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