move Rust sources to top level, C sources into c_src

[bcachefs-tools-debian] / c_src / libbcachefs / seqmutex.h

diff --git a/c_src/libbcachefs/seqmutex.h b/c_src/libbcachefs/seqmutex.h
new file mode 100644 (file)
index 0000000..c1860d8
--- /dev/null
+++ b/c_src/libbcachefs/seqmutex.h
@@ -0,0 +1,48 @@
+/* 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);
+}
+
+static inline void seqmutex_unlock(struct seqmutex *lock)
+{
+       lock->seq++;
+       mutex_unlock(&lock->lock);
+}
+
+static inline u32 seqmutex_seq(struct seqmutex *lock)
+{
+       return lock->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 */