[linux-2.6-block.git] / fs / cachefiles / main.c

/* Network filesystem caching backend to use cache files on a premounted
 * filesystem
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/statfs.h>
#include <linux/sysctl.h>
#include <linux/miscdevice.h>
#define CREATE_TRACE_POINTS
#include "internal.h"

unsigned cachefiles_debug;
module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask");

MODULE_DESCRIPTION("Mounted-filesystem based cache");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");

struct kmem_cache *cachefiles_object_jar;

static struct miscdevice cachefiles_dev = {
	.minor	= MISC_DYNAMIC_MINOR,
	.name	= "cachefiles",
	.fops	= &cachefiles_daemon_fops,
};

static void cachefiles_object_init_once(void *_object)
{
	struct cachefiles_object *object = _object;

	memset(object, 0, sizeof(*object));
	spin_lock_init(&object->work_lock);
}

/*
 * initialise the fs caching module
 */
static int __init cachefiles_init(void)
{
	int ret;

	ret = misc_register(&cachefiles_dev);
	if (ret < 0)
		goto error_dev;

	/* create an object jar */
	ret = -ENOMEM;
	cachefiles_object_jar =
		kmem_cache_create("cachefiles_object_jar",
				  sizeof(struct cachefiles_object),
				  0,
				  SLAB_HWCACHE_ALIGN,
				  cachefiles_object_init_once);
	if (!cachefiles_object_jar) {
		pr_notice("Failed to allocate an object jar\n");
		goto error_object_jar;
	}

	ret = cachefiles_proc_init();
	if (ret < 0)
		goto error_proc;

	pr_info("Loaded\n");
	return 0;

error_proc:
	kmem_cache_destroy(cachefiles_object_jar);
error_object_jar:
	misc_deregister(&cachefiles_dev);
error_dev:
	pr_err("failed to register: %d\n", ret);
	return ret;
}

fs_initcall(cachefiles_init);

/*
 * clean up on module removal
 */
static void __exit cachefiles_exit(void)
{
	pr_info("Unloading\n");

	cachefiles_proc_cleanup();
	kmem_cache_destroy(cachefiles_object_jar);
	misc_deregister(&cachefiles_dev);
}

module_exit(cachefiles_exit);
Commit	Line	Data
9ae326a6 DH	1	/* Network filesystem caching backend to use cache files on a premounted
	2	* filesystem
	3	*
	4	* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public Licence
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the Licence, or (at your option) any later version.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/sched.h>
	16	#include <linux/completion.h>
	17	#include <linux/slab.h>
	18	#include <linux/fs.h>
	19	#include <linux/file.h>
	20	#include <linux/namei.h>
	21	#include <linux/mount.h>
	22	#include <linux/statfs.h>
	23	#include <linux/sysctl.h>
	24	#include <linux/miscdevice.h>
a18feb55	25	#define CREATE_TRACE_POINTS
9ae326a6 DH	26	#include "internal.h"
	27
	28	unsigned cachefiles_debug;
	29	module_param_named(debug, cachefiles_debug, uint, S_IWUSR \| S_IRUGO);
	30	MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask");
	31
	32	MODULE_DESCRIPTION("Mounted-filesystem based cache");
	33	MODULE_AUTHOR("Red Hat, Inc.");
	34	MODULE_LICENSE("GPL");
	35
	36	struct kmem_cache *cachefiles_object_jar;
	37
	38	static struct miscdevice cachefiles_dev = {
	39	.minor = MISC_DYNAMIC_MINOR,
	40	.name = "cachefiles",
	41	.fops = &cachefiles_daemon_fops,
	42	};
	43
	44	static void cachefiles_object_init_once(void *_object)
	45	{
	46	struct cachefiles_object *object = _object;
	47
	48	memset(object, 0, sizeof(*object));
	49	spin_lock_init(&object->work_lock);
	50	}
	51
	52	/*
	53	* initialise the fs caching module
	54	*/
	55	static int __init cachefiles_init(void)
	56	{
	57	int ret;
	58
	59	ret = misc_register(&cachefiles_dev);
	60	if (ret < 0)
	61	goto error_dev;
	62
	63	/* create an object jar */
	64	ret = -ENOMEM;
	65	cachefiles_object_jar =
	66	kmem_cache_create("cachefiles_object_jar",
	67	sizeof(struct cachefiles_object),
	68	0,
	69	SLAB_HWCACHE_ALIGN,
	70	cachefiles_object_init_once);
	71	if (!cachefiles_object_jar) {
0227d6ab	72	pr_notice("Failed to allocate an object jar\n");
9ae326a6 DH	73	goto error_object_jar;
	74	}
	75
	76	ret = cachefiles_proc_init();
	77	if (ret < 0)
	78	goto error_proc;
	79
0227d6ab	80	pr_info("Loaded\n");
9ae326a6 DH	81	return 0;
	82
	83	error_proc:
	84	kmem_cache_destroy(cachefiles_object_jar);
	85	error_object_jar:
	86	misc_deregister(&cachefiles_dev);
	87	error_dev:
6ff66ac7	88	pr_err("failed to register: %d\n", ret);
9ae326a6 DH	89	return ret;
	90	}
	91
	92	fs_initcall(cachefiles_init);
	93
	94	/*
	95	* clean up on module removal
	96	*/
	97	static void __exit cachefiles_exit(void)
	98	{
0227d6ab	99	pr_info("Unloading\n");
9ae326a6 DH	100
	101	cachefiles_proc_cleanup();
	102	kmem_cache_destroy(cachefiles_object_jar);
	103	misc_deregister(&cachefiles_dev);
	104	}
	105
	106	module_exit(cachefiles_exit);