Update man page for VOP_OPEN() after fdidx->fp conversion.

Reminded by: ru

share/man/man9/VOP_OPENCLOSE.9

@@ -28,7 +28,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 24, 1996
+.Dd June 5, 2007
 .Os
 .Dt VOP_OPEN 9
 .Sh NAME
@@ -39,7 +39,7 @@
 .In sys/param.h
 .In sys/vnode.h
 .Ft int
-.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" "int fdidx"
+.Fn VOP_OPEN "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td" "struct file *fp"
 .Ft int
 .Fn VOP_CLOSE "struct vnode *vp" "int mode" "struct ucred *cred" "struct thread *td"
 .Sh DESCRIPTION
@@ -57,14 +57,21 @@ The vnode of the file.
 The access mode required by the calling process.
 .It Fa td
 The thread which is accessing the file.
+.It Fa fp
+The file being opened.
 .El
 .Pp
-Additionally,
-.Fn VOP_OPEN
-can accept a file descriptor number in
-.Fa fdidx ;
-this is useful for file systems which require such information, e.g.,
+Pointer to the file
+.Fa fp
+is useful for file systems which require such information, e.g.,
 .Xr fdescfs 5 .
+Use
+.Ql NULL
+as
+.Fa fp
+argument to
+.Fn VOP_OPEN
+for in-kernel opens.
 .Pp
 The access mode is a set of flags, including
 .Dv FREAD ,
@@ -85,20 +92,13 @@ Note that
 .Fa vn_close
 expects an unlocked, referenced vnode and will dereference the vnode prior
 to returning.
-.Sh IMPLEMENTATION NOTES
-The
-.Fa fdidx
-argument to
-.Fn VOP_OPEN
-is currently unused, use
-.Ql \-1
-for the meantime; however, this will change in future.
 .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 thread *td)
+vop_open(struct vnode *vp, int mode, struct ucred *cred, struct thread *td,
+    struct file *fp)
 {
     /*
      * Most file systems don't do much here.