On 4/29/21 8:50 AM, mwilck@suse.com wrote:

+	if (hdr.dxfer_len > (queue_max_hw_sectors(bdev->bd_disk->queue) << 9))
+		return -EIO;

How about using SECTOR_SHIFT instead of the number 9?

+		/*
+		 * Errors resulting from invalid parameters shouldn't be retried
+		 * on another path.
+		 */
+		switch (rc) {
+		case -ENOIOCTLCMD:
+		case -EFAULT:
+		case -EINVAL:
+		case -EPERM:
+			goto out;
+		default:
+			break;
+		}

Will -ENOMEM result in an immediate retry? Is that what's desired?

+		if (rhdr.info & SG_INFO_CHECK) {
+			int result;
+			blk_status_t sts;
+
+			__set_status_byte(&result, rhdr.status);
+			__set_msg_byte(&result, rhdr.msg_status);
+			__set_host_byte(&result, rhdr.host_status);
+			__set_driver_byte(&result, rhdr.driver_status);
+
+			sts = __scsi_result_to_blk_status(&result, result);
+			rhdr.host_status = host_byte(result);
+
+			/* See if this is a target or path error. */
+			if (sts == BLK_STS_OK)
+				rc = 0;
+			else if (blk_path_error(sts))
+				rc = -EIO;
+			else {
+				rc = blk_status_to_errno(sts);
+				goto out;
+			}
+		}

Will SAM_STAT_CHECK_CONDITION be treated as an I/O error? Is that what's
desired? If not, does that mean that scsi_result_to_blk_status()
shouldn't be used but instead that a custom SCSI result conversion is
needed?

If __scsi_result_to_blk_status() is the right function to call, how
about making that function accept the driver status, host status, msg
and SAM status as four separate arguments such that the __set_*_byte()
calls can be left out?

+			char *argv[2] = { "fail_path", bdbuf };

Can the above array be declared static?

Thanks,

Bart.