Linux kernel mirror (for testing)
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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);