1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2012 Red Hat. All rights reserved. 4 */ 5 6 #ifndef BTRFS_RCU_STRING_H 7 #define BTRFS_RCU_STRING_H 8 9 struct rcu_string { 10 struct rcu_head rcu; 11 char str[]; 12 }; 13 14 static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask) 15 { 16 size_t len = strlen(src) + 1; 17 struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) + 18 (len * sizeof(char)), mask); 19 if (!ret) 20 return ret; 21 strncpy(ret->str, src, len); 22 return ret; 23 } 24 25 static inline void rcu_string_free(struct rcu_string *str) 26 { 27 if (str) 28 kfree_rcu(str, rcu); 29 } 30 31 #define printk_in_rcu(fmt, ...) do { \ 32 rcu_read_lock(); \ 33 printk(fmt, __VA_ARGS__); \ 34 rcu_read_unlock(); \ 35 } while (0) 36 37 #define printk_ratelimited_in_rcu(fmt, ...) do { \ 38 rcu_read_lock(); \ 39 printk_ratelimited(fmt, __VA_ARGS__); \ 40 rcu_read_unlock(); \ 41 } while (0) 42 43 #define rcu_str_deref(rcu_str) ({ \ 44 struct rcu_string *__str = rcu_dereference(rcu_str); \ 45 __str->str; \ 46 }) 47 48 #endif 49