drbd: New configuration parameters for dealing with network congestion

net {
    on_congestion {block|pull-ahead|disconnect};
    congestion-fill {sectors};
    congestion-extents {al-extents};
}

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

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 9e27d82a9a19..f969d8717e23 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1323,6 +1323,8 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
         new_conf->wire_protocol    = DRBD_PROT_C;
         new_conf->ping_timeo       = DRBD_PING_TIMEO_DEF;
         new_conf->rr_conflict      = DRBD_RR_CONFLICT_DEF;
+        new_conf->on_congestion    = DRBD_ON_CONGESTION_DEF;
+        new_conf->cong_extents     = DRBD_CONG_EXTENTS_DEF;
 
         if (!net_conf_from_tags(mdev, nlp->tag_list, new_conf)) {
                 retcode = ERR_MANDATORY_TAG;
@@ -1344,6 +1346,11 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
                 }
         }
 
+        if (new_conf->on_congestion != OC_BLOCK && new_conf->wire_protocol != DRBD_PROT_A) {
+                retcode = ERR_CONG_NOT_PROTO_A;
+                goto fail;
+        }
+
         if (mdev->state.role == R_PRIMARY && new_conf->want_lose) {
                 retcode = ERR_DISCARD;
                 goto fail;