drbd: Move sequence number logic into drbd_receiver.c and simplify it

These things are only used there.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_int.h

@@ -2355,33 +2355,6 @@ static inline int drbd_set_ed_uuid(struct drbd_conf *mdev, u64 val)
 	return changed;
 }
 
-static inline int seq_cmp(u32 a, u32 b)
-{
-	/* we assume wrap around at 32bit.
-	 * for wrap around at 24bit (old atomic_t),
-	 * we'd have to
-	 *  a <<= 8; b <<= 8;
-	 */
-	return (s32)(a) - (s32)(b);
-}
-#define seq_lt(a, b) (seq_cmp((a), (b)) < 0)
-#define seq_gt(a, b) (seq_cmp((a), (b)) > 0)
-#define seq_ge(a, b) (seq_cmp((a), (b)) >= 0)
-#define seq_le(a, b) (seq_cmp((a), (b)) <= 0)
-/* CAUTION: please no side effects in arguments! */
-#define seq_max(a, b) ((u32)(seq_gt((a), (b)) ? (a) : (b)))
-
-static inline void update_peer_seq(struct drbd_conf *mdev, unsigned int new_seq)
-{
-	unsigned int m;
-	spin_lock(&mdev->peer_seq_lock);
-	m = seq_max(mdev->peer_seq, new_seq);
-	mdev->peer_seq = m;
-	spin_unlock(&mdev->peer_seq_lock);
-	if (m == new_seq)
-		wake_up(&mdev->seq_wait);
-}
-
 static inline void drbd_update_congested(struct drbd_conf *mdev)
 {
 	struct sock *sk = mdev->tconn->data.socket->sk;

drivers/block/drbd/drbd_receiver.c

@@ -1621,6 +1621,33 @@ static int e_send_discard_ack(struct drbd_conf *mdev, struct drbd_work *w, int u
 	return ok;
 }
 
+static bool seq_greater(u32 a, u32 b)
+{
+	/*
+	 * We assume 32-bit wrap-around here.
+	 * For 24-bit wrap-around, we would have to shift:
+	 *  a <<= 8; b <<= 8;
+	 */
+	return (s32)a - (s32)b > 0;
+}
+
+static u32 seq_max(u32 a, u32 b)
+{
+	return seq_greater(a, b) ? a : b;
+}
+
+static void update_peer_seq(struct drbd_conf *mdev, unsigned int new_seq)
+{
+	unsigned int m;
+
+	spin_lock(&mdev->peer_seq_lock);
+	m = seq_max(mdev->peer_seq, new_seq);
+	mdev->peer_seq = m;
+	spin_unlock(&mdev->peer_seq_lock);
+	if (m == new_seq)
+		wake_up(&mdev->seq_wait);
+}
+
 /* Called from receive_Data.
  * Synchronize packets on sock with packets on msock.
  *
@@ -1651,7 +1678,7 @@ static int drbd_wait_peer_seq(struct drbd_conf *mdev, const u32 packet_seq)
 	spin_lock(&mdev->peer_seq_lock);
 	for (;;) {
 		prepare_to_wait(&mdev->seq_wait, &wait, TASK_INTERRUPTIBLE);
-		if (seq_le(packet_seq, mdev->peer_seq+1))
+		if (!seq_greater(packet_seq, mdev->peer_seq + 1))
 			break;
 		if (signal_pending(current)) {
 			ret = -ERESTARTSYS;