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  * $FreeBSD$
   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  * If a NULL cnp is provided, no '/' is appended to the resulting path.
  258  */
  259 char *
  260 devfs_fqpn(char *buf, struct devfs_mount *dmp, struct devfs_dirent *dd,
  261     struct componentname *cnp)
  262 {
  263         int i;
  264         struct devfs_dirent *de;
  265 
  266         sx_assert(&dmp->dm_lock, SA_LOCKED);
  267 
  268         i = SPECNAMELEN;
  269         buf[i] = '\0';
  270         if (cnp != NULL)
  271                 i -= cnp->cn_namelen;
  272         if (i < 0)
  273                  return (NULL);
  274         if (cnp != NULL)
  275                 bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
  276         de = dd;
  277         while (de != dmp->dm_rootdir) {
  278                 if (cnp != NULL || i < SPECNAMELEN) {
  279                         i--;
  280                         if (i < 0)
  281                                  return (NULL);
  282                         buf[i] = '/';
  283                 }
  284                 i -= de->de_dirent->d_namlen;
  285                 if (i < 0)
  286                          return (NULL);
  287                 bcopy(de->de_dirent->d_name, buf + i,
  288                     de->de_dirent->d_namlen);
  289                 de = devfs_parent_dirent(de);
  290                 if (de == NULL)
  291                         return (NULL);
  292         }
  293         return (buf + i);
  294 }
  295 
  296 static int
  297 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
  298         struct devfs_dirent *de)
  299 {
  300         int not_found;
  301 
  302         not_found = 0;
  303         if (de->de_flags & DE_DOOMED)
  304                 not_found = 1;
  305         if (DEVFS_DE_DROP(de)) {
  306                 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
  307                 devfs_dirent_free(de);
  308         }
  309         if (DEVFS_DMP_DROP(dmp)) {
  310                 KASSERT(not_found == 1,
  311                         ("DEVFS mount struct freed before dirent"));
  312                 not_found = 2;
  313                 sx_xunlock(&dmp->dm_lock);
  314                 devfs_unmount_final(dmp);
  315         }
  316         if (not_found == 1 || (drop_dm_lock && not_found != 2))
  317                 sx_unlock(&dmp->dm_lock);
  318         return (not_found);
  319 }
  320 
  321 static void
  322 devfs_insmntque_dtr(struct vnode *vp, void *arg)
  323 {
  324         struct devfs_dirent *de;
  325 
  326         de = (struct devfs_dirent *)arg;
  327         mtx_lock(&devfs_de_interlock);
  328         vp->v_data = NULL;
  329         de->de_vnode = NULL;
  330         mtx_unlock(&devfs_de_interlock);
  331         vgone(vp);
  332         vput(vp);
  333 }
  334 
  335 /*
  336  * devfs_allocv shall be entered with dmp->dm_lock held, and it drops
  337  * it on return.
  338  */
  339 int
  340 devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode,
  341     struct vnode **vpp)
  342 {
  343         int error;
  344         struct vnode *vp;
  345         struct cdev *dev;
  346         struct devfs_mount *dmp;
  347         struct cdevsw *dsw;
  348 
  349         dmp = VFSTODEVFS(mp);
  350         if (de->de_flags & DE_DOOMED) {
  351                 sx_xunlock(&dmp->dm_lock);
  352                 return (ENOENT);
  353         }
  354 loop:
  355         DEVFS_DE_HOLD(de);
  356         DEVFS_DMP_HOLD(dmp);
  357         mtx_lock(&devfs_de_interlock);
  358         vp = de->de_vnode;
  359         if (vp != NULL) {
  360                 VI_LOCK(vp);
  361                 mtx_unlock(&devfs_de_interlock);
  362                 sx_xunlock(&dmp->dm_lock);
  363                 vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread);
  364                 sx_xlock(&dmp->dm_lock);
  365                 if (devfs_allocv_drop_refs(0, dmp, de)) {
  366                         vput(vp);
  367                         return (ENOENT);
  368                 }
  369                 else if ((vp->v_iflag & VI_DOOMED) != 0) {
  370                         mtx_lock(&devfs_de_interlock);
  371                         if (de->de_vnode == vp) {
  372                                 de->de_vnode = NULL;
  373                                 vp->v_data = NULL;
  374                         }
  375                         mtx_unlock(&devfs_de_interlock);
  376                         vput(vp);
  377                         goto loop;
  378                 }
  379                 sx_xunlock(&dmp->dm_lock);
  380                 *vpp = vp;
  381                 return (0);
  382         }
  383         mtx_unlock(&devfs_de_interlock);
  384         if (de->de_dirent->d_type == DT_CHR) {
  385                 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
  386                         devfs_allocv_drop_refs(1, dmp, de);
  387                         return (ENOENT);
  388                 }
  389                 dev = &de->de_cdp->cdp_c;
  390         } else {
  391                 dev = NULL;
  392         }
  393         error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
  394         if (error != 0) {
  395                 devfs_allocv_drop_refs(1, dmp, de);
  396                 printf("devfs_allocv: failed to allocate new vnode\n");
  397                 return (error);
  398         }
  399 
  400         if (de->de_dirent->d_type == DT_CHR) {
  401                 vp->v_type = VCHR;
  402                 VI_LOCK(vp);
  403                 dev_lock();
  404                 dev_refl(dev);
  405                 /* XXX: v_rdev should be protect by vnode lock */
  406                 vp->v_rdev = dev;
  407                 KASSERT(vp->v_usecount == 1,
  408                     ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
  409                 dev->si_usecount += vp->v_usecount;
  410                 /* Special casing of ttys for deadfs.  Probably redundant. */
  411                 dsw = dev->si_devsw;
  412                 if (dsw != NULL && (dsw->d_flags & D_TTY) != 0)
