drbd: serialize sending of resync uuid with pending w_send_oos
To improve the latency of IO requests during bitmap exchange,
we recently allowed writes while waiting for the bitmap, sending "set
out-of-sync" information packets for any newly dirtied bits.
We have to make sure that the new resync-uuid does not overtake
these "set oos" packets. Once the resync-uuid is received, the
sync target starts the resync process, and expects the bitmap to
only be cleared, not re-set.
If we use this protocol extension, we queue the generation and sending
of the resync-uuid on the worker, which naturally serializes with all
previously queued packets.
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_int.h b/drivers/block/drbd/drbd_int.h
index 5a2d0ec..ec06e74 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1204,7 +1204,7 @@
extern int drbd_send_protocol(struct drbd_conf *mdev);
extern int drbd_send_uuids(struct drbd_conf *mdev);
extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev);
-extern int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val);
+extern int drbd_gen_and_send_sync_uuid(struct drbd_conf *mdev);
extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags);
extern int _drbd_send_state(struct drbd_conf *mdev);
extern int drbd_send_state(struct drbd_conf *mdev);