btree_write_buffer: ensure atomic64_sub_return_release availability

[bcachefs-tools-debian] / include / linux / atomic.h

diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index f1464cf3e0c371721745f78de13b2f03496eecc0..2c983cd4efb871822a0ef5652235759d3bcb4b86 100644 (file)
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -324,6 +324,12 @@ static inline s64 atomic64_cmpxchg_acquire(atomic64_t *v, s64 old, s64 new)
        return atomic64_cmpxchg(v, old, new);
 }
 
+static inline s64 atomic64_sub_return_release(s64 i, atomic64_t *v)
+{
+       smp_mb__before_atomic();
+       return atomic64_sub_return(i, v);
+}
+
 #endif
 
 #endif /* __TOOLS_LINUX_ATOMIC_H */