scsi: core: Set sc_data_direction to DMA_NONE for no-transfer commands

No having the special DMA_NONE logic makes libata rather unhappy.

Link: https://lore.kernel.org/r/20201008200611.1818099-3-hch@lst.de
Fixes: 40b93836a136 ("scsi: core: Use rq_dma_dir in scsi_setup_cmnd()")
Reported-by: Qian Cai <cai@redhat.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6b0fccd..1a2e9ba 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1545,7 +1545,10 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
        cmd->request = req;
        cmd->tag = req->tag;
        cmd->prot_op = SCSI_PROT_NORMAL;
-       cmd->sc_data_direction = rq_dma_dir(req);
+       if (blk_rq_bytes(req))
+               cmd->sc_data_direction = rq_dma_dir(req);
+       else
+               cmd->sc_data_direction = DMA_NONE;
 
        sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
        cmd->sdb.table.sgl = sg;