diff --git a/qla2x00t/qla2x00-target/qla2x00t.c b/qla2x00t/qla2x00-target/qla2x00t.c
index 3741f88fa..85e81b59e 100644
--- a/qla2x00t/qla2x00-target/qla2x00t.c
+++ b/qla2x00t/qla2x00-target/qla2x00t.c
@@ -5823,8 +5823,10 @@ static void q2t_on_hw_pending_cmd_timeout(struct scst_cmd *scst_cmd)
 
 		q2t_cleanup_hw_pending_cmd(ha, cmd);
 
-		scst_rx_data(scst_cmd, SCST_RX_STATUS_ERROR_FATAL,
-				SCST_CONTEXT_THREAD);
+		/* It might be sporadic, hence retriable */
+		scst_set_cmd_error(scst_cmd,
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
+		scst_rx_data(scst_cmd, SCST_RX_STATUS_ERROR_SENSE_SET, SCST_CONTEXT_THREAD);
 		goto out_unlock;
 	} else if (cmd->state == Q2T_STATE_ABORTED) {
 		TRACE_MGMT_DBG("Force finishing aborted cmd %p (tag %d)",
diff --git a/scst/include/scst_const.h b/scst/include/scst_const.h
index c18f874fa..c1b5f4440 100644
--- a/scst/include/scst_const.h
+++ b/scst/include/scst_const.h
@@ -298,7 +298,7 @@ static inline int scst_sense_response_code(const uint8_t *sense)
 #define scst_sense_read_error			MEDIUM_ERROR,    0x11, 0
 
 /* HARDWARE_ERROR is 4 */
-#define scst_sense_hardw_error			HARDWARE_ERROR,  0x44, 0
+#define scst_sense_hardw_error			HARDWARE_ERROR,  0x44, 0 /* non-retriable */
 
 /* ILLEGAL_REQUEST is 5 */
 #define scst_sense_invalid_opcode		ILLEGAL_REQUEST, 0x20, 0
@@ -333,6 +333,7 @@ static inline int scst_sense_response_code(const uint8_t *sense)
 
 /* ABORTED_COMMAND is 0xb */
 #define scst_sense_aborted_command		ABORTED_COMMAND, 0x00, 0
+#define scst_sense_internal_failure		ABORTED_COMMAND, 0x44, 0 /* retriable */
 
 /* MISCOMPARE is 0xe */
 #define scst_sense_miscompare_error		MISCOMPARE,      0x1D, 0
diff --git a/scst/src/dev_handlers/scst_disk.c b/scst/src/dev_handlers/scst_disk.c
index 684aca4ff..555c8c093 100644
--- a/scst/src/dev_handlers/scst_disk.c
+++ b/scst/src/dev_handlers/scst_disk.c
@@ -536,7 +536,7 @@ out:
 	return res;
 
 out_err_restore:
-	scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+	scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_internal_failure));
 	goto out_restore;
 
 out_error:
diff --git a/scst/src/dev_handlers/scst_tape.c b/scst/src/dev_handlers/scst_tape.c
index ec4e85bc8..4aeba2417 100644
--- a/scst/src/dev_handlers/scst_tape.c
+++ b/scst/src/dev_handlers/scst_tape.c
@@ -291,7 +291,7 @@ static int tape_done(struct scst_cmd *cmd)
 			PRINT_ERROR("Sense format 0x%x is not supported",
 				scst_sense_response_code(cmd->sense));
 			scst_set_cmd_error(cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 			goto out;
 		}
 
diff --git a/scst/src/dev_handlers/scst_user.c b/scst/src/dev_handlers/scst_user.c
index 0ba4f86bc..3b0ebc8bd 100644
--- a/scst/src/dev_handlers/scst_user.c
+++ b/scst/src/dev_handlers/scst_user.c
@@ -1260,7 +1260,7 @@ out_unmap:
 	ucmd->data_pages = NULL;
 	res = -EFAULT;
 	if (ucmd->cmd != NULL)
-		scst_set_cmd_error(ucmd->cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+		scst_set_cmd_error(ucmd->cmd, SCST_LOAD_SENSE(scst_sense_internal_failure));
 	goto out_err;
 }
 
