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
rcu_string_strdup(const char * src,gfp_t mask)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 /* Warn if the source got unexpectedly truncated. */
22 if (WARN_ON(strscpy(ret->str, src, len) < 0)) {
23 kfree(ret);
24 return NULL;
25 }
26 return ret;
27 }
28
rcu_string_free(struct rcu_string * str)29 static inline void rcu_string_free(struct rcu_string *str)
30 {
31 if (str)
32 kfree_rcu(str, rcu);
33 }
34
35 #define printk_in_rcu(fmt, ...) do { \
36 rcu_read_lock(); \
37 printk(fmt, __VA_ARGS__); \
38 rcu_read_unlock(); \
39 } while (0)
40
41 #define printk_ratelimited_in_rcu(fmt, ...) do { \
42 rcu_read_lock(); \
43 printk_ratelimited(fmt, __VA_ARGS__); \
44 rcu_read_unlock(); \
45 } while (0)
46
47 #define rcu_str_deref(rcu_str) ({ \
48 struct rcu_string *__str = rcu_dereference(rcu_str); \
49 __str->str; \
50 })
51
52 #endif
53
