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
15 static 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
20 struct fscache_netfs afs_cache_netfs = {
21 .name = "afs",
22 .version = 2,
23 };
24
25 struct fscache_cookie_def afs_cell_cache_index_def = {
26 .name = "AFS.cell",
27 .type = FSCACHE_COOKIE_TYPE_INDEX,
28 };
29
30 struct fscache_cookie_def afs_volume_cache_index_def = {
31 .name = "AFS.volume",
32 .type = FSCACHE_COOKIE_TYPE_INDEX,
33 };
34
35 struct 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 */
afs_vnode_cache_check_aux(void * cookie_netfs_data,const void * buffer,uint16_t buflen,loff_t object_size)44 static 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 }
73