.\"	$OpenBSD: uvn_attach.9,v 1.1 2019/12/05 15:14:28 mpi Exp $
.\"	$NetBSD: uvm.9,v 1.14 2000/06/29 06:08:44 mrg Exp $
.\"
.\" Copyright (c) 1998 Matthew R. Green
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
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.Dd $Mdocdate: December 5 2019 $
.Dt UVN_ATTACH 9
.Os
.Sh NAME
.Nm uvn_attach ,
.Nm uvm_vnp_setsize ,
.Nm uvm_vnp_sync ,
.Nm uvm_vnp_terminate ,
.Nm uvm_vnp_uncache
.Nd memory mapping files and devices
.Sh SYNOPSIS
.In sys/param.h
.In uvm/uvm.h
.Ft struct uvm_object *
.Fn uvn_attach "struct vnode *vp" "vm_prot_t accessprot"
.Ft void
.Fn uvm_vnp_setsize "struct vnode *vp" "voff_t newsize"
.Ft void
.Fn uvm_vnp_sync "struct mount *mp"
.Ft void
.Fn uvm_vnp_terminate "struct vnode *vp"
.Ft boolean_t
.Fn uvm_vnp_uncache "struct vnode *vp"
.Sh DESCRIPTION
The
.Fn uvn_attach
function attaches a UVM object to vnode
.Fa vp ,
creating the object if necessary.
The object is returned.
.Pp
The
.Fn uvm_vnp_setsize
function sets the size of vnode
.Fa vp
to
.Fa newsize .
Caller must hold a reference to the vnode.
If the vnode shrinks, pages no longer used are discarded.
This function will be removed when the file system and VM buffer caches
are merged.
.Pp
The
.Fn uvm_vnp_sync
function flushes dirty vnodes from either the mount point passed in
.Fa mp ,
or all dirty vnodes if
.Fa mp
is
.Dv NULL .
This function will be removed when the file system and VM buffer caches
are merged.
.Pp
The
.Fn uvm_vnp_terminate
function frees all VM resources allocated to vnode
.Fa vp .
If the vnode still has references, it will not be destroyed; however
all future operations using this vnode will fail.
This function will be removed when the file system and VM buffer caches
are merged.
.Pp
The
.Fn uvm_vnp_uncache
function disables vnode
.Fa vp
from persisting when all references are freed.
This function will be removed when the file system and UVM caches
are unified.
Returns true if there is no active vnode.
.Sh SEE ALSO
.Xr uvm_init 9