1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /* Network filesystem caching backend to use cache files on a premounted
3*4882a593Smuzhiyun * filesystem
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
6*4882a593Smuzhiyun * Written by David Howells (dhowells@redhat.com)
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/init.h>
11*4882a593Smuzhiyun #include <linux/sched.h>
12*4882a593Smuzhiyun #include <linux/completion.h>
13*4882a593Smuzhiyun #include <linux/slab.h>
14*4882a593Smuzhiyun #include <linux/fs.h>
15*4882a593Smuzhiyun #include <linux/file.h>
16*4882a593Smuzhiyun #include <linux/namei.h>
17*4882a593Smuzhiyun #include <linux/mount.h>
18*4882a593Smuzhiyun #include <linux/statfs.h>
19*4882a593Smuzhiyun #include <linux/sysctl.h>
20*4882a593Smuzhiyun #include <linux/miscdevice.h>
21*4882a593Smuzhiyun #define CREATE_TRACE_POINTS
22*4882a593Smuzhiyun #include "internal.h"
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun unsigned cachefiles_debug;
25*4882a593Smuzhiyun module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO);
26*4882a593Smuzhiyun MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask");
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun MODULE_DESCRIPTION("Mounted-filesystem based cache");
29*4882a593Smuzhiyun MODULE_AUTHOR("Red Hat, Inc.");
30*4882a593Smuzhiyun MODULE_LICENSE("GPL");
31*4882a593Smuzhiyun MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun struct kmem_cache *cachefiles_object_jar;
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun static struct miscdevice cachefiles_dev = {
36*4882a593Smuzhiyun .minor = MISC_DYNAMIC_MINOR,
37*4882a593Smuzhiyun .name = "cachefiles",
38*4882a593Smuzhiyun .fops = &cachefiles_daemon_fops,
39*4882a593Smuzhiyun };
40*4882a593Smuzhiyun
cachefiles_object_init_once(void * _object)41*4882a593Smuzhiyun static void cachefiles_object_init_once(void *_object)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun struct cachefiles_object *object = _object;
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun memset(object, 0, sizeof(*object));
46*4882a593Smuzhiyun spin_lock_init(&object->work_lock);
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun /*
50*4882a593Smuzhiyun * initialise the fs caching module
51*4882a593Smuzhiyun */
cachefiles_init(void)52*4882a593Smuzhiyun static int __init cachefiles_init(void)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun int ret;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun ret = misc_register(&cachefiles_dev);
57*4882a593Smuzhiyun if (ret < 0)
58*4882a593Smuzhiyun goto error_dev;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun /* create an object jar */
61*4882a593Smuzhiyun ret = -ENOMEM;
62*4882a593Smuzhiyun cachefiles_object_jar =
63*4882a593Smuzhiyun kmem_cache_create("cachefiles_object_jar",
64*4882a593Smuzhiyun sizeof(struct cachefiles_object),
65*4882a593Smuzhiyun 0,
66*4882a593Smuzhiyun SLAB_HWCACHE_ALIGN,
67*4882a593Smuzhiyun cachefiles_object_init_once);
68*4882a593Smuzhiyun if (!cachefiles_object_jar) {
69*4882a593Smuzhiyun pr_notice("Failed to allocate an object jar\n");
70*4882a593Smuzhiyun goto error_object_jar;
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun ret = cachefiles_proc_init();
74*4882a593Smuzhiyun if (ret < 0)
75*4882a593Smuzhiyun goto error_proc;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun pr_info("Loaded\n");
78*4882a593Smuzhiyun return 0;
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun error_proc:
81*4882a593Smuzhiyun kmem_cache_destroy(cachefiles_object_jar);
82*4882a593Smuzhiyun error_object_jar:
83*4882a593Smuzhiyun misc_deregister(&cachefiles_dev);
84*4882a593Smuzhiyun error_dev:
85*4882a593Smuzhiyun pr_err("failed to register: %d\n", ret);
86*4882a593Smuzhiyun return ret;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun fs_initcall(cachefiles_init);
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun /*
92*4882a593Smuzhiyun * clean up on module removal
93*4882a593Smuzhiyun */
cachefiles_exit(void)94*4882a593Smuzhiyun static void __exit cachefiles_exit(void)
95*4882a593Smuzhiyun {
96*4882a593Smuzhiyun pr_info("Unloading\n");
97*4882a593Smuzhiyun
98*4882a593Smuzhiyun cachefiles_proc_cleanup();
99*4882a593Smuzhiyun kmem_cache_destroy(cachefiles_object_jar);
100*4882a593Smuzhiyun misc_deregister(&cachefiles_dev);
101*4882a593Smuzhiyun }
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun module_exit(cachefiles_exit);
104