[PATCH 1/2] nvme-tcp: start error recovery when read_sock fails

[Hannes Reinecke]

From: Martin Belanger <martin.belanger at dell.com>

nvme_tcp_recv_skb() disables the queue and starts error recovery on any
errors. But if the transport encounters an error before ->read_sock()
is called (and hence before nvme_tcp_recv_skb() is called) no further
action is taken. This causes nvme_tcp_io_work() to stall until a command
times out.

This patch checks for any error returned from ->read_sock(), and starts
error recovery when the queue is still enabled (ie if nvme_tcp_recv_skb()
has not detected the error).

Signed-off-by: Martin Belanger <martin.belanger at dell.com>
Signed-off-by: Hannes Reinecke <hare at kernel.org>
---
 drivers/nvme/host/tcp.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 7eec983c0ead..2f1ae3968678 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1422,7 +1422,23 @@ static int nvme_tcp_try_recv(struct nvme_tcp_queue *queue)
 	queue->nr_cqe = 0;
 	consumed = sock->ops->read_sock(sk, &rd_desc, nvme_tcp_recv_skb);
 	release_sock(sk);
-	return consumed == -EAGAIN ? 0 : consumed;
+	if (consumed == -EAGAIN)
+		return 0;
+
+	/*
+	 * read_sock() might encounter an error before calling
+	 * nvme_tcp_recv_skb(), so we need to check if we need
+	 * to start error recovery here.
+	 */
+	if (unlikely(consumed < 0 && queue->rd_enabled)) {
+		dev_err(queue->ctrl->ctrl.device,
+			"queue %d: receive failed: %d\n",
+			nvme_tcp_queue_id(queue), consumed);
+		queue->rd_enabled = false;
+		nvme_tcp_error_recovery(&queue->ctrl->ctrl);
+	}
+
+	return consumed;
 }
 
 static void nvme_tcp_io_work(struct work_struct *w)
-- 
2.51.0