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/8.0/sys/fs/devfs/devfs_vnops.c 194532 2009-06-20 14:50:32Z ed $
   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 {
   87 
   88         *dswp = devvn_refthread(fp->f_vnode, devp);
   89         if (*devp != fp->f_data) {
   90                 if (*dswp != NULL)
   91                         dev_relthread(*devp);
   92                 return (ENXIO);
   93         }
   94         KASSERT((*devp)->si_refcount > 0,
   95             ("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
   96         if (*dswp == NULL)
   97                 return (ENXIO);
   98         curthread->td_fpop = fp;
   99         return (0);
  100 }
  101 
  102 int
  103 devfs_get_cdevpriv(void **datap)
  104 {
  105         struct file *fp;
  106         struct cdev_privdata *p;
  107         int error;
  108 
  109         fp = curthread->td_fpop;
  110         if (fp == NULL)
  111                 return (EBADF);
  112         p = fp->f_cdevpriv;
  113         if (p != NULL) {
  114                 error = 0;
  115                 *datap = p->cdpd_data;
  116         } else
  117                 error = ENOENT;
  118         return (error);
  119 }
  120 
  121 int
  122 devfs_set_cdevpriv(void *priv, cdevpriv_dtr_t priv_dtr)
  123 {
  124         struct file *fp;
  125         struct cdev_priv *cdp;
  126         struct cdev_privdata *p;
  127         int error;
  128 
  129         fp = curthread->td_fpop;
  130         if (fp == NULL)
  131                 return (ENOENT);
  132         cdp = cdev2priv((struct cdev *)fp->f_data);
  133         p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK);
  134         p->cdpd_data = priv;
  135         p->cdpd_dtr = priv_dtr;
  136         p->cdpd_fp = fp;
  137         mtx_lock(&cdevpriv_mtx);
  138         if (fp->f_cdevpriv == NULL) {
  139                 LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list);
  140                 fp->f_cdevpriv = p;
  141                 mtx_unlock(&cdevpriv_mtx);
  142                 error = 0;
  143         } else {
  144                 mtx_unlock(&cdevpriv_mtx);
  145                 free(p, M_CDEVPDATA);
  146                 error = EBUSY;
  147         }
  148         return (error);
  149 }
  150 
  151 void
  152 devfs_destroy_cdevpriv(struct cdev_privdata *p)
  153 {
  154 
  155         mtx_assert(&cdevpriv_mtx, MA_OWNED);
  156         p->cdpd_fp->f_cdevpriv = NULL;
  157         LIST_REMOVE(p, cdpd_list);
  158         mtx_unlock(&cdevpriv_mtx);
  159         (p->cdpd_dtr)(p->cdpd_data);
  160         free(p, M_CDEVPDATA);
  161 }
  162 
  163 void
  164 devfs_fpdrop(struct file *fp)
  165 {
  166         struct cdev_privdata *p;
  167 
  168         mtx_lock(&cdevpriv_mtx);
  169         if ((p = fp->f_cdevpriv) == NULL) {
  170                 mtx_unlock(&cdevpriv_mtx);
  171                 return;
  172         }
  173         devfs_destroy_cdevpriv(p);
  174 }
  175 
  176 void
  177 devfs_clear_cdevpriv(void)
  178 {
  179         struct file *fp;
  180 
  181         fp = curthread->td_fpop;
  182         if (fp == NULL)
  183                 return;
  184         devfs_fpdrop(fp);
  185 }
  186 
  187 static int
  188 devfs_vptocnp(struct vop_vptocnp_args *ap)
  189 {
  190         struct vnode *vp = ap->a_vp;
  191         struct vnode **dvp = ap->a_vpp;
  192         struct devfs_mount *dmp;
  193         char *buf = ap->a_buf;
  194         int *buflen = ap->a_buflen;
  195         struct devfs_dirent *dd, *de;
  196         int i, error;
  197 
  198         dmp = VFSTODEVFS(vp->v_mount);
  199         i = *buflen;
  200         dd = vp->v_data;
  201         error = 0;
  202 
  203         sx_xlock(&dmp->dm_lock);
  204 
  205         if (vp->v_type == VCHR) {
  206                 i -= strlen(dd->de_cdp->cdp_c.si_name);
  207                 if (i < 0) {
  208                         error = ENOMEM;
  209                         goto finished;
  210                 }
  211                 bcopy(dd->de_cdp->cdp_c.si_name, buf + i,
  212                     strlen(dd->de_cdp->cdp_c.si_name));
  213                 de = dd->de_dir;
  214         } else if (vp->v_type == VDIR) {
  215                 if (dd == dmp->dm_rootdir) {
  216                         *dvp = vp;
  217                         vhold(*dvp);
  218                         goto finished;
  219                 }
  220                 i -= dd->de_dirent->d_namlen;
  221                 if (i < 0) {
  222                         error = ENOMEM;
  223                         goto finished;
  224                 }
  225                 bcopy(dd->de_dirent->d_name, buf + i,
  226                     dd->de_dirent->d_namlen);
  227                 de = dd;
  228         } else {
  229                 error = ENOENT;
  230                 goto finished;
  231         }
  232         *buflen = i;
  233         de = TAILQ_FIRST(&de->de_dlist);        /* "." */
  234         de = TAILQ_NEXT(de, de_list);           /* ".." */
  235         de = de->de_dir;
  236         mtx_lock(&devfs_de_interlock);
  237         *dvp = de->de_vnode;
  238         if (*dvp != NULL) {
  239                 VI_LOCK(*dvp);
  240                 mtx_unlock(&devfs_de_interlock);
  241                 vholdl(*dvp);
  242                 VI_UNLOCK(*dvp);
  243         } else {
  244                 mtx_unlock(&devfs_de_interlock);
  245                 error = ENOENT;
  246         }
  247 finished:
  248         sx_xunlock(&dmp->dm_lock);
  249         return (error);
  250 }
  251 
  252 /*
  253  * Construct the fully qualified path name relative to the mountpoint
  254  */
  255 static char *
  256 devfs_fqpn(char *buf, struct vnode *dvp, struct componentname *cnp)
  257 {
  258         int i;
  259         struct devfs_dirent *de, *dd;
  260         struct devfs_mount *dmp;
  261 
  262         dmp = VFSTODEVFS(dvp->v_mount);
  263         dd = dvp->v_data;
  264         i = SPECNAMELEN;
  265         buf[i] = '\0';
  266         i -= cnp->cn_namelen;
  267         if (i < 0)
  268                  return (NULL);
  269         bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
  270         de = dd;
  271         while (de != dmp->dm_rootdir) {
  272                 i--;
  273                 if (i < 0)
  274                          return (NULL);
  275                 buf[i] = '/';
  276                 i -= de->de_dirent->d_namlen;
  277                 if (i < 0)
  278                          return (NULL);
  279                 bcopy(de->de_dirent->d_name, buf + i,
  280                     de->de_dirent->d_namlen);
  281                 de = TAILQ_FIRST(&de->de_dlist);        /* "." */
  282                 de = TAILQ_NEXT(de, de_list);           /* ".." */
  283                 de = de->de_dir;
  284         }
  285         return (buf + i);
  286 }
  287 
  288 static int
  289 devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
  290         struct devfs_dirent *de)
  291 {
  292         int not_found;
  293 
  294         not_found = 0;
  295         if (de->de_flags & DE_DOOMED)
  296                 not_found = 1;
  297         if (DEVFS_DE_DROP(de)) {
  298                 KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
  299                 devfs_dirent_free(de);
  300         }
  301         if (DEVFS_DMP_DROP(dmp)) {
  302                 KASSERT(not_found == 1,
  303                         ("DEVFS mount struct freed before dirent"));
  304                 not_found = 2;
  305                 sx_xunlock(&dmp->dm_lock);
  306                 devfs_unmount_final(dmp);
  307         }
  308         if (not_found == 1 || (drop_dm_lock && not_found != 2))
  309                 sx_unlock(&dmp->dm_lock);
  310         return (not_found);
  311 }
  312 
  313 static void
  314 devfs_insmntque_dtr(struct vnode *vp, void *arg)
  315 {
  316         struct devfs_dirent *de;
  317 
  318         de = (struct devfs_dirent *)arg;
  319         mtx_lock(&devfs_de_interlock);
  320         vp->v_data = NULL;
  321         de->de_vnode = NULL;
  322         mtx_unlock(&devfs_de_interlock);
  323         vgone(vp);
  324         vput(vp);
  325 }
  326 
  327 /*
  328  * devfs_allocv shall be entered with dmp->dm_lock held, and it drops
  329  * it on return.