  413                         vp->v_vflag |= VV_ISTTY;
  414                 dev_unlock();
  415                 VI_UNLOCK(vp);
  416                 if ((dev->si_flags & SI_ETERNAL) != 0)
  417                         vp->v_vflag |= VV_ETERNALDEV;
  418                 vp->v_op = &devfs_specops;
  419         } else if (de->de_dirent->d_type == DT_DIR) {
  420                 vp->v_type = VDIR;
  421         } else if (de->de_dirent->d_type == DT_LNK) {
  422                 vp->v_type = VLNK;
  423         } else {
  424                 vp->v_type = VBAD;
  425         }
  426         VN_LOCK_ASHARE(vp);
  427         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
  428         mtx_lock(&devfs_de_interlock);
  429         vp->v_data = de;
  430         de->de_vnode = vp;
  431         mtx_unlock(&devfs_de_interlock);
  432         error = insmntque1(vp, mp, devfs_insmntque_dtr, de);
  433         if (error != 0) {
  434                 (void) devfs_allocv_drop_refs(1, dmp, de);
  435                 return (error);
  436         }
  437         if (devfs_allocv_drop_refs(0, dmp, de)) {
  438                 vput(vp);
  439                 return (ENOENT);
  440         }
  441 #ifdef MAC
  442         mac_devfs_vnode_associate(mp, de, vp);
  443 #endif
  444         sx_xunlock(&dmp->dm_lock);
  445         *vpp = vp;
  446         return (0);
  447 }
  448 
  449 static int
  450 devfs_access(struct vop_access_args *ap)
  451 {
  452         struct vnode *vp = ap->a_vp;
  453         struct devfs_dirent *de;
  454         int error;
  455 
  456         de = vp->v_data;
  457         if (vp->v_type == VDIR)
  458                 de = de->de_dir;
  459 
  460         error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
  461             ap->a_accmode, ap->a_cred, NULL);
  462         if (!error)
  463                 return (error);
  464         if (error != EACCES)
  465                 return (error);
  466         /* We do, however, allow access to the controlling terminal */
  467         if (!(ap->a_td->td_proc->p_flag & P_CONTROLT))
  468                 return (error);
  469         if (ap->a_td->td_proc->p_session->s_ttyvp == de->de_vnode)
  470                 return (0);
  471         return (error);
  472 }
  473 
  474 /* ARGSUSED */
  475 static int
  476 devfs_close(struct vop_close_args *ap)
  477 {
  478         struct vnode *vp = ap->a_vp, *oldvp;
  479         struct thread *td = ap->a_td;
  480         struct cdev *dev = vp->v_rdev;
  481         struct cdevsw *dsw;
  482         int vp_locked, error, ref;
  483 
  484         /*
  485          * XXX: Don't call d_close() if we were called because of
  486          * XXX: insmntque1() failure.
  487          */
  488         if (vp->v_data == NULL)
  489                 return (0);
  490 
  491         /*
  492          * Hack: a tty device that is a controlling terminal
  493          * has a reference from the session structure.
  494          * We cannot easily tell that a character device is
  495          * a controlling terminal, unless it is the closing
  496          * process' controlling terminal.  In that case,
  497          * if the reference count is 2 (this last descriptor
  498          * plus the session), release the reference from the session.
  499          */
  500         oldvp = NULL;
  501         sx_xlock(&proctree_lock);
  502         if (td && vp == td->td_proc->p_session->s_ttyvp) {
  503                 SESS_LOCK(td->td_proc->p_session);
  504                 VI_LOCK(vp);
  505                 if (count_dev(dev) == 2 && (vp->v_iflag & VI_DOOMED) == 0) {
  506                         td->td_proc->p_session->s_ttyvp = NULL;
  507                         oldvp = vp;
  508                 }
  509                 VI_UNLOCK(vp);
  510                 SESS_UNLOCK(td->td_proc->p_session);
  511         }
  512         sx_xunlock(&proctree_lock);
  513         if (oldvp != NULL)
  514                 vrele(oldvp);
  515         /*
  516          * We do not want to really close the device if it
  517          * is still in use unless we are trying to close it
  518          * forcibly. Since every use (buffer, vnode, swap, cmap)
  519          * holds a reference to the vnode, and because we mark
  520          * any other vnodes that alias this device, when the
  521          * sum of the reference counts on all the aliased
  522          * vnodes descends to one, we are on last close.
  523          */
  524         dsw = dev_refthread(dev, &ref);
  525         if (dsw == NULL)
  526                 return (ENXIO);
  527         VI_LOCK(vp);
  528         if (vp->v_iflag & VI_DOOMED) {
  529                 /* Forced close. */
  530         } else if (dsw->d_flags & D_TRACKCLOSE) {
  531                 /* Keep device updated on status. */
  532         } else if (count_dev(dev) > 1) {
  533                 VI_UNLOCK(vp);
  534                 dev_relthread(dev, ref);
  535                 return (0);
  536         }
  537         vholdl(vp);
  538         VI_UNLOCK(vp);
  539         vp_locked = VOP_ISLOCKED(vp);
  540         VOP_UNLOCK(vp, 0);
  541         KASSERT(dev->si_refcount > 0,
  542             ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
  543         error = dsw->d_close(dev, ap->a_fflag, S_IFCHR, td);
  544         dev_relthread(dev, ref);
  545         vn_lock(vp, vp_locked | LK_RETRY);
  546         vdrop(vp);
  547         return (error);
  548 }
  549 
  550 static int
  551 devfs_close_f(struct file *fp, struct thread *td)
  552 {
  553         int error;
  554         struct file *fpop;
  555 
  556         /*
  557          * NB: td may be NULL if this descriptor is closed due to
  558          * garbage collection from a closed UNIX domain socket.
  559          */
  560         fpop = curthread->td_fpop;
  561         curthread->td_fpop = fp;
  562         error = vnops.fo_close(fp, td);
  563         curthread->td_fpop = fpop;
  564 
  565         /*
  566          * The f_cdevpriv cannot be assigned non-NULL value while we
  567          * are destroying the file.
