usr/src/sys.386bsd/ufs/mfs_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.
 *
 *      @(#)mfs_vnops.c 7.22 (Berkeley) 4/16/91
 */

#include "param.h"
#include "systm.h"
#include "time.h"
#include "kernel.h"
#include "proc.h"
#include "buf.h"
#include "vnode.h"

#include "mfsnode.h"
#include "mfsiom.h"

#include "machine/vmparam.h"

/*
 * mfs vnode operations.
 */
struct vnodeops mfs_vnodeops = {
        mfs_lookup,             /* lookup */
        mfs_create,             /* create */
        mfs_mknod,              /* mknod */
        mfs_open,               /* open */
        mfs_close,              /* close */
        mfs_access,             /* access */
        mfs_getattr,            /* getattr */
        mfs_setattr,            /* setattr */
        mfs_read,               /* read */
        mfs_write,              /* write */
        mfs_ioctl,              /* ioctl */
        mfs_select,             /* select */
        mfs_mmap,               /* mmap */
        mfs_fsync,              /* fsync */
        mfs_seek,               /* seek */
        mfs_remove,             /* remove */
        mfs_link,               /* link */
        mfs_rename,             /* rename */
        mfs_mkdir,              /* mkdir */
        mfs_rmdir,              /* rmdir */
        mfs_symlink,            /* symlink */
        mfs_readdir,            /* readdir */
        mfs_readlink,           /* readlink */
        mfs_abortop,            /* abortop */
        mfs_inactive,           /* inactive */
        mfs_reclaim,            /* reclaim */
        mfs_lock,               /* lock */
        mfs_unlock,             /* unlock */
        mfs_bmap,               /* bmap */
        mfs_strategy,           /* strategy */
        mfs_print,              /* print */
        mfs_islocked,           /* islocked */
        mfs_advlock,            /* advlock */
};

/*
 * Vnode Operations.
 *
 * Open called to allow memory filesystem to initialize and
 * validate before actual IO. Record our process identifier
 * so we can tell when we are doing I/O to ourself.
 */
/* ARGSUSED */
mfs_open(vp, mode, cred, p)
        register struct vnode *vp;
        int mode;
        struct ucred *cred;
        struct proc *p;
{

        if (vp->v_type != VBLK) {
                panic("mfs_ioctl not VBLK");
                /* NOTREACHED */
        }
        return (0);
}

/*
 * Ioctl operation.
 */
/* ARGSUSED */
mfs_ioctl(vp, com, data, fflag, cred, p)
        struct vnode *vp;
        int com;
        caddr_t data;
        int fflag;
        struct ucred *cred;
        struct proc *p;
{

        return (-1);
}

/*
 * Pass I/O requests to the memory filesystem process.
 */
mfs_strategy(bp)
        register struct buf *bp;
{
        register struct mfsnode *mfsp;
        struct vnode *vp;
        struct proc *p = curproc;               /* XXX */

        if (vfinddev(bp->b_dev, VBLK, &vp) || vp->v_usecount == 0)
                panic("mfs_strategy: bad dev");
        mfsp = VTOMFS(vp);
        if (mfsp->mfs_pid == p->p_pid) {
                mfs_doio(bp, mfsp->mfs_baseoff);
        } else {
                bp->av_forw = mfsp->mfs_buflist;
                mfsp->mfs_buflist = bp;
                wakeup((caddr_t)vp);
        }
        return (0);
}

/*
 * Memory file system I/O.
 *
 * Trivial since buffer has already been mapping into KVA space.
 */
mfs_doio(bp, base)
        register struct buf *bp;
        caddr_t base;
{
        base += (bp->b_blkno << DEV_BSHIFT);
        if (bp->b_flags & B_READ)
                bp->b_error = copyin(base, bp->b_un.b_addr, bp->b_bcount);
        else
                bp->b_error = copyout(bp->b_un.b_addr, base, bp->b_bcount);
        if (bp->b_error)
                bp->b_flags |= B_ERROR;
        biodone(bp);
}

/*
 * This is a noop, simply returning what one has been given.
 */
mfs_bmap(vp, bn, vpp, bnp)
        struct vnode *vp;
        daddr_t bn;
        struct vnode **vpp;
        daddr_t *bnp;
{

        if (vpp != NULL)
                *vpp = vp;
        if (bnp != NULL)
                *bnp = bn;
        return (0);
}

/*
 * Memory filesystem close routine
 */
/* ARGSUSED */
mfs_close(vp, flag, cred, p)
        register struct vnode *vp;
        int flag;
        struct ucred *cred;
        struct proc *p;
{
        register struct mfsnode *mfsp = VTOMFS(vp);
        register struct buf *bp;

        /*
         * Finish any pending I/O requests.
         */
        while (bp = mfsp->mfs_buflist) {
                mfsp->mfs_buflist = bp->av_forw;
                mfs_doio(bp, mfsp->mfs_baseoff);
                wakeup((caddr_t)bp);
        }
        /*
         * On last close of a memory filesystem
         * we must invalidate any in core blocks, so that
         * we can, free up its vnode.
         */
        vflushbuf(vp, 0);
        if (vinvalbuf(vp, 1))
                return (0);
        /*
         * There should be no way to have any more uses of this
         * vnode, so if we find any other uses, it is a panic.
         */
        if (vp->v_usecount > 1)
                printf("mfs_close: ref count %d > 1\n", vp->v_usecount);
        if (vp->v_usecount > 1 || mfsp->mfs_buflist)
                panic("mfs_close");
        /*
         * Send a request to the filesystem server to exit.
         */
        mfsp->mfs_buflist = (struct buf *)(-1);
        wakeup((caddr_t)vp);
        return (0);
}

/*
 * Memory filesystem inactive routine
 */
/* ARGSUSED */
mfs_inactive(vp, p)
        struct vnode *vp;
        struct proc *p;
{

        if (VTOMFS(vp)->mfs_buflist != (struct buf *)(-1))
                panic("mfs_inactive: not inactive");
        return (0);
}

/*
 * Print out the contents of an mfsnode.
 */
mfs_print(vp)
        struct vnode *vp;
{
        register struct mfsnode *mfsp = VTOMFS(vp);

        printf("tag VT_MFS, pid %d, base %d, size %d\n", mfsp->mfs_pid,
                mfsp->mfs_baseoff, mfsp->mfs_size);
}

/*
 * Block device bad operation
 */
mfs_badop()
{

        panic("mfs_badop called\n");
        /* NOTREACHED */
}

/*
 * Memory based filesystem initialization.
 */
mfs_init()
{

}