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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Network filesystem caching backend to use cache files on a premounted3 * filesystem4 *5 * Copyright (C) 2021 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#include <linux/netfs.h>22#include <trace/events/netfs.h>23#define CREATE_TRACE_POINTS24#include "internal.h"25 26unsigned cachefiles_debug;27module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO);28MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask");29 30MODULE_DESCRIPTION("Mounted-filesystem based cache");31MODULE_AUTHOR("Red Hat, Inc.");32MODULE_LICENSE("GPL");33 34struct kmem_cache *cachefiles_object_jar;35 36static struct miscdevice cachefiles_dev = {37 .minor = MISC_DYNAMIC_MINOR,38 .name = "cachefiles",39 .fops = &cachefiles_daemon_fops,40};41 42/*43 * initialise the fs caching module44 */45static int __init cachefiles_init(void)46{47 int ret;48 49 ret = cachefiles_register_error_injection();50 if (ret < 0)51 goto error_einj;52 ret = misc_register(&cachefiles_dev);53 if (ret < 0)54 goto error_dev;55 56 /* create an object jar */57 ret = -ENOMEM;58 cachefiles_object_jar =59 kmem_cache_create("cachefiles_object_jar",60 sizeof(struct cachefiles_object),61 0, SLAB_HWCACHE_ALIGN, NULL);62 if (!cachefiles_object_jar) {63 pr_notice("Failed to allocate an object jar\n");64 goto error_object_jar;65 }66 67 pr_info("Loaded\n");68 return 0;69 70error_object_jar:71 misc_deregister(&cachefiles_dev);72error_dev:73 cachefiles_unregister_error_injection();74error_einj:75 pr_err("failed to register: %d\n", ret);76 return ret;77}78 79fs_initcall(cachefiles_init);80 81/*82 * clean up on module removal83 */84static void __exit cachefiles_exit(void)85{86 pr_info("Unloading\n");87 88 kmem_cache_destroy(cachefiles_object_jar);89 misc_deregister(&cachefiles_dev);90 cachefiles_unregister_error_injection();91}92 93module_exit(cachefiles_exit);94