  568          */
  569         if (fp->f_cdevpriv != NULL)
  570                 devfs_fpdrop(fp);
  571         return (error);
  572 }
  573 
  574 static int
  575 devfs_fsync(struct vop_fsync_args *ap)
  576 {
  577         int error;
  578         struct bufobj *bo;
  579         struct devfs_dirent *de;
  580 
  581         if (!vn_isdisk(ap->a_vp, &error)) {
  582                 bo = &ap->a_vp->v_bufobj;
  583                 de = ap->a_vp->v_data;
  584                 if (error == ENXIO && bo->bo_dirty.bv_cnt > 0) {
  585                         printf("Device %s went missing before all of the data "
  586                             "could be written to it; expect data loss.\n",
  587                             de->de_dirent->d_name);
  588 
  589                         error = vop_stdfsync(ap);
  590                         if (bo->bo_dirty.bv_cnt != 0 || error != 0)
  591                                 panic("devfs_fsync: vop_stdfsync failed.");
  592                 }
  593 
  594                 return (0);
  595         }
  596 
  597         return (vop_stdfsync(ap));
  598 }
  599 
  600 static int
  601 devfs_getattr(struct vop_getattr_args *ap)
  602 {
  603         struct vnode *vp = ap->a_vp;
  604         struct vattr *vap = ap->a_vap;
  605         int error = 0;
  606         struct devfs_dirent *de;
  607         struct cdev *dev;
  608 
  609         de = vp->v_data;
  610         KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
  611         if (vp->v_type == VDIR) {
  612                 de = de->de_dir;
  613                 KASSERT(de != NULL,
  614                     ("Null dir dirent in devfs_getattr vp=%p", vp));
  615         }
  616         vap->va_uid = de->de_uid;
  617         vap->va_gid = de->de_gid;
  618         vap->va_mode = de->de_mode;
  619         if (vp->v_type == VLNK)
  620                 vap->va_size = strlen(de->de_symlink);
  621         else if (vp->v_type == VDIR)
  622                 vap->va_size = vap->va_bytes = DEV_BSIZE;
  623         else
  624                 vap->va_size = 0;
  625         if (vp->v_type != VDIR)
  626                 vap->va_bytes = 0;
  627         vap->va_blocksize = DEV_BSIZE;
  628         vap->va_type = vp->v_type;
  629 
  630 #define fix(aa)                                                 \
  631         do {                                                    \
  632                 if ((aa).tv_sec <= 3600) {                      \
  633                         (aa).tv_sec = boottime.tv_sec;          \
  634                         (aa).tv_nsec = boottime.tv_usec * 1000; \
  635                 }                                               \
  636         } while (0)
  637 
  638         if (vp->v_type != VCHR)  {
  639                 fix(de->de_atime);
  640                 vap->va_atime = de->de_atime;
  641                 fix(de->de_mtime);
  642                 vap->va_mtime = de->de_mtime;
  643                 fix(de->de_ctime);
  644                 vap->va_ctime = de->de_ctime;
  645         } else {
  646                 dev = vp->v_rdev;
  647                 fix(dev->si_atime);
  648                 vap->va_atime = dev->si_atime;
  649                 fix(dev->si_mtime);
  650                 vap->va_mtime = dev->si_mtime;
  651                 fix(dev->si_ctime);
  652                 vap->va_ctime = dev->si_ctime;
  653 
  654                 vap->va_rdev = cdev2priv(dev)->cdp_inode;
  655         }
  656         vap->va_gen = 0;
  657         vap->va_flags = 0;
  658         vap->va_filerev = 0;
  659         vap->va_nlink = de->de_links;
  660         vap->va_fileid = de->de_inode;
  661 
  662         return (error);
  663 }
  664 
  665 /* ARGSUSED */
  666 static int
  667 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
  668 {
  669         struct cdev *dev;
  670         struct cdevsw *dsw;
  671         struct vnode *vp;
  672         struct vnode *vpold;
  673         int error, i, ref;
  674         const char *p;
  675         struct fiodgname_arg *fgn;
  676         struct file *fpop;
  677 
  678         fpop = td->td_fpop;
  679         error = devfs_fp_check(fp, &dev, &dsw, &ref);
  680         if (error)
  681                 return (error);
  682 
  683         if (com == FIODTYPE) {
  684                 *(int *)data = dsw->d_flags & D_TYPEMASK;
  685                 td->td_fpop = fpop;
  686                 dev_relthread(dev, ref);
  687                 return (0);
  688         } else if (com == FIODGNAME) {
  689                 fgn = data;
  690                 p = devtoname(dev);
  691                 i = strlen(p) + 1;
  692                 if (i > fgn->len)
  693                         error = EINVAL;
  694                 else
  695                         error = copyout(p, fgn->buf, i);
  696                 td->td_fpop = fpop;
  697                 dev_relthread(dev, ref);
  698                 return (error);
  699         }
  700         error = dsw->d_ioctl(dev, com, data, fp->f_flag, td);
  701         td->td_fpop = NULL;
  702         dev_relthread(dev, ref);
  703         if (error == ENOIOCTL)
  704                 error = ENOTTY;
  705         if (error == 0 && com == TIOCSCTTY) {
  706                 vp = fp->f_vnode;
  707 
  708                 /* Do nothing if reassigning same control tty */
  709                 sx_slock(&proctree_lock);
  710                 if (td->td_proc->p_session->s_ttyvp == vp) {
  711                         sx_sunlock(&proctree_lock);
  712                         return (0);
  713                 }
  714 
  715                 vpold = td->td_proc->p_session->s_ttyvp;
  716                 VREF(vp);
  717                 SESS_LOCK(td->td_proc->p_session);
  718                 td->td_proc->p_session->s_ttyvp = vp;
  719                 SESS_UNLOCK(td->td_proc->p_session);
  720 
  721                 sx_sunlock(&proctree_lock);
  722 
  723                 /* Get rid of reference to old control tty */
  724                 if (vpold)
  725                         vrele(vpold);
  726         }
  727         return (error);
  728 }
  729 
  730 /* ARGSUSED */
  731 static int
  732 devfs_kqfilter_f(struct file *fp, struct knote *kn)
  733 {
  734         struct cdev *dev;
  735         struct cdevsw *dsw;
  736         int error, ref;
  737         struct file *fpop;
  738         struct thread *td;
  739 
  740         td = curthread;
  741         fpop = td->td_fpop;
  742         error = devfs_fp_check(fp, &dev, &dsw, &ref);
  743         if (error)
  744                 return (error);
  745         error = dsw->d_kqfilter(dev, kn);
  746         td->td_fpop = fpop;
  747         dev_relthread(dev, ref);
  748         return (error);
  749 }
  750 
  751 static inline int
  752 devfs_prison_check(struct devfs_dirent *de, struct ucred *tcr)
  753 {
  754         struct cdev_priv *cdp;
  755         struct ucred *dcr;
  756 
  757         cdp = de->de_cdp;
  758         if (cdp == NULL)
  759                 return (0);
