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