LXR linux/fs/lockd/procfs.c

   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 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
  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_operations);
  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