  330  */
  331 int
  332 devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp)
  333 {
  334         int error;
  335         struct vnode *vp;
  336         struct cdev *dev;
  337         struct devfs_mount *dmp;
  338 
  339         dmp = VFSTODEVFS(mp);
  340         if (de->de_flags & DE_DOOMED) {
  341                 sx_xunlock(&dmp->dm_lock);
  342                 return (ENOENT);
  343         }
  344         DEVFS_DE_HOLD(de);
  345         DEVFS_DMP_HOLD(dmp);
  346         mtx_lock(&devfs_de_interlock);
  347         vp = de->de_vnode;
  348         if (vp != NULL) {
  349                 VI_LOCK(vp);
  350                 mtx_unlock(&devfs_de_interlock);
  351                 sx_xunlock(&dmp->dm_lock);
  352                 error = vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, curthread);
  353                 sx_xlock(&dmp->dm_lock);
  354                 if (devfs_allocv_drop_refs(0, dmp, de)) {
  355                         if (error == 0)
  356                                 vput(vp);
  357                         return (ENOENT);
  358                 }
  359                 else if (error) {
  360                         sx_xunlock(&dmp->dm_lock);
  361                         return (error);
  362                 }
  363                 sx_xunlock(&dmp->dm_lock);
  364                 *vpp = vp;
  365                 return (0);
  366         }
  367         mtx_unlock(&devfs_de_interlock);
  368         if (de->de_dirent->d_type == DT_CHR) {
  369                 if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
  370                         devfs_allocv_drop_refs(1, dmp, de);
  371                         return (ENOENT);
  372                 }
  373                 dev = &de->de_cdp->cdp_c;
  374         } else {
  375                 dev = NULL;
  376         }
  377         error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
  378         if (error != 0) {
  379                 devfs_allocv_drop_refs(1, dmp, de);
  380                 printf("devfs_allocv: failed to allocate new vnode\n");
  381                 return (error);
  382         }
  383 
  384         if (de->de_dirent->d_type == DT_CHR) {
  385                 vp->v_type = VCHR;
  386                 VI_LOCK(vp);
  387                 dev_lock();
  388                 dev_refl(dev);
  389                 /* XXX: v_rdev should be protect by vnode lock */
  390                 vp->v_rdev = dev;
  391                 KASSERT(vp->v_usecount == 1,
  392                     ("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
  393                 dev->si_usecount += vp->v_usecount;
  394                 dev_unlock();
  395                 VI_UNLOCK(vp);
  396                 vp->v_op = &devfs_specops;
  397         } else if (de->de_dirent->d_type == DT_DIR) {
  398                 vp->v_type = VDIR;
  399         } else if (de->de_dirent->d_type == DT_LNK) {
  400                 vp->v_type = VLNK;
  401         } else {
  402                 vp->v_type = VBAD;
  403         }
  404         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
  405         mtx_lock(&devfs_de_interlock);
  406         vp->v_data = de;
  407         de->de_vnode = vp;
  408         mtx_unlock(&devfs_de_interlock);
  409         error = insmntque1(vp, mp, devfs_insmntque_dtr, de);
  410         if (error != 0) {
  411                 (void) devfs_allocv_drop_refs(1, dmp, de);
  412                 return (error);
  413         }
  414         if (devfs_allocv_drop_refs(0, dmp, de)) {
  415                 vput(vp);
  416                 return (ENOENT);
  417         }
  418 #ifdef MAC
  419         mac_devfs_vnode_associate(mp, de, vp);
  420 #endif
  421         sx_xunlock(&dmp->dm_lock);
  422         *vpp = vp;
  423         return (0);
  424 }
  425 
  426 static int
  427 devfs_access(struct vop_access_args *ap)
  428 {
  429         struct vnode *vp = ap->a_vp;
  430         struct devfs_dirent *de;
  431         int error;
  432 
  433         de = vp->v_data;
  434         if (vp->v_type == VDIR)
  435                 de = de->de_dir;
  436 
  437         error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
  438             ap->a_accmode, ap->a_cred, NULL);
  439         if (!error)
  440                 return (error);
  441         if (error != EACCES)
  442                 return (error);
  443         /* We do, however, allow access to the controlling terminal */
  444         if (!(ap->a_td->td_proc->p_flag & P_CONTROLT))
  445                 return (error);
  446         if (ap->a_td->td_proc->p_session->s_ttyvp == de->de_vnode)
  447                 return (0);
  448         return (error);
  449 }
  450 
  451 /* ARGSUSED */
  452 static int
  453 devfs_close(struct vop_close_args *ap)
  454 {
  455         struct vnode *vp = ap->a_vp, *oldvp;
  456         struct thread *td = ap->a_td;
  457         struct cdev *dev = vp->v_rdev;
  458         struct cdevsw *dsw;
  459         int vp_locked, error;
  460 
  461         /*
  462          * Hack: a tty device that is a controlling terminal
  463          * has a reference from the session structure.
  464          * We cannot easily tell that a character device is
  465          * a controlling terminal, unless it is the closing
  466          * process' controlling terminal.  In that case,
  467          * if the reference count is 2 (this last descriptor
  468          * plus the session), release the reference from the session.
