sys/kern/dead_vnops.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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.
 *
 *      from: @(#)dead_vnops.c  7.13 (Berkeley) 4/15/91
 *      $Id$
 */

#include "param.h"
#include "systm.h"
#include "time.h"
#include "vnode.h"
#include "errno.h"
#include "namei.h"
#include "buf.h"

/*
 * Prototypes for dead operations on vnodes.
 */
int     dead_badop(),
        dead_ebadf();
int     dead_lookup __P((
                struct vnode *vp,
                struct nameidata *ndp,
                struct proc *p));
#define dead_create ((int (*) __P(( \
                struct nameidata *ndp, \
                struct vattr *vap, \
                struct proc *p))) dead_badop)
#define dead_mknod ((int (*) __P(( \
                struct nameidata *ndp, \
                struct vattr *vap, \
                struct ucred *cred, \
                struct proc *p))) dead_badop)
int     dead_open __P((
                struct vnode *vp,
                int mode,
                struct ucred *cred,
                struct proc *p));
#define dead_close ((int (*) __P(( \
                struct vnode *vp, \
                int fflag, \
                struct ucred *cred, \
                struct proc *p))) nullop)
#define dead_access ((int (*) __P(( \
                struct vnode *vp, \
                int mode, \
                struct ucred *cred, \
                struct proc *p))) dead_ebadf)
#define dead_getattr ((int (*) __P(( \
                struct vnode *vp, \
                struct vattr *vap, \
                struct ucred *cred, \
                struct proc *p))) dead_ebadf)
#define dead_setattr ((int (*) __P(( \
                struct vnode *vp, \
                struct vattr *vap, \
                struct ucred *cred, \
                struct proc *p))) dead_ebadf)
int     dead_read __P((
                struct vnode *vp,
                struct uio *uio,
                int ioflag,
                struct ucred *cred));
int     dead_write __P((
                struct vnode *vp,
                struct uio *uio,
                int ioflag,
                struct ucred *cred));
int     dead_ioctl __P((
                struct vnode *vp,
                int command,
                caddr_t data,
                int fflag,
                struct ucred *cred,
                struct proc *p));
int     dead_select __P((
                struct vnode *vp,
                int which,
                int fflags,
                struct ucred *cred,
                struct proc *p));
#define dead_mmap ((int (*) __P(( \
                struct vnode *vp, \
                int fflags, \
                struct ucred *cred, \
                struct proc *p))) dead_badop)
#define dead_fsync ((int (*) __P(( \
                struct vnode *vp, \
                int fflags, \
                struct ucred *cred, \
                int waitfor, \
                struct proc *p))) nullop)
#define dead_seek ((int (*) __P(( \
                struct vnode *vp, \
                off_t oldoff, \
                off_t newoff, \
                struct ucred *cred))) nullop)
#define dead_remove ((int (*) __P(( \
                struct nameidata *ndp, \
                struct proc *p))) dead_badop)
#define dead_link ((int (*) __P(( \
                struct vnode *vp, \
                struct nameidata *ndp, \
                struct proc *p))) dead_badop)
#define dead_rename ((int (*) __P(( \
                struct nameidata *fndp, \
                struct nameidata *tdnp, \
                struct proc *p))) dead_badop)
#define dead_mkdir ((int (*) __P(( \
                struct nameidata *ndp, \
                struct vattr *vap, \
                struct proc *p))) dead_badop)
#define dead_rmdir ((int (*) __P(( \
                struct nameidata *ndp, \
                struct proc *p))) dead_badop)
#define dead_symlink ((int (*) __P(( \
                struct nameidata *ndp, \
                struct vattr *vap, \
                char *target, \
                struct proc *p))) dead_badop)
#define dead_readdir ((int (*) __P(( \
                struct vnode *vp, \
                struct uio *uio, \
                struct ucred *cred, \
                int *eofflagp))) dead_ebadf)
#define dead_readlink ((int (*) __P(( \
                struct vnode *vp, \
                struct uio *uio, \
                struct ucred *cred))) dead_ebadf)
#define dead_abortop ((int (*) __P(( \
                struct nameidata *ndp))) dead_badop)
#define dead_inactive ((int (*) __P(( \
                struct vnode *vp, \
                struct proc *p))) nullop)
#define dead_reclaim ((int (*) __P(( \
                struct vnode *vp))) nullop)
int     dead_lock __P((
                struct vnode *vp));
#define dead_unlock ((int (*) __P(( \
                struct vnode *vp))) nullop)
int     dead_bmap __P((
                struct vnode *vp,
                daddr_t bn,
                struct vnode **vpp,
                daddr_t *bnp));
int     dead_strategy __P((
                struct buf *bp));
int     dead_print __P((
                struct vnode *vp));
#define dead_islocked ((int (*) __P(( \
                struct vnode *vp))) nullop)
#define dead_advlock ((int (*) __P(( \
                struct vnode *vp, \
                caddr_t id, \
                int op, \
                struct flock *fl, \
                int flags))) dead_ebadf)

