target: Return descriptor format sense data in case the LU spans 64bi…

…t sectors

In case a LU spans 64bit sectors, fixed size sense data information
field is only 32 bits which means the sector information will be truncated.

Thus, if the LU spans 64bit sectors, use descriptor format sense data to
correctly report sector information.

Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_hba.c

@@ -176,3 +176,8 @@ core_delete_hba(struct se_hba *hba)
 	kfree(hba);
 	return 0;
 }
+
+bool target_sense_desc_format(struct se_device *dev)
+{
+	return dev->transport->get_blocks(dev) > U32_MAX;
+}

drivers/target/target_core_spc.c

@@ -761,7 +761,12 @@ static int spc_modesense_control(struct se_cmd *cmd, u8 pc, u8 *p)
 	if (pc == 1)
 		goto out;
 
-	p[2] = 2;
+	/* GLTSD: No implicit save of log parameters */
+	p[2] = (1 << 1);
+	if (target_sense_desc_format(dev))
+		/* D_SENSE: Descriptor format sense data for 64bit sectors */
+		p[2] |= (1 << 2);
+
 	/*
 	 * From spc4r23, 7.4.7 Control mode page
 	 *
@@ -1144,6 +1149,7 @@ static sense_reason_t spc_emulate_request_sense(struct se_cmd *cmd)
 	unsigned char *rbuf;
 	u8 ua_asc = 0, ua_ascq = 0;
 	unsigned char buf[SE_SENSE_BUF];
+	bool desc_format = target_sense_desc_format(cmd->se_dev);
 
 	memset(buf, 0, SE_SENSE_BUF);
 
@@ -1158,10 +1164,10 @@ static sense_reason_t spc_emulate_request_sense(struct se_cmd *cmd)
 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 
 	if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq))
-		scsi_build_sense_buffer(0, buf, UNIT_ATTENTION,
+		scsi_build_sense_buffer(desc_format, buf, UNIT_ATTENTION,
 					ua_asc, ua_ascq);
 	else
-		scsi_build_sense_buffer(0, buf, NO_SENSE, 0x0, 0x0);
+		scsi_build_sense_buffer(desc_format, buf, NO_SENSE, 0x0, 0x0);
 
 	memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 	transport_kunmap_data_sg(cmd);

drivers/target/target_core_transport.c

@@ -2735,6 +2735,7 @@ static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
 	u8 *buffer = cmd->sense_buffer;
 	int r = (__force int)reason;
 	u8 asc, ascq;
+	bool desc_format = target_sense_desc_format(cmd->se_dev);
 
 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
 		si = &sense_info_table[r];
@@ -2754,7 +2755,7 @@ static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
 		ascq = si->ascq;
 	}
 
-	scsi_build_sense_buffer(0, buffer, si->key, asc, ascq);
+	scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
 	if (si->add_sector_info)
 		return scsi_set_sense_information(buffer,
 						  cmd->scsi_sense_length,

include/target/target_core_backend.h

@@ -93,4 +93,6 @@ bool	target_lun_is_rdonly(struct se_cmd *);
 sense_reason_t passthrough_parse_cdb(struct se_cmd *cmd,
 	sense_reason_t (*exec_cmd)(struct se_cmd *cmd));
 
+bool target_sense_desc_format(struct se_device *dev);
+
 #endif /* TARGET_CORE_BACKEND_H */