[apple/xnu.git] / bsd / miscfs / devfs / devfs_vnops.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright 1997,1998 Julian Elischer.  All rights reserved.
 * julian@freebsd.org
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 * devfs_vnops.c
 */

/*
 * HISTORY
 *  Clark Warner (warner_c@apple.com) Tue Feb 10 2000
 *  - Added err_copyfile to the vnode operations table
 *  Dieter Siegmund (dieter@apple.com) Thu Apr  8 14:08:19 PDT 1999
 *  - instead of duplicating specfs here, created a vnode-ops table
 *    that redirects most operations to specfs (as is done with ufs);
 *  - removed routines that made no sense
 *  - cleaned up reclaim: replaced devfs_vntodn() with a macro VTODN()
 *  - cleaned up symlink, link locking
 *  - added the devfs_lock to protect devfs data structures against
 *    driver's calling devfs_add_devswf()/etc.
 *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
 *  - free the devfs devnode in devfs_inactive(), not just in devfs_reclaim()
 *    to free up kernel memory as soon as it's available
 *  - got rid of devfsspec_{read, write}
 *  Dieter Siegmund (dieter@apple.com) Fri Sep 17 09:58:38 PDT 1999
 *  - update the mod/access times
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/disklabel.h>
#include <sys/lock.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <miscfs/specfs/specdev.h>
#include <sys/dirent.h>
#include <sys/vmmeter.h>
#include <sys/vm.h>

#include "devfsdefs.h"

/*
 * Convert a component of a pathname into a pointer to a locked node.
 * This is a very central and rather complicated routine.
 * If the file system is not maintained in a strict tree hierarchy,
 * this can result in a deadlock situation (see comments in code below).
 *
 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
 * whether the name is to be looked up, created, renamed, or deleted.
 * When CREATE, RENAME, or DELETE is specified, information usable in
 * creating, renaming, or deleting a directory entry may be calculated.
 * If flag has LOCKPARENT or'ed into it and the target of the pathname
 * exists, lookup returns both the target and its parent directory locked.
 * When creating or renaming and LOCKPARENT is specified, the target may
 * not be ".".  When deleting and LOCKPARENT is specified, the target may
 * be "."., but the caller must check to ensure it does an vrele and DNUNLOCK
 * instead of two DNUNLOCKs.
 *
 * Overall outline of devfs_lookup:
 *
 *      check accessibility of directory
 *      null terminate the component (lookup leaves the whole string alone)
 *      look for name in cache, if found, then if at end of path
 *        and deleting or creating, drop it, else return name
 *      search for name in directory, to found or notfound
 * notfound:
 *      if creating, return locked directory,
 *      else return error
 * found:
 *      if at end of path and deleting, return information to allow delete
 *      if at end of path and rewriting (RENAME and LOCKPARENT), lock target
 *        node and return info to allow rewrite
 *      if not at end, add name to cache; if at end and neither creating
 *        nor deleting, add name to cache
 * On return to lookup, remove the null termination we put in at the start.
 *
 * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent node unlocked.
 */
static int
devfs_lookup(struct vop_lookup_args *ap)
        /*struct vop_lookup_args {
                struct vnode * a_dvp; directory vnode ptr
                struct vnode ** a_vpp; where to put the result
                struct componentname * a_cnp; the name we want
        };*/
{
        struct componentname *cnp = ap->a_cnp;
        struct vnode *dir_vnode = ap->a_dvp;
        struct vnode **result_vnode = ap->a_vpp;
        devnode_t *   dir_node;       /* the directory we are searching */
        devnode_t *   node = NULL;       /* the node we are searching for */
        devdirent_t * nodename;
        int flags = cnp->cn_flags;
        int op = cnp->cn_nameiop;       /* LOOKUP, CREATE, RENAME, or DELETE */
        int lockparent = flags & LOCKPARENT;
        int wantparent = flags & (LOCKPARENT|WANTPARENT);
        int error = 0;
        struct proc *p = cnp->cn_proc;
        char    heldchar;       /* the char at the end of the name componet */

        *result_vnode = NULL; /* safe not sorry */ /*XXX*/

        if (dir_vnode->v_usecount == 0)
            printf("devfs_lookup: dir had no refs ");
        dir_node = VTODN(dir_vnode);

        /*
         * Check accessiblity of directory.
         */
        if (dir_node->dn_type != DEV_DIR) {
                return (ENOTDIR);
        }

        if ((error = VOP_ACCESS(dir_vnode, VEXEC, cnp->cn_cred, p)) != 0) {
                return (error);
        }

        /* temporarily terminate string component */
        heldchar = cnp->cn_nameptr[cnp->cn_namelen];
        cnp->cn_nameptr[cnp->cn_namelen] = '\0';
        DEVFS_LOCK(p);
        nodename = dev_findname(dir_node,cnp->cn_nameptr);
        if (nodename) {
            /* entry exists */
            node = nodename->de_dnp;
            node->dn_last_lookup = nodename; /* for unlink */
            /* Do potential vnode allocation here inside the lock 
             * to make sure that our device node has a non-NULL dn_vn
             * associated with it.  The device node might otherwise
             * get deleted out from under us (see devfs_dn_free()).
             */
            error = devfs_dntovn(node, result_vnode, p);
        }
        DEVFS_UNLOCK(p);
        /* restore saved character */
        cnp->cn_nameptr[cnp->cn_namelen] = heldchar;

        if (error)
            return (error);

        if (!nodename) { /* no entry */
                /* If it doesn't exist and we're not the last component,
                 * or we're at the last component, but we're not creating
                 * or renaming, return ENOENT.
                 */
                if (!(flags & ISLASTCN) || !(op == CREATE || op == RENAME)) {
                        return ENOENT;
                }
                /*
                 * Access for write is interpreted as allowing
                 * creation of files in the directory.
                 */
                if ((error = VOP_ACCESS(dir_vnode, VWRITE,
                                cnp->cn_cred, p)) != 0)
                {
                        return (error);
                }
                /*
                 * We return with the directory locked, so that
                 * the parameters we set up above will still be
                 * valid if we actually decide to add a new entry.
                 * We return ni_vp == NULL to indicate that the entry
                 * does not currently exist; we leave a pointer to
                 * the (locked) directory vnode in namei_data->ni_dvp.
                 * The pathname buffer is saved so that the name
                 * can be obtained later.
                 *
                 * NB - if the directory is unlocked, then this
                 * information cannot be used.
                 */
                cnp->cn_flags |= SAVENAME;
                if (!lockparent)
                        VOP_UNLOCK(dir_vnode, 0, p);
                return (EJUSTRETURN);
        }

