Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 lock->seq++;
23}
24
25static inline u32 seqmutex_unlock(struct seqmutex *lock)
26{
27 u32 seq = lock->seq;
28 mutex_unlock(&lock->lock);
29 return seq;
30}
31
32static inline bool seqmutex_relock(struct seqmutex *lock, u32 seq)
33{
34 if (lock->seq != seq || !mutex_trylock(&lock->lock))
35 return false;
36
37 if (lock->seq != seq) {
38 mutex_unlock(&lock->lock);
39 return false;
40 }
41
42 return true;
43}
44
45#endif /* _BCACHEFS_SEQMUTEX_H */