  760         dcr = cdp->cdp_c.si_cred;
  761         if (dcr == NULL)
  762                 return (0);
  763 
  764         return (prison_check(tcr, dcr));
  765 }
  766 
  767 static int
  768 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
  769 {
  770         struct componentname *cnp;
  771         struct vnode *dvp, **vpp;
  772         struct thread *td;
  773         struct devfs_dirent *de, *dd;
  774         struct devfs_dirent **dde;
  775         struct devfs_mount *dmp;
  776         struct cdev *cdev;
  777         int error, flags, nameiop, dvplocked;
  778         char specname[SPECNAMELEN + 1], *pname;
  779 
  780         cnp = ap->a_cnp;
  781         vpp = ap->a_vpp;
  782         dvp = ap->a_dvp;
  783         pname = cnp->cn_nameptr;
  784         td = cnp->cn_thread;
  785         flags = cnp->cn_flags;
  786         nameiop = cnp->cn_nameiop;
  787         dmp = VFSTODEVFS(dvp->v_mount);
  788         dd = dvp->v_data;
  789         *vpp = NULLVP;
  790 
  791         if ((flags & ISLASTCN) && nameiop == RENAME)
  792                 return (EOPNOTSUPP);
  793 
  794         if (dvp->v_type != VDIR)
  795                 return (ENOTDIR);
  796 
  797         if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
  798                 return (EIO);
  799 
  800         error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
  801         if (error)
  802                 return (error);
  803 
  804         if (cnp->cn_namelen == 1 && *pname == '.') {
  805                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  806                         return (EINVAL);
  807                 *vpp = dvp;
  808                 VREF(dvp);
  809                 return (0);
  810         }
  811 
  812         if (flags & ISDOTDOT) {
  813                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  814                         return (EINVAL);
  815                 de = devfs_parent_dirent(dd);
  816                 if (de == NULL)
  817                         return (ENOENT);
  818                 dvplocked = VOP_ISLOCKED(dvp);
  819                 VOP_UNLOCK(dvp, 0);
  820                 error = devfs_allocv(de, dvp->v_mount,
  821                     cnp->cn_lkflags & LK_TYPE_MASK, vpp);
  822                 *dm_unlock = 0;
  823                 vn_lock(dvp, dvplocked | LK_RETRY);
  824                 return (error);
  825         }
  826 
  827         DEVFS_DMP_HOLD(dmp);
  828         devfs_populate(dmp);
  829         if (DEVFS_DMP_DROP(dmp)) {
  830                 *dm_unlock = 0;
  831                 sx_xunlock(&dmp->dm_lock);
  832                 devfs_unmount_final(dmp);
  833                 return (ENOENT);
  834         }
  835         dd = dvp->v_data;
  836         de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen);
  837         while (de == NULL) {    /* While(...) so we can use break */
  838 
  839                 if (nameiop == DELETE)
  840                         return (ENOENT);
  841 
  842                 /*
  843                  * OK, we didn't have an entry for the name we were asked for
  844                  * so we try to see if anybody can create it on demand.
  845                  */
  846                 pname = devfs_fqpn(specname, dmp, dd, cnp);
  847                 if (pname == NULL)
  848                         break;
  849 
  850                 cdev = NULL;
  851                 DEVFS_DMP_HOLD(dmp);
  852                 sx_xunlock(&dmp->dm_lock);
  853                 sx_slock(&clone_drain_lock);
  854                 EVENTHANDLER_INVOKE(dev_clone,
  855                     td->td_ucred, pname, strlen(pname), &cdev);
  856                 sx_sunlock(&clone_drain_lock);
  857                 sx_xlock(&dmp->dm_lock);
  858                 if (DEVFS_DMP_DROP(dmp)) {
  859                         *dm_unlock = 0;
  860                         sx_xunlock(&dmp->dm_lock);
  861                         devfs_unmount_final(dmp);
  862                         if (cdev != NULL)
  863                                 dev_rel(cdev);
  864                         return (ENOENT);
  865                 }
  866                 if (cdev == NULL)
  867                         break;
  868 
  869                 DEVFS_DMP_HOLD(dmp);
  870                 devfs_populate(dmp);
  871                 if (DEVFS_DMP_DROP(dmp)) {
  872                         *dm_unlock = 0;
  873                         sx_xunlock(&dmp->dm_lock);
  874                         devfs_unmount_final(dmp);
  875                         dev_rel(cdev);
  876                         return (ENOENT);
  877                 }
  878 
  879                 dev_lock();
  880                 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
  881                 if (dde != NULL && *dde != NULL)
  882                         de = *dde;
  883                 dev_unlock();
  884                 dev_rel(cdev);
  885                 break;
  886         }
  887 
  888         if (de == NULL || de->de_flags & DE_WHITEOUT) {
  889                 if ((nameiop == CREATE || nameiop == RENAME) &&
  890                     (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
  891                         cnp->cn_flags |= SAVENAME;
  892                         return (EJUSTRETURN);
  893                 }
  894                 return (ENOENT);
  895         }
  896 
  897         if (devfs_prison_check(de, td->td_ucred))
  898                 return (ENOENT);
  899 
  900         if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
  901                 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  902                 if (error)
  903                         return (error);
  904                 if (*vpp == dvp) {
  905                         VREF(dvp);
  906                         *vpp = dvp;
  907                         return (0);
  908                 }
  909         }
  910         error = devfs_allocv(de, dvp->v_mount, cnp->cn_lkflags & LK_TYPE_MASK,
  911             vpp);
  912         *dm_unlock = 0;
  913         return (error);
  914 }
  915 
  916 static int
  917 devfs_lookup(struct vop_lookup_args *ap)
  918 {
  919         int j;
  920         struct devfs_mount *dmp;
  921         int dm_unlock;
  922 
  923         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
  924         dm_unlock = 1;
  925         sx_xlock(&dmp->dm_lock);
  926         j = devfs_lookupx(ap, &dm_unlock);
  927         if (dm_unlock == 1)
  928                 sx_xunlock(&dmp->dm_lock);
  929         return (j);
  930 }
  931 
  932 static int
  933 devfs_mknod(struct vop_mknod_args *ap)
  934 {
  935         struct componentname *cnp;
  936         struct vnode *dvp, **vpp;
  937         struct devfs_dirent *dd, *de;
  938         struct devfs_mount *dmp;
  939         int error;
  940 
  941         /*
  942          * The only type of node we should be creating here is a
  943          * character device, for anything else return EOPNOTSUPP.
