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) 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_POINTS |
24 | #include "internal.h" |
25 | |
26 | unsigned cachefiles_debug; |
27 | module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO); |
28 | MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask" ); |
29 | |
30 | MODULE_DESCRIPTION("Mounted-filesystem based cache" ); |
31 | MODULE_AUTHOR("Red Hat, Inc." ); |
32 | MODULE_LICENSE("GPL" ); |
33 | |
34 | struct kmem_cache *cachefiles_object_jar; |
35 | |
36 | static 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 module |
44 | */ |
45 | static 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(misc: &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(name: "cachefiles_object_jar" , |
60 | size: sizeof(struct cachefiles_object), |
61 | align: 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 | |
70 | error_object_jar: |
71 | misc_deregister(misc: &cachefiles_dev); |
72 | error_dev: |
73 | cachefiles_unregister_error_injection(); |
74 | error_einj: |
75 | pr_err("failed to register: %d\n" , ret); |
76 | return ret; |
77 | } |
78 | |
79 | fs_initcall(cachefiles_init); |
80 | |
81 | /* |
82 | * clean up on module removal |
83 | */ |
84 | static void __exit cachefiles_exit(void) |
85 | { |
86 | pr_info("Unloading\n" ); |
87 | |
88 | kmem_cache_destroy(s: cachefiles_object_jar); |
89 | misc_deregister(misc: &cachefiles_dev); |
90 | cachefiles_unregister_error_injection(); |
91 | } |
92 | |
93 | module_exit(cachefiles_exit); |
94 | |