1/* AFS caching stuff
 2 *
 3 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 4 * Written by David Howells (dhowells@redhat.com)
 5 *
 6 * This program is free software; you can redistribute it and/or
 7 * modify it under the terms of the GNU General Public License
 8 * as published by the Free Software Foundation; either version
 9 * 2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/sched.h>
13#include "internal.h"
14
15static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
16						       const void *buffer,
17						       uint16_t buflen,
18						       loff_t object_size);
19
20struct fscache_netfs afs_cache_netfs = {
21	.name			= "afs",
22	.version		= 2,
23};
24
25struct fscache_cookie_def afs_cell_cache_index_def = {
26	.name		= "AFS.cell",
27	.type		= FSCACHE_COOKIE_TYPE_INDEX,
28};
29
30struct fscache_cookie_def afs_volume_cache_index_def = {
31	.name		= "AFS.volume",
32	.type		= FSCACHE_COOKIE_TYPE_INDEX,
33};
34
35struct fscache_cookie_def afs_vnode_cache_index_def = {
36	.name		= "AFS.vnode",
37	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
38	.check_aux	= afs_vnode_cache_check_aux,
39};
40
41/*
42 * check that the auxiliary data indicates that the entry is still valid
43 */
44static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
45						       const void *buffer,
46						       uint16_t buflen,
47						       loff_t object_size)
48{
49	struct afs_vnode *vnode = cookie_netfs_data;
50	struct afs_vnode_cache_aux aux;
51
52	_enter("{%x,%x,%llx},%p,%u",
53	       vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
54	       buffer, buflen);
55
56	memcpy(&aux, buffer, sizeof(aux));
57
58	/* check the size of the data is what we're expecting */
59	if (buflen != sizeof(aux)) {
60		_leave(" = OBSOLETE [len %hx != %zx]", buflen, sizeof(aux));
61		return FSCACHE_CHECKAUX_OBSOLETE;
62	}
63
64	if (vnode->status.data_version != aux.data_version) {
65		_leave(" = OBSOLETE [vers %llx != %llx]",
66		       aux.data_version, vnode->status.data_version);
67		return FSCACHE_CHECKAUX_OBSOLETE;
68	}
69
70	_leave(" = SUCCESS");
71	return FSCACHE_CHECKAUX_OKAY;
72}