/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <fs/fs_subr.h>

#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/modctl.h>
#include <sys/objfs.h>
#include <sys/objfs_impl.h>
#include <sys/vfs_opreg.h>
#include <sys/systm.h>

extern int last_module_id;

static int objfs_root_do_lookup(vnode_t *, const char *, vnode_t **, ino64_t *,
    cred_t *, int, int *, pathname_t *);
static int objfs_root_do_readdir(vnode_t *, void *, int *,
    offset_t *, offset_t *, void *, int);

vnode_t *
objfs_create_root(vfs_t *vfsp)
{
        vnode_t *vp = gfs_root_create(sizeof (objfs_rootnode_t), vfsp,
            objfs_ops_root, OBJFS_INO_ROOT, NULL, NULL, OBJFS_NAME_MAX,
            objfs_root_do_readdir, objfs_root_do_lookup);

        return (vp);
}

/* ARGSUSED */
static int
objfs_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
        caller_context_t *ct)
{
        vap->va_type = VDIR;
        vap->va_mode = 0555;
        vap->va_nodeid = gfs_file_inode(vp);
        vap->va_nlink = objfs_nobjs() + 2;
        vap->va_size = vap->va_nlink;
        vap->va_atime.tv_sec = vp->v_vfsp->vfs_mtime;
        vap->va_atime.tv_nsec = 0;
        vap->va_mtime = vap->va_ctime = vap->va_atime;
        return (objfs_common_getattr(vp, vap));
}

/* ARGSUSED */
static int
objfs_root_do_lookup(vnode_t *vp, const char *nm, vnode_t **vpp, ino64_t *inop,
    cred_t *cr, int flags, int *deflags, pathname_t *rpnp)
{
        int result = ENOENT;
        struct modctl *mp;

        /*
         * Run through all the loaded modules on the system looking for
         * a matching module name.
         */
        mutex_enter(&mod_lock);
        mp = &modules;
        do {
                if (mp->mod_loaded &&
                    strcmp(nm, mp->mod_modname) == 0) {
                        /*
                         * We drop mod_lock in order to do allocations,
                         * as modctls are persistent.
                         */
                        mutex_exit(&mod_lock);
                        *vpp = objfs_create_odirnode(vp, mp);
                        *inop = OBJFS_INO_ODIR(mp->mod_id);
                        mutex_enter(&mod_lock);
                        result = 0;
                        break;
                }
        } while ((mp = mp->mod_next) != &modules);
        mutex_exit(&mod_lock);

        return (result);
}

/* ARGSUSED */
int
objfs_root_do_readdir(vnode_t *vp, void *dp, int *eofp,
    offset_t *offp, offset_t *nextp, void *data, int flags)
{
        struct modctl **mpp = data;
        struct modctl *mp = *mpp;
        struct dirent64 *odp = dp;

        ASSERT(!(flags & V_RDDIR_ENTFLAGS));

        mutex_enter(&mod_lock);

        /* Check for EOF */
        if (*offp >= last_module_id) {
                *eofp = 1;
                mutex_exit(&mod_lock);
                return (0);
        }

        /*
         * Find the appropriate modctl
         */
        while (mp->mod_id < *offp) {
                mp = mp->mod_next;
                ASSERT(mp != &modules);
        }

        while (!mp->mod_loaded && mp != &modules)
                mp = mp->mod_next;

        if (mp == &modules && *offp != 0) {
                *eofp = 1;
                mutex_exit(&mod_lock);
                return (0);
        }

        /*
         * The modctl will not change, as they are persistent.
         */
        mutex_exit(&mod_lock);

        (void) strncpy(odp->d_name, mp->mod_modname, OBJFS_NAME_MAX);
        odp->d_ino = OBJFS_INO_ODIR(mp->mod_id);
        *offp = mp->mod_id;
        *nextp = mp->mod_id + 1;

        return (0);
}

/* ARGSUSED */
static int
objfs_root_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
        caller_context_t *ct, int flags)
{
        struct modctl *mp = &modules;

        return (gfs_dir_readdir(vp, uiop, eofp, &mp, cr, ct, flags));
}

const fs_operation_def_t objfs_tops_root[] = {
        { VOPNAME_OPEN,         { .vop_open = objfs_dir_open } },
        { VOPNAME_CLOSE,        { .vop_close = objfs_common_close } },
        { VOPNAME_IOCTL,        { .error = fs_inval } },
        { VOPNAME_GETATTR,      { .vop_getattr = objfs_root_getattr } },
        { VOPNAME_ACCESS,       { .vop_access = objfs_dir_access } },
        { VOPNAME_READDIR,      { .vop_readdir = objfs_root_readdir } },
        { VOPNAME_LOOKUP,       { .vop_lookup = gfs_vop_lookup } },
        { VOPNAME_SEEK,         { .vop_seek = fs_seek } },
        { VOPNAME_INACTIVE,     { .vop_inactive = gfs_vop_inactive } },
        { NULL }
};