target/sbc: Add LBPRZ attribute + control CDB emulation

This change sets the LBPRZ flag in EVPD page b2h and READ CAPACITY (16)
based on a new unmap_zeroes_data device attribute. This flag is set
automatically for iblock based on underlying block device queue's
discard_zeroes_data flag.

Signed-off-by: Jamie Pocas <jamie.pocas@emc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 0a2c74008e53..dc8b796dbcc7 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -63,6 +63,8 @@
 #define DA_UNMAP_GRANULARITY_DEFAULT            0
 /* Default unmap_granularity_alignment */
 #define DA_UNMAP_GRANULARITY_ALIGNMENT_DEFAULT  0
+/* Default unmap_zeroes_data */
+#define DA_UNMAP_ZEROES_DATA_DEFAULT            0
 /* Default max_write_same_len, disabled by default */
 #define DA_MAX_WRITE_SAME_LEN                   0
 /* Use a model alias based on the configfs backend device name */
@@ -674,6 +676,7 @@ struct se_dev_attrib {
         int             force_pr_aptpl;
         int             is_nonrot;
         int             emulate_rest_reord;
+        int             unmap_zeroes_data;
         u32             hw_block_size;
         u32             block_size;
         u32             hw_max_sectors;