  944          */
  945         if (ap->a_vap->va_type != VCHR)
  946                 return (EOPNOTSUPP);
  947         dvp = ap->a_dvp;
  948         dmp = VFSTODEVFS(dvp->v_mount);
  949 
  950         cnp = ap->a_cnp;
  951         vpp = ap->a_vpp;
  952         dd = dvp->v_data;
  953 
  954         error = ENOENT;
  955         sx_xlock(&dmp->dm_lock);
  956         TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
  957                 if (cnp->cn_namelen != de->de_dirent->d_namlen)
  958                         continue;
  959                 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
  960                     de->de_dirent->d_namlen) != 0)
  961                         continue;
  962                 if (de->de_flags & DE_WHITEOUT)
  963                         break;
  964                 goto notfound;
  965         }
  966         if (de == NULL)
  967                 goto notfound;
  968         de->de_flags &= ~DE_WHITEOUT;
  969         error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp);
  970         return (error);
  971 notfound:
  972         sx_xunlock(&dmp->dm_lock);
  973         return (error);
  974 }
  975 
  976 /* ARGSUSED */
  977 static int
  978 devfs_open(struct vop_open_args *ap)
  979 {
  980         struct thread *td = ap->a_td;
  981         struct vnode *vp = ap->a_vp;
  982         struct cdev *dev = vp->v_rdev;
  983         struct file *fp = ap->a_fp;
  984         int error, ref, vlocked;
  985         struct cdevsw *dsw;
  986         struct file *fpop;
  987 
  988         if (vp->v_type == VBLK)
  989                 return (ENXIO);
  990 
  991         if (dev == NULL)
  992                 return (ENXIO);
  993 
  994         /* Make this field valid before any I/O in d_open. */
  995         if (dev->si_iosize_max == 0)
  996                 dev->si_iosize_max = DFLTPHYS;
  997 
  998         dsw = dev_refthread(dev, &ref);
  999         if (dsw == NULL)
 1000                 return (ENXIO);
 1001         if (fp == NULL && dsw->d_fdopen != NULL) {
 1002                 dev_relthread(dev, ref);
 1003                 return (ENXIO);
 1004         }
 1005 
 1006         vlocked = VOP_ISLOCKED(vp);
 1007         VOP_UNLOCK(vp, 0);
 1008 
 1009         fpop = td->td_fpop;
 1010         td->td_fpop = fp;
 1011         if (fp != NULL) {
 1012                 fp->f_data = dev;
 1013                 fp->f_vnode = vp;
 1014         }
 1015         if (dsw->d_fdopen != NULL)
 1016                 error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
 1017         else
 1018                 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
 1019         td->td_fpop = fpop;
 1020 
 1021         vn_lock(vp, vlocked | LK_RETRY);
 1022         dev_relthread(dev, ref);
 1023         if (error != 0) {
 1024                 if (error == ERESTART)
 1025                         error = EINTR;
 1026                 return (error);
 1027         }
 1028 
 1029 #if 0   /* /dev/console */
 1030         KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp"));
 1031 #else
 1032         if (fp == NULL)
 1033                 return (error);
 1034 #endif
 1035         if (fp->f_ops == &badfileops)
 1036                 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
 1037         return (error);
 1038 }
 1039 
 1040 static int
 1041 devfs_pathconf(struct vop_pathconf_args *ap)
 1042 {
 1043 
 1044         switch (ap->a_name) {
 1045         case _PC_MAC_PRESENT:
 1046 #ifdef MAC
 1047                 /*
 1048                  * If MAC is enabled, devfs automatically supports
 1049                  * trivial non-persistant label storage.
 1050                  */
 1051                 *ap->a_retval = 1;
 1052 #else
 1053                 *ap->a_retval = 0;
 1054 #endif
 1055                 return (0);
 1056         default:
 1057                 return (vop_stdpathconf(ap));
 1058         }
 1059         /* NOTREACHED */
 1060 }
 1061 
 1062 /* ARGSUSED */
 1063 static int
 1064 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
 1065 {
 1066         struct cdev *dev;
 1067         struct cdevsw *dsw;
 1068         int error, ref;
 1069         struct file *fpop;
 1070 
 1071         fpop = td->td_fpop;
 1072         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1073         if (error)
 1074                 return (poll_no_poll(events));
 1075         error = dsw->d_poll(dev, events, td);
 1076         td->td_fpop = fpop;
 1077         dev_relthread(dev, ref);
 1078         return(error);
 1079 }
 1080 
 1081 /*
 1082  * Print out the contents of a special device vnode.
 1083  */
 1084 static int
 1085 devfs_print(struct vop_print_args *ap)
 1086 {
 1087 
 1088         printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
 1089         return (0);
 1090 }
 1091 
 1092 /* ARGSUSED */
 1093 static int
 1094 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1095 {
 1096         struct cdev *dev;
 1097         int ioflag, error, ref, resid;
 1098         struct cdevsw *dsw;
 1099         struct file *fpop;
 1100 
 1101         fpop = td->td_fpop;
 1102         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1103         if (error)
 1104                 return (error);
 1105         resid = uio->uio_resid;
 1106         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
 1107         if (ioflag & O_DIRECT)
 1108                 ioflag |= IO_DIRECT;
 1109 
 1110         if ((flags & FOF_OFFSET) == 0)
 1111                 uio->uio_offset = fp->f_offset;
 1112 
 1113         error = dsw->d_read(dev, uio, ioflag);
 1114         if (uio->uio_resid != resid || (error == 0 && resid != 0))
 1115                 vfs_timestamp(&dev->si_atime);
 1116         td->td_fpop = fpop;
 1117         dev_relthread(dev, ref);
 1118 
 1119         if ((flags & FOF_OFFSET) == 0)
 1120                 fp->f_offset = uio->uio_offset;
 1121         fp->f_nextoff = uio->uio_offset;
 1122         return (error);
 1123 }
 1124 
 1125 static int
 1126 devfs_readdir(struct vop_readdir_args *ap)
 1127 {
 1128         int error;
 1129         struct uio *uio;
 1130         struct dirent *dp;
 1131         struct devfs_dirent *dd;
 1132         struct devfs_dirent *de;
 1133         struct devfs_mount *dmp;
 1134         off_t off;
 1135         int *tmp_ncookies = NULL;
 1136 
 1137         if (ap->a_vp->v_type != VDIR)
 1138                 return (ENOTDIR);
 1139 
 1140         uio = ap->a_uio;
 1141         if (uio->uio_offset < 0)
 1142                 return (EINVAL);
 1143 
 1144         /*
 1145          * XXX: This is a temporary hack to get around this filesystem not
 1146          * supporting cookies. We store the location of the ncookies pointer
 1147          * in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
 1148          * and set the number of cookies to 0. We then set the pointer to
 1149          * NULL so that vfs_read_dirent doesn't try to call realloc() on 
 1150          * ap->a_cookies. Later in this function, we restore the ap->a_ncookies
 1151          * pointer to its original location before returning to the caller.
