drbd: factored tl_restart() out of tl_clear().

If IO was frozen for a temporal network outage, resend the
content of the transfer-log into the newly established connection.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index d9df1a1c40b9..39c2cc3614e4 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -634,6 +634,20 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
                 /* else: done by handed_over_to_network */
                 break;
 
+        case resend:
+                /* If RQ_NET_OK is already set, we got a P_WRITE_ACK or P_RECV_ACK
+                   before the connection loss; only P_BARRIER_ACK was missing.
+                   Trowing them out of the TL here by pretending we got a BARRIER_ACK
+                   TODO: Either resync them, or ensure peer was not rebooted. */
+                if (!(req->rq_state & RQ_NET_OK)) {
+                        if (req->w.cb) {
+                                drbd_queue_work(&mdev->data.work, &req->w);
+                                rv = req->rq_state & RQ_WRITE ? MR_WRITE : MR_READ;
+                        }
+                        break;
+                }
+                /* else, fall through to barrier_acked */
+
         case barrier_acked:
                 if (!(req->rq_state & RQ_WRITE))
                         break;