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 | #include <linux/types.h> |
10 | #include <linux/string.h> |
11 | #include <linux/slab.h> |
12 | #include <linux/rcupdate.h> |
13 | #include <linux/printk.h> |
14 | |
15 | struct rcu_string { |
16 | struct rcu_head rcu; |
17 | char str[]; |
18 | }; |
19 | |
20 | static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask) |
21 | { |
22 | size_t len = strlen(src) + 1; |
23 | struct rcu_string *ret = kzalloc(size: sizeof(struct rcu_string) + |
24 | (len * sizeof(char)), flags: mask); |
25 | if (!ret) |
26 | return ret; |
27 | /* Warn if the source got unexpectedly truncated. */ |
28 | if (WARN_ON(strscpy(ret->str, src, len) < 0)) { |
29 | kfree(objp: ret); |
30 | return NULL; |
31 | } |
32 | return ret; |
33 | } |
34 | |
35 | static inline void rcu_string_free(struct rcu_string *str) |
36 | { |
37 | if (str) |
38 | kfree_rcu(str, rcu); |
39 | } |
40 | |
41 | #define printk_in_rcu(fmt, ...) do { \ |
42 | rcu_read_lock(); \ |
43 | printk(fmt, __VA_ARGS__); \ |
44 | rcu_read_unlock(); \ |
45 | } while (0) |
46 | |
47 | #define printk_ratelimited_in_rcu(fmt, ...) do { \ |
48 | rcu_read_lock(); \ |
49 | printk_ratelimited(fmt, __VA_ARGS__); \ |
50 | rcu_read_unlock(); \ |
51 | } while (0) |
52 | |
53 | #define rcu_str_deref(rcu_str) ({ \ |
54 | struct rcu_string *__str = rcu_dereference(rcu_str); \ |
55 | __str->str; \ |
56 | }) |
57 | |
58 | #endif |
59 | |