1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Procfs support for lockd
4 *
5 * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
6 */
7
8 #include <linux/fs.h>
9 #include <linux/proc_fs.h>
10 #include <linux/module.h>
11 #include <linux/nsproxy.h>
12 #include <net/net_namespace.h>
13
14 #include "netns.h"
15 #include "procfs.h"
16
17 /*
18 * We only allow strings that start with 'Y', 'y', or '1'.
19 */
20 static ssize_t
nlm_end_grace_write(struct file * file,const char __user * buf,size_t size,loff_t * pos)21 nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
22 loff_t *pos)
23 {
24 char *data;
25 struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
26 lockd_net_id);
27
28 if (size < 1)
29 return -EINVAL;
30
31 data = simple_transaction_get(file, buf, size);
32 if (IS_ERR(data))
33 return PTR_ERR(data);
34
35 switch(data[0]) {
36 case 'Y':
37 case 'y':
38 case '1':
39 locks_end_grace(&ln->lockd_manager);
40 break;
41 default:
42 return -EINVAL;
43 }
44
45 return size;
46 }
47
48 static ssize_t
nlm_end_grace_read(struct file * file,char __user * buf,size_t size,loff_t * pos)49 nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
50 loff_t *pos)
51 {
52 struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
53 lockd_net_id);
54 char resp[3];
55
56 resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
57 resp[1] = '\n';
58 resp[2] = '\0';
59
60 return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
61 }
62
63 static const struct file_operations lockd_end_grace_operations = {
64 .write = nlm_end_grace_write,
65 .read = nlm_end_grace_read,
66 .llseek = default_llseek,
67 .release = simple_transaction_release,
68 };
69
70 int __init
lockd_create_procfs(void)71 lockd_create_procfs(void)
72 {
73 struct proc_dir_entry *entry;
74
75 entry = proc_mkdir("fs/lockd", NULL);
76 if (!entry)
77 return -ENOMEM;
78 entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
79 &lockd_end_grace_operations);
80 if (!entry) {
81 remove_proc_entry("fs/lockd", NULL);
82 return -ENOMEM;
83 }
84 return 0;
85 }
86
87 void __exit
lockd_remove_procfs(void)88 lockd_remove_procfs(void)
89 {
90 remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
91 remove_proc_entry("fs/lockd", NULL);
92 }
93