target: Report bad sector in sense data for DIF errors

SPC-4 states that data-integrity errors shall also report
the failed sector in CHECK_CONDITION response sense data
information field.

Signed-off-by: Sagi Grimberg <[e-mail]>
Signed-off-by: Nicholas Bellinger <[e-mail]>

drivers/target/target_core_sbc.c

···
 			if (rc) {
 				kunmap_atomic(paddr);
 				kunmap_atomic(daddr);
+				cmd->bad_sector = sector;
 				return rc;
 			}
 
···
 			if (rc) {
 				kunmap_atomic(paddr);
 				kunmap_atomic(daddr);
+				cmd->bad_sector = sector;
 				return rc;
 			}
 

drivers/target/target_core_transport.c

···
 	return 0;
 }
 
+static
+void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
+{
+	/* Place failed LBA in sense data information descriptor 0. */
+	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
+	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
+	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
+	buffer[SPC_VALIDITY_OFFSET] = 0x80;
+
+	/* Descriptor Information: failing sector */
+	put_unaligned_be64(bad_sector, &buffer[12]);
+}
+
 int
 transport_send_check_condition_and_sense(struct se_cmd *cmd,
 		sense_reason_t reason, int from_transport)
···
 		/* LOGICAL BLOCK GUARD CHECK FAILED */
 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
+		transport_err_sector_info(buffer, cmd->bad_sector);
 		break;
 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
 		/* CURRENT ERROR */
···
 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
+		transport_err_sector_info(buffer, cmd->bad_sector);
 		break;
 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
 		/* CURRENT ERROR */
···
 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
+		transport_err_sector_info(buffer, cmd->bad_sector);
 		break;
 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
 	default:

include/target/target_core_base.h

···
 /* Used by transport_send_check_condition_and_sense() */
 #define SPC_SENSE_KEY_OFFSET			2
 #define SPC_ADD_SENSE_LEN_OFFSET		7
+#define SPC_DESC_TYPE_OFFSET			8
+#define SPC_ADDITIONAL_DESC_LEN_OFFSET		9
+#define SPC_VALIDITY_OFFSET			10
 #define SPC_ASC_KEY_OFFSET			12
 #define SPC_ASCQ_KEY_OFFSET			13
 #define TRANSPORT_IQN_LEN			224
···
 	unsigned int		t_prot_nents;
 	enum target_prot_ho	prot_handover;
 	sense_reason_t		pi_err;
-	u32			block_num;
+	sector_t		bad_sector;
 };
 
 struct se_ua {