target: Pass through I/O topology for block backstores
In addition to block size (already implemented), passing through
alignment offset, logical-to-phys block exponent, I/O granularity and
optimal I/O length will allow initiators to properly handle layout on
LUNs with 4K block sizes.
Tested with various weird values via scsi_debug module.
One thing to look at with this patch is the new block limits values --
instead of granularity 1 optimal 8192, Lio will now be returning whatever
the block device says, which may affect performance.
Signed-off-by: Andy Grover <agrover@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 6c17295..61a30f0 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -105,12 +105,22 @@
buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
buf[11] = dev->dev_attrib.block_size & 0xff;
+
+ if (dev->transport->get_lbppbe)
+ buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
+
+ if (dev->transport->get_alignment_offset_lbas) {
+ u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
+ buf[14] = (lalba >> 8) & 0x3f;
+ buf[15] = lalba & 0xff;
+ }
+
/*
* Set Thin Provisioning Enable bit following sbc3r22 in section
* READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
*/
if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
- buf[14] = 0x80;
+ buf[14] |= 0x80;
rbuf = transport_kmap_data_sg(cmd);
if (rbuf) {