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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_SEQMUTEX_H
#define _BCACHEFS_SEQMUTEX_H
#include <linux/mutex.h>
struct seqmutex {
struct mutex lock;
u32 seq;
};
#define seqmutex_init(_lock) mutex_init(&(_lock)->lock)
static inline bool seqmutex_trylock(struct seqmutex *lock)
{
return mutex_trylock(&lock->lock);
}
static inline void seqmutex_lock(struct seqmutex *lock)
{
mutex_lock(&lock->lock);
lock->seq++;
}
static inline u32 seqmutex_unlock(struct seqmutex *lock)
{
u32 seq = lock->seq;
mutex_unlock(&lock->lock);
return seq;
}
static inline bool seqmutex_relock(struct seqmutex *lock, u32 seq)
{
if (lock->seq != seq || !mutex_trylock(&lock->lock))
return false;
if (lock->seq != seq) {
mutex_unlock(&lock->lock);
return false;
}
return true;
}
#endif /* _BCACHEFS_SEQMUTEX_H */
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