IB/iser: Post initial receive buffers before sending the final login request
An iser target may send iscsi NO-OP PDUs as soon as it marks the iSER
iSCSI session as fully operative. This means that there is window
where there are no posted receive buffers on the initiator side, so
it's possible for the iSER RC connection to break because of RNR NAK /
retry errors. To fix this, rely on the flags bits in the login
request to have FFP (0x3) in the lower nibble as a marker for the
final login request, and post an initial chunk of receive buffers
before sending that login request instead of after getting the login
response.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 9a43cb0..db43b31 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -364,6 +364,9 @@
}
ib_conn = ep->dd_data;
+ if (iser_alloc_rx_descriptors(ib_conn))
+ return -ENOMEM;
+
/* binds the iSER connection retrieved from the previously
* connected ep_handle to the iSCSI layer connection. exchanges
* connection pointers */
@@ -398,19 +401,6 @@
iser_conn->ib_conn = NULL;
}
-static int
-iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
-{
- struct iscsi_conn *conn = cls_conn->dd_data;
- int err;
-
- err = iser_conn_set_full_featured_mode(conn);
- if (err)
- return err;
-
- return iscsi_conn_start(cls_conn);
-}
-
static void iscsi_iser_session_destroy(struct iscsi_cls_session *cls_session)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
@@ -724,7 +714,7 @@
.get_conn_param = iscsi_conn_get_param,
.get_ep_param = iscsi_iser_get_ep_param,
.get_session_param = iscsi_session_get_param,
- .start_conn = iscsi_iser_conn_start,
+ .start_conn = iscsi_conn_start,
.stop_conn = iscsi_iser_conn_stop,
/* iscsi host params */
.get_host_param = iscsi_host_get_param,