  469          */
  470         oldvp = NULL;
  471         sx_xlock(&proctree_lock);
  472         if (td && vp == td->td_proc->p_session->s_ttyvp) {
  473                 SESS_LOCK(td->td_proc->p_session);
  474                 VI_LOCK(vp);
  475                 if (count_dev(dev) == 2 && (vp->v_iflag & VI_DOOMED) == 0) {
  476                         td->td_proc->p_session->s_ttyvp = NULL;
  477                         oldvp = vp;
  478                 }
  479                 VI_UNLOCK(vp);
  480                 SESS_UNLOCK(td->td_proc->p_session);
  481         }
  482         sx_xunlock(&proctree_lock);
  483         if (oldvp != NULL)
  484                 vrele(oldvp);
  485         /*
  486          * We do not want to really close the device if it
  487          * is still in use unless we are trying to close it
  488          * forcibly. Since every use (buffer, vnode, swap, cmap)
  489          * holds a reference to the vnode, and because we mark
  490          * any other vnodes that alias this device, when the
  491          * sum of the reference counts on all the aliased
  492          * vnodes descends to one, we are on last close.
  493          */
  494         dsw = dev_refthread(dev);
  495         if (dsw == NULL)
  496                 return (ENXIO);
  497         VI_LOCK(vp);
  498         if (vp->v_iflag & VI_DOOMED) {
  499                 /* Forced close. */
  500         } else if (dsw->d_flags & D_TRACKCLOSE) {
  501                 /* Keep device updated on status. */
  502         } else if (count_dev(dev) > 1) {
  503                 VI_UNLOCK(vp);
  504                 dev_relthread(dev);
  505                 return (0);
  506         }
  507         vholdl(vp);
  508         VI_UNLOCK(vp);
  509         vp_locked = VOP_ISLOCKED(vp);
  510         VOP_UNLOCK(vp, 0);
  511         KASSERT(dev->si_refcount > 0,
  512             ("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
  513         error = dsw->d_close(dev, ap->a_fflag, S_IFCHR, td);
  514         dev_relthread(dev);
  515         vn_lock(vp, vp_locked | LK_RETRY);
  516         vdrop(vp);
  517         return (error);
  518 }
  519 
  520 static int
  521 devfs_close_f(struct file *fp, struct thread *td)
  522 {
  523         int error;
  524         struct file *fpop;
  525 
  526         fpop = td->td_fpop;
  527         td->td_fpop = fp;
  528         error = vnops.fo_close(fp, td);
  529         td->td_fpop = fpop;
  530         return (error);
  531 }
  532 
  533 static int
  534 devfs_fsync(struct vop_fsync_args *ap)
  535 {
  536         int error;
  537         struct bufobj *bo;
  538         struct devfs_dirent *de;
  539 
  540         if (!vn_isdisk(ap->a_vp, &error)) {
  541                 bo = &ap->a_vp->v_bufobj;
  542                 de = ap->a_vp->v_data;
  543                 if (error == ENXIO && bo->bo_dirty.bv_cnt > 0) {
  544                         printf("Device %s went missing before all of the data "
  545                             "could be written to it; expect data loss.\n",
  546                             de->de_dirent->d_name);
  547 
  548                         error = vop_stdfsync(ap);
  549                         if (bo->bo_dirty.bv_cnt != 0 || error != 0)
  550                                 panic("devfs_fsync: vop_stdfsync failed.");
  551                 }
  552 
  553                 return (0);
  554         }
  555 
  556         return (vop_stdfsync(ap));
  557 }
  558 
  559 static int
  560 devfs_getattr(struct vop_getattr_args *ap)
  561 {
  562         struct vnode *vp = ap->a_vp;
  563         struct vattr *vap = ap->a_vap;
  564         int error = 0;
  565         struct devfs_dirent *de;
  566         struct cdev *dev;
  567 
  568         de = vp->v_data;
  569         KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
  570         if (vp->v_type == VDIR) {
  571                 de = de->de_dir;
  572                 KASSERT(de != NULL,
  573                     ("Null dir dirent in devfs_getattr vp=%p", vp));
  574         }
  575         vap->va_uid = de->de_uid;
  576         vap->va_gid = de->de_gid;
  577         vap->va_mode = de->de_mode;
  578         if (vp->v_type == VLNK)
  579                 vap->va_size = strlen(de->de_symlink);
  580         else if (vp->v_type == VDIR)
  581                 vap->va_size = vap->va_bytes = DEV_BSIZE;
  582         else
  583                 vap->va_size = 0;
  584         if (vp->v_type != VDIR)
  585                 vap->va_bytes = 0;
  586         vap->va_blocksize = DEV_BSIZE;
  587         vap->va_type = vp->v_type;
  588 
  589 #define fix(aa)                                                 \
  590         do {                                                    \
  591                 if ((aa).tv_sec <= 3600) {                      \
  592                         (aa).tv_sec = boottime.tv_sec;          \
  593                         (aa).tv_nsec = boottime.tv_usec * 1000; \
  594                 }                                               \
  595         } while (0)
  596 
  597         if (vp->v_type != VCHR)  {
  598                 fix(de->de_atime);
  599                 vap->va_atime = de->de_atime;
  600                 fix(de->de_mtime);
  601                 vap->va_mtime = de->de_mtime;
  602                 fix(de->de_ctime);
  603                 vap->va_ctime = de->de_ctime;
  604         } else {
  605                 dev = vp->v_rdev;
  606                 fix(dev->si_atime);
  607                 vap->va_atime = dev->si_atime;
  608                 fix(dev->si_mtime);
  609                 vap->va_mtime = dev->si_mtime;
  610                 fix(dev->si_ctime);
  611                 vap->va_ctime = dev->si_ctime;
  612 
  613                 vap->va_rdev = cdev2priv(dev)->cdp_inode;
  614         }
  615         vap->va_gen = 0;
  616         vap->va_flags = 0;
  617         vap->va_filerev = 0;
  618         vap->va_nlink = de->de_links;
  619         vap->va_fileid = de->de_inode;
  620 
  621         return (error);
  622 }
  623 
  624 /* ARGSUSED */
  625 static int
  626 devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
  627 {
  628         struct cdev *dev;
  629         struct cdevsw *dsw;
  630         struct vnode *vp;
  631         struct vnode *vpold;
  632         int error, i;
  633         const char *p;
  634         struct fiodgname_arg *fgn;
  635         struct file *fpop;
  636 
  637         fpop = td->td_fpop;
  638         error = devfs_fp_check(fp, &dev, &dsw);
  639         if (error)
  640                 return (error);
  641 
  642         if (com == FIODTYPE) {
  643                 *(int *)data = dsw->d_flags & D_TYPEMASK;
  644                 td->td_fpop = fpop;
  645                 dev_relthread(dev);
  646                 return (0);
  647         } else if (com == FIODGNAME) {
  648                 fgn = data;
  649                 p = devtoname(dev);
  650                 i = strlen(p) + 1;
  651                 if (i > fgn->len)
  652                         error = EINVAL;
  653                 else
  654                         error = copyout(p, fgn->buf, i);
  655                 td->td_fpop = fpop;
  656                 dev_relthread(dev);
  657                 return (error);
  658         }
  659         error = dsw->d_ioctl(dev, com, data, fp->f_flag, td);
  660         td->td_fpop = NULL;
  661         dev_relthread(dev);
  662         if (error == ENOIOCTL)
  663                 error = ENOTTY;
  664         if (error == 0 && com == TIOCSCTTY) {
  665                 vp = fp->f_vnode;
  666 
  667                 /* Do nothing if reassigning same control tty */
  668                 sx_slock(&proctree_lock);
  669                 if (td->td_proc->p_session->s_ttyvp == vp) {
  670                         sx_sunlock(&proctree_lock);
  671                         return (0);
  672                 }
  673 
  674                 vpold = td->td_proc->p_session->s_ttyvp;
  675                 VREF(vp);
  676                 SESS_LOCK(td->td_proc->p_session);