        /*
         * If deleting, and at end of pathname, return
         * parameters which can be used to remove file.
         * If the wantparent flag isn't set, we return only
         * the directory (in namei_data->ni_dvp), otherwise we go
         * on and lock the node, being careful with ".".
         */
        if (op == DELETE && (flags & ISLASTCN)) {
                /*
                 * Write access to directory required to delete files.
                 */
                if ((error = VOP_ACCESS(dir_vnode, VWRITE,
                                cnp->cn_cred, p)) != 0)
                        return (error);
                /*
                 * we are trying to delete '.'.  What does this mean? XXX
                 */
                if (dir_node == node) {
                        VREF(dir_vnode);
                        *result_vnode = dir_vnode;
                        return (0);
                }
#ifdef NOTYET
                /*
                 * If directory is "sticky", then user must own
                 * the directory, or the file in it, else she
                 * may not delete it (unless she's root). This
                 * implements append-only directories.
                 */
                if ((dir_node->mode & ISVTX) &&
                    cnp->cn_cred->cr_uid != 0 &&
                    cnp->cn_cred->cr_uid != dir_node->uid &&
                    cnp->cn_cred->cr_uid != node->uid) {
                        VOP_UNLOCK(*result_vnode, 0, p);
                        return (EPERM);
                }
#endif
                if (!lockparent)
                        VOP_UNLOCK(dir_vnode, 0, p);
                return (0);
        }

        /*
         * If rewriting (RENAME), return the vnode and the
         * information required to rewrite the present directory
         * Must get node of directory entry to verify it's a
         * regular file, or empty directory.
         */
        if (op == RENAME && wantparent && (flags & ISLASTCN)) {
                /*
                 * Are we allowed to change the holding directory?
                 */
                if ((error = VOP_ACCESS(dir_vnode, VWRITE,
                                cnp->cn_cred, p)) != 0)
                        return (error);
                /*
                 * Careful about locking second node.
                 * This can only occur if the target is ".".
                 */
                if (dir_node == node)
                        return (EISDIR);
                /* hmm save the 'from' name (we need to delete it) */
                cnp->cn_flags |= SAVENAME;
                if (!lockparent)
                        VOP_UNLOCK(dir_vnode, 0, p);
                return (0);
        }

        /*
         * Step through the translation in the name.  We do not unlock the
         * directory because we may need it again if a symbolic link
         * is relative to the current directory.  Instead we save it
         * unlocked as "saved_dir_node" XXX.  We must get the target
         * node before unlocking
         * the directory to insure that the node will not be removed
         * before we get it.  We prevent deadlock by always fetching
         * nodes from the root, moving down the directory tree. Thus
         * when following backward pointers ".." we must unlock the
         * parent directory before getting the requested directory.
         * There is a potential race condition here if both the current
         * and parent directories are removed before the lock for the
         * node associated with ".." returns.  We hope that this occurs
         * infrequently since we cannot avoid this race condition without
         * implementing a sophisticated deadlock detection algorithm.
         * Note also that this simple deadlock detection scheme will not
         * work if the file system has any hard links other than ".."
         * that point backwards in the directory structure.
         */
        if (flags & ISDOTDOT) {
                VOP_UNLOCK(dir_vnode, 0, p);    /* race to get the node */
                if (lockparent && (flags & ISLASTCN))
                        vn_lock(dir_vnode, LK_EXCLUSIVE | LK_RETRY, p);
        } else if (dir_node == node) {
#if 0
            /* 
             * this next statement is wrong: we already did a vget in 
             * devfs_dntovn(); DWS 4/16/1999
             */
                 VREF(dir_vnode);        /* we want ourself, ie "." */
#endif
                *result_vnode = dir_vnode;
        } else {
                if (!lockparent || (flags & ISLASTCN))
                        VOP_UNLOCK(dir_vnode, 0, p);
        }

        return (0);
}

static int
devfs_access(struct vop_access_args *ap)
        /*struct vop_access_args  {
                struct vnode *a_vp;
                int  a_mode;
                struct ucred *a_cred;
                struct proc *a_p;
        } */ 
{
        /*
         *  mode is filled with a combination of VREAD, VWRITE,
         *  and/or VEXEC bits turned on.  In an octal number these
         *  are the Y in 0Y00.
         */
        struct vnode *vp = ap->a_vp;
        int mode = ap->a_mode;
        struct ucred *cred = ap->a_cred;
        devnode_t *     file_node;
        gid_t   *gp;
        int     i;
        struct proc *p = ap->a_p;

        file_node = VTODN(vp);
        /* 
         * if we are not running as a process, we are in the 
         * kernel and we DO have permission
         */
        if (p == NULL)
            return 0;

        /*
         * Access check is based on only one of owner, group, public.
         * If not owner, then check group. If not a member of the
         * group, then check public access.
         */
        if (cred->cr_uid != file_node->dn_uid)
        {
                /* failing that.. try groups */
                mode >>= 3;
                gp = cred->cr_groups;
                for (i = 0; i < cred->cr_ngroups; i++, gp++)
                {
                        if (file_node->dn_gid == *gp)
                        {
                                goto found;
                        }
                }
                /* failing that.. try general access */
                mode >>= 3;
found:
                ;
        }
        if ((file_node->dn_mode & mode) == mode)
                return (0);
        /*
         *  Root gets to do anything.
         * but only use suser prives as a last resort
         * (Use of super powers is recorded in ap->a_p->p_acflag)
         */
        if( suser(cred, &ap->a_p->p_acflag) == 0) /* XXX what if no proc? */
                return 0;
        return (EACCES);
}

static int
devfs_getattr(struct vop_getattr_args *ap)
        /*struct vop_getattr_args {
                struct vnode *a_vp;
                struct vattr *a_vap;
                struct ucred *a_cred;
                struct proc *a_p;
        } */ 
{
        struct vnode *vp = ap->a_vp;
        struct vattr *vap = ap->a_vap;
        devnode_t *     file_node;
        struct timeval  tv;

