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> 25#include "internal.h" 26 27unsigned cachefiles_debug; 28module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO); 29MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask"); 30 31MODULE_DESCRIPTION("Mounted-filesystem based cache"); 32MODULE_AUTHOR("Red Hat, Inc."); 33MODULE_LICENSE("GPL"); 34 35struct kmem_cache *cachefiles_object_jar; 36 37static struct miscdevice cachefiles_dev = { 38 .minor = MISC_DYNAMIC_MINOR, 39 .name = "cachefiles", 40 .fops = &cachefiles_daemon_fops, 41}; 42 43static void cachefiles_object_init_once(void *_object) 44{ 45 struct cachefiles_object *object = _object; 46 47 memset(object, 0, sizeof(*object)); 48 spin_lock_init(&object->work_lock); 49} 50 51/* 52 * initialise the fs caching module 53 */ 54static int __init cachefiles_init(void) 55{ 56 int ret; 57 58 ret = misc_register(&cachefiles_dev); 59 if (ret < 0) 60 goto error_dev; 61 62 /* create an object jar */ 63 ret = -ENOMEM; 64 cachefiles_object_jar = 65 kmem_cache_create("cachefiles_object_jar", 66 sizeof(struct cachefiles_object), 67 0, 68 SLAB_HWCACHE_ALIGN, 69 cachefiles_object_init_once); 70 if (!cachefiles_object_jar) { 71 printk(KERN_NOTICE 72 "CacheFiles: Failed to allocate an object jar\n"); 73 goto error_object_jar; 74 } 75 76 ret = cachefiles_proc_init(); 77 if (ret < 0) 78 goto error_proc; 79 80 printk(KERN_INFO "CacheFiles: Loaded\n"); 81 return 0; 82 83error_proc: 84 kmem_cache_destroy(cachefiles_object_jar); 85error_object_jar: 86 misc_deregister(&cachefiles_dev); 87error_dev: 88 kerror("failed to register: %d", ret); 89 return ret; 90} 91 92fs_initcall(cachefiles_init); 93 94/* 95 * clean up on module removal 96 */ 97static void __exit cachefiles_exit(void) 98{ 99 printk(KERN_INFO "CacheFiles: Unloading\n"); 100 101 cachefiles_proc_cleanup(); 102 kmem_cache_destroy(cachefiles_object_jar); 103 misc_deregister(&cachefiles_dev); 104} 105 106module_exit(cachefiles_exit); 107