  677                 td->td_proc->p_session->s_ttyvp = vp;
  678                 SESS_UNLOCK(td->td_proc->p_session);
  679 
  680                 sx_sunlock(&proctree_lock);
  681 
  682                 /* Get rid of reference to old control tty */
  683                 if (vpold)
  684                         vrele(vpold);
  685         }
  686         return (error);
  687 }
  688 
  689 /* ARGSUSED */
  690 static int
  691 devfs_kqfilter_f(struct file *fp, struct knote *kn)
  692 {
  693         struct cdev *dev;
  694         struct cdevsw *dsw;
  695         int error;
  696         struct file *fpop;
  697         struct thread *td;
  698 
  699         td = curthread;
  700         fpop = td->td_fpop;
  701         error = devfs_fp_check(fp, &dev, &dsw);
  702         if (error)
  703                 return (error);
  704         error = dsw->d_kqfilter(dev, kn);
  705         td->td_fpop = fpop;
  706         dev_relthread(dev);
  707         return (error);
  708 }
  709 
  710 static inline int
  711 devfs_prison_check(struct devfs_dirent *de, struct ucred *tcr)
  712 {
  713         struct cdev_priv *cdp;
  714         struct ucred *dcr;
  715 
  716         cdp = de->de_cdp;
  717         if (cdp == NULL)
  718                 return (0);
  719         dcr = cdp->cdp_c.si_cred;
  720         if (dcr == NULL)
  721                 return (0);
  722 
  723         return (prison_check(tcr, dcr));
  724 }
  725 
  726 static int
  727 devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
  728 {
  729         struct componentname *cnp;
  730         struct vnode *dvp, **vpp;
  731         struct thread *td;
  732         struct devfs_dirent *de, *dd;
  733         struct devfs_dirent **dde;
  734         struct devfs_mount *dmp;
  735         struct cdev *cdev;
  736         int error, flags, nameiop;
  737         char specname[SPECNAMELEN + 1], *pname;
  738 
  739         cnp = ap->a_cnp;
  740         vpp = ap->a_vpp;
  741         dvp = ap->a_dvp;
  742         pname = cnp->cn_nameptr;
  743         td = cnp->cn_thread;
  744         flags = cnp->cn_flags;
  745         nameiop = cnp->cn_nameiop;
  746         dmp = VFSTODEVFS(dvp->v_mount);
  747         dd = dvp->v_data;
  748         *vpp = NULLVP;
  749 
  750         if ((flags & ISLASTCN) && nameiop == RENAME)
  751                 return (EOPNOTSUPP);
  752 
  753         if (dvp->v_type != VDIR)
  754                 return (ENOTDIR);
  755 
  756         if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
  757                 return (EIO);
  758 
  759         error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
  760         if (error)
  761                 return (error);
  762 
  763         if (cnp->cn_namelen == 1 && *pname == '.') {
  764                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  765                         return (EINVAL);
  766                 *vpp = dvp;
  767                 VREF(dvp);
  768                 return (0);
  769         }
  770 
  771         if (flags & ISDOTDOT) {
  772                 if ((flags & ISLASTCN) && nameiop != LOOKUP)
  773                         return (EINVAL);
  774                 VOP_UNLOCK(dvp, 0);
  775                 de = TAILQ_FIRST(&dd->de_dlist);        /* "." */
  776                 de = TAILQ_NEXT(de, de_list);           /* ".." */
  777                 de = de->de_dir;
  778                 error = devfs_allocv(de, dvp->v_mount, vpp);
  779                 *dm_unlock = 0;
  780                 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
  781                 return (error);
  782         }
  783 
  784         DEVFS_DMP_HOLD(dmp);
  785         devfs_populate(dmp);
  786         if (DEVFS_DMP_DROP(dmp)) {
  787                 *dm_unlock = 0;
  788                 sx_xunlock(&dmp->dm_lock);
  789                 devfs_unmount_final(dmp);
  790                 return (ENOENT);
  791         }
  792         dd = dvp->v_data;
  793         de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen);
  794         while (de == NULL) {    /* While(...) so we can use break */
  795 
  796                 if (nameiop == DELETE)
  797                         return (ENOENT);
  798 
  799                 /*
  800                  * OK, we didn't have an entry for the name we were asked for
  801                  * so we try to see if anybody can create it on demand.
  802                  */
  803                 pname = devfs_fqpn(specname, dvp, cnp);
  804                 if (pname == NULL)
  805                         break;
  806 
  807                 cdev = NULL;
  808                 DEVFS_DMP_HOLD(dmp);
  809                 sx_xunlock(&dmp->dm_lock);
  810                 sx_slock(&clone_drain_lock);
  811                 EVENTHANDLER_INVOKE(dev_clone,
  812                     td->td_ucred, pname, strlen(pname), &cdev);
  813                 sx_sunlock(&clone_drain_lock);
  814                 sx_xlock(&dmp->dm_lock);
  815                 if (DEVFS_DMP_DROP(dmp)) {
  816                         *dm_unlock = 0;
  817                         sx_xunlock(&dmp->dm_lock);
  818                         devfs_unmount_final(dmp);
  819                         return (ENOENT);
  820                 }
  821                 if (cdev == NULL)
  822                         break;
  823 
  824                 DEVFS_DMP_HOLD(dmp);
  825                 devfs_populate(dmp);
  826                 if (DEVFS_DMP_DROP(dmp)) {
  827                         *dm_unlock = 0;
  828                         sx_xunlock(&dmp->dm_lock);
  829                         devfs_unmount_final(dmp);
  830                         return (ENOENT);
  831                 }
  832 
  833                 dev_lock();
  834                 dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
  835                 if (dde != NULL && *dde != NULL)
  836                         de = *dde;
  837                 dev_unlock();
  838                 dev_rel(cdev);
  839                 break;
  840         }
  841 
  842         if (de == NULL || de->de_flags & DE_WHITEOUT) {
  843                 if ((nameiop == CREATE || nameiop == RENAME) &&
  844                     (flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
  845                         cnp->cn_flags |= SAVENAME;
  846                         return (EJUSTRETURN);
  847                 }
  848                 return (ENOENT);
  849         }
  850 
  851         if (devfs_prison_check(de, td->td_ucred))
  852                 return (ENOENT);
  853 
  854         if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
  855                 error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
  856                 if (error)
  857                         return (error);
  858                 if (*vpp == dvp) {
  859                         VREF(dvp);
  860                         *vpp = dvp;
  861                         return (0);
  862                 }
  863         }
  864         error = devfs_allocv(de, dvp->v_mount, vpp);
  865         *dm_unlock = 0;
  866         return (error);
  867 }
  868 
  869 static int
  870 devfs_lookup(struct vop_lookup_args *ap)
  871 {
  872         int j;
  873         struct devfs_mount *dmp;
  874         int dm_unlock;
  875 
  876         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
  877         dm_unlock = 1;
  878         sx_xlock(&dmp->dm_lock);
  879         j = devfs_lookupx(ap, &dm_unlock);
  880         if (dm_unlock == 1)
  881                 sx_xunlock(&dmp->dm_lock);
  882         return (j);
  883 }
  884 
  885 static int
  886 devfs_mknod(struct vop_mknod_args *ap)
  887 {
  888         struct componentname *cnp;
  889         struct vnode *dvp, **vpp;
  890         struct devfs_dirent *dd, *de;
  891         struct devfs_mount *dmp;
  892         int error;
  893 
  894         /*
  895          * The only type of node we should be creating here is a
  896          * character device, for anything else return EOPNOTSUPP.
