NetBSD/lib/libpuffs/puffs_node.3

.\"	$NetBSD: puffs_node.3,v 1.2 2007/06/24 18:16:36 pooka Exp $
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.\" Copyright (c) 2007 Antti Kantee.  All rights reserved.
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.Dd June 24, 2007
.Dt PUFFS_NODE 3
.Os
.Sh NAME
.Nm puffs_node
.Nd puffs node routines
.Sh LIBRARY
.Lb libpuffs
.Sh SYNOPSIS
.In puffs.h
.Ft struct puffs_node *
.Fn puffs_pn_new "struct puffs_usermount *pu" "void *priv"
.Ft void *
.Fo puffs_nodewalk_fn
.Fa "struct puffs_usermount *pu" "struct puffs_node *pn" "void *arg"
.Fc
.Ft void *
.Fo puffs_pn_nodewalk
.Fa "struct puffs_usermount *pu" "puffs_nodewalk_fn nwfn" "void *arg"
.Fc
.Ft void
.Fn puffs_pn_remove "struct puffs_node *pn"
.Ft void
.Fn puffs_pn_put "struct puffs_node *pn"
.Sh DESCRIPTION
.Em IMPORTANT NOTE!
This document describes interfaces which are not yet guaranteed to be
stable.
In case you update your system sources, please recompile everything
and fix complation errors.
If your sources are out-of-sync, incorrect operation may result.
The interfaces in this document will most likely be hugely simplified
in later versions or made transparent to the implementation.
.Pp
.Em MORE IMPORTANT STUFF!
It should especially be noted, that it is yet completely unsure, how
much of the internals contents of
.Vt struct puffs_node
will be exposed to file systems in the end.
.Pp
.Bl -tag -width xxxx
.It Fn puffs_pn_new pu priv
Create a new node and attach it to the mountpoint
.Ar pu .
The argument
.Ar priv
can be used for associating file system specific data with the new
node and will not be accessed by puffs.
.It Fn puffs_nodewalk_fn pu pn arg
A callback for
.Fn puffs_nodewalk .
The list of nodes is iterated in the argument
.Ar pn
and the argument
.Ar arg
is the argument given to
.Fn puffs_nodewalk .
.It Fn puffs_nodewalk pu nwfn arg
Walk all nodes associted with the mountpoint
.Ar pu
and call
.Fn nwfn
for them.
The walk is aborted if
.Fn puffs_nodewalk_fn
returns a value which is not
.Dv NULL .
This value is also returned this function.
In case the whole set of nodes is traversed,
.Dv NULL
is returned.
This function is useful for example in handling the
.Fn puffs_fs_sync
callback, when cached data for every node should be flushed to stable
storage.
.It Fn puffs_pn_remove pn
Signal that a node has been removed from the file system, but do not
yet release resources associated with the node.
This will prevent the nodewalk functions from accessing the node.
If necessary, this is usually called from
.Fn puffs_node_remove
and
.Fn puffs_node_rmdir .
.It Fn puffs_pn_put pn
Free all resources associated with node
.Ar pn .
This is typically called from
.Fn puffs_node_reclaim .
.Pp
.El
.Sh SEE ALSO
.Xr puffs 3