scsi_debug: allow huge transfer length for read/write commands
This change enables to test read/write commands with huge transfer
length such as 1GB. For example:
# modprobe scsi_debug dev_size_mb=1024 clustering=1 opts=1
# cat /sys/block/$DEV/queue/max_hw_sectors_kb > \
/sys/block/$DEV/queue/max_sectors_kb
# fio --name=test --rw=write --bs=1g --size=1g --filename=/dev/$DEV \
--mem=mmaphuge --direct=1
The data type of max_sectors in scsi_host_template has been extended
to unsigned int by the previous change. So we can increase it from
0xffff to 0xffffffff to allow such huge transfer length.
Also, this increases sg_tablesize and max_segment_size, otherwise the
maximum transfer length is limited to 64MB.
(sg_tablesize * max_segment_size = 256 * 256KB)
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 1328a26..c4ad52c 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2484,7 +2484,7 @@
if (sdp->host->cmd_per_lun)
scsi_adjust_queue_depth(sdp, SDEBUG_TAGGED_QUEUING,
sdp->host->cmd_per_lun);
- blk_queue_max_segment_size(sdp->request_queue, 256 * 1024);
+ blk_queue_max_segment_size(sdp->request_queue, -1U);
if (scsi_debug_no_uld)
sdp->no_uld_attach = 1;
return 0;
@@ -3946,9 +3946,9 @@
.bios_param = scsi_debug_biosparam,
.can_queue = SCSI_DEBUG_CANQUEUE,
.this_id = 7,
- .sg_tablesize = 256,
+ .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,
.cmd_per_lun = 16,
- .max_sectors = 0xffff,
+ .max_sectors = -1U,
.use_clustering = DISABLE_CLUSTERING,
.module = THIS_MODULE,
};