struct vnodeops dead_vnodeops = {
        dead_lookup,    /* lookup */
        dead_create,    /* create */
        dead_mknod,     /* mknod */
        dead_open,      /* open */
        dead_close,     /* close */
        dead_access,    /* access */
        dead_getattr,   /* getattr */
        dead_setattr,   /* setattr */
        dead_read,      /* read */
        dead_write,     /* write */
        dead_ioctl,     /* ioctl */
        dead_select,    /* select */
        dead_mmap,      /* mmap */
        dead_fsync,     /* fsync */
        dead_seek,      /* seek */
        dead_remove,    /* remove */
        dead_link,      /* link */
        dead_rename,    /* rename */
        dead_mkdir,     /* mkdir */
        dead_rmdir,     /* rmdir */
        dead_symlink,   /* symlink */
        dead_readdir,   /* readdir */
        dead_readlink,  /* readlink */
        dead_abortop,   /* abortop */
        dead_inactive,  /* inactive */
        dead_reclaim,   /* reclaim */
        dead_lock,      /* lock */
        dead_unlock,    /* unlock */
        dead_bmap,      /* bmap */
        dead_strategy,  /* strategy */
        dead_print,     /* print */
        dead_islocked,  /* islocked */
        dead_advlock,   /* advlock */
};

/*
 * Trivial lookup routine that always fails.
 */
/* ARGSUSED */
dead_lookup(vp, ndp, p)
        struct vnode *vp;
        struct nameidata *ndp;
        struct proc *p;
{

        ndp->ni_dvp = vp;
        ndp->ni_vp = NULL;
        return (ENOTDIR);
}

/*
 * Open always fails as if device did not exist.
 */
/* ARGSUSED */
dead_open(vp, mode, cred, p)
        struct vnode *vp;
        int mode;
        struct ucred *cred;
        struct proc *p;
{

        return (ENXIO);
}

/*
 * Vnode op for read
 */
/* ARGSUSED */
dead_read(vp, uio, ioflag, cred)
        struct vnode *vp;
        struct uio *uio;
        int ioflag;
        struct ucred *cred;
{

        if (chkvnlock(vp))
                panic("dead_read: lock");
        /*
         * Return EOF for character devices, EIO for others
         */
        if (vp->v_type != VCHR)
                return (EIO);
        return (0);
}

/*
 * Vnode op for write
 */
/* ARGSUSED */
dead_write(vp, uio, ioflag, cred)
        register struct vnode *vp;
        struct uio *uio;
        int ioflag;
        struct ucred *cred;
{

        if (chkvnlock(vp))
                panic("dead_write: lock");
        return (EIO);
}

/*
 * Device ioctl operation.
 */
/* ARGSUSED */
dead_ioctl(vp, com, data, fflag, cred, p)
        struct vnode *vp;
        register int com;
        caddr_t data;
        int fflag;
        struct ucred *cred;
        struct proc *p;
{

        if (!chkvnlock(vp))
                return (EBADF);
        return (VOP_IOCTL(vp, com, data, fflag, cred, p));
}

/* ARGSUSED */
dead_select(vp, which, fflags, cred, p)
        struct vnode *vp;
        int which, fflags;
        struct ucred *cred;
        struct proc *p;
{

        /*
         * Let the user find out that the descriptor is gone.
         */
        return (1);
}

/*
 * Just call the device strategy routine
 */
dead_strategy(bp)
        register struct buf *bp;
{

        if (bp->b_vp == NULL || !chkvnlock(bp->b_vp)) {
                bp->b_flags |= B_ERROR;
                biodone(bp);
                return (EIO);
        }
        return (VOP_STRATEGY(bp));
}

/*
 * Wait until the vnode has finished changing state.
 */
dead_lock(vp)
        struct vnode *vp;
{

        if (!chkvnlock(vp))
                return (0);
        return (VOP_LOCK(vp));
}

/*
 * Wait until the vnode has finished changing state.
 */
dead_bmap(vp, bn, vpp, bnp)
        struct vnode *vp;
        daddr_t bn;
        struct vnode **vpp;
        daddr_t *bnp;
{

        if (!chkvnlock(vp))
                return (EIO);
        return (VOP_BMAP(vp, bn, vpp, bnp));
}

/*
 * Print out the contents of a dead vnode.
 */
/* ARGSUSED */
dead_print(vp)
        struct vnode *vp;
{

        printf("tag VT_NON, dead vnode\n");
}

/*
 * Empty vnode failed operation
 */
dead_ebadf()
{

        return (EBADF);
}

/*
 * Empty vnode bad operation
 */
dead_badop()
{

        panic("dead_badop called");
        /* NOTREACHED */
}

/*
 * Empty vnode null operation
 */
dead_nullop()
{

        return (0);
}

/*
 * We have to wait during times when the vnode is
 * in a state of change.
 */
chkvnlock(vp)
        register struct vnode *vp;
{
        int locked = 0;

        while (vp->v_flag & VXLOCK) {
                vp->v_flag |= VXWANT;
                sleep((caddr_t)vp, PINOD);
                locked = 1;
        }
        return (locked);
}