drbd: __req_mod: make DISCARD_WRITE and independend case

cherry-picked and adapted from drbd 9 devel branch

This looks cleaner to me,
and also gets rid of the other ugly if-inside-case-fall-through.

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_req.c b/drivers/block/drbd/drbd_req.c
index 329528d..f2ba43e 100644 (file)
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -609,13 +609,19 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
        case DISCARD_WRITE:
                /* for discarded conflicting writes of multiple primaries,
                 * there is no need to keep anything in the tl, potential
-                * node crashes are covered by the activity log. */
-               mod_rq_state(req, NULL, 0, RQ_NET_DONE);
-               /* fall through */
+                * node crashes are covered by the activity log.
+                *
+                * If this request had been marked as RQ_POSTPONED before,
+                * it will actually not be discarded, but "restarted",
+                * resubmitted from the retry worker context. */
+               D_ASSERT(req->rq_state & RQ_NET_PENDING);
+               D_ASSERT(req->rq_state & RQ_EXP_WRITE_ACK);
+               mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_DONE|RQ_NET_OK);
+               break;
+
        case WRITE_ACKED_BY_PEER_AND_SIS:
+               req->rq_state |= RQ_NET_SIS;
        case WRITE_ACKED_BY_PEER:
-               if (what == WRITE_ACKED_BY_PEER_AND_SIS)
-                       req->rq_state |= RQ_NET_SIS;
                D_ASSERT(req->rq_state & RQ_EXP_WRITE_ACK);
                /* protocol C; successfully written on peer.
                 * Nothing more to do here.