        file_node = VTODN(vp);
        tv = time;
        dn_times(file_node, tv, tv);
        vap->va_rdev = 0;/* default value only */
        vap->va_mode = file_node->dn_mode;
        switch (file_node->dn_type)
        {
        case    DEV_DIR:
                vap->va_rdev = (dev_t)file_node->dn_dvm;
                vap->va_mode |= (S_IFDIR);
                break;
        case    DEV_CDEV:
                vap->va_rdev = file_node->dn_typeinfo.dev;
                vap->va_mode |= (S_IFCHR);
                break;
        case    DEV_BDEV:
                vap->va_rdev = file_node->dn_typeinfo.dev;
                vap->va_mode |= (S_IFBLK);
                break;
        case    DEV_SLNK:
                vap->va_mode |= (S_IFLNK);
                break;
        }
        vap->va_type = vp->v_type;
        vap->va_nlink = file_node->dn_links;
        vap->va_uid = file_node->dn_uid;
        vap->va_gid = file_node->dn_gid;
        vap->va_fsid = (int32_t)(void *)file_node->dn_dvm;
        vap->va_fileid = (int32_t)(void *)file_node;
        vap->va_size = file_node->dn_len; /* now a u_quad_t */
        /* this doesn't belong here */
        if (vp->v_type == VBLK)
                vap->va_blocksize = BLKDEV_IOSIZE;
        else if (vp->v_type == VCHR)
                vap->va_blocksize = MAXPHYSIO;
        else
                vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
        /* if the time is bogus, set it to the boot time */
        if (file_node->dn_ctime.tv_sec == 0)
            file_node->dn_ctime.tv_sec = boottime.tv_sec;
        if (file_node->dn_mtime.tv_sec == 0)
            file_node->dn_mtime.tv_sec = boottime.tv_sec;
        if (file_node->dn_atime.tv_sec == 0)
            file_node->dn_atime.tv_sec = boottime.tv_sec;
        vap->va_ctime = file_node->dn_ctime;
        vap->va_mtime = file_node->dn_mtime;
        vap->va_atime = file_node->dn_atime;
        vap->va_gen = 0;
        vap->va_flags = 0;
        vap->va_bytes = file_node->dn_len;              /* u_quad_t */
        vap->va_filerev = 0; /* XXX */          /* u_quad_t */
        vap->va_vaflags = 0; /* XXX */
        return 0;
}

static int
devfs_setattr(struct vop_setattr_args *ap)
        /*struct vop_setattr_args  {
                struct vnode *a_vp;
                struct vattr *a_vap;
                struct ucred *a_cred;
                struct proc *a_p;
        } */ 
{
        struct vnode *vp = ap->a_vp;
        struct vattr *vap = ap->a_vap;
        struct ucred *cred = ap->a_cred;
        struct proc *p = ap->a_p;
        int error = 0;
        gid_t *gp;
        int i;
        devnode_t *     file_node;
        struct timeval atimeval, mtimeval;

        if (vap->va_flags != VNOVAL)    /* XXX needs to be implemented */
                return (EOPNOTSUPP);

        file_node = VTODN(vp);

        if ((vap->va_type != VNON)  ||
            (vap->va_nlink != VNOVAL)  ||
            (vap->va_fsid != VNOVAL)  ||
            (vap->va_fileid != VNOVAL)  ||
            (vap->va_blocksize != VNOVAL)  ||
            (vap->va_rdev != VNOVAL)  ||
            (vap->va_bytes != VNOVAL)  ||
            (vap->va_gen != VNOVAL ))
        {
                return EINVAL;
        }

        /*
         * Go through the fields and update iff not VNOVAL.
         */
        if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
            if (cred->cr_uid != file_node->dn_uid &&
                (error = suser(cred, &p->p_acflag)) &&
                ((vap->va_vaflags & VA_UTIMES_NULL) == 0 || 
                 (error = VOP_ACCESS(vp, VWRITE, cred, p))))
                return (error);
            if (vap->va_atime.tv_sec != VNOVAL)
                file_node->dn_flags |= DN_ACCESS;
            if (vap->va_mtime.tv_sec != VNOVAL)
                file_node->dn_flags |= DN_CHANGE | DN_UPDATE;
            atimeval.tv_sec = vap->va_atime.tv_sec;
            atimeval.tv_usec = vap->va_atime.tv_nsec / 1000;
            mtimeval.tv_sec = vap->va_mtime.tv_sec;
            mtimeval.tv_usec = vap->va_mtime.tv_nsec / 1000;
            if (error = VOP_UPDATE(vp, &atimeval, &mtimeval, 1))
                return (error);
        }

        /*
         * Change the permissions.. must be root or owner to do this.
         */
        if (vap->va_mode != (u_short)VNOVAL) {
                if ((cred->cr_uid != file_node->dn_uid)
                 && (error = suser(cred, &p->p_acflag)))
                        return (error);
                file_node->dn_mode &= ~07777;
                file_node->dn_mode |= vap->va_mode & 07777;
        }

        /*
         * Change the owner.. must be root to do this.
         */
        if (vap->va_uid != (uid_t)VNOVAL) {
                if (error = suser(cred, &p->p_acflag))
                        return (error);
                file_node->dn_uid = vap->va_uid;
        }

        /*
         * Change the group.. must be root or owner to do this.
         * If we are the owner, we must be in the target group too.
         * don't use suser() unless you have to as it reports
         * whether you needed suser powers or not.
         */
        if (vap->va_gid != (gid_t)VNOVAL) {
                if (cred->cr_uid == file_node->dn_uid){
                        gp = cred->cr_groups;
                        for (i = 0; i < cred->cr_ngroups; i++, gp++) {
                                if (vap->va_gid == *gp)
                                        goto cando; 
                        }
                }
                /*
                 * we can't do it with normal privs,
                 * do we have an ace up our sleeve?
                 */
                if (error = suser(cred, &p->p_acflag))
                        return (error);
cando:
                file_node->dn_gid = vap->va_gid;
        }
#if 0
        /*
         * Copied from somewhere else
         * but only kept as a marker and reminder of the fact that
         * flags should be handled some day
         */
        if (vap->va_flags != VNOVAL) {
                if (error = suser(cred, &p->p_acflag))
                        return error;
                if (cred->cr_uid == 0)
                ;
                else {
                }
        }
#endif
        return error;
}

static int
devfs_read(struct vop_read_args *ap)
        /*struct vop_read_args {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */
{
        devnode_t * dn_p = VTODN(ap->a_vp);

        switch (ap->a_vp->v_type) {
          case VDIR: {
              dn_p->dn_flags |= DN_ACCESS;
              return VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred,
                                 NULL, NULL, NULL);
          }
          default: {
              printf("devfs_read(): bad file type %d", ap->a_vp->v_type);
              return(EINVAL);
              break;
          }
        }
        return (0); /* not reached */
}

static int
devfs_close(ap)
        struct vop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                struct ucred *a_cred;
                struct proc *a_p;
        } */ *ap;
{
        struct vnode *          vp = ap->a_vp;
        register devnode_t *    dnp = VTODN(vp);

        simple_lock(&vp->v_interlock);
        if (vp->v_usecount > 1)
            dn_times(dnp, time, time);
        simple_unlock(&vp->v_interlock);
        return (0);
}

static int
devfsspec_close(ap)
        struct vop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                struct ucred *a_cred;
                struct proc *a_p;
        } */ *ap;
{
        struct vnode *          vp = ap->a_vp;
        register devnode_t *    dnp = VTODN(vp);

        simple_lock(&vp->v_interlock);
        if (vp->v_usecount > 1)
            dn_times(dnp, time, time);
        simple_unlock(&vp->v_interlock);
        return (VOCALL (spec_vnodeop_p, VOFFSET(vop_close), ap));
}

static int
devfsspec_read(struct vop_read_args *ap)
        /*struct vop_read_args {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */
{
    VTODN(ap->a_vp)->dn_flags |= DN_ACCESS;
    return (VOCALL (spec_vnodeop_p, VOFFSET(vop_read), ap));
}

static int
devfsspec_write(struct vop_write_args *ap)
        /*struct vop_write_args  {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */
{
    VTODN(ap->a_vp)->dn_flags |= DN_CHANGE | DN_UPDATE;
    return (VOCALL (spec_vnodeop_p, VOFFSET(vop_write), ap));
}