 1152          */
 1153         if (ap->a_ncookies != NULL) {
 1154                 tmp_ncookies = ap->a_ncookies;
 1155                 *ap->a_ncookies = 0;
 1156                 ap->a_ncookies = NULL;
 1157         }
 1158 
 1159         dmp = VFSTODEVFS(ap->a_vp->v_mount);
 1160         sx_xlock(&dmp->dm_lock);
 1161         DEVFS_DMP_HOLD(dmp);
 1162         devfs_populate(dmp);
 1163         if (DEVFS_DMP_DROP(dmp)) {
 1164                 sx_xunlock(&dmp->dm_lock);
 1165                 devfs_unmount_final(dmp);
 1166                 if (tmp_ncookies != NULL)
 1167                         ap->a_ncookies = tmp_ncookies;
 1168                 return (EIO);
 1169         }
 1170         error = 0;
 1171         de = ap->a_vp->v_data;
 1172         off = 0;
 1173         TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
 1174                 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
 1175                 if (dd->de_flags & DE_WHITEOUT)
 1176                         continue;
 1177                 if (devfs_prison_check(dd, ap->a_cred))
 1178                         continue;
 1179                 if (dd->de_dirent->d_type == DT_DIR)
 1180                         de = dd->de_dir;
 1181                 else
 1182                         de = dd;
 1183                 dp = dd->de_dirent;
 1184                 if (dp->d_reclen > uio->uio_resid)
 1185                         break;
 1186                 dp->d_fileno = de->de_inode;
 1187                 if (off >= uio->uio_offset) {
 1188                         error = vfs_read_dirent(ap, dp, off);
 1189                         if (error)
 1190                                 break;
 1191                 }
 1192                 off += dp->d_reclen;
 1193         }
 1194         sx_xunlock(&dmp->dm_lock);
 1195         uio->uio_offset = off;
 1196 
 1197         /*
 1198          * Restore ap->a_ncookies if it wasn't originally NULL in the first
 1199          * place.
 1200          */
 1201         if (tmp_ncookies != NULL)
 1202                 ap->a_ncookies = tmp_ncookies;
 1203 
 1204         return (error);
 1205 }
 1206 
 1207 static int
 1208 devfs_readlink(struct vop_readlink_args *ap)
 1209 {
 1210         struct devfs_dirent *de;
 1211 
 1212         de = ap->a_vp->v_data;
 1213         return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
 1214 }
 1215 
 1216 static int
 1217 devfs_reclaim(struct vop_reclaim_args *ap)
 1218 {
 1219         struct vnode *vp = ap->a_vp;
 1220         struct devfs_dirent *de;
 1221         struct cdev *dev;
 1222 
 1223         mtx_lock(&devfs_de_interlock);
 1224         de = vp->v_data;
 1225         if (de != NULL) {
 1226                 de->de_vnode = NULL;
 1227                 vp->v_data = NULL;
 1228         }
 1229         mtx_unlock(&devfs_de_interlock);
 1230 
 1231         vnode_destroy_vobject(vp);
 1232 
 1233         VI_LOCK(vp);
 1234         dev_lock();
 1235         dev = vp->v_rdev;
 1236         vp->v_rdev = NULL;
 1237 
 1238         if (dev == NULL) {
 1239                 dev_unlock();
 1240                 VI_UNLOCK(vp);
 1241                 return (0);
 1242         }
 1243 
 1244         dev->si_usecount -= vp->v_usecount;
 1245         dev_unlock();
 1246         VI_UNLOCK(vp);
 1247         dev_rel(dev);
 1248         return (0);
 1249 }
 1250 
 1251 static int
 1252 devfs_remove(struct vop_remove_args *ap)
 1253 {
 1254         struct vnode *vp = ap->a_vp;
 1255         struct devfs_dirent *dd;
 1256         struct devfs_dirent *de;
 1257         struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
 1258 
 1259         sx_xlock(&dmp->dm_lock);
 1260         dd = ap->a_dvp->v_data;
 1261         de = vp->v_data;
 1262         if (de->de_cdp == NULL) {
 1263                 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
 1264                 devfs_delete(dmp, de, 1);
 1265         } else {
 1266                 de->de_flags |= DE_WHITEOUT;
 1267         }
 1268         sx_xunlock(&dmp->dm_lock);
 1269         return (0);
 1270 }
 1271 
 1272 /*
 1273  * Revoke is called on a tty when a terminal session ends.  The vnode
 1274  * is orphaned by setting v_op to deadfs so we need to let go of it
 1275  * as well so that we create a new one next time around.
