From 1a1efe1deff03bab3d8dc28196c9f6d7555154b6 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Sun, 3 Mar 2019 08:52:21 -0700
Subject: [PATCH 1796/2944] nvme-pci: only call nvme_unmap_data for requests
 transferring data

fix #29327388

commit b15c592de37ed9d71499a3b8a750d1b235fcba3d upstream

This mirrors how nvme_map_pci is called and will allow simplifying some
checks in nvme_unmap_pci later on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
---
 drivers/nvme/host/pci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 8b1ee2f..708a278 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -930,7 +930,8 @@ static void nvme_pci_complete_rq(struct request *req)
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 
 	nvme_cleanup_cmd(req);
-	nvme_unmap_data(iod->nvmeq->dev, req);
+	if (blk_rq_nr_phys_segments(req))
+		nvme_unmap_data(iod->nvmeq->dev, req);
 	nvme_complete_rq(req);
 }
 
-- 
1.8.3.1