From: Ye Bin <yebin10@xxxxxxxxxx> After commit 1bad6c4a57ef ("scsi: zero per-cmd private driver data for each MQ I/O"), xen-scsifront/virtio_scsi/snic driver remove code that zeroes driver-private command data. If request do retry will lead to driver-private command data remains. Before commit 464a00c9e0ad ("scsi: core: Kill DRIVER_SENSE") if virtio_scsi do capacity expansion, first request may return UA then request will do retry, as driver-private command data remains, request will return UA again. As a result, the request keeps retrying, and the request times out and fails. So zeroes driver-private command data when request do retry. Fixes: f7de50da1479 ("scsi: xen-scsifront: Remove code that zeroes driver-private command data") Fixes: c2bb87318baa ("scsi: virtio_scsi: Remove code that zeroes driver-private command data") Fixes: c3006a926468 ("scsi: snic: Remove code that zeroes driver-private command data") Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index be0890e4e706..f1cfe0bb89b2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1669,13 +1669,6 @@ static blk_status_t scsi_prepare_cmd(struct request *req) if (in_flight) __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); - /* - * Only clear the driver-private command data if the LLD does not supply - * a function to initialize that data. - */ - if (!shost->hostt->init_cmd_priv) - memset(cmd + 1, 0, shost->hostt->cmd_size); - cmd->prot_op = SCSI_PROT_NORMAL; if (blk_rq_bytes(req)) cmd->sc_data_direction = rq_dma_dir(req); @@ -1842,6 +1835,13 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, if (!scsi_host_queue_ready(q, shost, sdev, cmd)) goto out_dec_target_busy; + /* + * Only clear the driver-private command data if the LLD does not supply + * a function to initialize that data. + */ + if (shost->hostt->cmd_size && !shost->hostt->init_cmd_priv) + memset(cmd + 1, 0, shost->hostt->cmd_size); + if (!(req->rq_flags & RQF_DONTPREP)) { ret = scsi_prepare_cmd(req); if (ret != BLK_STS_OK) -- 2.34.1