165 devfs_fpdrop(struct file *fp)
  166 {
  167         struct cdev_privdata *p;
  168 
  169         mtx_lock(&cdevpriv_mtx);
  170         if ((p = fp->f_cdevpriv) == NULL) {
  171                 mtx_unlock(&cdevpriv_mtx);
  172                 return;
  173         }
  174         devfs_destroy_cdevpriv(p);
  175 }
  176 
  177 void
  178 devfs_clear_cdevpriv(void)
  179 {
  180         struct file *fp;
  181 
  182         fp = curthread->td_fpop;
  183         if (fp == NULL)
  184                 return;
  185         devfs_fpdrop(fp);
  186 }
  187 
  188 static int
  189 devfs_vptocnp(struct vop_vptocnp_args *ap)
  190 {
  191         struct vnode *vp = ap->a_vp;
  192         struct vnode **dvp = ap->a_vpp;
  193         struct devfs_mount *dmp;
  194         char *buf = ap->a_buf;
  195         int *buflen = ap->a_buflen;
  196         struct devfs_dirent *dd, *de;
  197         int i, error;
  198 
  199         dmp = VFSTODEVFS(vp->v_mount);
  200         i = *buflen;
  201         dd = vp->v_data;
  202         error = 0;
  203 
  204         sx_xlock(&dmp->dm_lock);
  205 
  206         if (vp->v_type == VCHR) {
  207                 i -= strlen(dd->de_cdp->cdp_c.si_name);
  208                 if (i < 0) {
  209                         error = ENOMEM;
  210                         goto finished;
  211                 }
  212                 bcopy(dd->de_cdp->cdp_c.si_name, buf + i,
  213                     strlen(dd->de_cdp->cdp_c.si_name));
  214                 de = dd->de_dir;
  215         } else if (vp->v_type == VDIR) {
  216                 if (dd == dmp->dm_rootdir) {
  217                         *dvp = vp;
  218                         vhold(*dvp);
  219                         goto finished;
  220                 }
  221                 i -= dd->de_dirent->d_namlen;
  222                 if (i < 0) {
  223                         error = ENOMEM;
  224                         goto finished;
  225                 }
  226                 bcopy(dd->de_dirent->d_name, buf + i,
  227                     dd->de_dirent->d_namlen);
  228                 de = dd;
  229         } else {
  230                 error = ENOENT;
  231                 goto finished;
  232         }
  233         *buflen = i;
  234         de = devfs_parent_dirent(de);
  235         if (de == NULL) {
  236                 error = ENOENT;
  237                 goto finished;
  238         }
  239         mtx_lock(&devfs_de_interlock);
  240         *dvp = de->de_vnode;
  241         if (*dvp != NULL) {
  242                 VI_LOCK(*dvp);
  243                 mtx_unlock(&devfs_de_interlock);
  244                 vholdl(*dvp);
  245                 VI_UNLOCK(*dvp);
  246         } else {
  247                 mtx_unlock(&devfs_de_interlock);
  248                 error = ENOENT;
  249         }
  250 finished:
  251         sx_xunlock(&dmp->dm_lock);
  252         return (error);
  253 }
  254 
  255 /*
  256  * Construct the fully qualified path name relative to the mountpoint
  257  */
  258 static char *
  259 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
  260 {
  261         int i;
  262         struct devfs_dirent *de, *dd;
  263         struct devfs_mount *dmp;
  264 
  265         dmp = VFSTODEVFS(dvp->v_mount);
  266         dd = dvp->v_data;
  267         i = SPECNAMELEN;
  268         buf[i] = '\0';
  269         i -= cnp->cn_namelen;
  270         if (i < 0)
  271                  return (NULL);
  272         bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
  273         de = dd;
  274         while (de != dmp->dm_rootdir) {
  275                 i--;
  276                 if (i < 0)
  277                          return (NULL);
  278                 buf[i] = '/';
  279                 i -= de->de_dirent->d_namlen;
  280                 if (i < 0)
  281                          return (NULL);
  282                 bcopy(de->de_dirent->d_name, buf + i,
  283                     de->de_dirent->d_namlen);
  284                 de = devfs_parent_dirent(de);
  285                 if (de == NULL)
  286                         return (NULL);
  287         }
  288         return (buf + i);
  289 }
  290 
  291 static int
  292 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
  293         struct devfs_dirent *de)
  294 {
  295         int not_found;
  296 
  297         not_found = 0;
  298         if (de->de_flags & DE_DOOMED)
  299                 not_found = 1;
  300         if (DEVFS_DE_DROP(de)) {
  301                 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
  302                 devfs_dirent_free(de);
  303         }
  304         if (DEVFS_DMP_DROP(dmp)) {
  305                 KASSERT(not_found == 1,
  306                         ("DEVFS mount struct freed before dirent"));
  307                 not_found = 2;
  308                 sx_xunlock(&dmp->dm_lock);
  309                 devfs_unmount_final(dmp);
  310         }
  311         if (not_found == 1 || (drop_dm_lock && not_found != 2))
  312                 sx_unlock(&dmp->dm_lock);
  313         return (not_found);
  314 }
  315 
  316 static void
  317 devfs_insmntque_dtr(struct vnode *vp, void *arg)
  318 {
  319         struct devfs_dirent *de;
  320 
  321         de = (struct devfs_dirent *)arg;
  322         mtx_lock(&devfs_de_interlock);
  323         vp->v_data = NULL;
  324         de->de_vnode = NULL;
  325         mtx_unlock(&devfs_de_interlock);
  326         vgone(vp);
  327         vput(vp);
  328 }
  329 
  330 /*
  331  * devfs_allocv shall be entered with dmp->dm_lock held, and it drops
  332  * it on return.