@@ -1377,8 +1377,8 @@ out_inval:
 	res = -EINVAL;
 	goto out_abnormal;
 
-out_hwerr_res_set:
-	scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+out_intern_fail_res_set:
+	scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_internal_failure));
 
 out_abnormal:
 	scst_set_cmd_abnormal_done_state(cmd);
@@ -1393,7 +1393,7 @@ out_status:
 
 		res = scst_alloc_sense(cmd, 0);
 		if (res != 0)
-			goto out_hwerr_res_set;
+			goto out_intern_fail_res_set;
 
 		sense_len = min_t(int, cmd->sense_buflen, preply->sense_len);
 
@@ -1403,7 +1403,7 @@ out_status:
 		if (rc != 0) {
 			PRINT_ERROR("Failed to copy %d sense's bytes", rc);
 			res = -EFAULT;
-			goto out_hwerr_res_set;
+			goto out_intern_fail_res_set;
 		}
 		cmd->sense_valid_len = sense_len;
 	}
@@ -1495,7 +1495,7 @@ static int dev_user_process_reply_exec(struct scst_user_cmd *ucmd,
 				if (unlikely((ereply->pbuf & ~PAGE_MASK) != 0)) {
 					PRINT_ERROR("Supplied pbuf %llx isn't "
 						"page aligned", ereply->pbuf);
-					goto out_hwerr;
+					goto out_intern_fail;
 				}
 				pages = cmd->sg_cnt;
 			} else
@@ -1540,7 +1540,7 @@ static int dev_user_process_reply_exec(struct scst_user_cmd *ucmd,
 		if (rc != 0) {
 			PRINT_ERROR("Failed to copy %d sense's bytes", rc);
 			res = -EFAULT;
-			goto out_hwerr_res_set;
+			goto out_intern_fail_res_set;
 		}
 		cmd->sense_valid_len = sense_len;
 	}
@@ -1560,16 +1560,16 @@ out_inval:
 		(long long unsigned int)cmd->lun, scst_get_opcode_name(cmd), cmd);
 	PRINT_BUFFER("Invalid exec_reply", reply, sizeof(*reply));
 
-out_hwerr:
+out_intern_fail:
 	res = -EINVAL;
 
-out_hwerr_res_set:
+out_intern_fail_res_set:
 	if (ucmd->background_exec) {
 		ucmd_put(ucmd);
 		goto out;
 	} else {
 		scst_set_cmd_error(cmd,
-				   SCST_LOAD_SENSE(scst_sense_hardw_error));
+				   SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out_compl;
 	}
 
@@ -2261,7 +2261,7 @@ static void dev_user_unjam_cmd(struct scst_user_cmd *ucmd, int busy,
 				scst_set_busy(ucmd->cmd);
 			else
 				scst_set_cmd_error(ucmd->cmd,
-				       SCST_LOAD_SENSE(scst_sense_hardw_error));
+				       SCST_LOAD_SENSE(scst_sense_internal_failure));
 		}
 		scst_set_cmd_abnormal_done_state(ucmd->cmd);
 
@@ -2292,7 +2292,7 @@ static void dev_user_unjam_cmd(struct scst_user_cmd *ucmd, int busy,
 				scst_set_busy(ucmd->cmd);
 			else
 				scst_set_cmd_error(ucmd->cmd,
-				       SCST_LOAD_SENSE(scst_sense_hardw_error));
+				       SCST_LOAD_SENSE(scst_sense_internal_failure));
 		}
 
 		ucmd->cmd->scst_cmd_done(ucmd->cmd, SCST_CMD_STATE_DEFAULT,
diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index 8aa6576dc..57ee0572e 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -4787,7 +4787,7 @@ static enum compl_status_e fileio_exec_read(struct vdisk_cmd_params *p)
 	if (unlikely(length < 0)) {
 		PRINT_ERROR("scst_get_buf_first() failed: %zd", length);
 		scst_set_cmd_error(cmd,
-		    SCST_LOAD_SENSE(scst_sense_hardw_error));
+		    SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out;
 	}
 