  897          */
  898         if (ap->a_vap->va_type != VCHR)
  899                 return (EOPNOTSUPP);
  900         dvp = ap->a_dvp;
  901         dmp = VFSTODEVFS(dvp->v_mount);
  902 
  903         cnp = ap->a_cnp;
  904         vpp = ap->a_vpp;
  905         dd = dvp->v_data;
  906 
  907         error = ENOENT;
  908         sx_xlock(&dmp->dm_lock);
  909         TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
  910                 if (cnp->cn_namelen != de->de_dirent->d_namlen)
  911                         continue;
  912                 if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
  913                     de->de_dirent->d_namlen) != 0)
  914                         continue;
  915                 if (de->de_flags & DE_WHITEOUT)
  916                         break;
  917                 goto notfound;
  918         }
  919         if (de == NULL)
  920                 goto notfound;
  921         de->de_flags &= ~DE_WHITEOUT;
  922         error = devfs_allocv(de, dvp->v_mount, vpp);
  923         return (error);
  924 notfound:
  925         sx_xunlock(&dmp->dm_lock);
  926         return (error);
  927 }
  928 
  929 /* ARGSUSED */
  930 static int
  931 devfs_open(struct vop_open_args *ap)
  932 {
  933         struct thread *td = ap->a_td;
  934         struct vnode *vp = ap->a_vp;
  935         struct cdev *dev = vp->v_rdev;
  936         struct file *fp = ap->a_fp;
  937         int error;
  938         struct cdevsw *dsw;
  939         struct file *fpop;
  940 
  941         if (vp->v_type == VBLK)
  942                 return (ENXIO);
  943 
  944         if (dev == NULL)
  945                 return (ENXIO);
  946 
  947         /* Make this field valid before any I/O in d_open. */
  948         if (dev->si_iosize_max == 0)
  949                 dev->si_iosize_max = DFLTPHYS;
  950 
  951         dsw = dev_refthread(dev);
  952         if (dsw == NULL)
  953                 return (ENXIO);
  954 
  955         /* XXX: Special casing of ttys for deadfs.  Probably redundant. */
  956         if (dsw->d_flags & D_TTY)
  957                 vp->v_vflag |= VV_ISTTY;
  958 
  959         VOP_UNLOCK(vp, 0);
  960 
  961         fpop = td->td_fpop;
  962         td->td_fpop = fp;
  963         if (fp != NULL) {
  964                 fp->f_data = dev;
  965                 fp->f_vnode = vp;
  966         }
  967         if (dsw->d_fdopen != NULL)
  968                 error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
  969         else
  970                 error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
  971         td->td_fpop = fpop;
  972 
  973         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
  974 
  975         dev_relthread(dev);
  976 
  977         if (error)
  978                 return (error);
  979 
  980 #if 0   /* /dev/console */
  981         KASSERT(fp != NULL,
  982              ("Could not vnode bypass device on NULL fp"));
  983 #else
  984         if(fp == NULL)
  985                 return (error);
  986 #endif
  987         if (fp->f_ops == &badfileops)
  988                 finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
  989         return (error);
  990 }
  991 
  992 static int
  993 devfs_pathconf(struct vop_pathconf_args *ap)
  994 {
  995 
  996         switch (ap->a_name) {
  997         case _PC_MAC_PRESENT:
  998 #ifdef MAC
  999                 /*
 1000                  * If MAC is enabled, devfs automatically supports
 1001                  * trivial non-persistant label storage.
 1002                  */
 1003                 *ap->a_retval = 1;
 1004 #else
 1005                 *ap->a_retval = 0;
 1006 #endif
 1007                 return (0);
 1008         default:
 1009                 return (vop_stdpathconf(ap));
 1010         }
 1011         /* NOTREACHED */
 1012 }
 1013 
 1014 /* ARGSUSED */
 1015 static int
 1016 devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
 1017 {
 1018         struct cdev *dev;
 1019         struct cdevsw *dsw;
 1020         int error;
 1021         struct file *fpop;
 1022 
 1023         fpop = td->td_fpop;
 1024         error = devfs_fp_check(fp, &dev, &dsw);
 1025         if (error)
 1026                 return (poll_no_poll(events));
 1027         error = dsw->d_poll(dev, events, td);
 1028         td->td_fpop = fpop;
 1029         dev_relthread(dev);
 1030         return(error);
 1031 }
 1032 
 1033 /*
 1034  * Print out the contents of a special device vnode.
