LXR linux/fs/lockd/procfs.c

   1/*
   2 * Procfs support for lockd
   3 *
   4 * Copyright (c) 2014 Jeff Layton <jlayton@primarydata.com>
   5 */
   6
   7#include <linux/fs.h>
   8#include <linux/proc_fs.h>
   9#include <linux/module.h>
  10#include <linux/nsproxy.h>
  11#include <net/net_namespace.h>
  12
  13#include "netns.h"
  14#include "procfs.h"
  15
  16/*
  17 * We only allow strings that start with 'Y', 'y', or '1'.
  18 */
  19static ssize_t
  20nlm_end_grace_write(struct file *file, const char __user *buf, size_t size,
  21                    loff_t *pos)
  22{
  23        char *data;
  24        struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
  25                                           lockd_net_id);
  26
  27        if (size < 1)
  28                return -EINVAL;
  29
  30        data = simple_transaction_get(file, buf, size);
  31        if (IS_ERR(data))
  32                return PTR_ERR(data);
  33
  34        switch(data[0]) {
  35        case 'Y':
  36        case 'y':
  37        case '1':
  38                locks_end_grace(&ln->lockd_manager);
  39                break;
  40        default:
  41                return -EINVAL;
  42        }
  43
  44        return size;
  45}
  46
  47static ssize_t
  48nlm_end_grace_read(struct file *file, char __user *buf, size_t size,
  49                   loff_t *pos)
  50{
  51        struct lockd_net *ln = net_generic(current->nsproxy->net_ns,
  52                                           lockd_net_id);
  53        char resp[3];
  54
  55        resp[0] = list_empty(&ln->lockd_manager.list) ? 'Y' : 'N';
  56        resp[1] = '\n';
  57        resp[2] = '\0';
  58
  59        return simple_read_from_buffer(buf, size, pos, resp, sizeof(resp));
  60}
  61
  62static const struct file_operations lockd_end_grace_operations = {
  63        .write          = nlm_end_grace_write,
  64        .read           = nlm_end_grace_read,
  65        .llseek         = default_llseek,
  66        .release        = simple_transaction_release,
  67        .owner          = THIS_MODULE,
  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