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>
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 31f6875..b4e1dab 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1621,6 +1621,33 @@
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 @@
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;
