[PATCH 5.3 068/197] nvme-pci: Set the prp2 correctly when using more than 4k page

From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:20:11 EST

From: Kevin Hao <haokexin@xxxxxxxxx>

commit a4f40484e7f1dff56bb9f286cc59ffa36e0259eb upstream.

In the current code, the nvme is using a fixed 4k PRP entry size,
but if the kernel use a page size which is more than 4k, we should
consider the situation that the bv_offset may be larger than the
dev->ctrl.page_size. Otherwise we may miss setting the prp2 and then
cause the command can't be executed correctly.

Fixes: dff824b2aadb ("nvme-pci: optimize mapping of small single segment requests")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Kevin Hao <haokexin@xxxxxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/nvme/host/pci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -769,7 +769,8 @@ static blk_status_t nvme_setup_prp_simpl
struct bio_vec *bv)
struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
- unsigned int first_prp_len = dev->ctrl.page_size - bv->bv_offset;
+ unsigned int offset = bv->bv_offset & (dev->ctrl.page_size - 1);
+ unsigned int first_prp_len = dev->ctrl.page_size - offset;

iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
if (dma_mapping_error(dev->dev, iod->first_dma))