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 @@ -1029,10 +1029,10 @@ 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)