@@ -4816,7 +4816,7 @@ static enum compl_status_e fileio_exec_read(struct vdisk_cmd_params *p)
 		} else if (unlikely(length < 0)) {
 			PRINT_ERROR("scst_get_buf_next() failed: %zd", length);
 			scst_set_cmd_error(cmd,
-			    SCST_LOAD_SENSE(scst_sense_hardw_error));
+			    SCST_LOAD_SENSE(scst_sense_internal_failure));
 			goto out_set_fs;
 		}
 
@@ -4910,7 +4910,7 @@ static enum compl_status_e fileio_exec_write(struct vdisk_cmd_params *p)
 	if (unlikely(length < 0)) {
 		PRINT_ERROR("scst_get_buf_first() failed: %zd", length);
 		scst_set_cmd_error(cmd,
-		    SCST_LOAD_SENSE(scst_sense_hardw_error));
+		    SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out;
 	}
 
@@ -4939,7 +4939,7 @@ static enum compl_status_e fileio_exec_write(struct vdisk_cmd_params *p)
 		} else if (unlikely(length < 0)) {
 			PRINT_ERROR("scst_get_buf_next() failed: %zd", length);
 			scst_set_cmd_error(cmd,
-			    SCST_LOAD_SENSE(scst_sense_hardw_error));
+			    SCST_LOAD_SENSE(scst_sense_internal_failure));
 			goto out_set_fs;
 		}
 
@@ -5176,8 +5176,10 @@ static void blockio_exec_rw(struct vdisk_cmd_params *p, bool write, bool fua)
 
 	/* Allocate and initialize blockio_work struct */
 	blockio_work = kmem_cache_alloc(blockio_work_cachep, gfp_mask);
-	if (blockio_work == NULL)
-		goto out_no_mem;
+	if (blockio_work == NULL) {
+		scst_set_busy(cmd);
+		goto finish_cmd;
+	}
 
 #if 0
 	{
@@ -5199,6 +5201,18 @@ static void blockio_exec_rw(struct vdisk_cmd_params *p, bool write, bool fua)
 	need_new_bio = 1;
 
 	length = scst_get_sg_page_first(cmd, &page, &offset);
+	/*
+	 * bv_len and bv_offset must be a multiple of 512 (SECTOR_SIZE), so
+	 * check this here.
+	 */
+	if (WARN_ONCE((length & 511) != 0 || (offset & 511) != 0,
+		      "Refused bio with invalid length %d and/or offset %d.\n",
+		      length, offset)) {
+		scst_set_cmd_error(cmd,
+				   SCST_LOAD_SENSE(scst_sense_hardw_error));
+		goto free_bio;
+	}
+
 	while (length > 0) {
 		int len, bytes, off, thislen;
 		struct page *pg;
@@ -5219,7 +5233,8 @@ static void blockio_exec_rw(struct vdisk_cmd_params *p, bool write, bool fua)
 					PRINT_ERROR("Failed to create bio "
 						"for data segment %d (cmd %p)",
 						cmd->get_sg_buf_entry_num, cmd);
-					goto out_no_bio;
+					scst_set_busy(cmd);
+					goto free_bio;
 				}
 
 				bios++;
@@ -5303,7 +5318,7 @@ out:
 	TRACE_EXIT();
 	return;
 
-out_no_bio:
+free_bio:
 	while (hbio) {
 		bio = hbio;
 		hbio = hbio->bi_next;
@@ -5311,8 +5326,7 @@ out_no_bio:
 	}
 	kmem_cache_free(blockio_work_cachep, blockio_work);
 
-out_no_mem:
-	scst_set_busy(cmd);
+finish_cmd:
 	cmd->completed = 1;
 	cmd->scst_cmd_done(cmd, SCST_CMD_STATE_DEFAULT, SCST_CONTEXT_SAME);
 	goto out;
@@ -5677,7 +5691,7 @@ static enum compl_status_e vdev_exec_verify(struct vdisk_cmd_params *p)
 	if (length < 0) {
 		PRINT_ERROR("scst_get_buf_() failed: %zd", length);
 		scst_set_cmd_error(cmd,
-		    SCST_LOAD_SENSE(scst_sense_hardw_error));
+		    SCST_LOAD_SENSE(scst_sense_internal_failure));
 	}
 
 out_free:
@@ -5735,7 +5749,7 @@ static enum compl_status_e vdisk_exec_caw(struct vdisk_cmd_params *p)
 			scst_set_busy(cmd);
 		else
 			scst_set_cmd_error(cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out;
 	}
 
