On 04/12/2017 09:21 AM, Johannes Thumshirn wrote:
> 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.
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Fixes: fd3fc0b4d730 scsi: don't BUG_ON() empty DMA transfers
> Cc: <stable@xxxxxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> ---
> Changes to v1:
> * s/iscsi_prep_fn()/scsi_prep_fn()
> * Add Cc stable
>
> drivers/scsi/scsi_lib.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 19125d72f322..5558e212368b 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1061,10 +1061,10 @@ 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(!blk_rq_nr_phys_segments(rq)))
> - return -EINVAL;
> + goto err_exit;
>
> error = scsi_init_sgtable(rq, &cmd->sdb);
> if (error)
>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
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