1// SPDX-License-Identifier: GPL-2.0-or-later 2/* Network filesystem caching backend to use cache files on a premounted 3 * filesystem 4 * 5 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 6 * Written by David Howells (dhowells@redhat.com) 7 */ 8 9#include <linux/module.h> 10#include <linux/init.h> 11#include <linux/sched.h> 12#include <linux/completion.h> 13#include <linux/slab.h> 14#include <linux/fs.h> 15#include <linux/file.h> 16#include <linux/namei.h> 17#include <linux/mount.h> 18#include <linux/statfs.h> 19#include <linux/sysctl.h> 20#include <linux/miscdevice.h> 21#define CREATE_TRACE_POINTS 22#include "internal.h" 23 24unsigned cachefiles_debug; 25module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO); 26MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask"); 27 28MODULE_DESCRIPTION("Mounted-filesystem based cache"); 29MODULE_AUTHOR("Red Hat, Inc."); 30MODULE_LICENSE("GPL"); 31 32struct kmem_cache *cachefiles_object_jar; 33 34static struct miscdevice cachefiles_dev = { 35 .minor = MISC_DYNAMIC_MINOR, 36 .name = "cachefiles", 37 .fops = &cachefiles_daemon_fops, 38}; 39 40static void cachefiles_object_init_once(void *_object) 41{ 42 struct cachefiles_object *object = _object; 43 44 memset(object, 0, sizeof(*object)); 45 spin_lock_init(&object->work_lock); 46} 47 48/* 49 * initialise the fs caching module 50 */ 51static int __init cachefiles_init(void) 52{ 53 int ret; 54 55 ret = misc_register(&cachefiles_dev); 56 if (ret < 0) 57 goto error_dev; 58 59 /* create an object jar */ 60 ret = -ENOMEM; 61 cachefiles_object_jar = 62 kmem_cache_create("cachefiles_object_jar", 63 sizeof(struct cachefiles_object), 64 0, 65 SLAB_HWCACHE_ALIGN, 66 cachefiles_object_init_once); 67 if (!cachefiles_object_jar) { 68 pr_notice("Failed to allocate an object jar\n"); 69 goto error_object_jar; 70 } 71 72 ret = cachefiles_proc_init(); 73 if (ret < 0) 74 goto error_proc; 75 76 pr_info("Loaded\n"); 77 return 0; 78 79error_proc: 80 kmem_cache_destroy(cachefiles_object_jar); 81error_object_jar: 82 misc_deregister(&cachefiles_dev); 83error_dev: 84 pr_err("failed to register: %d\n", ret); 85 return ret; 86} 87 88fs_initcall(cachefiles_init); 89 90/* 91 * clean up on module removal 92 */ 93static void __exit cachefiles_exit(void) 94{ 95 pr_info("Unloading\n"); 96 97 cachefiles_proc_cleanup(); 98 kmem_cache_destroy(cachefiles_object_jar); 99 misc_deregister(&cachefiles_dev); 100} 101 102module_exit(cachefiles_exit); 103