usr/src/sys/deprecated/lofs/lofs_vfsops.c

/*
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)lofs_vfsops.c       8.3 (Berkeley) %G%
 *
 * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
 */

/*
 * Loopback Filesystem
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/lofs/lofs.h>

/*
 * Mount loopback copy of existing name space
 */
int
lofs_mount(mp, path, data, ndp, p)
        struct mount *mp;
        char *path;
        caddr_t data;
        struct nameidata *ndp;
        struct proc *p;
{
        int error = 0;
        struct lofs_args args;
        struct vnode *vp;
        struct vnode *rootvp;
        struct lofsmount *amp;
        u_int size;

        /*
         * Update is a no-op
         */
        if (mp->mnt_flag & MNT_UPDATE)
                return (EOPNOTSUPP);

        /*
         * Get argument
         */
        if (error = copyin(data, (caddr_t)&args, sizeof(struct lofs_args)))
                return (error);

        /*
         * Find target node
         */
        NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
                UIO_USERSPACE, args.target, p);
        if (error = namei(ndp))
                return (error);

        /*
         * Sanity check on target vnode
         */
        vp = ndp->ni_vp;
        vrele(ndp->ni_dvp);
        ndp->ni_dvp = 0;

        if (vp->v_type != VDIR) {
                vput(vp);
                return (EINVAL);
        }

        amp = (struct lofsmount *) malloc(sizeof(struct lofsmount),
                                M_UFSMNT, M_WAITOK);    /* XXX */

        /*
         * Save reference to underlying target FS
         */
        amp->looped_vfs = vp->v_mount;

        /*
         * Save reference.  Each mount also holds
         * a reference on the root vnode.
         */
        error = make_lofs(mp, &vp);
        /*
         * Unlock the node (either the target or the alias)
         */
        VOP_UNLOCK(vp);
        /*
         * Make sure the node alias worked
         */
        if (error) {
                vrele(vp);
                free(amp, M_UFSMNT);    /* XXX */
                return (error);
        }

        /*
         * Keep a held reference to the root vnode.
         * It is vrele'd in lofs_unmount.
         */
        rootvp = vp;
        rootvp->v_flag |= VROOT;
        amp->rootvp = rootvp;
        if (LOFSVP(rootvp)->v_mount->mnt_flag & MNT_LOCAL)
                mp->mnt_flag |= MNT_LOCAL;
        mp->mnt_data = (qaddr_t) amp;
        getnewfsid(mp, MOUNT_LOFS);

        (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
        bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
        (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
            &size);
        bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
        return (0);
}

/*
 * VFS start.  Nothing needed here - the start routine
 * on the underlying filesystem will have been called
 * when that filesystem was mounted.
 */
int
lofs_start(mp, flags, p)
        struct mount *mp;
        int flags;
        struct proc *p;
{

        return (0);
}

/*
 * Free reference to looped FS
 */
int
lofs_unmount(mp, mntflags, p)
        struct mount *mp;
        int mntflags;
        struct proc *p;
{
        struct vnode *rootvp = VFSTOLOFS(mp)->rootvp;
        int error;
        int flags = 0;
        extern int doforce;

        if (mntflags & MNT_FORCE) {
                /* lofs can never be rootfs so don't check for it */
                if (!doforce)
                        return (EINVAL);
                flags |= FORCECLOSE;
        }

        /*
         * Clear out buffer cache.  I don't think we
         * ever get anything cached at this level at the
         * moment, but who knows...
         */
        if (rootvp->v_usecount > 1)
                return (EBUSY);
        if (error = vflush(mp, rootvp, flags))
                return (error);

        /*
         * Release reference on underlying root vnode
         */
        vrele(rootvp);
        /*
         * And blow it away for future re-use
         */
        vgone(rootvp);
        /*
         * Finally, throw away the lofsmount structure
         */
        free(mp->mnt_data, M_UFSMNT);   /* XXX */
        mp->mnt_data = 0;
        return (0);
}

int
lofs_root(mp, vpp)
        struct mount *mp;
        struct vnode **vpp;
{
        struct vnode *vp;

        /*
         * Return locked reference to root.
         */
        vp = VFSTOLOFS(mp)->rootvp;
        VREF(vp);
        VOP_LOCK(vp);
        *vpp = vp;
        return (0);
}

int
lofs_quotactl(mp, cmd, uid, arg, p)
        struct mount *mp;
        int cmd;
        uid_t uid;
        caddr_t arg;
        struct proc *p;
{
        return (VFS_QUOTACTL(VFSTOLOFS(mp)->looped_vfs, cmd, uid, arg, p));
}

int
lofs_statfs(mp, sbp, p)
        struct mount *mp;
        struct statfs *sbp;
        struct proc *p;
{
        int error;
        struct statfs mstat;

        bzero(&mstat, sizeof(mstat));

        error = VFS_STATFS(VFSTOLOFS(mp)->looped_vfs, &mstat, p);
        if (error)
                return (error);

        /* now copy across the "interesting" information and fake the rest */
        sbp->f_type = mstat.f_type;
        sbp->f_flags = mstat.f_flags;
        sbp->f_bsize = mstat.f_bsize;
        sbp->f_iosize = mstat.f_iosize;
        sbp->f_blocks = mstat.f_blocks;
        sbp->f_bfree = mstat.f_bfree;
        sbp->f_bavail = mstat.f_bavail;
        sbp->f_files = mstat.f_files;
        sbp->f_ffree = mstat.f_ffree;
        if (sbp != &mp->mnt_stat) {
                bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
                bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
                bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
        }
        return (0);
}

int
lofs_sync(mp, waitfor)
struct mount *mp;
int waitfor;
{
        return (0);
}

/*
 * LOFS flat namespace lookup.
 * Currently unsupported.
 */
int
lofs_vget(mp, ino, vpp)
        struct mount *mp;
        ino_t ino;
        struct vnode **vpp;
{

        return (EOPNOTSUPP);
}

int
lofs_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
        register struct mount *mp;
        struct fid *fhp;
        struct mbuf *nam;
        struct vnode **vpp;
        int *exflagsp;
        struct ucred **credanonp;
{
        return (VFS_FHTOVP(VFSTOLOFS(mp)->looped_vfs, fhp, nam, vpp, exflagsp, credanonp));
}

int
lofs_vptofh(vp, fhp)
        struct vnode *vp;
        struct fid *fhp;
{
        return (VFS_VPTOFH(LOFSVP(vp), fhp));
}

struct vfsops lofs_vfsops = {
        lofs_mount,
        lofs_start,
        lofs_unmount,
        lofs_root,
        lofs_quotactl,
        lofs_statfs,
        lofs_sync,
        lofs_vget,
        lofs_fhtovp,
        lofs_vptofh,
        lofs_init,
};