target: Add Third Party Copy (3PC) bit in INQUIRY response

This patch adds the Third Party Copy (3PC) bit to signal support
for EXTENDED_COPY within standard inquiry response data.

Also add emulate_3pc device attribute in configfs (enabled by default)
to allow the exposure of this bit to be disabled, if necessary.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 894e83bc223d..566dd2794679 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -95,6 +95,12 @@ spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
          */
         spc_fill_alua_data(lun->lun_sep, buf);
 
+        /*
+         * Set Third-Party Copy (3PC) bit to indicate support for EXTENDED_COPY
+         */
+        if (dev->dev_attrib.emulate_3pc)
+                buf[5] |= 0x8;
+
         buf[7] = 0x2; /* CmdQue=1 */
 
         snprintf(&buf[8], 8, "LIO-ORG");