ext4: journal credits calulation cleanup and fix for non-extent writepage

[linux.git] / fs / afs / main.c

/* AFS client file system
 *
 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/sched.h>
#include "internal.h"

MODULE_DESCRIPTION("AFS Client File System");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");

unsigned afs_debug;
module_param_named(debug, afs_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(debug, "AFS debugging mask");

static char *rootcell;

module_param(rootcell, charp, 0);
MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");

#ifdef AFS_CACHING_SUPPORT
static struct cachefs_netfs_operations afs_cache_ops = {
	.get_page_cookie	= afs_cache_get_page_cookie,
};

struct cachefs_netfs afs_cache_netfs = {
	.name			= "afs",
	.version		= 0,
	.ops			= &afs_cache_ops,
};
#endif

struct afs_uuid afs_uuid;

/*
 * get a client UUID
 */
static int __init afs_get_client_UUID(void)
{
	struct timespec ts;
	u64 uuidtime;
	u16 clockseq;
	int ret;

	/* read the MAC address of one of the external interfaces and construct
	 * a UUID from it */
	ret = afs_get_MAC_address(afs_uuid.node, sizeof(afs_uuid.node));
	if (ret < 0)
		return ret;

	getnstimeofday(&ts);
	uuidtime = (u64) ts.tv_sec * 1000 * 1000 * 10;
	uuidtime += ts.tv_nsec / 100;
	uuidtime += AFS_UUID_TO_UNIX_TIME;
	afs_uuid.time_low = uuidtime;
	afs_uuid.time_mid = uuidtime >> 32;
	afs_uuid.time_hi_and_version = (uuidtime >> 48) & AFS_UUID_TIMEHI_MASK;
	afs_uuid.time_hi_and_version = AFS_UUID_VERSION_TIME;

	get_random_bytes(&clockseq, 2);
	afs_uuid.clock_seq_low = clockseq;
	afs_uuid.clock_seq_hi_and_reserved =
		(clockseq >> 8) & AFS_UUID_CLOCKHI_MASK;
	afs_uuid.clock_seq_hi_and_reserved = AFS_UUID_VARIANT_STD;

	_debug("AFS UUID: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
	       afs_uuid.time_low,
	       afs_uuid.time_mid,
	       afs_uuid.time_hi_and_version,
	       afs_uuid.clock_seq_hi_and_reserved,
	       afs_uuid.clock_seq_low,
	       afs_uuid.node[0], afs_uuid.node[1], afs_uuid.node[2],
	       afs_uuid.node[3], afs_uuid.node[4], afs_uuid.node[5]);

	return 0;
}

/*
 * initialise the AFS client FS module
 */
static int __init afs_init(void)
{
	int ret;

	printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 registering.\n");

	ret = afs_get_client_UUID();
	if (ret < 0)
		return ret;

	/* register the /proc stuff */
	ret = afs_proc_init();
	if (ret < 0)
		return ret;

#ifdef AFS_CACHING_SUPPORT
	/* we want to be able to cache */
	ret = cachefs_register_netfs(&afs_cache_netfs,
				     &afs_cache_cell_index_def);
	if (ret < 0)
		goto error_cache;
#endif

	/* initialise the cell DB */
	ret = afs_cell_init(rootcell);
	if (ret < 0)
		goto error_cell_init;

	/* initialise the VL update process */
	ret = afs_vlocation_update_init();
	if (ret < 0)
		goto error_vl_update_init;

	/* initialise the callback update process */
	ret = afs_callback_update_init();

	/* create the RxRPC transport */
	ret = afs_open_socket();
	if (ret < 0)
		goto error_open_socket;

	/* register the filesystems */
	ret = afs_fs_init();
	if (ret < 0)
		goto error_fs;

	return ret;

error_fs:
	afs_close_socket();
error_open_socket:
error_vl_update_init:
error_cell_init:
#ifdef AFS_CACHING_SUPPORT
	cachefs_unregister_netfs(&afs_cache_netfs);
error_cache:
#endif
	afs_callback_update_kill();
	afs_vlocation_purge();
	afs_cell_purge();
	afs_proc_cleanup();
	rcu_barrier();
	printk(KERN_ERR "kAFS: failed to register: %d\n", ret);
	return ret;
}

/* XXX late_initcall is kludgy, but the only alternative seems to create
 * a transport upon the first mount, which is worse. Or is it?
 */
late_initcall(afs_init);	/* must be called after net/ to create socket */

/*
 * clean up on module removal
 */
static void __exit afs_exit(void)
{
	printk(KERN_INFO "kAFS: Red Hat AFS client v0.1 unregistering.\n");

	afs_fs_exit();
	afs_kill_lock_manager();
	afs_close_socket();
	afs_purge_servers();
	afs_callback_update_kill();
	afs_vlocation_purge();
	flush_scheduled_work();
	afs_cell_purge();
#ifdef AFS_CACHING_SUPPORT
	cachefs_unregister_netfs(&afs_cache_netfs);
#endif
	afs_proc_cleanup();
	rcu_barrier();
}

module_exit(afs_exit);