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 44132e9e8..62cd4197c 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4959,7 +4959,7 @@ static void scst_complete_request_sense(struct scst_cmd *req_cmd)
 			PRINT_ERROR("%s", "Unable to get the sense via "
 				"REQUEST SENSE, returning HARDWARE ERROR");
 			scst_set_cmd_error(orig_cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 		}
 	}
 
@@ -6483,7 +6483,7 @@ int scst_get_buf_full_sense(struct scst_cmd *cmd, uint8_t **buf)
 			scst_set_busy(cmd);
 		else
 			scst_set_cmd_error(cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out;
 	}
 
@@ -10505,7 +10505,7 @@ void tm_dbg_release_cmd(struct scst_cmd *cmd)
 				if (((scst_random() % 10) == 5)) {
 					scst_set_cmd_error(cmd,
 						SCST_LOAD_SENSE(
-						scst_sense_hardw_error));
+							scst_sense_internal_failure));
 					/* It's completed now */
 				}
 			}
diff --git a/scst/src/scst_pres.c b/scst/src/scst_pres.c
index cc06ac361..f17cd5e36 100644
--- a/scst/src/scst_pres.c
+++ b/scst/src/scst_pres.c
@@ -1032,7 +1032,7 @@ out:
        * the affected initiator.
        */
 		if (cmd != NULL)
-			scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+			scst_set_cmd_error(cmd, SCST_LOAD_SENSE(scst_sense_internal_failure));
 #endif
 	}
 
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 175af61bf..7e43b6747 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -3516,7 +3516,7 @@ static bool scst_check_auto_sense(struct scst_cmd *cmd)
 				"%s)", cmd->host_status, cmd, scst_get_opcode_name(cmd),
 				cmd->tgt->tgt_name, cmd->dev->virt_name);
 			scst_set_cmd_error(cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 		}
 	}
 
@@ -3544,7 +3544,7 @@ static int scst_pre_dev_done(struct scst_cmd *cmd)
 			PRINT_ERROR("%s", "Unable to issue REQUEST SENSE, "
 				    "returning HARDWARE ERROR");
 			scst_set_cmd_error(cmd,
-				SCST_LOAD_SENSE(scst_sense_hardw_error));
+				SCST_LOAD_SENSE(scst_sense_internal_failure));
 		}
 		goto out;
 	}
@@ -3580,7 +3580,7 @@ next:
 					"MODE_SENSE buffer");
 				scst_set_cmd_error(cmd,
 					SCST_LOAD_SENSE(
-						scst_sense_hardw_error));
+						scst_sense_internal_failure));
 				err = true;
 			} else if (length > 2 && cmd->cdb[0] == MODE_SENSE)
 				address[2] |= 0x80;   /* Write Protect*/
@@ -3621,7 +3621,7 @@ next:
 				PRINT_ERROR("%s", "Unable to get INQUIRY "
 				    "buffer");
 				scst_set_cmd_error(cmd,
-				       SCST_LOAD_SENSE(scst_sense_hardw_error));
+				       SCST_LOAD_SENSE(scst_sense_internal_failure));
 				err = true;
 			}
 			if (buflen > 0)
diff --git a/usr/fileio/common.c b/usr/fileio/common.c
index ac98120af..75d09a7d7 100644
--- a/usr/fileio/common.c
+++ b/usr/fileio/common.c
@@ -209,7 +209,7 @@ static int do_exec(struct vdisk_cmd *vcmd)
 
 #ifdef DEBUG_SENSE
 	if ((random() % 100000) == 75) {
-		set_cmd_error(vcmd, SCST_LOAD_SENSE(scst_sense_hardw_error));
+		set_cmd_error(vcmd, SCST_LOAD_SENSE(scst_sense_internal_failure));
 		goto out;
 	}
 #endif