cdnode.4 (2010 09)

c
cdnode(4) cdnode(4)
NAME
cdnode - format of a CDFS cdnode
SYNOPSIS
#include <sys/types.h>
#include <sys/cdnode.h>
DESCRIPTION
This entry describes the cdnode structure and related concepts for the CDFS file system.
The CDFS file system does not have the concept of a separate entity called an inode. The information
normally found in an HFS inode is kept in a cdnode data structure. However, the cdnode data structure
does not reside on the physical media, but instead is kept in kernel memory space only. The cdnode
information is used to uniquely identify a file.
The information kept in the cdnode structure is obtained from two other data structures in the CDFS file
system:
1. Directory record for the file or directory, and
2. Extended attribute record (XAR) for the file or directory, if one exists.
Because few files usually have XARs associated with them, the cdnode information most often consists
only of attributes given by the directory record for the file.
Since cdnodes are kept in kernel memory, they cannot be directly accessed by the user. The
stat()
system call attempts to map whatever information is included in the cdnode for a given file into the stan-
dard stat structure (see stat (2)). However, since a cdnode includes information that does not have
corresponding fields in the stat structure, that information cannot be mapped and therefore cannot be
accessed. No method is provided to access an entire cdnode structure.
FILES
/usr/include/sys/cdnode.h
/usr/include/sys/cdfsdir.h
SEE ALSO
stat(2), cdrom(4).
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1