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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _BCACHEFS_SEQMUTEX_H
3#define _BCACHEFS_SEQMUTEX_H
4
5#include <linux/mutex.h>
6
7struct seqmutex {
8 struct mutex lock;
9 u32 seq;
10};
11
12#define seqmutex_init(_lock) mutex_init(&(_lock)->lock)
13
14static inline bool seqmutex_trylock(struct seqmutex *lock)
15{
16 return mutex_trylock(&lock->lock);
17}
18
19static inline void seqmutex_lock(struct seqmutex *lock)
20{
21 mutex_lock(&lock->lock);
22}
23
24static inline void seqmutex_unlock(struct seqmutex *lock)
25{
26 lock->seq++;
27 mutex_unlock(&lock->lock);
28}
29
30static inline u32 seqmutex_seq(struct seqmutex *lock)
31{
32 return lock->seq;
33}
34
35static inline bool seqmutex_relock(struct seqmutex *lock, u32 seq)
36{
37 if (lock->seq != seq || !mutex_trylock(&lock->lock))
38 return false;
39
40 if (lock->seq != seq) {
41 mutex_unlock(&lock->lock);
42 return false;
43 }
44
45 return true;
46}
47
48#endif /* _BCACHEFS_SEQMUTEX_H */