4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Thumshirn <jthumshirn@xxxxxxx> 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@xxxxxxx> Fixes: fd3fc0b4d730 scsi: don't BUG_ON() empty DMA transfers Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -1038,10 +1038,10 @@ 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)