 1035  */
 1036 static int
 1037 devfs_print(struct vop_print_args *ap)
 1038 {
 1039 
 1040         printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
 1041         return (0);
 1042 }
 1043 
 1044 /* ARGSUSED */
 1045 static int
 1046 devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1047 {
 1048         struct cdev *dev;
 1049         int ioflag, error, resid;
 1050         struct cdevsw *dsw;
 1051         struct file *fpop;
 1052 
 1053         fpop = td->td_fpop;
 1054         error = devfs_fp_check(fp, &dev, &dsw);
 1055         if (error)
 1056                 return (error);
 1057         resid = uio->uio_resid;
 1058         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
 1059         if (ioflag & O_DIRECT)
 1060                 ioflag |= IO_DIRECT;
 1061 
 1062         if ((flags & FOF_OFFSET) == 0)
 1063                 uio->uio_offset = fp->f_offset;
 1064 
 1065         error = dsw->d_read(dev, uio, ioflag);
 1066         if (uio->uio_resid != resid || (error == 0 && resid != 0))
 1067                 vfs_timestamp(&dev->si_atime);
 1068         td->td_fpop = fpop;
 1069         dev_relthread(dev);
 1070 
 1071         if ((flags & FOF_OFFSET) == 0)
 1072                 fp->f_offset = uio->uio_offset;
 1073         fp->f_nextoff = uio->uio_offset;
 1074         return (error);
 1075 }
 1076 
 1077 static int
 1078 devfs_readdir(struct vop_readdir_args *ap)
 1079 {
 1080         int error;
 1081         struct uio *uio;
 1082         struct dirent *dp;
 1083         struct devfs_dirent *dd;
 1084         struct devfs_dirent *de;
 1085         struct devfs_mount *dmp;
 1086         off_t off;
 1087         int *tmp_ncookies = NULL;
 1088 
 1089         if (ap->a_vp->v_type != VDIR)
 1090                 return (ENOTDIR);
 1091 
 1092         uio = ap->a_uio;
 1093         if (uio->uio_offset < 0)
 1094                 return (EINVAL);
 1095 
 1096         /*
 1097          * XXX: This is a temporary hack to get around this filesystem not
 1098          * supporting cookies. We store the location of the ncookies pointer
 1099          * in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
 1100          * and set the number of cookies to 0. We then set the pointer to
 1101          * NULL so that vfs_read_dirent doesn't try to call realloc() on 
 1102          * ap->a_cookies. Later in this function, we restore the ap->a_ncookies
 1103          * pointer to its original location before returning to the caller.
 1104          */
 1105         if (ap->a_ncookies != NULL) {
 1106                 tmp_ncookies = ap->a_ncookies;
 1107                 *ap->a_ncookies = 0;
 1108                 ap->a_ncookies = NULL;
 1109         }
 1110 
 1111         dmp = VFSTODEVFS(ap->a_vp->v_mount);
 1112         sx_xlock(&dmp->dm_lock);
 1113         DEVFS_DMP_HOLD(dmp);
 1114         devfs_populate(dmp);
 1115         if (DEVFS_DMP_DROP(dmp)) {
 1116                 sx_xunlock(&dmp->dm_lock);
 1117                 devfs_unmount_final(dmp);
 1118                 if (tmp_ncookies != NULL)
 1119                         ap->a_ncookies = tmp_ncookies;
 1120                 return (EIO);
 1121         }
 1122         error = 0;
 1123         de = ap->a_vp->v_data;
 1124         off = 0;
 1125         TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
 1126                 KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
 1127                 if (dd->de_flags & DE_WHITEOUT)
 1128                         continue;
 1129                 if (devfs_prison_check(dd, ap->a_cred))
 1130                         continue;
 1131                 if (dd->de_dirent->d_type == DT_DIR)
 1132                         de = dd->de_dir;
 1133                 else
 1134                         de = dd;
 1135                 dp = dd->de_dirent;
 1136                 if (dp->d_reclen > uio->uio_resid)
 1137                         break;
 1138                 dp->d_fileno = de->de_inode;
 1139                 if (off >= uio->uio_offset) {
 1140                         error = vfs_read_dirent(ap, dp, off);
 1141                         if (error)
 1142                                 break;
 1143                 }
 1144                 off += dp->d_reclen;
 1145         }
 1146         sx_xunlock(&dmp->dm_lock);
 1147         uio->uio_offset = off;
 1148 
 1149         /*
 1150          * Restore ap->a_ncookies if it wasn't originally NULL in the first
 1151          * place.
 1152          */
 1153         if (tmp_ncookies != NULL)
 1154                 ap->a_ncookies = tmp_ncookies;
 1155 
 1156         return (error);
 1157 }
 1158 
 1159 static int
 1160 devfs_readlink(struct vop_readlink_args *ap)
 1161 {
 1162         struct devfs_dirent *de;
 1163 
 1164         de = ap->a_vp->v_data;
 1165         return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
 1166 }
 1167 
 1168 static int
 1169 devfs_reclaim(struct vop_reclaim_args *ap)
 1170 {
 1171         struct vnode *vp = ap->a_vp;
 1172         struct devfs_dirent *de;
 1173         struct cdev *dev;
 1174 
 1175         mtx_lock(&devfs_de_interlock);
 1176         de = vp->v_data;
 1177         if (de != NULL) {
 1178                 de->de_vnode = NULL;
 1179                 vp->v_data = NULL;
 1180         }
 1181         mtx_unlock(&devfs_de_interlock);
 1182 
 1183         vnode_destroy_vobject(vp);
 1184 
 1185         VI_LOCK(vp);
 1186         dev_lock();
 1187         dev = vp->v_rdev;
 1188         vp->v_rdev = NULL;
 1189 
 1190         if (dev == NULL) {
 1191                 dev_unlock();
 1192                 VI_UNLOCK(vp);
 1193                 return (0);
 1194         }
 1195 
 1196         dev->si_usecount -= vp->v_usecount;
 1197         dev_unlock();
 1198         VI_UNLOCK(vp);
 1199         dev_rel(dev);
 1200         return (0);
 1201 }
 1202 
 1203 static int
 1204 devfs_remove(struct vop_remove_args *ap)
 1205 {
 1206         struct vnode *vp = ap->a_vp;
 1207         struct devfs_dirent *dd;
 1208         struct devfs_dirent *de;
 1209         struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
 1210 
 1211         sx_xlock(&dmp->dm_lock);
 1212         dd = ap->a_dvp->v_data;
 1213         de = vp->v_data;
 1214         if (de->de_cdp == NULL) {
 1215                 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
 1216                 devfs_delete(dmp, de, 1);
 1217         } else {
 1218                 de->de_flags |= DE_WHITEOUT;
 1219         }
 1220         sx_xunlock(&dmp->dm_lock);
 1221         return (0);
 1222 }
 1223 
 1224 /*
 1225  * Revoke is called on a tty when a terminal session ends.  The vnode
 1226  * is orphaned by setting v_op to deadfs so we need to let go of it
 1227  * as well so that we create a new one next time around.
