/*
   * Copyright (C) 2012 Red Hat.  All rights reserved.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public
   * License v2 as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public
   * License along with this program; if not, write to the
   * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   * Boston, MA 021110-1307, USA.
   */
  
  struct rcu_string {
  	struct rcu_head rcu;
  	char str[0];
  };
  
  static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
  {
  	size_t len = strlen(src) + 1;
  	struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) +
  					 (len * sizeof(char)), mask);
  	if (!ret)
  		return ret;
  	strncpy(ret->str, src, len);
  	return ret;
  }
  
  static inline void rcu_string_free(struct rcu_string *str)
  {
  	if (str)
  		kfree_rcu(str, rcu);
  }
  
  #define printk_in_rcu(fmt, ...) do {	\
  	rcu_read_lock();		\
  	printk(fmt, __VA_ARGS__);	\
  	rcu_read_unlock();		\
  } while (0)
  
  #define printk_ratelimited_in_rcu(fmt, ...) do {	\
  	rcu_read_lock();				\
  	printk_ratelimited(fmt, __VA_ARGS__);		\
  	rcu_read_unlock();				\
  } while (0)
  
  #define rcu_str_deref(rcu_str) ({				\
  	struct rcu_string *__str = rcu_dereference(rcu_str);	\
  	__str->str;						\
  })