  333  */
  334 int
  335 devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode,
  336     struct vnode **vpp)
  337 {
  338         int error;
  339         struct vnode *vp;
  340         struct cdev *dev;
  341         struct devfs_mount *dmp;
  342         struct cdevsw *dsw;
  343 
  344         dmp = VFSTODEVFS(mp);
  345         if (de->de_flags & DE_DOOMED) {
  346                 sx_xunlock(&dmp->dm_lock);
  347                 return (ENOENT);
  348         }
  349 loop:
  350         DEVFS_DE_HOLD(de);
  351         DEVFS_DMP_HOLD(dmp);
  352         mtx_lock(&devfs_de_interlock);
  353         vp = de->de_vnode;
  354         if (vp != NULL) {
  355                 VI_LOCK(vp);
  356                 mtx_unlock(&devfs_de_interlock);
  357                 sx_xunlock(&dmp->dm_lock);
  358                 vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread);
  359                 sx_xlock(&dmp->dm_lock);
  360                 if (devfs_allocv_drop_refs(0, dmp, de)) {
  361                         vput(vp);
  362                         return (ENOENT);
  363                 }
  364                 else if ((vp->v_iflag & VI_DOOMED) != 0) {
  365                         mtx_lock(&devfs_de_interlock);
  366                         if (de->de_vnode == vp) {
  367                                 de->de_vnode = NULL;
  368                                 vp->v_data = NULL;
  369                         }
  370                         mtx_unlock(&devfs_de_interlock);
  371                         vput(vp);
  372                         goto loop;
  373                 }
  374                 sx_xunlock(&dmp->dm_lock);
  375                 *vpp = vp;
  376                 return (0);
  377         }
  378         mtx_unlock(&devfs_de_interlock);
  379         if (de->de_dirent->d_type == DT_CHR) {
  380                 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
  381                         devfs_allocv_drop_refs(1, dmp, de);
  382                         return (ENOENT);
  383                 }
  384                 dev = &de->de_cdp->cdp_c;
  385         } else {
  386                 dev = NULL;
  387         }
  388         error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
  389         if (error != 0) {
  390                 devfs_allocv_drop_refs(1, dmp, de);
  391                 printf("devfs_allocv: failed to allocate new vnode\n");
  392                 return (error);
  393         }
  394 
  395         if (de->de_dirent->d_type == DT_CHR) {
  396                 vp->v_type = VCHR;
  397                 VI_LOCK(vp);
  398                 dev_lock();
  399                 dev_refl(dev);
  400                 /* XXX: v_rdev should be protect by vnode lock */
  401                 vp->v_rdev = dev;
  402                 KASSERT(vp->v_usecount == 1,
  403                     ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
  404                 dev->si_usecount += vp->v_usecount;
  405                 /* Special casing of ttys for deadfs.  Probably redundant. */
  406                 dsw = dev->si_devsw;
  407                 if (dsw != NULL && (dsw->d_flags & D_TTY) != 0)
  408                         vp->v_vflag |= VV_ISTTY;
  409                 dev_unlock();
  410                 VI_UNLOCK(vp);
  411                 if ((dev->si_flags & SI_ETERNAL) != 0)
  412                         vp->v_vflag |= VV_ETERNALDEV;
  413                 vp->v_op = &devfs_specops;
  414         } else if (de->de_dirent->d_type == DT_DIR) {
  415                 vp->v_type = VDIR;
  416         } else if (de->de_dirent->d_type == DT_LNK) {
  417                 vp->v_type = VLNK;
  418         } else {
  419                 vp->v_type = VBAD;
  420         }
  421         VN_LOCK_ASHARE(vp);
  422         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
  423         mtx_lock(&devfs_de_interlock);
  424         vp->v_data = de;
  425         de->de_vnode = vp;
  426         mtx_unlock(&devfs_de_interlock);
  427         error = insmntque1(vp, mp, devfs_insmntque_dtr, de);
  428         if (error != 0) {
  429                 (void) devfs_allocv_drop_refs(1, dmp, de);
  430                 return (error);
  431         }
  432         if (devfs_allocv_drop_refs(0, dmp, de)) {
  433                 vput(vp);
  434                 return (ENOENT);
  435         }
  436 #ifdef MAC
  437         mac_devfs_vnode_associate(mp, de, vp);
  438 #endif
  439         sx_xunlock(&dmp->dm_lock);
  440         *vpp = vp;
  441         return (0);
  442 }
  443 
  444 static int
  445 devfs_access(struct vop_access_args *ap)
  446 {
  447         struct vnode *vp = ap->a_vp;
  448         struct devfs_dirent *de;
  449         int error;
  450 
  451         de = vp->v_data;
  452         if (vp->v_type == VDIR)
  453                 de = de->de_dir;
  454 
  455         error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
  456             ap->a_accmode, ap->a_cred, NULL);
  457         if (!error)
  458                 return (error);
  459         if (error != EACCES)
  460                 return (error);
  461         /* We do, however, allow access to the controlling terminal */
  462         if (!(ap->a_td->td_proc->p_flag & P_CONTROLT))
  463                 return (error);
  464         if (ap->a_td->td_proc->p_session->s_ttyvp == de->de_vnode)
  465                 return (0);
  466         return (error);
  467 }
  468 
  469 /* ARGSUSED */
  470 static int
  471 devfs_close(struct vop_close_args *ap)
  472 {
  473         struct vnode *vp = ap->a_vp, *oldvp;
  474         struct thread *td = ap->a_td;
  475         struct cdev *dev = vp->v_rdev;
  476         struct cdevsw *dsw;
  477         int vp_locked, error, ref;
  478 
  479         /*
  480          * XXX: Don't call d_close() if we were called because of
  481          * XXX: insmntque1() failure.
  482          */
  483         if (vp->v_data == NULL)
  484                 return (0);
  485 
  486         /*
  487          * Hack: a tty device that is a controlling terminal
  488          * has a reference from the session structure.
  489          * We cannot easily tell that a character device is
  490          * a controlling terminal, unless it is the closing
  491          * process' controlling terminal.  In that case,
  492          * if the reference count is 2 (this last descriptor
  493          * plus the session), release the reference from the session.
  494          */
  495         oldvp = NULL;
  496         sx_xlock(&proctree_lock);
  497         if (td && vp == td->td_proc->p_session->s_ttyvp) {
  498                 SESS_LOCK(td->td_proc->p_session);
  499                 VI_LOCK(vp);
  500                 if (count_dev(dev) == 2 && (vp->v_iflag & VI_DOOMED) == 0) {
  501                         td->td_proc->p_session->s_ttyvp = NULL;
  502                         oldvp = vp;
  503                 }
  504                 VI_UNLOCK(vp);
  505                 SESS_UNLOCK(td->td_proc->p_session);
  506         }
  507         sx_xunlock(&proctree_lock);
  508         if (oldvp != NULL)
  509                 vrele(oldvp);
  510         /*
  511          * We do not want to really close the device if it
  512          * is still in use unless we are trying to close it
  513          * forcibly. Since every use (buffer, vnode, swap, cmap)
  514          * holds a reference to the vnode, and because we mark
  515          * any other vnodes that alias this device, when the
  516          * sum of the reference counts on all the aliased
  517          * vnodes descends to one, we are on last close.