/*
 *  Write data to a file or directory.
 */
static int
devfs_write(struct vop_write_args *ap)
        /*struct vop_write_args  {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                struct ucred *a_cred;
        } */
{
        switch (ap->a_vp->v_type) {
        case VDIR:
                return(EISDIR);
        default:
                printf("devfs_write(): bad file type %d", ap->a_vp->v_type);
                return (EINVAL);
        }
        return 0; /* not reached */
}

static int
devfs_remove(struct vop_remove_args *ap)
        /*struct vop_remove_args  {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ 
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        devnode_t *  tp;
        devnode_t *  tdp;
        devdirent_t * tnp;
        int doingdirectory = 0;
        int error = 0;
        uid_t ouruid = cnp->cn_cred->cr_uid;
        struct proc *p = cnp->cn_proc;

        /*
         * Lock our directories and get our name pointers
         * assume that the names are null terminated as they
         * are the end of the path. Get pointers to all our
         * devfs structures.
         */
        tp = VTODN(vp);
        tdp = VTODN(dvp);
        /*
         * Assuming we are atomic, dev_lookup left this for us
         */
        tnp = tp->dn_last_lookup;

        /*
         * Check we are doing legal things WRT the new flags
         */
        if ((tp->dn_flags & (IMMUTABLE | APPEND))
          || (tdp->dn_flags & APPEND) /*XXX eh?*/ ) {
            error = EPERM;
            goto abort;
        }

        /*
         * Make sure that we don't try do something stupid
         */
        if ((tp->dn_type) == DEV_DIR) {
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ( (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') 
                    || (cnp->cn_flags&ISDOTDOT) ) {
                        error = EINVAL;
                        goto abort;
                }
                doingdirectory++;
        }

        /***********************************
         * Start actually doing things.... *
         ***********************************/
        tdp->dn_flags |= DN_CHANGE | DN_UPDATE;

        /*
         * own the parent directory, or the destination of the rename,
         * otherwise the destination may not be changed (except by
         * root). This implements append-only directories.
         * XXX shoudn't this be in generic code? 
         */
        if ((tdp->dn_mode & S_ISTXT)
          && ouruid != 0
          && ouruid != tdp->dn_uid
          && ouruid != tp->dn_uid ) {
            error = EPERM;
            goto abort;
        }
        /*
         * Target must be empty if a directory and have no links
         * to it. Also, ensure source and target are compatible
         * (both directories, or both not directories).
         */
        if (( doingdirectory) && (tp->dn_links > 2)) {
            error = ENOTEMPTY;
            goto abort;
        }
        DEVFS_LOCK(p);
        dev_free_name(tnp);
        DEVFS_UNLOCK(p);
 abort:
        if (dvp == vp)
            vrele(vp);
        else
            vput(vp);
        vput(dvp);
        return (error);
}

/*
 */
static int
devfs_link(struct vop_link_args *ap)
        /*struct vop_link_args  {
                struct vnode *a_tdvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
        } */ 
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *cnp = ap->a_cnp;
        struct proc *p = cnp->cn_proc;
        devnode_t * fp;
        devnode_t * tdp;
        devdirent_t * tnp;
        int error = 0;
        struct timeval tv;

        /*
         * First catch an arbitrary restriction for this FS
         */
        if (cnp->cn_namelen > DEVMAXNAMESIZE) {
                error = ENAMETOOLONG;
                goto out1;
        }

        /*
         * Lock our directories and get our name pointers
         * assume that the names are null terminated as they
         * are the end of the path. Get pointers to all our
         * devfs structures.
         */
        tdp = VTODN(tdvp);
        fp = VTODN(vp);
        
        if (tdvp->v_mount != vp->v_mount) {
                error = EXDEV;
                VOP_ABORTOP(tdvp, cnp); 
                goto out2;
        }
        if (tdvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE, p))) {
                VOP_ABORTOP(tdvp, cnp);
                goto out2;
        }

        /*
         * Check we are doing legal things WRT the new flags
         */
        if (fp->dn_flags & (IMMUTABLE | APPEND)) {
                VOP_ABORTOP(tdvp, cnp);
                error = EPERM;
                goto out1;
        }

        /***********************************
         * Start actually doing things.... *
         ***********************************/
        fp->dn_flags |= DN_CHANGE;
        tv = time;
        error = VOP_UPDATE(vp, &tv, &tv, 1);
        if (!error) {
            DEVFS_LOCK(p);
            error = dev_add_name(cnp->cn_nameptr, tdp, NULL, fp, &tnp);
            DEVFS_UNLOCK(p);
        }
out1:
        if (tdvp != vp)
                VOP_UNLOCK(vp, 0, p);
out2:
        vput(tdvp);
        return (error);
}

/*
 * Check if source directory is in the path of the target directory.
 * Target is supplied locked, source is unlocked.
 * The target is always vput before returning.
 */
int
devfs_checkpath(source, target)
        devnode_t *source, *target;
{
    int error = 0;
    devnode_t * ntmp;
    devnode_t * tmp;
    struct vnode *vp;

    vp = target->dn_vn;
    tmp = target;

    do {
        if (tmp == source) {
            error = EINVAL;
            break;
        }
        ntmp = tmp;
    } while ((tmp = tmp->dn_typeinfo.Dir.parent) != ntmp);

