VOP_READDIR

NAME

VOP_READDIR — read contents of a directory

SYNOPSIS

#include <sys/param.h>
#include <sys/dirent.h>
#include <sys/vnode.h>

int
VOP_READDIR(struct vnode *vp, struct uio *uio, struct ucred *cred, int *eofflag, int *ncookies, u_long **cookies);

DESCRIPTION

Read directory entries.

vp: The vnode of the directory.
uio: Where to read the directory contents.
cred: The caller's credentials.
eofflag: Return end of file status (NULL if not wanted).
ncookies: Number of directory cookies generated for NFS (NULL if not wanted).
cookies: Directory seek cookies generated for NFS (NULL if not wanted).

The directory contents are read into struct dirent structures. If the on-disc data structures differ from this then they should be translated.

LOCKS

The directory should be locked on entry and will still be locked on exit.

RETURN VALUES

Zero is returned on success, otherwise an error code is returned.

If this is called from the NFS server, the extra arguments eofflag, ncookies and cookies are given. The value of *eofflag should be set to TRUE if the end of the directory is reached while reading. The directory seek cookies are returned to the NFS client and may be used later to restart a directory read part way through the directory. There should be one cookie returned per directory entry. The value of the cookie should be the offset within the directory where the on-disc version of the appropriate directory entry starts. Memory for the cookies should be allocated using:

	...; 
	*ncookies = number of entries read; 
	*cookies = malloc(*ncookies * sizeof(u_long), M_TEMP, M_WAITOK);

ERRORS

[EINVAL]: An attempt was made to read from an illegal offset in the directory.
[EIO]: A read error occurred while reading the directory.
[EINTEGRITY]: Corrupted data was detected while reading the directory.

AUTHORS

This manual page was written by Doug Rabson.

March 30, 2020

Debian