target: Return an error for WRITE SAME with ANCHOR==1

Per SBC-3, since we report ANC_SUP==0 in VPD page B2h, we need to return
an error (ILLEGAL REQUEST/INVALID FIELD IN CDB) for all WRITE SAME
requests with ANCHOR==1.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 4714c6f8da4b..d9b92b2c524d 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -263,6 +263,11 @@ sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *o
                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
                 return TCM_INVALID_CDB_FIELD;
         }
+        /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
+        if (flags[0] & 0x10) {
+                pr_warn("WRITE SAME with ANCHOR not supported\n");
+                return TCM_INVALID_CDB_FIELD;
+        }
         /*
          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
          * translated into block discard requests within backend code.