[PATCH 1/4] scsi: Fix passthrough retry counter handling

[Mike Christie <michael.christie@oracle.com>]

Passthrough users will set the scsi_cmnd->allowed value and were
expecting up to $allowed retries. The problem is that before:

commit 6aded12b10e0 ("scsi: core: Remove struct scsi_request")

we used to set the retries on the scsi_request then copy them over to
scsi_cmnd->allowed in scsi_setup_scsi_cmnd. With that patch we now set
scsi_cmnd->allowed to 0 in scsi_prepare_cmd then for passthrough
commands never set it again.

This patch adds a check for passthrough commands where if set then we
leave the allowed field alone since the submitter already set it.

Fixes: 6aded12b10e0 ("scsi: core: Remove struct scsi_request")
Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/scsi/scsi_lib.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 4dbd29ab1dcc..3ef85c8b689d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1541,8 +1541,10 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
 
 	scsi_init_command(sdev, cmd);
 
+	if (!blk_rq_is_passthrough(req))
+		cmd->allowed = 0;
+
 	cmd->eh_eflags = 0;
-	cmd->allowed = 0;
 	cmd->prot_type = 0;
 	cmd->prot_flags = 0;
 	cmd->submitter = 0;
-- 
2.18.2