fs/ctfs/ctfs_latest.c

	ctfs_latest.c revision da6c28aaf62fa55f0fdb8004aa40f88f23bf53f0
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/cred.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/gfs.h>
#include <sys/vnode.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/sysmacros.h>
#include <fs/fs_subr.h>
#include <sys/contract.h>
#include <sys/contract_impl.h>
#include <sys/ctfs.h>
#include <sys/ctfs_impl.h>
#include <sys/file.h>

/*
 * CTFS routines for the /system/contract/<type>/latest vnode.
 */

/*
 * ctfs_create_latenode
 */
vnode_t *
ctfs_create_latenode(vnode_t *pvp)
{
    return (gfs_file_create(sizeof (ctfs_latenode_t), pvp,
        ctfs_ops_latest));
}

/*
 * ctfs_latest_nested_open
 *
 * The latest node is just a doorway to the status file; this function
 * is used by ctfs_latest_access, ctfs_latest_open, and
 * ctfs_latest_getattr to obtain that file.
 */
static vnode_t *
ctfs_latest_nested_open(vnode_t *vp, cred_t *cr)
{
    contract_t *ct = ttolwp(curthread)->lwp_ct_latest[
        gfs_file_index(gfs_file_parent(vp))];

    if (ct) {
        vnode_t *cvp, *svp;

        cvp = ctfs_create_cdirnode(gfs_file_parent(vp), ct);

        gfs_file_set_index(cvp, -1);

        VERIFY(gfs_dir_lookup(cvp, "status", &svp, cr) == 0);

        VN_RELE(cvp);

        return (svp);
    }

    return (NULL);
}

/*
 * ctfs_latest_access - VOP_ACCESS entry point
 *
 * Fails if there isn't a latest contract.
 */
/* ARGSUSED */
static int
ctfs_latest_access(
    vnode_t *vp,
    int mode,
    int flags,
    cred_t *cr,
    caller_context_t *ct)
{
    vnode_t *nvp;

    if (mode & (VEXEC | VWRITE))
        return (EACCES);

    if (nvp = ctfs_latest_nested_open(vp, cr)) {
        VN_RELE(nvp);
        return (0);
    }

    return (ESRCH);
}

/*
 * ctfs_latest_open - VOP_OPEN entry point
 *
 * After checking the mode bits, opens and returns the status file for
 * the LWP's latest contract.
 */
static int
ctfs_latest_open(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
{
    vnode_t *nvp;

    if (flag != (FREAD | FOFFMAX))
        return (EINVAL);

    if (nvp = ctfs_latest_nested_open(*vpp, cr)) {
        VN_RELE(*vpp);
        *vpp = nvp;
        return (VOP_OPEN(vpp, flag, cr, ct));
    }

    return (ESRCH);
}

/*
 * ctfs_latest_getattr - the VOP_GETATTR entry point
 *
 * Fetches and calls VOP_GETATTR on the status file for the LWP's
 * latest contract.  Otherwise it fakes up something bland.
 */
static int
ctfs_latest_getattr(
    vnode_t *vp,
    vattr_t *vap,
    int flags,
    cred_t *cr,
    caller_context_t *ct)
{
    vnode_t *nvp;

    if (nvp = ctfs_latest_nested_open(vp, cr)) {
        int res = VOP_GETATTR(nvp, vap, flags, cr, ct);
        VN_RELE(nvp);
        return (res);
    }

    vap->va_type = VREG;
    vap->va_mode = 0444;
    vap->va_nlink = 1;
    vap->va_size = 0;
    vap->va_ctime.tv_sec = vp->v_vfsp->vfs_mtime;
    vap->va_ctime.tv_nsec = 0;
    vap->va_atime = vap->va_mtime = vap->va_ctime;
    ctfs_common_getattr(vp, vap);

    return (0);
}

const fs_operation_def_t ctfs_tops_latest[] = {
    { VOPNAME_OPEN,     { .vop_open = ctfs_latest_open } },
    { VOPNAME_CLOSE,    { .error = fs_inval } },
    { VOPNAME_IOCTL,    { .error = fs_inval } },
    { VOPNAME_GETATTR,  { .vop_getattr = ctfs_latest_getattr } },
    { VOPNAME_ACCESS,   { .vop_access = ctfs_latest_access } },
    { VOPNAME_READDIR,  { .error = fs_notdir } },
    { VOPNAME_LOOKUP,   { .error = fs_notdir } },
    { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } },
    { NULL, NULL }
};