linuxdebug/fs/lockd/procfs.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* Procfs support for lockd
*
* Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
*/
#include <linux/fs.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include "netns.h"
#include "procfs.h"
/*
* We only allow strings that start with 'Y', 'y', or '1'.
*/
static ssize_t
nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
loff_t *pos)
{
char *data;
struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
lockd_net_id);
if (size < 1)
return -EINVAL;
data = simple_transaction_get(file, buf, size);
if (IS_ERR(data))
return PTR_ERR(data);
switch(data[0]) {
case 'Y':
case 'y':
case '1':
locks_end_grace(&ln->lockd_manager);
break;
default:
return -EINVAL;
}
return size;
}
static ssize_t
nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
loff_t *pos)
{
struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
lockd_net_id);
char resp[3];
resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
resp[1] = '\n';
resp[2] = '\0';
return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
}
static const struct proc_ops lockd_end_grace_proc_ops = {
.proc_write = nlm_end_grace_write,
.proc_read = nlm_end_grace_read,
.proc_lseek = default_llseek,
.proc_release = simple_transaction_release,
};
int __init
lockd_create_procfs(void)
{
struct proc_dir_entry *entry;
entry = proc_mkdir("fs/lockd", NULL);
if (!entry)
return -ENOMEM;
entry = proc_create("nlm_end_grace", S_IRUGO|S_IWUSR, entry,
&lockd_end_grace_proc_ops);
if (!entry) {
remove_proc_entry("fs/lockd", NULL);
return -ENOMEM;
}
return 0;
}
void __exit
lockd_remove_procfs(void)
{
remove_proc_entry("fs/lockd/nlm_end_grace", NULL);
remove_proc_entry("fs/lockd", NULL);
}