 1276  *
 1277  */
 1278 static int
 1279 devfs_revoke(struct vop_revoke_args *ap)
 1280 {
 1281         struct vnode *vp = ap->a_vp, *vp2;
 1282         struct cdev *dev;
 1283         struct cdev_priv *cdp;
 1284         struct devfs_dirent *de;
 1285         int i;
 1286 
 1287         KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
 1288 
 1289         dev = vp->v_rdev;
 1290         cdp = cdev2priv(dev);
 1291  
 1292         dev_lock();
 1293         cdp->cdp_inuse++;
 1294         dev_unlock();
 1295 
 1296         vhold(vp);
 1297         vgone(vp);
 1298         vdrop(vp);
 1299 
 1300         VOP_UNLOCK(vp,0);
 1301  loop:
 1302         for (;;) {
 1303                 mtx_lock(&devfs_de_interlock);
 1304                 dev_lock();
 1305                 vp2 = NULL;
 1306                 for (i = 0; i <= cdp->cdp_maxdirent; i++) {
 1307                         de = cdp->cdp_dirents[i];
 1308                         if (de == NULL)
 1309                                 continue;
 1310 
 1311                         vp2 = de->de_vnode;
 1312                         if (vp2 != NULL) {
 1313                                 dev_unlock();
 1314                                 VI_LOCK(vp2);
 1315                                 mtx_unlock(&devfs_de_interlock);
 1316                                 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
 1317                                     curthread))
 1318                                         goto loop;
 1319                                 vhold(vp2);
 1320                                 vgone(vp2);
 1321                                 vdrop(vp2);
 1322                                 vput(vp2);
 1323                                 break;
 1324                         } 
 1325                 }
 1326                 if (vp2 != NULL) {
 1327                         continue;
 1328                 }
 1329                 dev_unlock();
 1330                 mtx_unlock(&devfs_de_interlock);
 1331                 break;
 1332         }
 1333         dev_lock();
 1334         cdp->cdp_inuse--;
 1335         if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
 1336                 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
 1337                 dev_unlock();
 1338                 dev_rel(&cdp->cdp_c);
 1339         } else
 1340                 dev_unlock();
 1341 
 1342         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 1343         return (0);
 1344 }
 1345 
 1346 static int
 1347 devfs_rioctl(struct vop_ioctl_args *ap)
 1348 {
 1349         struct vnode *vp;
 1350         struct devfs_mount *dmp;
 1351         int error;
 1352 
 1353         vp = ap->a_vp;
 1354         vn_lock(vp, LK_SHARED | LK_RETRY);
 1355         if (vp->v_iflag & VI_DOOMED) {
 1356                 VOP_UNLOCK(vp, 0);
 1357                 return (EBADF);
 1358         }
 1359         dmp = VFSTODEVFS(vp->v_mount);
 1360         sx_xlock(&dmp->dm_lock);
 1361         VOP_UNLOCK(vp, 0);
 1362         DEVFS_DMP_HOLD(dmp);
 1363         devfs_populate(dmp);
 1364         if (DEVFS_DMP_DROP(dmp)) {
 1365                 sx_xunlock(&dmp->dm_lock);
 1366                 devfs_unmount_final(dmp);
 1367                 return (ENOENT);
 1368         }
 1369         error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
 1370         sx_xunlock(&dmp->dm_lock);
 1371         return (error);
 1372 }
 1373 
 1374 static int
 1375 devfs_rread(struct vop_read_args *ap)
 1376 {
 1377 
 1378         if (ap->a_vp->v_type != VDIR)
 1379                 return (EINVAL);
 1380         return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
 1381 }
 1382 
 1383 static int
 1384 devfs_setattr(struct vop_setattr_args *ap)
 1385 {
 1386         struct devfs_dirent *de;
 1387         struct vattr *vap;
 1388         struct vnode *vp;
 1389         struct thread *td;
 1390         int c, error;
 1391         uid_t uid;
 1392         gid_t gid;
 1393 
 1394         vap = ap->a_vap;
 1395         vp = ap->a_vp;
 1396         td = curthread;
 1397         if ((vap->va_type != VNON) ||
 1398             (vap->va_nlink != VNOVAL) ||
 1399             (vap->va_fsid != VNOVAL) ||
 1400             (vap->va_fileid != VNOVAL) ||
 1401             (vap->va_blocksize != VNOVAL) ||
 1402             (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
 1403             (vap->va_rdev != VNOVAL) ||
 1404             ((int)vap->va_bytes != VNOVAL) ||
 1405             (vap->va_gen != VNOVAL)) {
 1406                 return (EINVAL);
 1407         }
 1408 
 1409         de = vp->v_data;
 1410         if (vp->v_type == VDIR)
 1411                 de = de->de_dir;
 1412 
 1413         error = c = 0;
 1414         if (vap->va_uid == (uid_t)VNOVAL)
 1415                 uid = de->de_uid;
 1416         else
 1417                 uid = vap->va_uid;
 1418         if (vap->va_gid == (gid_t)VNOVAL)
 1419                 gid = de->de_gid;
 1420         else
 1421                 gid = vap->va_gid;
 1422         if (uid != de->de_uid || gid != de->de_gid) {
 1423                 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
 1424                     (gid != de->de_gid && !groupmember(gid, ap->a_cred))) {
 1425                         error = priv_check(td, PRIV_VFS_CHOWN);
 1426                         if (error)
 1427                                 return (error);
 1428                 }
 1429                 de->de_uid = uid;
 1430                 de->de_gid = gid;
 1431                 c = 1;
 1432         }
 1433 
 1434         if (vap->va_mode != (mode_t)VNOVAL) {
 1435                 if (ap->a_cred->cr_uid != de->de_uid) {
 1436                         error = priv_check(td, PRIV_VFS_ADMIN);
 1437                         if (error)
 1438                                 return (error);
 1439                 }
 1440                 de->de_mode = vap->va_mode;
 1441                 c = 1;
 1442         }
 1443 
 1444         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
 1445                 /* See the comment in ufs_vnops::ufs_setattr(). */
 1446                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
 1447                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
 1448                     (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
 1449                         return (error);
 1450                 if (vap->va_atime.tv_sec != VNOVAL) {
 1451                         if (vp->v_type == VCHR)
 1452                                 vp->v_rdev->si_atime = vap->va_atime;
 1453                         else
 1454                                 de->de_atime = vap->va_atime;
 1455                 }
 1456                 if (vap->va_mtime.tv_sec != VNOVAL) {
 1457                         if (vp->v_type == VCHR)
 1458                                 vp->v_rdev->si_mtime = vap->va_mtime;
 1459                         else
 1460                                 de->de_mtime = vap->va_mtime;
 1461                 }
 1462                 c = 1;
 1463         }
 1464 
 1465         if (c) {
 1466                 if (vp->v_type == VCHR)
 1467                         vfs_timestamp(&vp->v_rdev->si_ctime);
 1468                 else
 1469                         vfs_timestamp(&de->de_mtime);
 1470         }
 1471         return (0);