  518          */
  519         dsw = dev_refthread(dev, &ref);
  520         if (dsw == NULL)
  521                 return (ENXIO);
  522         VI_LOCK(vp);
  523         if (vp->v_iflag & VI_DOOMED) {
  524                 /* Forced close. */
  525         } else if (dsw->d_flags & D_TRACKCLOSE) {
  526                 /* Keep device updated on status. */
  527         } else if (count_dev(dev) > 1) {
  528                 VI_UNLOCK(vp);
  529                 dev_relthread(dev, ref);
  530                 return (0);
  531         }
  532         vholdl(vp);
  533         VI_UNLOCK(vp);
  534         vp_locked = VOP_ISLOCKED(vp);
  535         VOP_UNLOCK(vp, 0);
  536         KASSERT(dev->si_refcount > 0,
  537             ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
  538         error = dsw->d_close(dev, ap->a_fflag, S_IFCHR, td);
  539         dev_relthread(dev, ref);
  540         vn_lock(vp, vp_locked | LK_RETRY);
  541         vdrop(vp);
  542         return (error);
  543 }
  544 
  545 static int
  546 devfs_close_f(struct file *fp, struct thread *td)
  547 {
  548         int error;
  549         struct file *fpop;
  550 
  551         /*
  552          * NB: td may be NULL if this descriptor is closed due to
  553          * garbage collection from a closed UNIX domain socket.
  554          */
  555         fpop = curthread->td_fpop;
  556         curthread->td_fpop = fp;
  557         error = vnops.fo_close(fp, td);
  558         curthread->td_fpop = fpop;
  559 
  560         /*
  561          * The f_cdevpriv cannot be assigned non-NULL value while we
  562          * are destroying the file.
  563          */
  564         if (fp->f_cdevpriv != NULL)
  565                 devfs_fpdrop(fp);
  566         return (error);
  567 }
  568 
  569 static int
  570 devfs_fsync(struct vop_fsync_args *ap)
  571 {
  572         int error;
  573         struct bufobj *bo;
  574         struct devfs_dirent *de;
  575 
  576         if (!vn_isdisk(ap->a_vp, &error)) {
  577                 bo = &ap->a_vp->v_bufobj;
  578                 de = ap->a_vp->v_data;
  579                 if (error == ENXIO && bo->bo_dirty.bv_cnt > 0) {
  580                         printf("Device %s went missing before all of the data "
  581                             "could be written to it; expect data loss.\n",
  582                             de->de_dirent->d_name);
  583 
  584                         error = vop_stdfsync(ap);
  585                         if (bo->bo_dirty.bv_cnt != 0 || error != 0)
  586                                 panic("devfs_fsync: vop_stdfsync failed.");
  587                 }
  588 
  589                 return (0);
  590         }
  591 
  592         return (vop_stdfsync(ap));
  593 }
  594 
  595 static int
  596 devfs_getattr(struct vop_getattr_args *ap)
  597 {
  598         struct vnode *vp = ap->a_vp;
  599         struct vattr *vap = ap->a_vap;
  600         int error = 0;
  601         struct devfs_dirent *de;
  602         struct cdev *dev;
  603 
  604         de = vp->v_data;
  605         KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
  606         if (vp->v_type == VDIR) {
  607                 de = de->de_dir;
  608                 KASSERT(de != NULL,
  609                     ("Null dir dirent in devfs_getattr vp=%p", vp));
  610         }
  611         vap->va_uid = de->de_uid;
  612         vap->va_gid = de->de_gid;
  613         vap->va_mode = de->de_mode;
  614         if (vp->v_type == VLNK)
  615                 vap->va_size = strlen(de->de_symlink);
  616         else if (vp->v_type == VDIR)
  617                 vap->va_size = vap->va_bytes = DEV_BSIZE;
  618         else
  619                 vap->va_size = 0;
  620         if (vp->v_type != VDIR)
  621                 vap->va_bytes = 0;
  622         vap->va_blocksize = DEV_BSIZE;
  623         vap->va_type = vp->v_type;
  624 
  625 #define fix(aa)                                                 \
  626         do {                                                    \
  627                 if ((aa).tv_sec <= 3600) {                      \
  628                         (aa).tv_sec = boottime.tv_sec;          \
  629                         (aa).tv_nsec = boottime.tv_usec * 1000; \
  630                 }                                               \
  631         } while (0)
  632 
  633         if (vp->v_type != VCHR)  {
  634                 fix(de->de_atime);
  635                 vap->va_atime = de->de_atime;
  636                 fix(de->de_mtime);
  637                 vap->va_mtime = de->de_mtime;
  638                 fix(de->de_ctime);
  639                 vap->va_ctime = de->de_ctime;
  640         } else {
  641                 dev = vp->v_rdev;
  642                 fix(dev->si_atime);
  643                 vap->va_atime = dev->si_atime;
  644                 fix(dev->si_mtime);
  645                 vap->va_mtime = dev->si_mtime;
  646                 fix(dev->si_ctime);
  647                 vap->va_ctime = dev->si_ctime;
  648 
  649                 vap->va_rdev = cdev2priv(dev)->cdp_inode;
  650         }
  651         vap->va_gen = 0;
  652         vap->va_flags = 0;
  653         vap->va_filerev = 0;
  654         vap->va_nlink = de->de_links;
  655         vap->va_fileid = de->de_inode;
  656 
  657         return (error);
  658 }
  659 
  660 /* ARGSUSED */
  661 static int
  662 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
  663 {
  664         struct cdev *dev;
  665         struct cdevsw *dsw;
  666         struct vnode *vp;
  667         struct vnode *vpold;
  668         int error, i, ref;
  669         const char *p;
  670         struct fiodgname_arg *fgn;
  671         struct file *fpop;
  672 
  673         fpop = td->td_fpop;
  674         error = devfs_fp_check(fp, &dev, &dsw, &ref);
  675         if (error)
  676                 return (error);
  677 
  678         if (com == FIODTYPE) {
  679                 *(int *)data = dsw->d_flags & D_TYPEMASK;
  680                 td->td_fpop = fpop;
  681                 dev_relthread(dev, ref);
  682                 return (0);
  683         } else if (com == FIODGNAME) {
  684                 fgn = data;
  685                 p = devtoname(dev);
  686                 i = strlen(p) + 1;
  687                 if (i > fgn->len)
  688                         error = EINVAL;
  689                 else
  690                         error = copyout(p, fgn->buf, i);
  691                 td->td_fpop = fpop;
  692                 dev_relthread(dev, ref);
  693                 return (error);
  694         }
  695         error = dsw->d_ioctl(dev, com, data, fp->f_flag, td);
  696         td->td_fpop = NULL;
  697         dev_relthread(dev, ref);
  698         if (error == ENOIOCTL)
  699                 error = ENOTTY;
  700         if (error == 0 && com == TIOCSCTTY) {
  701                 vp = fp->f_vnode;
  702 
  703                 /* Do nothing if reassigning same control tty */
  704                 sx_slock(&proctree_lock);
  705                 if (td->td_proc->p_session->s_ttyvp == vp) {
  706                         sx_sunlock(&proctree_lock);
  707                         return (0);
  708                 }
  709 
  710                 vpold = td->td_proc->p_session->s_ttyvp;
  711                 VREF(vp);
  712                 SESS_LOCK(td->td_proc->p_session);
  713                 td->td_proc->p_session->s_ttyvp = vp;
  714                 SESS_UNLOCK(td->td_proc->p_session);
  715 
  716                 sx_sunlock(&proctree_lock);
  717 
  718                 /* Get rid of reference to old control tty */
  719                 if (vpold)
  720                         vrele(vpold);
  721         }
  722         return (error);
  723 }
  724 
  725 /* ARGSUSED */
  726 static int
