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

.\" -*- nroff -*-
.\"
.\" Copyright (c) 1996 Doug Rabson
.\"
.\" All rights reserved.
.\"
.\" This program is free software.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd July 24, 1996
.Os
.Dt VOP_INACTIVE 9
.Sh NAME
.Nm VOP_INACTIVE ,
.Nm VOP_RECLAIM
.Nd reclaim filesystem resources for a vnode
.Sh SYNOPSIS
.Fd #include <sys/param.h>
.Fd #include <sys/vnode.h>
.Ft int
.Fn VOP_INACTIVE "struct vnode *vp" "struct proc *p"
.Ft int
.Fn VOP_RECLAIM "struct vnode *vp" "struct proc *p"
.Sh DESCRIPTION
.Pp
The arguments are:
.Bl -tag -width vp
.It Ar vp
the vnode being reclaimed
.El
.Pp
.Xr VOP_INACTIVE 9
is called when the kernel is no longer using the vnode.  This may be
because the reference count reaches zero or it may be that the
filesystem is being forcibly unmounted while there are open files.
It can be used to reclaim space for 'open but deleted' files.
.Xr VOP_RECLAIM 9
is called when a vnode is being reused for a different filesystem.
Any filesystem specific resources associated with the vnode should be
freed.
.Sh LOCKS
.Pp
For VOP_INACTIVE, the vp will be locked on entry.  Your VOP_INACTIVE code
must unlock the vp prior to returning.
.Pp
For VOP_RECLAIM, the vp will not be locked on entry and should be left
unlocked on return.
.Pp
.Sh PSEUDOCODE
.Bd -literal
int
vop_inactive(struct vnode *vp)
{
    if (link count of vp == 0) {
	/*
	 * Reclaim space in filesystem for vp.
	 */
	...;
    }
    VOP_UNLOCK(vp, 0, p);

    return 0;
}

int
vop_reclaim(struct vnode *vp)
{
    /*
     * Clean out the name cache.
     */
    cache_purge(vp);

    /*
     * Free filesystem-related data.
     */
    ...;

    return 0;
}
.Ed
.Sh SEE ALSO
.Xr vnode 9
.Sh AUTHORS
This man page was written by
.An Doug Rabson .