[PATCH] nvme-tcp: strict pdu pacing to avoid send stalls on TLS

[Hannes Reinecke]

TLS requires a strict pdu pacing via MSG_EOR to signal the end
of a record and subsequent encryption. If we do not set MSG_EOR
at the end of a sequence the record won't be closed, encryption
doesn't start, and we end up with a send stall as the message
will never be passed on to the TCP layer.
So do not check for the queue status when figuring out whether
MSG_MORE should be set but rather make it dependent on the current
command only.

Signed-off-by: Hannes Reinecke <hare at kernel.org>
---
 drivers/nvme/host/tcp.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 2b821cbbdf1f..b460ebf72a1a 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1049,7 +1049,7 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req)
 		int req_data_sent = req->data_sent;
 		int ret;
 
-		if (last && !queue->data_digest && !nvme_tcp_queue_more(queue))
+		if (last && !queue->data_digest)
 			msg.msg_flags |= MSG_EOR;
 		else
 			msg.msg_flags |= MSG_MORE;
@@ -1105,7 +1105,7 @@ static int nvme_tcp_try_send_cmd_pdu(struct nvme_tcp_request *req)
 	int len = sizeof(*pdu) + hdgst - req->offset;
 	int ret;
 
-	if (inline_data || nvme_tcp_queue_more(queue))
+	if (inline_data)
 		msg.msg_flags |= MSG_MORE;
 	else
 		msg.msg_flags |= MSG_EOR;
@@ -1175,17 +1175,12 @@ static int nvme_tcp_try_send_ddgst(struct nvme_tcp_request *req)
 	size_t offset = req->offset;
 	u32 h2cdata_left = req->h2cdata_left;
 	int ret;
-	struct msghdr msg = { .msg_flags = MSG_DONTWAIT };
+	struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_EOR };
 	struct kvec iov = {
 		.iov_base = (u8 *)&req->ddgst + req->offset,
 		.iov_len = NVME_TCP_DIGEST_LENGTH - req->offset
 	};
 
-	if (nvme_tcp_queue_more(queue))
-		msg.msg_flags |= MSG_MORE;
-	else
-		msg.msg_flags |= MSG_EOR;
-
 	ret = kernel_sendmsg(queue->sock, &msg, &iov, 1, iov.iov_len);
 	if (unlikely(ret <= 0))
 		return ret;
-- 
2.35.3