  727 devfs_kqfilter_f(struct file *fp, struct knote *kn)
  728 {
  729         struct cdev *dev;
  730         struct cdevsw *dsw;
  731         int error, ref;
  732         struct file *fpop;
  733         struct thread *td;
  734 
  735         td = curthread;
  736         fpop = td->td_fpop;
  737         error = devfs_fp_check(fp, &dev, &dsw, &ref);
  738         if (error)
  739                 return (error);
  740         error = dsw->d_kqfilter(dev, kn);
  741         td->td_fpop = fpop;
  742         dev_relthread(dev, ref);
  743         return (error);
  744 }
  745 
  746 static inline int
  747 devfs_prison_check(struct devfs_dirent *de, struct ucred *tcr)
  748 {
  749         struct cdev_priv *cdp;
  750         struct ucred *dcr;
  751 
  752         cdp = de->de_cdp;
  753         if (cdp == NULL)
  754                 return (0);
  755         dcr = cdp->cdp_c.si_cred;
  756         if (dcr == NULL)
  757                 return (0);
  758 
  759         return (prison_check(tcr, dcr));
  760 }
  761 
  762 static int
  763 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
  764 {
  765         struct componentname *cnp;
  766         struct vnode *dvp, **vpp;
  767         struct thread *td;
  768         struct devfs_dirent *de, *dd;
  769         struct devfs_dirent **dde;
  770         struct devfs_mount *dmp;
  771         struct cdev *cdev;
  772         int error, flags, nameiop, dvplocked;
  773         char specname[SPECNAMELEN + 1], *pname;
  774 
  775         cnp = ap->a_cnp;
  776         vpp = ap->a_vpp;
  777         dvp = ap->a_dvp;
  778         pname = cnp->cn_nameptr;
  779         td = cnp->cn_thread;
  780         flags = cnp->cn_flags;
  781         nameiop = cnp->cn_nameiop;
  782         dmp = VFSTODEVFS(dvp->v_mount);
  783         dd = dvp->v_data;
  784         *vpp = NULLVP;
  785 
  786         if ((flags & ISLASTCN) && nameiop == RENAME)
  787                 return (EOPNOTSUPP);
  788 
  789         if (dvp->v_type != VDIR)
  790                 return (ENOTDIR);
  791 
  792         if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
  793                 return (EIO);
  794 
  795         error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
  796         if (error)
  797                 return (error);
  798 
  799         if (cnp->cn_namelen == 1 && *pname == '.') {
  800                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  801                         return (EINVAL);
  802                 *vpp = dvp;
  803                 VREF(dvp);
  804                 return (0);
  805         }
  806 
  807         if (flags & ISDOTDOT) {
  808                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  809                         return (EINVAL);
  810                 de = devfs_parent_dirent(dd);
  811                 if (de == NULL)
  812                         return (ENOENT);
  813                 dvplocked = VOP_ISLOCKED(dvp);
  814                 VOP_UNLOCK(dvp, 0);
  815                 error = devfs_allocv(de, dvp->v_mount,
  816                     cnp->cn_lkflags & LK_TYPE_MASK, vpp);
  817                 *dm_unlock = 0;
  818                 vn_lock(dvp, dvplocked | LK_RETRY);
  819                 return (error);
  820         }
  821 
  822         DEVFS_DMP_HOLD(dmp);
  823         devfs_populate(dmp);
  824         if (DEVFS_DMP_DROP(dmp)) {
  825                 *dm_unlock = 0;
  826                 sx_xunlock(&dmp->dm_lock);
  827                 devfs_unmount_final(dmp);
  828                 return (ENOENT);
  829         }
  830         dd = dvp->v_data;
  831         de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen);
  832         while (de == NULL) {    /* While(...) so we can use break */
  833 
  834                 if (nameiop == DELETE)
  835                         return (ENOENT);
  836 
  837                 /*
  838                  * OK, we didn't have an entry for the name we were asked for
  839                  * so we try to see if anybody can create it on demand.
  840                  */
  841                 pname = devfs_fqpn(specname, dvp, cnp);
  842                 if (pname == NULL)
  843                         break;
  844 
  845                 cdev = NULL;
  846                 DEVFS_DMP_HOLD(dmp);
  847                 sx_xunlock(&dmp->dm_lock);
  848                 sx_slock(&clone_drain_lock);
  849                 EVENTHANDLER_INVOKE(dev_clone,
  850                     td->td_ucred, pname, strlen(pname), &cdev);
  851                 sx_sunlock(&clone_drain_lock);
  852                 sx_xlock(&dmp->dm_lock);
  853                 if (DEVFS_DMP_DROP(dmp)) {
  854                         *dm_unlock = 0;
  855                         sx_xunlock(&dmp->dm_lock);
  856                         devfs_unmount_final(dmp);
  857                         if (cdev != NULL)
  858                                 dev_rel(cdev);
  859                         return (ENOENT);
  860                 }
  861                 if (cdev == NULL)
  862                         break;
  863 
  864                 DEVFS_DMP_HOLD(dmp);
  865                 devfs_populate(dmp);
  866                 if (DEVFS_DMP_DROP(dmp)) {
  867                         *dm_unlock = 0;
  868                         sx_xunlock(&dmp->dm_lock);
  869                         devfs_unmount_final(dmp);
  870                         dev_rel(cdev);
  871                         return (ENOENT);
  872                 }
  873 
  874                 dev_lock();
  875                 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
  876                 if (dde != NULL && *dde != NULL)
  877                         de = *dde;
  878                 dev_unlock();
  879                 dev_rel(cdev);
  880                 break;
  881         }
  882 
  883         if (de == NULL || de->de_flags & DE_WHITEOUT) {
  884                 if ((nameiop == CREATE || nameiop == RENAME) &&
  885                     (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
  886                         cnp->cn_flags |= SAVENAME;
  887                         return (EJUSTRETURN);
  888                 }
  889                 return (ENOENT);
  890         }
  891 
  892         if (devfs_prison_check(de, td->td_ucred))
  893                 return (ENOENT);
  894 
  895         if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
  896                 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  897                 if (error)
  898                         return (error);
  899                 if (*vpp == dvp) {
  900                         VREF(dvp);
  901                         *vpp = dvp;
  902                         return (0);
  903                 }
  904         }
  905         error = devfs_allocv(de, dvp->v_mount, cnp->cn_lkflags & LK_TYPE_MASK,
  906             vpp);
  907         *dm_unlock = 0;
  908         return (error);
  909 }
  910 
  911 static int
  912 devfs_lookup(struct vop_lookup_args *ap)
  913 {
  914         int j;
  915         struct devfs_mount *dmp;
  916         int dm_unlock;
  917 
  918         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
  919         dm_unlock = 1;
  920         sx_xlock(&dmp->dm_lock);
  921         j = devfs_lookupx(ap, &dm_unlock);
  922         if (dm_unlock == 1)
  923                 sx_xunlock(&dmp->dm_lock);
  924         return (j);
  925 }
  926 
  927 static int
  928 devfs_mknod(struct vop_mknod_args *ap)
  929 {
  930         struct componentname *cnp;
  931         struct vnode *dvp, **vpp;
  932         struct devfs_dirent *dd, *de;
  933         struct devfs_mount *dmp;
  934         int error;
  935 
  936         /*
  937          * The only type of node we should be creating here is a
  938          * character device, for anything else return EOPNOTSUPP.