    if (vp != NULL)
        vput(vp);
    return (error);
}

/*
 * Rename system call. Seems overly complicated to me...
 *      rename("foo", "bar");
 * is essentially
 *      unlink("bar");
 *      link("foo", "bar");
 *      unlink("foo");
 * but ``atomically''.
 *
 * When the target exists, both the directory
 * and target vnodes are locked.
 * the source and source-parent vnodes are referenced
 *
 *
 * Basic algorithm is:
 *
 * 1) Bump link count on source while we're linking it to the
 *    target.  This also ensure the inode won't be deleted out
 *    from underneath us while we work (it may be truncated by
 *    a concurrent `trunc' or `open' for creation).
 * 2) Link source to destination.  If destination already exists,
 *    delete it first.
 * 3) Unlink source reference to node if still around. If a
 *    directory was moved and the parent of the destination
 *    is different from the source, patch the ".." entry in the
 *    directory.
 */
static int
devfs_rename(struct vop_rename_args *ap)
        /*struct vop_rename_args  {
                struct vnode *a_fdvp; 
                struct vnode *a_fvp;  
                struct componentname *a_fcnp;
                struct vnode *a_tdvp;
                struct vnode *a_tvp;
                struct componentname *a_tcnp;
        } */
{
        struct vnode *tvp = ap->a_tvp;
        struct vnode *tdvp = ap->a_tdvp;
        struct vnode *fvp = ap->a_fvp;
        struct vnode *fdvp = ap->a_fdvp;
        struct componentname *tcnp = ap->a_tcnp;
        struct componentname *fcnp = ap->a_fcnp;
        struct proc *p = fcnp->cn_proc;
        devnode_t *fp, *fdp, *tp, *tdp;
        devdirent_t *fnp,*tnp;
        int doingdirectory = 0;
        int error = 0;
        struct timeval tv;

        /*
         * First catch an arbitrary restriction for this FS
         */
        if(tcnp->cn_namelen > DEVMAXNAMESIZE) {
                error = ENAMETOOLONG;
                goto abortit;
        }

        /*
         * Lock our directories and get our name pointers
         * assume that the names are null terminated as they
         * are the end of the path. Get pointers to all our
         * devfs structures.
         */
        tdp = VTODN(tdvp);
        fdp = VTODN(fdvp);
        fp = VTODN(fvp);
        fnp = fp->dn_last_lookup;
        tp = NULL;
        tnp = NULL;
        if (tvp) {
            tp = VTODN(tvp);
            tnp = tp->dn_last_lookup;
        }
        
        /*
         * trying to move it out of devfs?
         * if we move a dir across mnt points. we need to fix all
         * the mountpoint pointers! XXX
         * so for now keep dirs within the same mount
         */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
abortit:
                VOP_ABORTOP(tdvp, tcnp); 
                if (tdvp == tvp) /* eh? */
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                VOP_ABORTOP(fdvp, fcnp); /* XXX, why not in NFS? */
                vrele(fdvp);
                vrele(fvp);
                return (error);
        }

        /*
         * Check we are doing legal things WRT the new flags
         */
        if ((tp && (tp->dn_flags & (IMMUTABLE | APPEND)))
          || (fp->dn_flags & (IMMUTABLE | APPEND))
          || (fdp->dn_flags & APPEND)) {
                error = EPERM;
                goto abortit;
        }

        /*
         * Make sure that we don't try do something stupid
         */
        if ((fp->dn_type) == DEV_DIR) {
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') 
                    || (fcnp->cn_flags&ISDOTDOT) 
                    || (tcnp->cn_namelen == 1 && tcnp->cn_nameptr[0] == '.') 
                    || (tcnp->cn_flags&ISDOTDOT) 
                    || (tdp == fp )) {
                        error = EINVAL;
                        goto abortit;
                }
                doingdirectory++;
        }

        /*
         * If ".." must be changed (ie the directory gets a new
         * parent) then the source directory must not be in the
         * directory hierarchy above the target, as this would
         * orphan everything below the source directory. Also
         * the user must have write permission in the source so
         * as to be able to change "..". 
         */
        if (doingdirectory && (tdp != fdp)) {
                devnode_t * tmp, *ntmp;
                error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
                tmp = tdp;
                do {
                        if(tmp == fp) {
                                /* XXX unlock stuff here probably */
                                error = EINVAL;
                                goto out;
                        }
                        ntmp = tmp;
                } while ((tmp = tmp->dn_typeinfo.Dir.parent) != ntmp);
        }

        /***********************************
         * Start actually doing things.... *
         ***********************************/
        fp->dn_flags |= DN_CHANGE;
        tv = time;
        if (error = VOP_UPDATE(fvp, &tv, &tv, 1)) {
            VOP_UNLOCK(fvp, 0, p);
            goto bad;
        }
        /*
         * Check if just deleting a link name.
         */
        if (fvp == tvp) {
                if (fvp->v_type == VDIR) {
                        error = EINVAL;
                        goto abortit;
                }

                /* Release destination completely. */
                VOP_ABORTOP(tdvp, tcnp);
                vput(tdvp);
                vput(tvp);

                /* Delete source. */
                VOP_ABORTOP(fdvp, fcnp); /*XXX*/
                vrele(fdvp);
                vrele(fvp);
                dev_free_name(fnp);
                return 0;
        }

        vrele(fdvp);

        /*
         * 1) Bump link count while we're moving stuff
         *    around.  If we crash somewhere before
         *    completing our work,  too bad :)
         */
        fp->dn_links++;
        /*
         * If the target exists zap it (unless it's a non-empty directory)
         * We could do that as well but won't
         */
        if (tp) {
                int ouruid = tcnp->cn_cred->cr_uid;
                /*
                 * If the parent directory is "sticky", then the user must
                 * own the parent directory, or the destination of the rename,
                 * otherwise the destination may not be changed (except by
                 * root). This implements append-only directories.
                 * XXX shoudn't this be in generic code? 
                 */
                if ((tdp->dn_mode & S_ISTXT)
                  && ouruid != 0
                  && ouruid != tdp->dn_uid
                  && ouruid != tp->dn_uid ) {
                        error = EPERM;
                        goto bad;
                }
                /*
                 * Target must be empty if a directory and have no links
                 * to it. Also, ensure source and target are compatible
                 * (both directories, or both not directories).
                 */
                if (( doingdirectory) && (tp->dn_links > 2)) {
                                error = ENOTEMPTY;
                                goto bad;
                }
                dev_free_name(tnp);
                tp = NULL;
        }
        dev_add_name(tcnp->cn_nameptr,tdp,NULL,fp,&tnp);
        fnp->de_dnp = NULL;
        fp->dn_links--; /* one less link to it.. */
        dev_free_name(fnp);
        fp->dn_links--; /* we added one earlier*/
        if (tdp)
                vput(tdvp);
        if (tp)
                vput(fvp);
        vrele(fvp);
        return (error);

bad:
        if (tp)
                vput(tvp);
        vput(tdvp);
out:
        if (vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY, p) == 0) {
                fp->dn_links--; /* we added one earlier*/
                vput(fvp);
        } else
                vrele(fvp);
        return (error);
}

