/*
 * Copyright (c) 1989 Jan-Simon Pendry
 * Copyright (c) 1989 Imperial College of Science, Technology & Medicine
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry at Imperial College, London.
 *
 * 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. 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: @(#)ifs_ops.c     8.1 (Berkeley) 6/6/93
 *      $Id: ifs_ops.c,v 1.7 2022/12/28 21:30:15 jmc Exp $
 */

#include "am.h"

#ifdef HAS_IFS

/*
 * Inheritance file system.
 * This implements a filesystem restart.
 *
 * This is a *gross* hack - it knows far too
 * much about the way other parts of the
 * system work.  See restart.c too.
 */
static char not_a_filesystem[] = "Attempting to inherit not-a-filesystem";
/*
 * This should never be called.
 */
static char *
ifs_match(am_opts *fo)
{
        plog(XLOG_FATAL, "ifs_match called!");
        return 0;
}

static int
ifs_init(mntfs *mf)
{
        mntfs *mf_link = (mntfs *) mf->mf_private;
        if (mf_link == 0) {
                plog(XLOG_FATAL, "%s", not_a_filesystem);
                return EINVAL;
        }
#ifdef notdef
        /*
         * Fill in attribute fields
         */
        mf_link->mf_fattr.type = NFLNK;
        mf_link->mf_fattr.mode = NFSMODE_LNK | 0777;
        mf_link->mf_fattr.nlink = 1;
        mf_link->mf_fattr.size = MAXPATHLEN / 4;
#endif
        if (mf_link->mf_ops->fs_init)
                return (*mf_link->mf_ops->fs_init)(mf_link);
        return 0;
}

static mntfs *
ifs_inherit(mntfs *mf)
{
        /*
         * Take the linked mount point and
         * propagate.
         */
        mntfs *mf_link = (mntfs *) mf->mf_private;
        if (mf_link == 0) {
                plog(XLOG_FATAL, "%s", not_a_filesystem);
                return 0;       /*XXX*/
        }

        mf_link->mf_fo = mf->mf_fo;
#ifdef notdef
        mf_link->mf_fattr.fileid = mf->mf_fattr.fileid;
#endif /* notdef */

        /*
         * Discard the old map.
         * Don't call am_unmounted since this
         * node was never really mounted in the
         * first place.
         */
        mf->mf_private = 0;
        free_mntfs(mf);
        /*
         * Free the dangling reference
         * to the mount link.
         */
        free_mntfs(mf_link);
        /*
         * Get a hold of the other entry
         */
        mf_link->mf_flags &= ~MFF_RESTART;

        /* Say what happened */
        plog(XLOG_INFO, "restarting %s on %s", mf_link->mf_info, mf_link->mf_mount);

        return mf_link;
}

static int
ifs_mount(am_node *mp)
{
        mntfs *newmf = ifs_inherit(mp->am_mnt);
        if (newmf) {
                mp->am_mnt = newmf;
                /*
                 * XXX - must do the am_mounted call here
                 */
                if (newmf->mf_ops->fs_flags & FS_MBACKGROUND)
                        am_mounted(mp);

                new_ttl(mp);
                return 0;
        }
        return EINVAL;
}

static int
ifs_fmount(mntfs *mf)
{
        am_node *mp = find_mf(mf);
        if (mp)
                return ifs_mount(mp);
        return ifs_inherit(mf) ? 0 : EINVAL;
}

static int
ifs_fumount(mntfs *mf)
{
        /*
         * Always succeed
         */
        return 0;
}

/*
 * Ops structure
 */
am_ops ifs_ops = {
        "inherit",
        ifs_match,
        ifs_init,
        ifs_mount,
        ifs_fmount,
        auto_fumount,
        ifs_fumount,
        efs_lookuppn,
        efs_readdir,
        0, /* ifs_readlink */
        0, /* ifs_mounted */
        0, /* ifs_umounted */
        find_afs_srvr,
        FS_DISCARD
};

#endif /* HAS_IFS */