  939          */
  940         if (ap->a_vap->va_type != VCHR)
  941                 return (EOPNOTSUPP);
  942         dvp = ap->a_dvp;
  943         dmp = VFSTODEVFS(dvp->v_mount);
  944 
  945         cnp = ap->a_cnp;
  946         vpp = ap->a_vpp;
  947         dd = dvp->v_data;
  948 
  949         error = ENOENT;
  950         sx_xlock(&dmp->dm_lock);
  951         TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
  952                 if (cnp->cn_namelen != de->de_dirent->d_namlen)
  953                         continue;
  954                 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
  955                     de->de_dirent->d_namlen) != 0)
  956                         continue;
  957                 if (de->de_flags & DE_WHITEOUT)
  958                         break;
  959                 goto notfound;
  960         }
  961         if (de == NULL)
  962                 goto notfound;
  963         de->de_flags &= ~DE_WHITEOUT;
  964         error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp);
  965         return (error);
  966 notfound:
  967         sx_xunlock(&dmp->dm_lock);
  968         return (error);
  969 }
  970 
  971 /* ARGSUSED */
  972 static int
  973 devfs_open(struct vop_open_args *ap)
  974 {
  975         struct thread *td = ap->a_td;
  976         struct vnode *vp = ap->a_vp;
  977         struct cdev *dev = vp->v_rdev;
  978         struct file *fp = ap->a_fp;
  979         int error, ref, vlocked;
  980         struct cdevsw *dsw;
  981         struct file *fpop;
  982 
  983         if (vp->v_type == VBLK)
  984                 return (ENXIO);
  985 
  986         if (dev == NULL)
  987                 return (ENXIO);
  988 
  989         /* Make this field valid before any I/O in d_open. */
  990         if (dev->si_iosize_max == 0)
  991                 dev->si_iosize_max = DFLTPHYS;
  992 
  993         dsw = dev_refthread(dev, &ref);
  994         if (dsw == NULL)
  995                 return (ENXIO);
  996         if (fp == NULL && dsw->d_fdopen != NULL) {
  997                 dev_relthread(dev, ref);
  998                 return (ENXIO);
  999         }
 1000 
 1001         vlocked = VOP_ISLOCKED(vp);
 1002         VOP_UNLOCK(vp, 0);
 1003 
 1004         fpop = td->td_fpop;
 1005         td->td_fpop = fp;
 1006         if (fp != NULL) {
 1007                 fp->f_data = dev;
 1008                 fp->f_vnode = vp;
 1009         }
 1010         if (dsw->d_fdopen != NULL)
 1011                 error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
 1012         else
 1013                 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
 1014         td->td_fpop = fpop;
 1015 
 1016         vn_lock(vp, vlocked | LK_RETRY);
 1017         dev_relthread(dev, ref);
 1018         if (error != 0) {
 1019                 if (error == ERESTART)
 1020                         error = EINTR;
 1021                 return (error);
 1022         }
 1023 
 1024 #if 0   /* /dev/console */
 1025         KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp"));
 1026 #else
 1027         if (fp == NULL)
 1028                 return (error);
 1029 #endif
 1030         if (fp->f_ops == &badfileops)
 1031                 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
 1032         return (error);
 1033 }
 1034 
 1035 static int
 1036 devfs_pathconf(struct vop_pathconf_args *ap)
 1037 {
 1038 
 1039         switch (ap->a_name) {
 1040         case _PC_MAC_PRESENT:
 1041 #ifdef MAC
 1042                 /*
 1043                  * If MAC is enabled, devfs automatically supports
 1044                  * trivial non-persistant label storage.
 1045                  */
 1046                 *ap->a_retval = 1;
 1047 #else
 1048                 *ap->a_retval = 0;
 1049 #endif
 1050                 return (0);
 1051         default:
 1052                 return (vop_stdpathconf(ap));
 1053         }
 1054         /* NOTREACHED */
 1055 }
 1056 
 1057 /* ARGSUSED */
 1058 static int
 1059 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
 1060 {
 1061         struct cdev *dev;
 1062         struct cdevsw *dsw;
 1063         int error, ref;
 1064         struct file *fpop;
 1065 
 1066         fpop = td->td_fpop;
 1067         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1068         if (error)
 1069                 return (poll_no_poll(events));
 1070         error = dsw->d_poll(dev, events, td);
 1071         td->td_fpop = fpop;
 1072         dev_relthread(dev, ref);
 1073         return(error);
 1074 }
 1075 
 1076 /*
 1077  * Print out the contents of a special device vnode.
 1078  */
 1079 static int
 1080 devfs_print(struct vop_print_args *ap)
 1081 {
 1082 
 1083         printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
 1084         return (0);
 1085 }
 1086 
 1087 /* ARGSUSED */
 1088 static int
 1089 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1090 {
 1091         struct cdev *dev;
 1092         int ioflag, error, ref, resid;
 1093         struct cdevsw *dsw;
 1094         struct file *fpop;
 1095 
 1096         fpop = td->td_fpop;
 1097         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1098         if (error)
 1099                 return (error);
 1100         resid = uio->uio_resid;
 1101         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
 1102         if (ioflag & O_DIRECT)
 1103                 ioflag |= IO_DIRECT;
 1104 
 1105         if ((flags & FOF_OFFSET) == 0)
 1106                 uio->uio_offset = fp->f_offset;
 1107 
 1108         error = dsw->d_read(dev, uio, ioflag);
 1109         if (uio->uio_resid != resid || (error == 0 && resid != 0))
 1110                 vfs_timestamp(&dev->si_atime);
 1111         td->td_fpop = fpop;
 1112         dev_relthread(dev, ref);
 1113 
 1114         if ((flags & FOF_OFFSET) == 0)
 1115                 fp->f_offset = uio->uio_offset;
 1116         fp->f_nextoff = uio->uio_offset;
 1117         return (error);
 1118 }
 1119 
 1120 static int
 1121 devfs_readdir(struct vop_readdir_args *ap)
 1122 {
 1123         int error;
 1124         struct uio *uio;
 1125         struct dirent *dp;
 1126         struct devfs_dirent *dd;
 1127         struct devfs_dirent *de;
 1128         struct devfs_mount *dmp;
 1129         off_t off;
 1130         int *tmp_ncookies = NULL;
 1131 
 1132         if (ap->a_vp->v_type != VDIR)
 1133                 return (ENOTDIR);
 1134 
 1135         uio = ap->a_uio;
 1136         if (uio->uio_offset < 0)
 1137                 return (EINVAL);
 1138 
 1139         /*
 1140          * XXX: This is a temporary hack to get around this filesystem not
 1141          * supporting cookies. We store the location of the ncookies pointer
 1142          * in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
 1143          * and set the number of cookies to 0. We then set the pointer to
 1144          * NULL so that vfs_read_dirent doesn't try to call realloc() on 
 1145          * ap->a_cookies. Later in this function, we restore the ap->a_ncookies
 1146          * pointer to its original location before returning to the caller.
