gpfsFcntlHeader_t structure

Contains declaration information for the gpfs_fcntl() subroutine.

Library

GPFS Library (libgpfs.a for AIX®, libgpfs.so for Linux®)

Structure

typedef struct
{
  int     totalLength;
  int     fcntlVersion;
  int     errorOffset;
  int     fcntlReserved;
} gpfsFcntlHeader_t;

Description

The gpfsFcntlHeader_t structure contains size, version, and error information for the gpfs_fcntl() subroutine.

Members

totalLength
This field must be set to the total length, in bytes, of the data structure being passed in this subroutine. This includes the length of the header and all hints and directives that follow the header.

The total size of the data structure cannot exceed the value of GPFS_MAX_FCNTL_LENGTH, as defined in the header file gpfs_fcntl.h. The current value of GPFS_MAX_FCNTL_LENGTH is 64 KB.

fcntlVersion
This field must be set to the current version number of the gpfs_fcntl() subroutine, as defined by GPFS_FCNTL_CURRENT_VERSION in the header file gpfs_fcntl.h. The current version number is one.
errorOffset
If an error occurs processing a system call, GPFS sets this field to the offset within the parameter area where the error was detected.
For example,
  1. An incorrect version number in the header would cause errorOffset to be set to zero.
  2. An error in the first hint following the header would set errorOffset to sizeof(header).
If no errors are found, GPFS does not alter this field.
fcntlReserved
This field is currently unused.

For compatibility with future versions of GPFS, set this field to zero.

Location

/usr/lpp/mmfs/lib/libgpfs.a for AIX

/usr/lpp/mmfs/lib/libgpfs.so for Linux