 1228  *
 1229  */
 1230 static int
 1231 devfs_revoke(struct vop_revoke_args *ap)
 1232 {
 1233         struct vnode *vp = ap->a_vp, *vp2;
 1234         struct cdev *dev;
 1235         struct cdev_priv *cdp;
 1236         struct devfs_dirent *de;
 1237         int i;
 1238 
 1239         KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
 1240 
 1241         dev = vp->v_rdev;
 1242         cdp = cdev2priv(dev);
 1243  
 1244         dev_lock();
 1245         cdp->cdp_inuse++;
 1246         dev_unlock();
 1247 
 1248         vhold(vp);
 1249         vgone(vp);
 1250         vdrop(vp);
 1251 
 1252         VOP_UNLOCK(vp,0);
 1253  loop:
 1254         for (;;) {
 1255                 mtx_lock(&devfs_de_interlock);
 1256                 dev_lock();
 1257                 vp2 = NULL;
 1258                 for (i = 0; i <= cdp->cdp_maxdirent; i++) {
 1259                         de = cdp->cdp_dirents[i];
 1260                         if (de == NULL)
 1261                                 continue;
 1262 
 1263                         vp2 = de->de_vnode;
 1264                         if (vp2 != NULL) {
 1265                                 dev_unlock();
 1266                                 VI_LOCK(vp2);
 1267                                 mtx_unlock(&devfs_de_interlock);
 1268                                 if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
 1269                                     curthread))
 1270                                         goto loop;
 1271                                 vhold(vp2);
 1272                                 vgone(vp2);
 1273                                 vdrop(vp2);
 1274                                 vput(vp2);
 1275                                 break;
 1276                         } 
 1277                 }
 1278                 if (vp2 != NULL) {
 1279                         continue;
 1280                 }
 1281                 dev_unlock();
 1282                 mtx_unlock(&devfs_de_interlock);
 1283                 break;
 1284         }
 1285         dev_lock();
 1286         cdp->cdp_inuse--;
 1287         if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
 1288                 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
 1289                 dev_unlock();
 1290                 dev_rel(&cdp->cdp_c);
 1291         } else
 1292                 dev_unlock();
 1293 
 1294         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 1295         return (0);
 1296 }
 1297 
 1298 static int
 1299 devfs_rioctl(struct vop_ioctl_args *ap)
 1300 {
 1301         struct vnode *vp;
 1302         struct devfs_mount *dmp;
 1303         int error;
 1304 
 1305         vp = ap->a_vp;
 1306         vn_lock(vp, LK_SHARED | LK_RETRY);
 1307         if (vp->v_iflag & VI_DOOMED) {
 1308                 VOP_UNLOCK(vp, 0);
 1309                 return (EBADF);
 1310         }
 1311         dmp = VFSTODEVFS(vp->v_mount);
 1312         sx_xlock(&dmp->dm_lock);
 1313         VOP_UNLOCK(vp, 0);
 1314         DEVFS_DMP_HOLD(dmp);
 1315         devfs_populate(dmp);
 1316         if (DEVFS_DMP_DROP(dmp)) {
 1317                 sx_xunlock(&dmp->dm_lock);
 1318                 devfs_unmount_final(dmp);
 1319                 return (ENOENT);
 1320         }
 1321         error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
 1322         sx_xunlock(&dmp->dm_lock);
 1323         return (error);
 1324 }
 1325 
 1326 static int
 1327 devfs_rread(struct vop_read_args *ap)
 1328 {
 1329 
 1330         if (ap->a_vp->v_type != VDIR)
 1331                 return (EINVAL);
 1332         return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
 1333 }
 1334 
 1335 static int
 1336 devfs_setattr(struct vop_setattr_args *ap)
 1337 {
 1338         struct devfs_dirent *de;
 1339         struct vattr *vap;
 1340         struct vnode *vp;
 1341         struct thread *td;
 1342         int c, error;
 1343         uid_t uid;
 1344         gid_t gid;
 1345 
 1346         vap = ap->a_vap;
 1347         vp = ap->a_vp;
 1348         td = curthread;
 1349         if ((vap->va_type != VNON) ||
 1350             (vap->va_nlink != VNOVAL) ||
 1351             (vap->va_fsid != VNOVAL) ||
 1352             (vap->va_fileid != VNOVAL) ||
 1353             (vap->va_blocksize != VNOVAL) ||
 1354             (vap->va_flags != VNOVAL && vap->va_flags != 0) ||
 1355             (vap->va_rdev != VNOVAL) ||
 1356             ((int)vap->va_bytes != VNOVAL) ||
 1357             (vap->va_gen != VNOVAL)) {
 1358                 return (EINVAL);
 1359         }
 1360 
 1361         de = vp->v_data;
 1362         if (vp->v_type == VDIR)
 1363                 de = de->de_dir;
 1364 
 1365         error = c = 0;
 1366         if (vap->va_uid == (uid_t)VNOVAL)
 1367                 uid = de->de_uid;
 1368         else
 1369                 uid = vap->va_uid;
 1370         if (vap->va_gid == (gid_t)VNOVAL)
 1371                 gid = de->de_gid;
 1372         else
 1373                 gid = vap->va_gid;
 1374         if (uid != de->de_uid || gid != de->de_gid) {
 1375                 if ((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
 1376                     (gid != de->de_gid && !groupmember(gid, ap->a_cred))) {
 1377                         error = priv_check(td, PRIV_VFS_CHOWN);
 1378                         if (error)
 1379                                 return (error);
 1380                 }
 1381                 de->de_uid = uid;
 1382                 de->de_gid = gid;
 1383                 c = 1;
 1384         }
 1385 
 1386         if (vap->va_mode != (mode_t)VNOVAL) {
 1387                 if (ap->a_cred->cr_uid != de->de_uid) {
 1388                         error = priv_check(td, PRIV_VFS_ADMIN);
 1389                         if (error)
 1390                                 return (error);
 1391                 }
 1392                 de->de_mode = vap->va_mode;
 1393                 c = 1;
 1394         }
 1395 
 1396         if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
 1397                 /* See the comment in ufs_vnops::ufs_setattr(). */
 1398                 if ((error = VOP_ACCESS(vp, VADMIN, ap->a_cred, td)) &&
 1399                     ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
 1400                     (error = VOP_ACCESS(vp, VWRITE, ap->a_cred, td))))
 1401                         return (error);
 1402                 if (vap->va_atime.tv_sec != VNOVAL) {
 1403                         if (vp->v_type == VCHR)
 1404                                 vp->v_rdev->si_atime = vap->va_atime;
 1405                         else
 1406                                 de->de_atime = vap->va_atime;
 1407                 }
 1408                 if (vap->va_mtime.tv_sec != VNOVAL) {
 1409                         if (vp->v_type == VCHR)
 1410                                 vp->v_rdev->si_mtime = vap->va_mtime;
 1411                         else
 1412                                 de->de_mtime = vap->va_mtime;
 1413                 }
 1414                 c = 1;
 1415         }
 1416 
 1417         if (c) {
 1418                 if (vp->v_type == VCHR)
 1419                         vfs_timestamp(&vp->v_rdev->si_ctime);
 1420                 else
 1421                         vfs_timestamp(&de->de_mtime);
