/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_LLITE

#include <linux/module.h>
#include <linux/types.h>
#include "../include/lustre_lite.h"
#include "../include/lustre_ha.h"
#include "../include/lustre_dlm.h"
#include <linux/init.h>
#include <linux/fs.h>
#include "../include/lprocfs_status.h"
#include "llite_internal.h"

static struct kmem_cache *ll_inode_cachep;

static struct inode *ll_alloc_inode(struct super_block *sb)
{
        struct ll_inode_info *lli;
        ll_stats_ops_tally(ll_s2sbi(sb), LPROC_LL_ALLOC_INODE, 1);
        OBD_SLAB_ALLOC_PTR_GFP(lli, ll_inode_cachep, GFP_NOFS);
        if (lli == NULL)
                return NULL;

        inode_init_once(&lli->lli_vfs_inode);
        return &lli->lli_vfs_inode;
}

static void ll_inode_destroy_callback(struct rcu_head *head)
{
        struct inode *inode = container_of(head, struct inode, i_rcu);
        struct ll_inode_info *ptr = ll_i2info(inode);
        OBD_SLAB_FREE_PTR(ptr, ll_inode_cachep);
}

static void ll_destroy_inode(struct inode *inode)
{
        call_rcu(&inode->i_rcu, ll_inode_destroy_callback);
}

/* exported operations */
struct super_operations lustre_super_operations = {
        .alloc_inode   = ll_alloc_inode,
        .destroy_inode = ll_destroy_inode,
        .evict_inode   = ll_delete_inode,
        .put_super     = ll_put_super,
        .statfs = ll_statfs,
        .umount_begin  = ll_umount_begin,
        .remount_fs    = ll_remount_fs,
        .show_options  = ll_show_options,
};
MODULE_ALIAS_FS("lustre");

void lustre_register_client_process_config(int (*cpc)(struct lustre_cfg *lcfg));

static int __init init_lustre_lite(void)
{
        struct proc_dir_entry *entry;
        lnet_process_id_t lnet_id;
        struct timeval tv;
        int i, rc, seed[2];

        CLASSERT(sizeof(LUSTRE_VOLATILE_HDR) == LUSTRE_VOLATILE_HDR_LEN + 1);

        /* print an address of _any_ initialized kernel symbol from this
         * module, to allow debugging with gdb that doesn't support data
         * symbols from modules.*/
        CDEBUG(D_INFO, "Lustre client module (%p).\n",
               &lustre_super_operations);

        rc = -ENOMEM;
        ll_inode_cachep = kmem_cache_create("lustre_inode_cache",
                                            sizeof(struct ll_inode_info),
                                            0, SLAB_HWCACHE_ALIGN, NULL);
        if (ll_inode_cachep == NULL)
                goto out_cache;

        ll_file_data_slab = kmem_cache_create("ll_file_data",
                                                 sizeof(struct ll_file_data), 0,
                                                 SLAB_HWCACHE_ALIGN, NULL);
        if (ll_file_data_slab == NULL)
                goto out_cache;

        ll_remote_perm_cachep = kmem_cache_create("ll_remote_perm_cache",
                                                  sizeof(struct ll_remote_perm),
                                                      0, 0, NULL);
        if (ll_remote_perm_cachep == NULL)
                goto out_cache;

        ll_rmtperm_hash_cachep = kmem_cache_create("ll_rmtperm_hash_cache",
                                                   REMOTE_PERM_HASHSIZE *
                                                   sizeof(struct list_head),
                                                   0, 0, NULL);
        if (ll_rmtperm_hash_cachep == NULL)
                goto out_cache;

        entry = lprocfs_register("llite", proc_lustre_root, NULL, NULL);
        if (IS_ERR(entry)) {
                rc = PTR_ERR(entry);
                CERROR("cannot register '/proc/fs/lustre/llite': rc = %d\n",
                       rc);
                goto out_cache;
        }

        proc_lustre_fs_root = entry;

        cfs_get_random_bytes(seed, sizeof(seed));

        /* Nodes with small feet have little entropy. The NID for this
         * node gives the most entropy in the low bits */
        for (i = 0;; i++) {
                if (LNetGetId(i, &lnet_id) == -ENOENT)
                        break;

                if (LNET_NETTYP(LNET_NIDNET(lnet_id.nid)) != LOLND)
                        seed[0] ^= LNET_NIDADDR(lnet_id.nid);
        }

        do_gettimeofday(&tv);
        cfs_srand(tv.tv_sec ^ seed[0], tv.tv_usec ^ seed[1]);

        init_timer(&ll_capa_timer);
        ll_capa_timer.function = ll_capa_timer_callback;
        rc = ll_capa_thread_start();
        if (rc != 0)
                goto out_proc;

        rc = vvp_global_init();
        if (rc != 0)
                goto out_capa;

        rc = ll_xattr_init();
        if (rc != 0)
                goto out_vvp;

        lustre_register_client_fill_super(ll_fill_super);
        lustre_register_kill_super_cb(ll_kill_super);
        lustre_register_client_process_config(ll_process_config);

        return 0;

out_vvp:
        vvp_global_fini();
out_capa:
        del_timer(&ll_capa_timer);
        ll_capa_thread_stop();
out_proc:
        lprocfs_remove(&proc_lustre_fs_root);
out_cache:
        if (ll_inode_cachep != NULL)
                kmem_cache_destroy(ll_inode_cachep);

        if (ll_file_data_slab != NULL)
                kmem_cache_destroy(ll_file_data_slab);

        if (ll_remote_perm_cachep != NULL)
                kmem_cache_destroy(ll_remote_perm_cachep);

        if (ll_rmtperm_hash_cachep != NULL)
                kmem_cache_destroy(ll_rmtperm_hash_cachep);

        return rc;
}

static void __exit exit_lustre_lite(void)
{
        lustre_register_client_fill_super(NULL);
        lustre_register_kill_super_cb(NULL);
        lustre_register_client_process_config(NULL);

        lprocfs_remove(&proc_lustre_fs_root);

        ll_xattr_fini();
        vvp_global_fini();
        del_timer(&ll_capa_timer);
        ll_capa_thread_stop();
        LASSERTF(capa_count[CAPA_SITE_CLIENT] == 0,
                 "client remaining capa count %d\n",
                 capa_count[CAPA_SITE_CLIENT]);

        kmem_cache_destroy(ll_inode_cachep);
        kmem_cache_destroy(ll_rmtperm_hash_cachep);

        kmem_cache_destroy(ll_remote_perm_cachep);

        kmem_cache_destroy(ll_file_data_slab);
}

MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
MODULE_DESCRIPTION("Lustre Lite Client File System");
MODULE_LICENSE("GPL");

module_init(init_lustre_lite);
module_exit(exit_lustre_lite);