 1472 }
 1473 
 1474 #ifdef MAC
 1475 static int
 1476 devfs_setlabel(struct vop_setlabel_args *ap)
 1477 {
 1478         struct vnode *vp;
 1479         struct devfs_dirent *de;
 1480 
 1481         vp = ap->a_vp;
 1482         de = vp->v_data;
 1483 
 1484         mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
 1485         mac_devfs_update(vp->v_mount, de, vp);
 1486 
 1487         return (0);
 1488 }
 1489 #endif
 1490 
 1491 static int
 1492 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
 1493 {
 1494 
 1495         return (vnops.fo_stat(fp, sb, cred, td));
 1496 }
 1497 
 1498 static int
 1499 devfs_symlink(struct vop_symlink_args *ap)
 1500 {
 1501         int i, error;
 1502         struct devfs_dirent *dd;
 1503         struct devfs_dirent *de;
 1504         struct devfs_mount *dmp;
 1505 
 1506         error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
 1507         if (error)
 1508                 return(error);
 1509         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
 1510         dd = ap->a_dvp->v_data;
 1511         de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
 1512         de->de_uid = 0;
 1513         de->de_gid = 0;
 1514         de->de_mode = 0755;
 1515         de->de_inode = alloc_unr(devfs_inos);
 1516         de->de_dir = dd;
 1517         de->de_dirent->d_type = DT_LNK;
 1518         i = strlen(ap->a_target) + 1;
 1519         de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
 1520         bcopy(ap->a_target, de->de_symlink, i);
 1521         sx_xlock(&dmp->dm_lock);
 1522 #ifdef MAC
 1523         mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
 1524 #endif
 1525         TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
 1526         devfs_rules_apply(dmp, de);
 1527         return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
 1528 }
 1529 
 1530 static int
 1531 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
 1532 {
 1533 
 1534         return (vnops.fo_truncate(fp, length, cred, td));
 1535 }
 1536 
 1537 /* ARGSUSED */
 1538 static int
 1539 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1540 {
 1541         struct cdev *dev;
 1542         int error, ioflag, ref, resid;
 1543         struct cdevsw *dsw;
 1544         struct file *fpop;
 1545 
 1546         fpop = td->td_fpop;
 1547         error = devfs_fp_check(fp, &dev, &dsw, &ref);
 1548         if (error)
 1549                 return (error);
 1550         KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
 1551         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
 1552         if (ioflag & O_DIRECT)
 1553                 ioflag |= IO_DIRECT;
 1554         if ((flags & FOF_OFFSET) == 0)
 1555                 uio->uio_offset = fp->f_offset;
 1556 
 1557         resid = uio->uio_resid;
 1558 
 1559         error = dsw->d_write(dev, uio, ioflag);
 1560         if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
 1561                 vfs_timestamp(&dev->si_ctime);
 1562                 dev->si_mtime = dev->si_ctime;
 1563         }
 1564         td->td_fpop = fpop;
 1565         dev_relthread(dev, ref);
 1566 
 1567         if ((flags & FOF_OFFSET) == 0)
 1568                 fp->f_offset = uio->uio_offset;
 1569         fp->f_nextoff = uio->uio_offset;
 1570         return (error);
 1571 }
 1572 
 1573 dev_t
 1574 dev2udev(struct cdev *x)
 1575 {
 1576         if (x == NULL)
 1577                 return (NODEV);
 1578         return (cdev2priv(x)->cdp_inode);
 1579 }
 1580 
 1581 static struct fileops devfs_ops_f = {
 1582         .fo_read =      devfs_read_f,
 1583         .fo_write =     devfs_write_f,
 1584         .fo_truncate =  devfs_truncate_f,
 1585         .fo_ioctl =     devfs_ioctl_f,
 1586         .fo_poll =      devfs_poll_f,
 1587         .fo_kqfilter =  devfs_kqfilter_f,
 1588         .fo_stat =      devfs_stat_f,
 1589         .fo_close =     devfs_close_f,
 1590         .fo_flags =     DFLAG_PASSABLE | DFLAG_SEEKABLE
 1591 };
 1592 
 1593 static struct vop_vector devfs_vnodeops = {
 1594         .vop_default =          &default_vnodeops,
 1595 
 1596         .vop_access =           devfs_access,
 1597         .vop_getattr =          devfs_getattr,
 1598         .vop_ioctl =            devfs_rioctl,
 1599         .vop_lookup =           devfs_lookup,
 1600         .vop_mknod =            devfs_mknod,
 1601         .vop_pathconf =         devfs_pathconf,
 1602         .vop_read =             devfs_rread,
 1603         .vop_readdir =          devfs_readdir,
 1604         .vop_readlink =         devfs_readlink,
 1605         .vop_reclaim =          devfs_reclaim,
 1606         .vop_remove =           devfs_remove,
 1607         .vop_revoke =           devfs_revoke,
 1608         .vop_setattr =          devfs_setattr,
 1609 #ifdef MAC
 1610         .vop_setlabel =         devfs_setlabel,
 1611 #endif
 1612         .vop_symlink =          devfs_symlink,
 1613         .vop_vptocnp =          devfs_vptocnp,
 1614 };
 1615 
 1616 static struct vop_vector devfs_specops = {
 1617         .vop_default =          &default_vnodeops,
 1618 
 1619         .vop_access =           devfs_access,
 1620         .vop_bmap =             VOP_PANIC,
 1621         .vop_close =            devfs_close,
 1622         .vop_create =           VOP_PANIC,
 1623         .vop_fsync =            devfs_fsync,
 1624         .vop_getattr =          devfs_getattr,
 1625         .vop_link =             VOP_PANIC,
 1626         .vop_mkdir =            VOP_PANIC,
 1627         .vop_mknod =            VOP_PANIC,
 1628         .vop_open =             devfs_open,
 1629         .vop_pathconf =         devfs_pathconf,
 1630         .vop_print =            devfs_print,
 1631         .vop_read =             VOP_PANIC,
 1632         .vop_readdir =          VOP_PANIC,
 1633         .vop_readlink =         VOP_PANIC,
 1634         .vop_reallocblks =      VOP_PANIC,
 1635         .vop_reclaim =          devfs_reclaim,
 1636         .vop_remove =           devfs_remove,
 1637         .vop_rename =           VOP_PANIC,
 1638         .vop_revoke =           devfs_revoke,
 1639         .vop_rmdir =            VOP_PANIC,
 1640         .vop_setattr =          devfs_setattr,
 1641 #ifdef MAC
 1642         .vop_setlabel =         devfs_setlabel,
 1643 #endif
 1644         .vop_strategy =         VOP_PANIC,
 1645         .vop_symlink =          VOP_PANIC,
 1646         .vop_vptocnp =          devfs_vptocnp,
 1647         .vop_write =            VOP_PANIC,
 1648 };
 1649 
 1650 /*
 1651  * Our calling convention to the device drivers used to be that we passed
 1652  * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_ 
 1653  * flags instead since that's what open(), close() and ioctl() takes and
 1654  * we don't really want vnode.h in device drivers.
 1655  * We solved the source compatibility by redefining some vnode flags to
 1656  * be the same as the fcntl ones and by sending down the bitwise OR of
 1657  * the respective fcntl/vnode flags.  These CTASSERTS make sure nobody
 1658  * pulls the rug out under this.
 1659  */
 1660 CTASSERT(O_NONBLOCK == IO_NDELAY);
 1661 CTASSERT(O_FSYNC == IO_SYNC);
Cache object: b1e455ac62f96d56f03e5e2629053d82
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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