 1422         }
 1423         return (0);
 1424 }
 1425 
 1426 #ifdef MAC
 1427 static int
 1428 devfs_setlabel(struct vop_setlabel_args *ap)
 1429 {
 1430         struct vnode *vp;
 1431         struct devfs_dirent *de;
 1432 
 1433         vp = ap->a_vp;
 1434         de = vp->v_data;
 1435 
 1436         mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
 1437         mac_devfs_update(vp->v_mount, de, vp);
 1438 
 1439         return (0);
 1440 }
 1441 #endif
 1442 
 1443 static int
 1444 devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
 1445 {
 1446 
 1447         return (vnops.fo_stat(fp, sb, cred, td));
 1448 }
 1449 
 1450 static int
 1451 devfs_symlink(struct vop_symlink_args *ap)
 1452 {
 1453         int i, error;
 1454         struct devfs_dirent *dd;
 1455         struct devfs_dirent *de;
 1456         struct devfs_mount *dmp;
 1457 
 1458         error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
 1459         if (error)
 1460                 return(error);
 1461         dmp = VFSTODEVFS(ap->a_dvp->v_mount);
 1462         dd = ap->a_dvp->v_data;
 1463         de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
 1464         de->de_uid = 0;
 1465         de->de_gid = 0;
 1466         de->de_mode = 0755;
 1467         de->de_inode = alloc_unr(devfs_inos);
 1468         de->de_dirent->d_type = DT_LNK;
 1469         i = strlen(ap->a_target) + 1;
 1470         de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
 1471         bcopy(ap->a_target, de->de_symlink, i);
 1472         sx_xlock(&dmp->dm_lock);
 1473 #ifdef MAC
 1474         mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
 1475 #endif
 1476         TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
 1477         return (devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp));
 1478 }
 1479 
 1480 static int
 1481 devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
 1482 {
 1483 
 1484         return (vnops.fo_truncate(fp, length, cred, td));
 1485 }
 1486 
 1487 /* ARGSUSED */
 1488 static int
 1489 devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct thread *td)
 1490 {
 1491         struct cdev *dev;
 1492         int error, ioflag, resid;
 1493         struct cdevsw *dsw;
 1494         struct file *fpop;
 1495 
 1496         fpop = td->td_fpop;
 1497         error = devfs_fp_check(fp, &dev, &dsw);
 1498         if (error)
 1499                 return (error);
 1500         KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
 1501         ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
 1502         if (ioflag & O_DIRECT)
 1503                 ioflag |= IO_DIRECT;
 1504         if ((flags & FOF_OFFSET) == 0)
 1505                 uio->uio_offset = fp->f_offset;
 1506 
 1507         resid = uio->uio_resid;
 1508 
 1509         error = dsw->d_write(dev, uio, ioflag);
 1510         if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
 1511                 vfs_timestamp(&dev->si_ctime);
 1512                 dev->si_mtime = dev->si_ctime;
 1513         }
 1514         td->td_fpop = fpop;
 1515         dev_relthread(dev);
 1516 
 1517         if ((flags & FOF_OFFSET) == 0)
 1518                 fp->f_offset = uio->uio_offset;
 1519         fp->f_nextoff = uio->uio_offset;
 1520         return (error);
 1521 }
 1522 
 1523 dev_t
 1524 dev2udev(struct cdev *x)
 1525 {
 1526         if (x == NULL)
 1527                 return (NODEV);
 1528         return (cdev2priv(x)->cdp_inode);
 1529 }
 1530 
 1531 static struct fileops devfs_ops_f = {
 1532         .fo_read =      devfs_read_f,
 1533         .fo_write =     devfs_write_f,
 1534         .fo_truncate =  devfs_truncate_f,
 1535         .fo_ioctl =     devfs_ioctl_f,
 1536         .fo_poll =      devfs_poll_f,
 1537         .fo_kqfilter =  devfs_kqfilter_f,
 1538         .fo_stat =      devfs_stat_f,
 1539         .fo_close =     devfs_close_f,
 1540         .fo_flags =     DFLAG_PASSABLE | DFLAG_SEEKABLE
 1541 };
 1542 
 1543 static struct vop_vector devfs_vnodeops = {
 1544         .vop_default =          &default_vnodeops,
 1545 
 1546         .vop_access =           devfs_access,
 1547         .vop_getattr =          devfs_getattr,
 1548         .vop_ioctl =            devfs_rioctl,
 1549         .vop_lookup =           devfs_lookup,
 1550         .vop_mknod =            devfs_mknod,
 1551         .vop_pathconf =         devfs_pathconf,
 1552         .vop_read =             devfs_rread,
 1553         .vop_readdir =          devfs_readdir,
 1554         .vop_readlink =         devfs_readlink,
 1555         .vop_reclaim =          devfs_reclaim,
 1556         .vop_remove =           devfs_remove,
 1557         .vop_revoke =           devfs_revoke,
 1558         .vop_setattr =          devfs_setattr,
 1559 #ifdef MAC
 1560         .vop_setlabel =         devfs_setlabel,
 1561 #endif
 1562         .vop_symlink =          devfs_symlink,
 1563         .vop_vptocnp =          devfs_vptocnp,
 1564 };
 1565 
 1566 static struct vop_vector devfs_specops = {
 1567         .vop_default =          &default_vnodeops,
 1568 
 1569         .vop_access =           devfs_access,
 1570         .vop_bmap =             VOP_PANIC,
 1571         .vop_close =            devfs_close,
 1572         .vop_create =           VOP_PANIC,
 1573         .vop_fsync =            devfs_fsync,
 1574         .vop_getattr =          devfs_getattr,
 1575         .vop_link =             VOP_PANIC,
 1576         .vop_mkdir =            VOP_PANIC,
 1577         .vop_mknod =            VOP_PANIC,
 1578         .vop_open =             devfs_open,
 1579         .vop_pathconf =         devfs_pathconf,
 1580         .vop_print =            devfs_print,
 1581         .vop_read =             VOP_PANIC,
 1582         .vop_readdir =          VOP_PANIC,
 1583         .vop_readlink =         VOP_PANIC,
 1584         .vop_reallocblks =      VOP_PANIC,
 1585         .vop_reclaim =          devfs_reclaim,
 1586         .vop_remove =           devfs_remove,
 1587         .vop_rename =           VOP_PANIC,
 1588         .vop_revoke =           devfs_revoke,
 1589         .vop_rmdir =            VOP_PANIC,
 1590         .vop_setattr =          devfs_setattr,
 1591 #ifdef MAC
 1592         .vop_setlabel =         devfs_setlabel,
 1593 #endif
 1594         .vop_strategy =         VOP_PANIC,
 1595         .vop_symlink =          VOP_PANIC,
 1596         .vop_vptocnp =          devfs_vptocnp,
 1597         .vop_write =            VOP_PANIC,
 1598 };
 1599 
 1600 /*
 1601  * Our calling convention to the device drivers used to be that we passed
 1602  * vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_ 
 1603  * flags instead since that's what open(), close() and ioctl() takes and
 1604  * we don't really want vnode.h in device drivers.
 1605  * We solved the source compatibility by redefining some vnode flags to
 1606  * be the same as the fcntl ones and by sending down the bitwise OR of
 1607  * the respective fcntl/vnode flags.  These CTASSERTS make sure nobody
 1608  * pulls the rug out under this.
 1609  */
 1610 CTASSERT(O_NONBLOCK == IO_NDELAY);
 1611 CTASSERT(O_FSYNC == IO_SYNC);
Cache object: ecb04ab1cf95678a5622c9460d9fc9e6
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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
