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 */
20static ssize_t
21nlm_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
48static ssize_t
49nlm_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
63static const struct proc_ops lockd_end_grace_proc_ops = {
64	.proc_write	= nlm_end_grace_write,
65	.proc_read	= nlm_end_grace_read,
66	.proc_lseek	= default_llseek,
67	.proc_release	= simple_transaction_release,
68};
69
70int __init
71lockd_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_proc_ops);
80	if (!entry) {
81		remove_proc_entry("fs/lockd", NULL);
82		return -ENOMEM;
83	}
84	return 0;
85}
86
87void __exit
88lockd_remove_procfs(void)
89{
90	remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
91	remove_proc_entry("fs/lockd", NULL);
92}
93