// 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] = '
  ';
  	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);
  }