 1147          */
 1148         if (ap->a_ncookies != NULL) {
 1149                 tmp_ncookies = ap->a_ncookies;
 1150                 *ap->a_ncookies = 0;
 1151                 ap->a_ncookies = NULL;
 1152         }
 1153 
 1154         dmp = VFSTODEVFS(ap->a_vp->v_mount);
 1155         sx_xlock(&dmp->dm_lock);
 1156         DEVFS_DMP_HOLD(dmp);
 1157         devfs_populate(dmp);
 1158         if (DEVFS_DMP_DROP(dmp)) {
 1159                 sx_xunlock(&dmp->dm_lock);
 1160                 devfs_unmount_final(dmp);
 1161                 if (tmp_ncookies != NULL)
 1162                         ap->a_ncookies = tmp_ncookies;
 1163                 return (EIO);
 1164         }
 1165         error = 0;
 1166         de = ap->a_vp->v_data;
 1167         off = 0;
 1168         TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
 1169                 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
 1170                 if (dd->de_flags & DE_WHITEOUT)
 1171                         continue;
 1172                 if (devfs_prison_check(dd, ap->a_cred))
 1173                         continue;
 1174                 if (dd->de_dirent->d_type == DT_DIR)
 1175                         de = dd->de_dir;
 1176                 else
 1177                         de = dd;
 1178                 dp = dd->de_dirent;
 1179                 if (dp->d_reclen > uio->uio_resid)
 1180                         break;
 1181                 dp->d_fileno = de->de_inode;
 1182                 if (off >= uio->uio_offset) {
 1183                         error = vfs_read_dirent(ap, dp, off);
 1184                         if (error)
 1185                                 break;
 1186                 }
 1187                 off += dp->d_reclen;
 1188         }
 1189         sx_xunlock(&dmp->dm_lock);
 1190         uio->uio_offset = off;
 1191 
 1192         /*
 1193          * Restore ap->a_ncookies if it wasn't originally NULL in the first
 1194          * place.
 1195          */
 1196         if (tmp_ncookies != NULL)
 1197                 ap->a_ncookies = tmp_ncookies;
 1198 
 1199         return (error);
 1200 }
 1201 
 1202 static int
 1203 devfs_readlink(struct vop_readlink_args *ap)
 1204 {
 1205         struct devfs_dirent *de;
 1206 
 1207         de = ap->a_vp->v_data;
 1208         return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
 1209 }
 1210 
 1211 static int
 1212 devfs_reclaim(struct vop_reclaim_args *ap)
 1213 {
 1214         struct vnode *vp = ap->a_vp;
 1215         struct devfs_dirent *de;
 1216         struct cdev *dev;
 1217 
 1218         mtx_lock(&devfs_de_interlock);
 1219         de = vp->v_data;
 1220         if (de != NULL) {
 1221                 de->de_vnode = NULL;
 1222                 vp->v_data = NULL;
 1223         }
 1224         mtx_unlock(&devfs_de_interlock);
 1225 
 1226         vnode_destroy_vobject(vp);
 1227 
 1228         VI_LOCK(vp);
 1229         dev_lock();
 1230         dev = vp->v_rdev;
 1231         vp->v_rdev = NULL;
 1232 
 1233         if (dev == NULL) {
 1234                 dev_unlock();
 1235                 VI_UNLOCK(vp);
 1236                 return (0);
 1237         }
 1238 
 1239         dev->si_usecount -= vp->v_usecount;
 1240         dev_unlock();
 1241         VI_UNLOCK(vp);
 1242         dev_rel(dev);
 1243         return (0);
 1244 }
 1245 
 1246 static int
 1247 devfs_remove(struct vop_remove_args *ap)
 1248 {
 1249         struct vnode *vp = ap->a_vp;
 1250         struct devfs_dirent *dd;
 1251         struct devfs_dirent *de;
 1252         struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
 1253 
 1254         sx_xlock(&dmp->dm_lock);
 1255         dd = ap->a_dvp->v_data;
 1256         de = vp->v_data;
 1257         if (de->de_cdp == NULL) {
 1258                 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
 1259                 devfs_delete(dmp, de, 1);
 1260         } else {
 1261                 de->de_flags |= DE_WHITEOUT;
 1262         }
 1263         sx_xunlock(&dmp->dm_lock);
 1264         return (0);
 1265 }
 1266 
 1267 /*
 1268  * Revoke is called on a tty when a terminal session ends.  The vnode
 1269  * is orphaned by setting v_op to deadfs so we need to let go of it
 1270  * as well so that we create a new one next time around.
