GPFS: Administration and Programming Reference - IRA Home

gpfsFcntlHeader_t Structure
Name
gpfsFcntlHeader_t – 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
Chapter 9. GPFS programming interfaces 353