diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 83087cbf9..d05eb024f 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -1058,7 +1058,7 @@ static enum compl_status_e vdisk_exec_send_diagnostic(struct vdisk_cmd_params *p
 
 static enum compl_status_e vdisk_invalid_opcode(struct vdisk_cmd_params *p)
 {
-	TRACE_DBG_SPECIAL("Invalid opcode %d", p->cmd->cdb[0]);
+	TRACE_DBG("Invalid opcode %d", p->cmd->cdb[0]);
 	return INVALID_OPCODE;
 }
 
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index a954c5e02..7215ece23 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4750,7 +4750,8 @@ struct scst_cmd *scst_alloc_cmd(const uint8_t *cdb,
 	cmd->queue_type = SCST_CMD_QUEUE_SIMPLE;
 	cmd->timeout = SCST_DEFAULT_TIMEOUT;
 	cmd->retries = 0;
-	cmd->data_len = SCST_DEF_DATA_LEN;
+	cmd->lba = SCST_DEF_LBA_DATA_LEN;
+	cmd->data_len = SCST_DEF_LBA_DATA_LEN;
 	cmd->is_send_status = 1;
 	cmd->resp_data_len = -1;
 	cmd->write_sg = &cmd->sg;
@@ -5565,6 +5566,7 @@ static int get_cdb_info_len_10(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
 	cmd->cdb_len = 10;
+	cmd->lba = 0;
 	/* It supposed to be already zeroed */
 	EXTRACHECKS_BUG_ON(cmd->bufflen != 0);
 	cmd->data_len = cmd->bufflen;
@@ -5574,6 +5576,7 @@ static int get_cdb_info_len_10(struct scst_cmd *cmd,
 static int get_cdb_info_block_limit(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = 6;
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5582,6 +5585,7 @@ static int get_cdb_info_block_limit(struct scst_cmd *cmd,
 static int get_cdb_info_read_capacity(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = 8;
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5594,6 +5598,8 @@ static int get_cdb_info_serv_act_in(struct scst_cmd *cmd,
 
 	TRACE_ENTRY();
 
+	cmd->lba = 0;
+
 	if ((cmd->cdb[1] & 0x1f) == SAI_READ_CAPACITY_16) {
 		cmd->op_name = "READ CAPACITY(16)";
 		cmd->bufflen = get_unaligned_be32(&cmd->cdb[10]);
@@ -5613,6 +5619,7 @@ static int get_cdb_info_serv_act_in(struct scst_cmd *cmd,
 static int get_cdb_info_single(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = 1;
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5623,6 +5630,7 @@ static int get_cdb_info_read_pos(struct scst_cmd *cmd,
 {
 	int res = 0;
 
+	cmd->lba = 0;
 	cmd->bufflen = get_unaligned_be16(cmd->cdb + sdbops->info_len_off);
 
 	switch (cmd->cdb[1] & 0x1f) {
@@ -5670,6 +5678,10 @@ out_inval:
 static int get_cdb_info_prevent_allow_medium_removal(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
+	cmd->data_len = 0;
+	/* It supposed to be already zeroed */
+	EXTRACHECKS_BUG_ON(cmd->bufflen != 0);
 	if ((cmd->cdb[4] & 3) == 0)
 		cmd->op_flags |= SCST_REG_RESERVE_ALLOWED |
 			SCST_WRITE_EXCL_ALLOWED | SCST_EXCL_ACCESS_ALLOWED;
@@ -5679,6 +5691,10 @@ static int get_cdb_info_prevent_allow_medium_removal(struct scst_cmd *cmd,
 static int get_cdb_info_start_stop(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
+	cmd->data_len = 0;
+	/* It supposed to be already zeroed */
+	EXTRACHECKS_BUG_ON(cmd->bufflen != 0);
 	if ((cmd->cdb[4] & 0xF1) == 0x1)
 		cmd->op_flags |= SCST_REG_RESERVE_ALLOWED |
 			SCST_WRITE_EXCL_ALLOWED | SCST_EXCL_ACCESS_ALLOWED;
@@ -5688,6 +5704,7 @@ static int get_cdb_info_start_stop(struct scst_cmd *cmd,
 static int get_cdb_info_len_3_read_elem_stat(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = get_unaligned_be24(cmd->cdb + sdbops->info_len_off);
 	cmd->data_len = cmd->bufflen;
 
