nvme-pci: Set the prp2 correctly when using more than 4k page

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@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 4b18196..869f462 100644 (file)
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -773,7 +773,8 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
                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))