usr/src/sys/miscfs/umapfs/umap_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
 * the UCLA Ficus project.
 *
 * 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.
 *
 *      @(#)umap_vfsops.c       8.3 (Berkeley) 1/21/94
 *
 * @(#)null_vfsops.c       1.5 (Berkeley) 7/10/92
 */

/*
 * Umap Layer
 * (See mount_umap(8) for a description of this layer.)
 */

#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/umapfs/umap.h>

/*
 * Mount umap layer
 */
int
umapfs_mount(mp, path, data, ndp, p)
        struct mount *mp;
        char *path;
        caddr_t data;
        struct nameidata *ndp;
        struct proc *p;
{
        struct umap_args args;
        struct vnode *lowerrootvp, *vp;
        struct vnode *umapm_rootvp;
        struct umap_mount *amp;
        u_int size;
        int error;

#ifdef UMAPFS_DIAGNOSTIC
        printf("umapfs_mount(mp = %x)\n", mp);
#endif

        /*
         * Update is a no-op
         */
        if (mp->mnt_flag & MNT_UPDATE) {
                return (EOPNOTSUPP);
                /* return (VFS_MOUNT(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, path, data, ndp, p));*/
        }

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

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

        /*
         * Sanity check on lower vnode
         */
        lowerrootvp = ndp->ni_vp;
#ifdef UMAPFS_DIAGNOSTIC
        printf("vp = %x, check for VDIR...\n", lowerrootvp);
#endif
        vrele(ndp->ni_dvp);
        ndp->ni_dvp = 0;

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

#ifdef UMAPFS_DIAGNOSTIC
        printf("mp = %x\n", mp);
#endif

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

        /*
         * Save reference to underlying FS
         */
        amp->umapm_vfs = lowerrootvp->v_mount;

        /*
         * Now copy in the number of entries and maps for umap mapping.
         */
        amp->info_nentries = args.nentries;
        amp->info_gnentries = args.gnentries;
        error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
            2*sizeof(u_long)*args.nentries);
        if (error)
                return (error);

#ifdef UMAP_DIAGNOSTIC
        printf("umap_mount:nentries %d\n",args.nentries);
        for (i = 0; i < args.nentries; i++)
                printf("   %d maps to %d\n", amp->info_mapdata[i][0],
                    amp->info_mapdata[i][1]);
#endif

        error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
            2*sizeof(u_long)*args.nentries);
        if (error)
                return (error);

#ifdef UMAP_DIAGNOSTIC
        printf("umap_mount:gnentries %d\n",args.gnentries);
        for (i = 0; i < args.gnentries; i++)
                printf("        group %d maps to %d\n",
                    amp->info_gmapdata[i][0],
                    amp->info_gmapdata[i][1]);
#endif


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

        /*
         * Keep a held reference to the root vnode.
         * It is vrele'd in umapfs_unmount.
         */
        umapm_rootvp = vp;
        umapm_rootvp->v_flag |= VROOT;
        amp->umapm_rootvp = umapm_rootvp;
        if (UMAPVPTOLOWERVP(umapm_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);
#ifdef UMAPFS_DIAGNOSTIC
        printf("umapfs_mount: lower %s, alias at %s\n",
                mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
#endif
        return (0);
}

/*
 * VFS start.  Nothing needed here - the start routine
 * on the underlying filesystem will have been called
 * when that filesystem was mounted.
 */
int
umapfs_start(mp, flags, p)
        struct mount *mp;
        int flags;
        struct proc *p;
{
        return (0);
        /* return (VFS_START(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, flags, p)); */
}

/*
 * Free reference to umap layer
 */
int
umapfs_unmount(mp, mntflags, p)
        struct mount *mp;
        int mntflags;
        struct proc *p;
{
        struct vnode *umapm_rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
        int error;
        int flags = 0;
        extern int doforce;

#ifdef UMAPFS_DIAGNOSTIC
        printf("umapfs_unmount(mp = %x)\n", mp);
#endif

        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...
         */
#ifdef notyet
        mntflushbuf(mp, 0);
        if (mntinvalbuf(mp, 1))
                return (EBUSY);
#endif
        if (umapm_rootvp->v_usecount > 1)
                return (EBUSY);
        if (error = vflush(mp, umapm_rootvp, flags))
                return (error);

#ifdef UMAPFS_DIAGNOSTIC
        vprint("alias root of lower", umapm_rootvp);
#endif
        /*
         * Release reference on underlying root vnode
         */
        vrele(umapm_rootvp);
        /*
         * And blow it away for future re-use
         */
        vgone(umapm_rootvp);
        /*
         * Finally, throw away the umap_mount structure
         */
        free(mp->mnt_data, M_UFSMNT);   /* XXX */
        mp->mnt_data = 0;
        return (0);
}

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

#ifdef UMAPFS_DIAGNOSTIC
        printf("umapfs_root(mp = %x, vp = %x->%x)\n", mp,
                        MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
                        UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp)
                        );
#endif

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

int
umapfs_quotactl(mp, cmd, uid, arg, p)
        struct mount *mp;
        int cmd;
        uid_t uid;
        caddr_t arg;
        struct proc *p;
{
        return (VFS_QUOTACTL(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, cmd, uid, arg, p));
}

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

#ifdef UMAPFS_DIAGNOSTIC
        printf("umapfs_statfs(mp = %x, vp = %x->%x)\n", mp,
                        MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
                        UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp)
                        );
#endif

        bzero(&mstat, sizeof(mstat));

        error = VFS_STATFS(MOUNTTOUMAPMOUNT(mp)->umapm_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
umapfs_sync(mp, waitfor, cred, p)
        struct mount *mp;
        int waitfor;
        struct ucred *cred;
        struct proc *p;
{
        /*
         * XXX - Assumes no data cached at umap layer.
         */
        return (0);
}

int
umapfs_vget(mp, ino, vpp)
        struct mount *mp;
        ino_t ino;
        struct vnode **vpp;
{

        return (VFS_VGET(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, ino, vpp));
}

int
umapfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
        struct mount *mp;
        struct fid *fidp;
        struct mbuf *nam;
        struct vnode **vpp;
        int *exflagsp;
        struct ucred**credanonp;
{

        return (VFS_FHTOVP(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, fidp, nam, vpp, exflagsp,credanonp));
}

int
umapfs_vptofh(vp, fhp)
        struct vnode *vp;
        struct fid *fhp;
{
        return (VFS_VPTOFH(UMAPVPTOLOWERVP(vp), fhp));
}

int umapfs_init __P((void));

struct vfsops umap_vfsops = {
        umapfs_mount,
        umapfs_start,
        umapfs_unmount,
        umapfs_root,
        umapfs_quotactl,
        umapfs_statfs,
        umapfs_sync,
        umapfs_vget,
        umapfs_fhtovp,
        umapfs_vptofh,
        umapfs_init,
};