[PATCH 4.4 003/101] scsi: return correct blkprep status code in case scsi_init_io() fails.

Greg Kroah-Hartman
2020-06-19T16:54:42Z

From: Johannes Thumshirn <jthumshirn@suse.de>

commit e7661a8e5ce10b5321882d0bbaf3f81070903319 upstream.

When instrumenting the SCSI layer to run into the
!blk_rq_nr_phys_segments(rq) case the following warning emitted from the
block layer:

blk_peek_request: bad return=-22

This happens because since commit fd3fc0b4d730 ("scsi: don't BUG_ON()
empty DMA transfers") we return the wrong error value from
scsi_prep_fn() back to the block layer.

[mkp: silenced checkpatch]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: fd3fc0b4d730 scsi: don't BUG_ON() empty DMA transfers
Cc: <stable@vger.kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[iwamatsu: - backport for 4.4.y and 4.9.y
- Use rq->nr_phys_segments instead of blk_rq_nr_phys_segments]
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/scsi_lib.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1118,10 +1118,10 @@ int scsi_init_io(struct scsi_cmnd *cmd)
struct scsi_device *sdev = cmd->device;
struct request *rq = cmd->request;
bool is_mq = (rq->mq_ctx != NULL);
- int error;
+ int error = BLKPREP_KILL;

if (WARN_ON_ONCE(!rq->nr_phys_segments))
- return -EINVAL;
+ goto err_exit;

error = scsi_init_sgtable(rq, &cmd->sdb);
if (error)