[PATCH] nvme-tcp: Do not terminate commands when in RESETTING

[hare at kernel.org]

From: Hannes Reinecke <hare at suse.de>

Terminating commands from the timeout handler might lead
to a data corruption as the timeout might trigger before
KATO expired.
This is the case when several commands have been started
before the keep-alive command and the command timeouts
trigger just after the keep-alive command has been sent.
Then the first command will trigger an error recovery,
but all the other commands will be aborted directly
and immediately retried.
So return BLK_EH_RESET_TIMER for I/O commands when
error recovery has been started to ensure that the
commands will be retried only after the KATO interval.

Signed-off-by: Hannes Reinecke <hare at suse.de>
---
 drivers/nvme/host/tcp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index b234f0674aeb..b9ec121b3fc6 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2429,6 +2429,18 @@ static enum blk_eh_timer_return nvme_tcp_timeout(struct request *rq)
 		 rq->tag, nvme_cid(rq), pdu->hdr.type, opc,
 		 nvme_opcode_str(qid, opc, fctype), qid);
 
+	/*
+	 * If the error recovery is started we should ignore all
+	 * I/O commands as they'll be aborted once error recovery starts.
+	 * Otherwise they'll be failed over immediately and might
+	 * cause data corruption.
+	 */
+	if (ctrl->state == NVME_CTRL_RESETTING && qid > 0) {
+		/* Avoid interfering with firmware download */
+		if (!WARN_ON(work_pending(&ctrl->fw_act_work)))
+			return BLK_EH_RESET_TIMER;
+	}
+
 	if (ctrl->state != NVME_CTRL_LIVE) {
 		/*
 		 * If we are resetting, connecting or deleting we should
-- 
2.35.3