X3T9.2/89-025

January 26, 1989

To:     X3T9.2
From:   John Lohmeyer, NCR Corporation
Subj:   SEARCH DATA Transfer Length Inconsistency

I had another interesting phone call:  The SEARCH DATA command is ambiguous 
about whether the transfer length field in the CDB is meant to indicate the 
length of the parameter list or the number of blocks to search.  This 
inconsistency dates back to SCSI-1.

I propose that we fix this inconsistency by making it clear that the transfer 
length field specifies the length of the parameter list.


REPLACE:


  A transfer length of zero indicates that no data shall be searched.  This 
condition shall be treated the same as an un-satisfied search. 

                          .
                          .
                          .
  The number of records field specifies the maximum number of records that 
shall be searched by this command.  An un-satisfied search shall terminate 
when the number of records or transfer length (from the command descriptor 
block) have been exhausted.


WITH:


  The transfer length field specifies the length of the SEARCH DATA parameter 
list in bytes.  A transfer length of zero indicates that no data shall be 
searched.  This condition shall be treated the same as an un-satisfied search.  
If the transfer length results in the truncation of the SEARCH DATA parameter 
list, the target shall terminate the command with CHECK CONDITION status.  The 
sense key shall be set to ILLEGAL REQUEST with the additional sense code set 
to INVALID FIELD IN PARAMETER LIST.

  IMPLEMENTORS NOTE:  Ambiguous wording in SCSI-1 standard could have been 
  interpreted to mean that the transfer length field is the maximum number of 
  blocks to search.

                          .
                          .
                          .

  The number of records field specifies the maximum number of records that 
shall be searched.  An un-satisfied search shall terminate when the number of 
records has been exhausted.