Commit dce5c4af authored by Ye Bin's avatar Ye Bin Committed by Martin K. Petersen
Browse files

scsi: core: Clear driver private data when retrying request 



After commit 1bad6c4a ("scsi: zero per-cmd private driver data for each
MQ I/O"), the xen-scsifront/virtio_scsi/snic drivers all removed code that
explicitly zeroed driver-private command data.

In combination with commit 464a00c9 ("scsi: core: Kill DRIVER_SENSE"),
after virtio_scsi performs a capacity expansion, the first request will
return a unit attention to indicate that the capacity has changed. And then
the original command is retried. As driver-private command data was not
cleared, the request would return UA again and eventually time out and fail.

Zero driver-private command data when a request is retried.

Fixes: f7de50da ("scsi: xen-scsifront: Remove code that zeroes driver-private command data")
Fixes: c2bb8731 ("scsi: virtio_scsi: Remove code that zeroes driver-private command data")
Fixes: c3006a92 ("scsi: snic: Remove code that zeroes driver-private command data")
Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20250217021628.2929248-1-yebin@huaweicloud.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 4fa382be

drivers/scsi/scsi_lib.c

+7 −7
Original line number Diff line number Diff line
@@ -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)