static int
devfs_symlink(struct vop_symlink_args *ap)
        /*struct vop_symlink_args {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
                char *a_target;
        } */
{
        struct componentname * cnp = ap->a_cnp;
        struct vnode *vp = NULL;
        int error = 0;
        devnode_t * dir_p;
        devnode_type_t typeinfo;
        devdirent_t * nm_p;
        devnode_t * dev_p;
        struct vattr *  vap = ap->a_vap;
        struct vnode * * vpp = ap->a_vpp;
        struct proc *p = cnp->cn_proc;
        struct timeval tv;

        dir_p = VTODN(ap->a_dvp);
        typeinfo.Slnk.name = ap->a_target;
        typeinfo.Slnk.namelen = strlen(ap->a_target);
        DEVFS_LOCK(p);
        error = dev_add_entry(cnp->cn_nameptr, dir_p, DEV_SLNK, 
                              &typeinfo, NULL, NULL, &nm_p);
        DEVFS_UNLOCK(p);
        if (error) {
            goto failure;
        }
        
        dev_p = nm_p->de_dnp;
        dev_p->dn_uid = dir_p->dn_uid;
        dev_p->dn_gid = dir_p->dn_gid;
        dev_p->dn_mode = vap->va_mode;
        dn_copy_times(dev_p, dir_p);
        error = devfs_dntovn(dev_p, vpp, p);
        if (error)
            goto failure;
        vp = *vpp;
        vput(vp);
 failure:
        if ((cnp->cn_flags & SAVESTART) == 0)
            FREE_ZONE(cnp->cn_pnbuf, cnp->cn_pnlen, M_NAMEI);
        vput(ap->a_dvp);
        return error;
}

/*
 * Mknod vnode call
 */
/* ARGSUSED */
int
devfs_mknod(ap)
        struct vop_mknod_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vattr *a_vap;
        } */ *ap;
{
        struct componentname * cnp = ap->a_cnp;
        devnode_t *     dev_p;
        devdirent_t *   devent;
        devnode_t *     dir_p;  /* devnode for parent directory */
        struct vnode *  dvp = ap->a_dvp;
        int             error = 0;
        devnode_type_t  typeinfo;
        struct vattr *  vap = ap->a_vap;
        struct vnode ** vpp = ap->a_vpp;
        struct proc *   p = cnp->cn_proc;

        *vpp = NULL;
        if (!vap->va_type == VBLK && !vap->va_type == VCHR) {
            error = EINVAL; /* only support mknod of special files */
            goto failure;
        }
        dir_p = VTODN(dvp);
        typeinfo.dev = vap->va_rdev;
        DEVFS_LOCK(p);
        error = dev_add_entry(cnp->cn_nameptr, dir_p, 
                              (vap->va_type == VBLK) ? DEV_BDEV : DEV_CDEV,
                              &typeinfo, NULL, NULL, &devent);
        DEVFS_UNLOCK(p);
        if (error) {
            goto failure;
        }
        dev_p = devent->de_dnp;
        error = devfs_dntovn(dev_p, vpp, p);
        if (error)
            goto failure;
        dev_p->dn_uid = cnp->cn_cred->cr_uid;
        dev_p->dn_gid = dir_p->dn_gid;
        dev_p->dn_mode = vap->va_mode;
 failure:
        if (*vpp) {
            vput(*vpp);
            *vpp = 0;
        }
        if ((cnp->cn_flags & SAVESTART) == 0)
            FREE_ZONE(cnp->cn_pnbuf, cnp->cn_pnlen, M_NAMEI);
        vput(dvp);
        return (error);
}

/*
 * Vnode op for readdir
 */
static int
devfs_readdir(struct vop_readdir_args *ap)
        /*struct vop_readdir_args {
                struct vnode *a_vp;
                struct uio *a_uio;
                struct ucred *a_cred;
                int *eofflag;
                int *ncookies;
                u_int **cookies;
        } */
{
        struct vnode *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
        struct dirent dirent;
        devnode_t * dir_node;
        devdirent_t *   name_node;
        char    *name;
        int error = 0;
        int reclen;
        int nodenumber;
        int     startpos,pos;
        struct proc *   p = uio->uio_procp;

        /*  set up refs to dir */
        dir_node = VTODN(vp);
        if(dir_node->dn_type != DEV_DIR)
                return(ENOTDIR);

        pos = 0;
        startpos = uio->uio_offset;
        DEVFS_LOCK(p);
        name_node = dir_node->dn_typeinfo.Dir.dirlist;
        nodenumber = 0;
        dir_node->dn_flags |= DN_ACCESS;

        while ((name_node || (nodenumber < 2)) && (uio->uio_resid > 0))
        {
                switch(nodenumber)
                {
                case    0:
                        dirent.d_fileno = (int32_t)(void *)dir_node;
                        name = ".";
                        dirent.d_namlen = 1;
                        dirent.d_type = DT_DIR;
                        break;
                case    1:
                        if(dir_node->dn_typeinfo.Dir.parent)
                            dirent.d_fileno
                                = (int32_t)dir_node->dn_typeinfo.Dir.parent;
                        else
                                dirent.d_fileno = (u_int32_t)dir_node;
                        name = "..";
                        dirent.d_namlen = 2;
                        dirent.d_type = DT_DIR;
                        break;
                default:
                        dirent.d_fileno = (int32_t)(void *)name_node->de_dnp;
                        dirent.d_namlen = strlen(name_node->de_name);
                        name = name_node->de_name;
                        switch(name_node->de_dnp->dn_type) {
                        case DEV_BDEV:
                                dirent.d_type = DT_BLK;
                                break;
                        case DEV_CDEV:
                                dirent.d_type = DT_CHR;
                                break;
                        case DEV_DIR:
                                dirent.d_type = DT_DIR;
                                break;
                        case DEV_SLNK:
                                dirent.d_type = DT_LNK;
                                break;
                        default:
                                dirent.d_type = DT_UNKNOWN;
                        }
                }
#define GENERIC_DIRSIZ(dp) \
    ((sizeof (struct dirent) - (MAXNAMLEN+1)) + (((dp)->d_namlen+1 + 3) &~ 3))

                reclen = dirent.d_reclen = GENERIC_DIRSIZ(&dirent);

                if(pos >= startpos)     /* made it to the offset yet? */
                {
                        if (uio->uio_resid < reclen) /* will it fit? */
                                break;
                        strcpy( dirent.d_name,name);
                        if ((error = uiomove ((caddr_t)&dirent,
                                        dirent.d_reclen, uio)) != 0)
                                break;
                }
                pos += reclen;
                if((nodenumber >1) && name_node)
                        name_node = name_node->de_next;
                nodenumber++;
        }
        DEVFS_UNLOCK(p);
        uio->uio_offset = pos;

        return (error);
}


/*
 */
static int
devfs_readlink(struct vop_readlink_args *ap)
        /*struct vop_readlink_args {
                struct vnode *a_vp;
                struct uio *a_uio;
                struct ucred *a_cred;
        } */
{
        struct vnode *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
        devnode_t * lnk_node;
        int error = 0;