 1271  *
 1272  */
 1273 static int
 1274 devfs_revoke(struct vop_revoke_args *ap)
 1275 {
 1276         struct vnode *vp = ap->a_vp, *vp2;
 1277         struct cdev *dev;
 1278         struct cdev_priv *cdp;
 1279         struct devfs_dirent *de;
 1280         int i;
 1281 
 1282         KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
 1283 
 1284         dev = vp->v_rdev;
 1285         cdp = cdev2priv(dev);
 1286  
 1287         dev_lock();
 1288         cdp->cdp_inuse++;
 1289         dev_unlock();
 1290 
 1291         vhold(vp);
 1292         vgone(vp);
 1293         vdrop(vp);
 1294 
 1295         VOP_UNLOCK(vp,0);
 1296  loop:
 1297         for (;;) {
 1298                 mtx_lock(&devfs_de_interlock);
 1299                 dev_lock();
 1300                 vp2 = NULL;
 1301                 for (i = 0; i <= cdp->cdp_maxdirent; i++) {
 1302                         de = cdp->cdp_dirents[i];
 1303                         if (de == NULL)
 1304                                 continue;
 1305 
 1306                         vp2 = de->de_vnode;
 1307                         if (vp2 != NULL) {
 1308                                 dev_unlock();
 1309                                 VI_LOCK(vp2);
 1310                                 mtx_unlock(&devfs_de_interlock);
 1311                                 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
 1312                                     curthread))
 1313                                         goto loop;
 1314                                 vhold(vp2);
 1315                                 vgone(vp2);
 1316                                 vdrop(vp2);
 1317                                 vput(vp2);
 1318                                 break;
 1319                         } 
 1320                 }
 1321                 if (vp2 != NULL) {
 1322                         continue;
 1323                 }
 1324                 dev_unlock();
 1325                 mtx_unlock(&devfs_de_interlock);
 1326                 break;
 1327         }
 1328         dev_lock();
 1329         cdp->cdp_inuse--;
 1330         if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
 1331                 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
 1332                 dev_unlock();
 1333                 dev_rel(&cdp->cdp_c);
 1334         } else
 1335                 dev_unlock();
 1336 
 1337         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 1338         return (0);
 1339 }
 1340 
 1341 static int
 1342 devfs_rioctl(struct vop_ioctl_args *ap)
 1343 {
 1344         struct vnode *vp;
 1345         struct devfs_mount *dmp;
 1346         int error;
 1347 
 1348         vp = ap->a_vp;
 1349         vn_lock(vp, LK_SHARED | LK_RETRY);
 1350         if (vp->v_iflag & VI_DOOMED) {
 1351                 VOP_UNLOCK(vp, 0);
 1352                 return (EBADF);
 1353         }
 1354         dmp = VFSTODEVFS(vp->v_mount);
 1355         sx_xlock(&dmp->dm_lock);
 1356         VOP_UNLOCK(vp, 0);
 1357         DEVFS_DMP_HOLD(dmp);
 1358         devfs_populate(dmp);
 1359         if (DEVFS_DMP_DROP(dmp)) {
 1360                 sx_xunlock(&dmp->dm_lock);
 1361                 devfs_unmount_final(dmp);
 1362                 return (ENOENT);
 1363         }
 1364         error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
 1365         sx_xunlock(&dmp->dm_lock);
 1366         return (error);
 1367 }
 1368 
 1369 static int
 1370 devfs_rread(struct vop_read_args *ap)
 1371 {
 1372 
 1373         if (ap->a_vp->v_type != VDIR)
 1374                 return (EINVAL);
 1375         return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
 1376 }
 1377 
 1378 static int
 1379 devfs_setattr(struct vop_setattr_args *ap)
 1380 {
 1381         struct devfs_dirent *de;
 1382         struct vattr *vap;
 1383         struct vnode *vp;
 1384         struct thread *td;
 1385         int c, error;
 1386         uid_t uid;
 1387         gid_t gid;
 1388 
 1389         vap = ap->a_vap;
 1390         vp = ap->a_vp;
 1391         td = curthread;
 1392         if ((vap->va_type != VNON) ||
 1393             (vap->va_nlink != VNOVAL) ||
 1394             (vap->va_fsid != VNOVAL) ||
 1395             (vap->va_fileid != VNOVAL) ||
 1396             (vap->va_blocksize != VNOVAL) ||
 1397             (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
 1398             (vap->va_rdev != VNOVAL) ||
 1399             ((int)vap->va_bytes != VNOVAL) ||
 1400             (vap->va_gen != VNOVAL)) {
 1401                 return (EINVAL);
 1402         }
 1403 
 1404         de = vp->v_data;
 1405         if (vp->v_type == VDIR)
 1406                 de = de->de_dir;
 1407 
 1408         error = c = 0;
 1409         if (vap->va_uid == (uid_t)VNOVAL)
 1410                 uid = de->de_uid;
 1411         else
 1412                 uid = vap->va_uid;
 1413         if (vap->va_gid == (gid_t)VNOVAL)
 1414                 gid = de->de_gid;
 1415         else
 1416                 gid = vap->va_gid;
 1417         if (uid != de->de_uid || gid != de->de_gid) {
 1418                 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
 1419                     (gid != de->de_gid && !groupmember(gid, ap->a_cred))) {
 1420                         error = priv_check(td, PRIV_VFS_CHOWN);
 1421                         if (error)
 1422                                 return (error);
 1423                 }
 1424                 de->de_uid = uid;
 1425                 de->de_gid = gid;
 1426                 c = 1;
 1427         }
 1428 
 1429         if (vap->va_mode != (mode_t)VNOVAL) {
 1430                 if (ap->a_cred->cr_uid != de->de_uid) {
 1431                         error = priv_check(td, PRIV_VFS_ADMIN);
 1432                         if (error)
 1433                                 return (error);
 1434                 }
 1435                 de->de_mode = vap->va_mode;
 1436                 c = 1;
 1437         }
 1438 
 1439         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
 1440                 /* See the comment in ufs_vnops::ufs_setattr(). */
 1441                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
 1442                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
 1443                     (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
 1444                         return (error);
 1445                 if (vap->va_atime.tv_sec != VNOVAL) {
 1446                         if (vp->v_type == VCHR)
 1447                                 vp->v_rdev->si_atime = vap->va_atime;
 1448                         else
 1449                                 de->de_atime = vap->va_atime;
 1450                 }
 1451                 if (vap->va_mtime.tv_sec != VNOVAL) {
 1452                         if (vp->v_type == VCHR)
 1453                                 vp->v_rdev->si_mtime = vap->va_mtime;
 1454                         else
 1455                                 de->de_mtime = vap->va_mtime;
 1456                 }
 1457                 c = 1;
 1458         }
 1459 
 1460         if (c) {
 1461                 if (vp->v_type == VCHR)
 1462                         vfs_timestamp(&vp->v_rdev->si_ctime);
 1463                 else
 1464                         vfs_timestamp(&de->de_mtime);
 1465         }
 1466         return (0);
 1467 }
 1468 
