gpfs_iopen() subroutine

Opens a file or directory by inode number.

Library

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

Synopsis

#include <gpfs.h>
gpfs_ifile_t *gpfs_iopen(gpfs_fssnap_handle_t *fssnapHandle, 
                         gpfs_ino_t ino, 
                         int open_flags,
                         const gpfs_iattr_t *statxbuf, 
                         const char *symLink);

Description

The gpfs_iopen() subroutine opens a user file or directory for backup. The file is identified by its inode number ino within the file system or snapshot identified by the fssnapHandle. The fssnapHandle parameter must be the same one that was used to create the inode scan that returned the inode number ino.

To read the file or directory, the open_flags must be set to GPFS_O_BACKUP. The statxbuf and symLink parameters are reserved for future use and must be set to NULL.

For an overview of using gpfs_iopen() in a backup application, see Using APIs to develop backup applications.

Note: Compile any program that uses this subroutine with the -lgpfs flag from the following library:

libgpfs.a for AIX
libgpfs.so for Linux

Parameters

fssnapHandle

File system snapshot handle.

ino

The inode number.

open_flags

GPFS_O_BACKUP: Read files for backup.
O_RDONLY: For gpfs_iread().

statxbuf

This parameter is reserved for future use and should always be set to NULL.

symLink

This parameter is reserved for future use and should always be set to NULL.

Exit status

If the gpfs_iopen() subroutine is successful, it returns a pointer to the inode's file handle.

If the gpfs_iopen() subroutine is unsuccessful, it returns NULL and the global error variable errno is set to indicate the nature of the error.

Exceptions

None.

Error status

Error codes include but are not limited to the following:

EINVAL: Missing or incorrect parameter.
ENOENT: The file does not exist in the file system.
ENOMEM: Unable to allocate memory for the request.
ENOSYS: The gpfs_iopen() subroutine is not available.
EPERM: The caller does not have superuser privileges.
ESTALE: Cached file system information was not valid.
GPFS_E_INVAL_FSSNAPHANDLE: The file system snapshot handle is not valid.
GPFS_E_INVAL_INUM: Users are not authorized to open the reserved inodes.

Examples

For an example using gpfs_iopen(), see /usr/lpp/mmfs/samples/util/tsreaddir.c.

Location

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

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