@@ -5710,6 +5727,7 @@ static int get_cdb_info_bidi_lba_4_len_2(struct scst_cmd *cmd,
 static int get_cdb_info_fmt(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	if (cmd->cdb[1] & 0x10/*FMTDATA*/) {
 		cmd->data_direction = SCST_DATA_WRITE;
 		cmd->op_flags |= SCST_UNKNOWN_LENGTH;
@@ -5736,6 +5754,7 @@ static int get_cdb_info_verify10(struct scst_cmd *cmd,
 static int get_cdb_info_verify6(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	if (cmd->cdb[1] & BYTCHK) {
 		cmd->bufflen = get_unaligned_be24(cmd->cdb + sdbops->info_len_off);
 		cmd->data_len = cmd->bufflen;
@@ -5783,6 +5802,7 @@ static int get_cdb_info_verify16(struct scst_cmd *cmd,
 static int get_cdb_info_len_1(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = (u32)cmd->cdb[sdbops->info_len_off];
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5811,6 +5831,7 @@ static int get_cdb_info_lba_2_len_1_256(struct scst_cmd *cmd,
 static int get_cdb_info_len_2(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = get_unaligned_be16(cmd->cdb + sdbops->info_len_off);
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5819,6 +5840,7 @@ static int get_cdb_info_len_2(struct scst_cmd *cmd,
 static int get_cdb_info_len_3(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = get_unaligned_be24(cmd->cdb + sdbops->info_len_off);
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5827,6 +5849,7 @@ static int get_cdb_info_len_3(struct scst_cmd *cmd,
 static int get_cdb_info_len_4(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
+	cmd->lba = 0;
 	cmd->bufflen = get_unaligned_be32(cmd->cdb + sdbops->info_len_off);
 	cmd->data_len = cmd->bufflen;
 	return 0;
@@ -5835,8 +5858,8 @@ static int get_cdb_info_len_4(struct scst_cmd *cmd,
 static int get_cdb_info_none(struct scst_cmd *cmd,
 	const struct scst_sdbops *sdbops)
 {
-	/* All supposed to be already zeroed, except data_len, which is -1 */
-	EXTRACHECKS_BUG_ON(cmd->lba != 0);
+	cmd->lba = 0;
+	/* It supposed to be already zeroed */
 	EXTRACHECKS_BUG_ON(cmd->bufflen != 0);
 	cmd->data_len = cmd->bufflen;
 	return 0;
diff --git a/scst/src/scst_priv.h b/scst/src/scst_priv.h
index a554c20c1..a4ce96537 100644
--- a/scst/src/scst_priv.h
+++ b/scst/src/scst_priv.h
@@ -109,7 +109,7 @@ extern unsigned long scst_trace_flag;
 
 #define SCST_TGT_RETRY_TIMEOUT               (3/2*HZ)
 
-#define SCST_DEF_DATA_LEN		     -1
+#define SCST_DEF_LBA_DATA_LEN		     -1
 
 extern struct mutex scst_mutex2;
 
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 13e2bd2be..433c57451 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -881,14 +881,16 @@ set_res:
 out:
 #ifdef CONFIG_SCST_EXTRACHECKS
 	/*
-	 * At this point either data_len must be initialized, or cmd
-	 * completed (with an error) and correct state set.
+	 * At this point either both lba and data_len must be initialized to
+	 * at least 0 for not data transfer commands, or cmd must be
+	 * completed (with an error) and have correct state set.
 	 */
-	if (unlikely((cmd->data_len == SCST_DEF_DATA_LEN)) &&
-	    (!cmd->completed ||
-	     (((cmd->state < SCST_CMD_STATE_PRE_XMIT_RESP) ||
-	       (cmd->state >= SCST_CMD_STATE_LAST_ACTIVE)) &&
-	      (cmd->state != SCST_CMD_STATE_PREPROCESSING_DONE)))) {
+	if (unlikely(((cmd->lba == SCST_DEF_LBA_DATA_LEN) ||
+		       (cmd->data_len == SCST_DEF_LBA_DATA_LEN)) &&
+		      (!cmd->completed ||
+		       (((cmd->state < SCST_CMD_STATE_PRE_XMIT_RESP) ||
+		         (cmd->state >= SCST_CMD_STATE_LAST_ACTIVE)) &&
+		        (cmd->state != SCST_CMD_STATE_PREPROCESSING_DONE))))) {
 		PRINT_CRIT_ERROR("Not initialized data_len for going to "
 			"execute command or bad state (cmd %p, data_len %d, "
 			"completed %d, state %d)", cmd, cmd->data_len,
@@ -2727,7 +2729,8 @@ static int scst_pre_exec_checks(struct scst_cmd *cmd)
 
 	TRACE_ENTRY();
 
-	EXTRACHECKS_BUG_ON(cmd->data_len == SCST_DEF_DATA_LEN);
+	EXTRACHECKS_BUG_ON(cmd->lba == SCST_DEF_LBA_DATA_LEN);
+	EXTRACHECKS_BUG_ON(cmd->data_len == SCST_DEF_LBA_DATA_LEN);
 
 	rc = __scst_check_local_events(cmd, false);
 	if (unlikely(rc != 0))