freebsd-nq/share/man/man9/VOP_OPENCLOSE.9

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.\" -*- nroff -*-
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.\" Copyright (c) 1996 Doug Rabson
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.\" $Id: VOP_OPENCLOSE.9,v 1.2 1997/03/04 10:02:15 dfr Exp $
.\"
.Dd July 24, 1996
.Os
.Dt VOP_OPEN 9
.Sh NAME
.Nm VOP_OPEN ,
.Nm VOP_CLOSE
.Nd open or close a file
.Sh SYNOPSIS
.Fd #include <sys/param.h>
.Fd #include <sys/vnode.h>
.Ft int
.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct proc *p"
.Ft int
.Fn VOP_CLOSE "struct vnode *vp" "int mode" "struct ucred *cred" "struct proc *p"
.Sh DESCRIPTION
The
.Xr VOP_OPEN 9
entry point is called before a file is accessed by a process and the
.Xr VOP_CLOSE 9
entry point is called after a file is finished with by the process.
.Pp
The arguments are:
.Bl -tag -width mode
.It Ar vp
the vnode of the file
.It Ar mode
the access mode required by the calling process
.It Ar p
the process which is accessing the file
.El
.Pp
The access mode is a set of flags, including
.Dv FREAD ,
.Dv FWRITE ,
.Dv O_NONBLOCK ,
.Dv O_APPEND .
.Sh LOCKS
The vnode
.Fa vp
should be locked on entry and will still be locked on exit for
.Xr VOP_OPEN 9
and unlocked on entry and exit for
.Xr VOP_CLOSE 9 .
.Sh RETURN VALUES
Zero is returned on success, otherwise an error code is returned.
.Sh PSEUDOCODE
.Bd -literal
int
vop_open(struct vnode *vp, int mode, struct ucred *cred, struct proc *p)
{
/*
* Most filesystems don't do much here.
*/
return 0;
}
.Ed
.Sh SEE ALSO
.Xr vnode 9 ,
.Xr VOP_LOOKUP 9
.Sh AUTHORS
This man page was written by Doug Rabson.