[PATCH 7/8] scsi: Retry unaligned zoned writes

[Bart Van Assche <bvanassche@acm.org>]

From ZBC-2: "The device server terminates with CHECK CONDITION status, with
the sense key set to ILLEGAL REQUEST, and the additional sense code set to
UNALIGNED WRITE COMMAND a write command, other than an entire medium write
same command, that specifies: a) the starting LBA in a sequential write
required zone set to a value that is not equal to the write pointer for that
sequential write required zone; or b) an ending LBA that is not equal to the
last logical block within a physical block (see SBC-5)."

I am not aware of any other conditions that may trigger the UNALIGNED
WRITE COMMAND response.

Retry unaligned writes in preparation of removing zone locking.

Increase the number of retries for write commands sent to a sequential
zone to the maximum number of outstanding commands.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/scsi_error.c | 7 +++++++
 drivers/scsi/sd.c         | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index a7960ad2d386..e17f36b0b18a 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -676,6 +676,13 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
 		fallthrough;
 
 	case ILLEGAL_REQUEST:
+		/*
+		 * Unaligned write command. Retry immediately if pipelining
+		 * zoned writes has been enabled.
+		 */
+		if (sshdr.asc == 0x21 && sshdr.ascq == 0x04 &&
+		    blk_queue_pipeline_zoned_writes(sdev->request_queue))
+			return NEEDS_RETRY;
 		if (sshdr.asc == 0x20 || /* Invalid command operation code */
 		    sshdr.asc == 0x21 || /* Logical block address out of range */
 		    sshdr.asc == 0x22 || /* Invalid function */
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 47dafe6b8a66..cd90b54a6597 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1207,6 +1207,9 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 	cmd->transfersize = sdp->sector_size;
 	cmd->underflow = nr_blocks << 9;
 	cmd->allowed = sdkp->max_retries;
+	if (blk_queue_pipeline_zoned_writes(rq->q) &&
+	    blk_rq_is_seq_zone_write(rq))
+		cmd->allowed += rq->q->nr_requests;
 	cmd->sdb.length = nr_blocks * sdp->sector_size;
 
 	SCSI_LOG_HLQUEUE(1,