HP Integrity NonStop H-Series User Manual
Page 18
Interfacing With the Open SCSI I/O Process (IOP)
Using the FILE_OPEN_ Procedure
subsequent file-system procedure calls. The syntax of the FILE_OPEN_ procedure call
is:
error
This integer value is returned from the file system to indicate the outcome of the
operation. See the parameter
filename:length
If the application or driver wants to open a device controlled by the Open SCSI
IOP, it must supply the name of the device (and the length of the name) as
specified to SYSGENR. This parameter pair is required.
filenum
On successful completion of a FILE_OPEN_ procedure call to open a SCSI driver,
filenum
returns a file number to be used for future I/O operations with that
device. If FILE_OPEN_ fails, a value of -1 is returned in
filenum
, and no further
I/O operations should be attempted using that value of
filenum.
access
This parameter is optional. If
access
appears, it specifies a direction mode. In
subsequent I/O operations that use the passthrough mode, the Open SCSI IOP
checks the direction bits in the flag field of the CAM control block (CCB) for
consistency with the direction mode specified by
access.
exclusion
The Open SCSI IOP does not directly handle this parameter.
nowait-depth
This parameter is optional. If
nowait-depth
is present and nonzero, it specifies
the number of nowait I/O operations that can be in progress for the file concurrently
with other processing. The Open SCSI IOP supports nowait I/O and a limit of 15
nowait I/O operations.
error := FILE_OPEN_ ( filename:length !
i:i
,filenum !
i,o
,[access] !
i
,[exclusion] !
i
,[nowait-depth] !
i
,[sync-depth] !
i
,[options] !
i
,[seq-buffer-id] !
i
,[seq-buffer-len] !
i
,[primary-processhandle] ); !
i