        /*  set up refs to dir */
        lnk_node = VTODN(vp);
        if(lnk_node->dn_type != DEV_SLNK)
                return(EINVAL);
        if ((error = VOP_ACCESS(vp, VREAD, ap->a_cred, NULL)) != 0) { /* XXX */
                return error;
        }
        error = uiomove(lnk_node->dn_typeinfo.Slnk.name, 
                        lnk_node->dn_typeinfo.Slnk.namelen, uio);
        return error;
}

static int
devfs_abortop(struct vop_abortop_args *ap)
        /*struct vop_abortop_args {
                struct vnode *a_dvp;
                struct componentname *a_cnp;
        } */
{
        if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF) {
                FREE_ZONE(ap->a_cnp->cn_pnbuf, ap->a_cnp->cn_pnlen, M_NAMEI);
        }
        return 0;
}


static int
devfs_reclaim(struct vop_reclaim_args *ap)
        /*struct vop_reclaim_args {
                struct vnode *a_vp;
        } */
{
    struct vnode *      vp = ap->a_vp;
    devnode_t *         dnp = VTODN(vp);
    
    if (dnp) {
        /* 
         * do the same as devfs_inactive in case it is not called
         * before us (can that ever happen?)
         */
        dnp->dn_vn = NULL;
        vp->v_data = NULL;
        if (dnp->dn_delete) {
            devnode_free(dnp);
        }
    }
    return(0);
}

/*
 * Print out the contents of a /devfs vnode.
 */
static int
devfs_print(struct vop_print_args *ap)
        /*struct vop_print_args {
                struct vnode *a_vp;
        } */
{

        return (0);
}

/**************************************************************************\
* pseudo ops *
\**************************************************************************/

/*
 *
 *      struct vop_inactive_args {
 *              struct vnode *a_vp;
 *              struct proc *a_p;
 *      } 
 */

static int
devfs_inactive(struct vop_inactive_args *ap)
{
    struct vnode *      vp = ap->a_vp;
    devnode_t *         dnp = VTODN(vp);
    
    if (dnp) {
        dnp->dn_vn = NULL;
        vp->v_data = NULL;
        if (dnp->dn_delete) {
            devnode_free(dnp);
        }
    }
    VOP_UNLOCK(vp, 0, ap->a_p);
    return (0);
}

int
devfs_update(ap)
        struct vop_update_args /* {
                struct vnode *a_vp;
                struct timeval *a_access;
                struct timeval *a_modify;
                int a_waitfor;
        } */ *ap;
{
        register struct fs *fs;
        int error;
        devnode_t * ip;

        ip = VTODN(ap->a_vp);
        if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY) {
                ip->dn_flags &=
                    ~(DN_ACCESS | DN_CHANGE | DN_MODIFIED | DN_UPDATE);
                return (0);
        }
        if ((ip->dn_flags &
            (DN_ACCESS | DN_CHANGE | DN_MODIFIED | DN_UPDATE)) == 0)
                return (0);
        dn_times(ip, time, time);
        return (0);
}

#define VOPFUNC int (*)(void *)

/* The following ops are used by directories and symlinks */
int (**devfs_vnodeop_p)(void *);
static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
        { &vop_default_desc, (VOPFUNC)vn_default_error },
        { &vop_lookup_desc, (VOPFUNC)devfs_lookup },            /* lookup */
        { &vop_create_desc, (VOPFUNC)err_create },              /* create */
        { &vop_whiteout_desc, (VOPFUNC)err_whiteout },          /* whiteout */
        { &vop_mknod_desc, (VOPFUNC)devfs_mknod },              /* mknod */
        { &vop_open_desc, (VOPFUNC)nop_open },                  /* open */
        { &vop_close_desc, (VOPFUNC)devfs_close },              /* close */
        { &vop_access_desc, (VOPFUNC)devfs_access },            /* access */
        { &vop_getattr_desc, (VOPFUNC)devfs_getattr },          /* getattr */
        { &vop_setattr_desc, (VOPFUNC)devfs_setattr },          /* setattr */
        { &vop_read_desc, (VOPFUNC)devfs_read },                /* read */
        { &vop_write_desc, (VOPFUNC)devfs_write },              /* write */
        { &vop_lease_desc, (VOPFUNC)nop_lease },                /* lease */
        { &vop_ioctl_desc, (VOPFUNC)err_ioctl },                /* ioctl */
        { &vop_select_desc, (VOPFUNC)err_select },              /* select */
        { &vop_revoke_desc, (VOPFUNC)err_revoke },              /* revoke */
        { &vop_mmap_desc, (VOPFUNC)err_mmap },                  /* mmap */
        { &vop_fsync_desc, (VOPFUNC)nop_fsync },                /* fsync */
        { &vop_seek_desc, (VOPFUNC)err_seek },                  /* seek */
        { &vop_remove_desc, (VOPFUNC)devfs_remove },            /* remove */
        { &vop_link_desc, (VOPFUNC)devfs_link },                /* link */
        { &vop_rename_desc, (VOPFUNC)devfs_rename },            /* rename */
        { &vop_mkdir_desc, (VOPFUNC)err_mkdir },                /* mkdir */
        { &vop_rmdir_desc, (VOPFUNC)err_rmdir },                /* rmdir */
        { &vop_symlink_desc, (VOPFUNC)devfs_symlink },          /* symlink */
        { &vop_readdir_desc, (VOPFUNC)devfs_readdir },          /* readdir */
        { &vop_readlink_desc, (VOPFUNC)devfs_readlink },        /* readlink */
        { &vop_abortop_desc, (VOPFUNC)devfs_abortop },          /* abortop */
        { &vop_inactive_desc, (VOPFUNC)devfs_inactive },        /* inactive */
        { &vop_reclaim_desc, (VOPFUNC)devfs_reclaim },          /* reclaim */
        { &vop_lock_desc, (VOPFUNC)nop_lock },                  /* lock */
        { &vop_unlock_desc, (VOPFUNC)nop_unlock },              /* unlock */
        { &vop_bmap_desc, (VOPFUNC)err_bmap },                  /* bmap */
        { &vop_strategy_desc, (VOPFUNC)err_strategy },          /* strategy */
        { &vop_print_desc, (VOPFUNC)err_print },                /* print */
        { &vop_islocked_desc, (VOPFUNC)nop_islocked },          /* islocked */
        { &vop_pathconf_desc, (VOPFUNC)err_pathconf },          /* pathconf */
        { &vop_advlock_desc, (VOPFUNC)err_advlock },            /* advlock */
        { &vop_blkatoff_desc, (VOPFUNC)err_blkatoff },          /* blkatoff */
        { &vop_valloc_desc, (VOPFUNC)err_valloc },              /* valloc */
        { &vop_reallocblks_desc, (VOPFUNC)err_reallocblks },    /* reallocblks */
        { &vop_vfree_desc, (VOPFUNC)err_vfree },                /* vfree */
        { &vop_truncate_desc, (VOPFUNC)err_truncate },          /* truncate */
        { &vop_update_desc, (VOPFUNC)devfs_update },            /* update */
        { &vop_bwrite_desc, (VOPFUNC)err_bwrite },
        { &vop_pagein_desc, (VOPFUNC)err_pagein },              /* Pagein */
        { &vop_pageout_desc, (VOPFUNC)err_pageout },            /* Pageout */
        { &vop_copyfile_desc, (VOPFUNC)err_copyfile },          /* Copyfile */
        { &vop_blktooff_desc, (VOPFUNC)err_blktooff },          /* blktooff */
        { &vop_offtoblk_desc, (VOPFUNC)err_offtoblk },          /* offtoblk */
        { &vop_cmap_desc, (VOPFUNC)err_cmap },          /* cmap */
        { (struct vnodeop_desc*)NULL, (int(*)())NULL }
};
struct vnodeopv_desc devfs_vnodeop_opv_desc =
        { &devfs_vnodeop_p, devfs_vnodeop_entries };