 1469 #ifdef MAC
 1470 static int
 1471 devfs_setlabel(struct vop_setlabel_args *ap)
 1472 {
 1473         struct vnode *vp;
 1474         struct devfs_dirent *de;
 1475 
 1476         vp = ap->a_vp;
 1477         de = vp->v_data;
 1478 
 1479         mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
 1480         mac_devfs_update(vp->v_mount, de, vp);
 1481 
 1482         return (0);
 1483 }
 1484 #endif
 1485 
 1486 static int
 1487 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
 1488 {
 1489 
 1490         return (vnops.fo_stat(fp, sb, cred, td));
 1491 }
 1492 
 1493 static int
 1494 devfs_symlink(struct vop_symlink_args *ap)
 1495 {
 1496         int i, error;
 1497         struct devfs_dirent *dd;
 1498         struct devfs_dirent *de;
 1499         struct devfs_mount *dmp;
 1500 
 1501         error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
 1502         if (error)
 1503                 return(error);
 1504         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
 1505         dd = ap->a_dvp->v_data;
 1506         de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
 1507         de->de_uid = 0;
 1508         de->de_gid = 0;
 1509         de->de_mode = 0755;
 1510         de->de_inode = alloc_unr(devfs_inos);
 1511         de->de_dirent->d_type = DT_LNK;
 1512         i = strlen(ap->a_target) + 1;
 1513         de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
 1514         bcopy(ap->a_target, de->de_symlink, i);
 1515         sx_xlock(&dmp->dm_lock);
 1516 #ifdef MAC
 1517         mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
 1518 #endif
 1519         TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
 1520         devfs_rules_apply(dmp, de);
 1521         return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
 1522 }
 1523 
 1524 static int
 1525 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
 1526 {
 1527 
 1528         return (vnops.fo_truncate(fp, length, cred, td));
 1529 }
 1530 
 1531 /* ARGSUSED */
 1532 static int
 1533 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1534 {
 1535         struct cdev *dev;
 1536         int error, ioflag, ref, resid;
 1537         struct cdevsw *dsw;
 1538         struct file *fpop;
 1539 
 1540         fpop = td->td_fpop;
 1541         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1542         if (error)
 1543                 return (error);
 1544         KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
 1545         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
 1546         if (ioflag & O_DIRECT)
 1547                 ioflag |= IO_DIRECT;
 1548         if ((flags & FOF_OFFSET) == 0)
 1549                 uio->uio_offset = fp->f_offset;
 1550 
 1551         resid = uio->uio_resid;
 1552 
 1553         error = dsw->d_write(dev, uio, ioflag);
 1554         if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
 1555                 vfs_timestamp(&dev->si_ctime);
 1556                 dev->si_mtime = dev->si_ctime;
 1557         }
 1558         td->td_fpop = fpop;
 1559         dev_relthread(dev, ref);
 1560 
 1561         if ((flags & FOF_OFFSET) == 0)
 1562                 fp->f_offset = uio->uio_offset;
 1563         fp->f_nextoff = uio->uio_offset;
 1564         return (error);
 1565 }
 1566 
 1567 dev_t
 1568 dev2udev(struct cdev *x)
 1569 {
 1570         if (x == NULL)
 1571                 return (NODEV);
 1572         return (cdev2priv(x)->cdp_inode);
 1573 }
 1574 
 1575 static struct fileops devfs_ops_f = {
 1576         .fo_read =      devfs_read_f,
 1577         .fo_write =     devfs_write_f,
 1578         .fo_truncate =  devfs_truncate_f,
 1579         .fo_ioctl =     devfs_ioctl_f,
 1580         .fo_poll =      devfs_poll_f,
 1581         .fo_kqfilter =  devfs_kqfilter_f,
 1582         .fo_stat =      devfs_stat_f,
 1583         .fo_close =     devfs_close_f,
 1584         .fo_flags =     DFLAG_PASSABLE | DFLAG_SEEKABLE
 1585 };
 1586 
 1587 static struct vop_vector devfs_vnodeops = {
 1588         .vop_default =          &default_vnodeops,
 1589 
 1590         .vop_access =           devfs_access,
 1591         .vop_getattr =          devfs_getattr,
 1592         .vop_ioctl =            devfs_rioctl,
 1593         .vop_lookup =           devfs_lookup,
 1594         .vop_mknod =            devfs_mknod,
 1595         .vop_pathconf =         devfs_pathconf,
 1596         .vop_read =             devfs_rread,
 1597         .vop_readdir =          devfs_readdir,
 1598         .vop_readlink =         devfs_readlink,
 1599         .vop_reclaim =          devfs_reclaim,
 1600         .vop_remove =           devfs_remove,
 1601         .vop_revoke =           devfs_revoke,
 1602         .vop_setattr =          devfs_setattr,
 1603 #ifdef MAC
 1604         .vop_setlabel =         devfs_setlabel,
 1605 #endif
 1606         .vop_symlink =          devfs_symlink,
 1607         .vop_vptocnp =          devfs_vptocnp,
 1608 };
 1609 
 1610 static struct vop_vector devfs_specops = {
 1611         .vop_default =          &default_vnodeops,
 1612 
 1613         .vop_access =           devfs_access,
 1614         .vop_bmap =             VOP_PANIC,
 1615         .vop_close =            devfs_close,
 1616         .vop_create =           VOP_PANIC,
 1617         .vop_fsync =            devfs_fsync,
 1618         .vop_getattr =          devfs_getattr,
 1619         .vop_link =             VOP_PANIC,
 1620         .vop_mkdir =            VOP_PANIC,
 1621         .vop_mknod =            VOP_PANIC,
 1622         .vop_open =             devfs_open,
 1623         .vop_pathconf =         devfs_pathconf,
 1624         .vop_print =            devfs_print,
 1625         .vop_read =             VOP_PANIC,
 1626         .vop_readdir =          VOP_PANIC,
 1627         .vop_readlink =         VOP_PANIC,
 1628         .vop_reallocblks =      VOP_PANIC,
 1629         .vop_reclaim =          devfs_reclaim,
 1630         .vop_remove =           devfs_remove,
 1631         .vop_rename =           VOP_PANIC,
 1632         .vop_revoke =           devfs_revoke,
 1633         .vop_rmdir =            VOP_PANIC,
 1634         .vop_setattr =          devfs_setattr,
 1635 #ifdef MAC
 1636         .vop_setlabel =         devfs_setlabel,
 1637 #endif
 1638         .vop_strategy =         VOP_PANIC,
 1639         .vop_symlink =          VOP_PANIC,
 1640         .vop_vptocnp =          devfs_vptocnp,
 1641         .vop_write =            VOP_PANIC,
 1642 };
 1643 
 1644 /*
 1645  * Our calling convention to the device drivers used to be that we passed
 1646  * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_ 
 1647  * flags instead since that's what open(), close() and ioctl() takes and
 1648  * we don't really want vnode.h in device drivers.
 1649  * We solved the source compatibility by redefining some vnode flags to
 1650  * be the same as the fcntl ones and by sending down the bitwise OR of
 1651  * the respective fcntl/vnode flags.  These CTASSERTS make sure nobody
 1652  * pulls the rug out under this.
 1653  */
 1654 CTASSERT(O_NONBLOCK == IO_NDELAY);
 1655 CTASSERT(O_FSYNC == IO_SYNC);
Cache object: a001313bbe976c63b164efd1112cdfdf
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FreeBSD/Linux Kernel Cross Reference sys/fs/devfs/devfs_vnops.c

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