/*
 * 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]);
	setup_timer(&ll_capa_timer, ll_capa_timer_callback, 0);
	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);