/* The following ops are used by the device nodes */
int (**devfs_spec_vnodeop_p)(void *);
static struct vnodeopv_entry_desc devfs_spec_vnodeop_entries[] = {
        { &vop_default_desc, (VOPFUNC)vn_default_error },
        { &vop_lookup_desc, (VOPFUNC)spec_lookup },             /* lookup */
        { &vop_create_desc, (VOPFUNC)spec_create },             /* create */
        { &vop_mknod_desc, (VOPFUNC)spec_mknod },               /* mknod */
        { &vop_open_desc, (VOPFUNC)spec_open },                 /* open */
        { &vop_close_desc, (VOPFUNC)devfsspec_close },          /* close */
        { &vop_access_desc, (VOPFUNC)devfs_access },            /* access */
        { &vop_getattr_desc, (VOPFUNC)devfs_getattr },          /* getattr */
        { &vop_setattr_desc, (VOPFUNC)devfs_setattr },          /* setattr */
        { &vop_read_desc, (VOPFUNC)devfsspec_read },            /* read */
        { &vop_write_desc, (VOPFUNC)devfsspec_write },          /* write */
        { &vop_lease_desc, (VOPFUNC)spec_lease_check },         /* lease */
        { &vop_ioctl_desc, (VOPFUNC)spec_ioctl },               /* ioctl */
        { &vop_select_desc, (VOPFUNC)spec_select },             /* select */
        { &vop_revoke_desc, (VOPFUNC)spec_revoke },             /* revoke */
        { &vop_mmap_desc, (VOPFUNC)spec_mmap },                 /* mmap */
        { &vop_fsync_desc, (VOPFUNC)spec_fsync },               /* fsync */
        { &vop_seek_desc, (VOPFUNC)spec_seek },                 /* seek */
        { &vop_remove_desc, (VOPFUNC)devfs_remove },            /* remove */
        { &vop_link_desc, (VOPFUNC)devfs_link },                /* link */
        { &vop_rename_desc, (VOPFUNC)spec_rename },             /* rename */
        { &vop_mkdir_desc, (VOPFUNC)spec_mkdir },               /* mkdir */
        { &vop_rmdir_desc, (VOPFUNC)spec_rmdir },               /* rmdir */
        { &vop_symlink_desc, (VOPFUNC)spec_symlink },           /* symlink */
        { &vop_readdir_desc, (VOPFUNC)spec_readdir },           /* readdir */
        { &vop_readlink_desc, (VOPFUNC)spec_readlink },         /* readlink */
        { &vop_abortop_desc, (VOPFUNC)spec_abortop },           /* abortop */
        { &vop_inactive_desc, (VOPFUNC)devfs_inactive },        /* inactive */
        { &vop_reclaim_desc, (VOPFUNC)devfs_reclaim },          /* reclaim */
        { &vop_lock_desc, (VOPFUNC)nop_lock },                  /* lock */
        { &vop_unlock_desc, (VOPFUNC)nop_unlock },              /* unlock */
        { &vop_bmap_desc, (VOPFUNC)spec_bmap },                 /* bmap */
        { &vop_strategy_desc, (VOPFUNC)spec_strategy },         /* strategy */
        { &vop_print_desc, (VOPFUNC)devfs_print },              /* print */
        { &vop_islocked_desc, (VOPFUNC)nop_islocked },          /* islocked */
        { &vop_pathconf_desc, (VOPFUNC)spec_pathconf },         /* pathconf */
        { &vop_advlock_desc, (VOPFUNC)spec_advlock },           /* advlock */
        { &vop_blkatoff_desc, (VOPFUNC)spec_blkatoff },         /* blkatoff */
        { &vop_valloc_desc, (VOPFUNC)spec_valloc },             /* valloc */
        { &vop_reallocblks_desc, (VOPFUNC)spec_reallocblks },   /* reallocblks */
        { &vop_vfree_desc, (VOPFUNC)nop_vfree },                /* vfree */
        { &vop_truncate_desc, (VOPFUNC)spec_truncate },         /* truncate */
        { &vop_update_desc, (VOPFUNC)devfs_update },            /* update */
        { &vop_bwrite_desc, (VOPFUNC)vn_bwrite },
        { &vop_devblocksize_desc, (VOPFUNC)spec_devblocksize }, /* devblocksize */
        { &vop_pagein_desc, (VOPFUNC)err_pagein },              /* Pagein */
        { &vop_pageout_desc, (VOPFUNC)err_pageout },            /* Pageout */
        { &vop_copyfile_desc, (VOPFUNC)err_copyfile },          /* Copyfile */
        { &vop_blktooff_desc, (VOPFUNC)spec_blktooff }, /* blktooff */
        { &vop_blktooff_desc, (VOPFUNC)spec_offtoblk  },        /* blkofftoblk */
        { &vop_cmap_desc, (VOPFUNC)spec_cmap }, /* cmap */
        { (struct vnodeop_desc*)NULL, (int(*)())NULL }
};
struct vnodeopv_desc devfs_spec_vnodeop_opv_desc =
        { &devfs_spec_vnodeop_p, devfs_spec_vnodeop_entries };