VOP_OPEN(9)

NAME
VOP_OPEN, VOP_CLOSE - open or close a file

SYNOPSIS
#include <sys/param.h>
#include <sys/vnode.h>
int
VOP_OPEN(struct vnode *vp, int mode, struct ucred *cred, struct proc *p);
int
VOP_CLOSE(struct vnode *vp, int mode);

DESCRIPTION
The VOP_OPEN(9) entry point is called before a file is accessed by a process and the VOP_CLOSE(9) entry point is called after a file is finished with by the process.

The arguments are:

vp  the vnode of the file

mode
    the access mode required by the calling process

p   the process which is accessing the file

The access mode is a set of flags, including FREAD, FWRITE, O_NONBLOCK, O_APPEND.

LOCKS
VOP_OPEN(9) expects vp to be locked on entry and will leave it locked on return.

VOP_CLOSE(9) expects at least a reference to be associated with the vnode and does not care whether the vnode is locked or not. The lock and reference state is left unchanged on return. Note that vn_close() expects an unlocked, referenced vnode and will dereference the vnode prior to returning.

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

PSEUDOCODE

    int
    vop_open(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
    {
        /*
         * Most filesystems don't do much here.
         */
        return 0;
    }

SEE ALSO
vnode(9), VOP_OLD_LOOKUP(9)

AUTHORS
This man page was written by Doug Rabson.