xref: /OK3568_Linux_fs/kernel/fs/afs/cache.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /* AFS caching stuff
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5*4882a593Smuzhiyun  * Written by David Howells (dhowells@redhat.com)
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #include <linux/sched.h>
9*4882a593Smuzhiyun #include "internal.h"
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
12*4882a593Smuzhiyun 						       const void *buffer,
13*4882a593Smuzhiyun 						       uint16_t buflen,
14*4882a593Smuzhiyun 						       loff_t object_size);
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun struct fscache_netfs afs_cache_netfs = {
17*4882a593Smuzhiyun 	.name			= "afs",
18*4882a593Smuzhiyun 	.version		= 2,
19*4882a593Smuzhiyun };
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun struct fscache_cookie_def afs_cell_cache_index_def = {
22*4882a593Smuzhiyun 	.name		= "AFS.cell",
23*4882a593Smuzhiyun 	.type		= FSCACHE_COOKIE_TYPE_INDEX,
24*4882a593Smuzhiyun };
25*4882a593Smuzhiyun 
26*4882a593Smuzhiyun struct fscache_cookie_def afs_volume_cache_index_def = {
27*4882a593Smuzhiyun 	.name		= "AFS.volume",
28*4882a593Smuzhiyun 	.type		= FSCACHE_COOKIE_TYPE_INDEX,
29*4882a593Smuzhiyun };
30*4882a593Smuzhiyun 
31*4882a593Smuzhiyun struct fscache_cookie_def afs_vnode_cache_index_def = {
32*4882a593Smuzhiyun 	.name		= "AFS.vnode",
33*4882a593Smuzhiyun 	.type		= FSCACHE_COOKIE_TYPE_DATAFILE,
34*4882a593Smuzhiyun 	.check_aux	= afs_vnode_cache_check_aux,
35*4882a593Smuzhiyun };
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun /*
38*4882a593Smuzhiyun  * check that the auxiliary data indicates that the entry is still valid
39*4882a593Smuzhiyun  */
afs_vnode_cache_check_aux(void * cookie_netfs_data,const void * buffer,uint16_t buflen,loff_t object_size)40*4882a593Smuzhiyun static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
41*4882a593Smuzhiyun 						       const void *buffer,
42*4882a593Smuzhiyun 						       uint16_t buflen,
43*4882a593Smuzhiyun 						       loff_t object_size)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun 	struct afs_vnode *vnode = cookie_netfs_data;
46*4882a593Smuzhiyun 	struct afs_vnode_cache_aux aux;
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	_enter("{%llx,%x,%llx},%p,%u",
49*4882a593Smuzhiyun 	       vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
50*4882a593Smuzhiyun 	       buffer, buflen);
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun 	memcpy(&aux, buffer, sizeof(aux));
53*4882a593Smuzhiyun 
54*4882a593Smuzhiyun 	/* check the size of the data is what we're expecting */
55*4882a593Smuzhiyun 	if (buflen != sizeof(aux)) {
56*4882a593Smuzhiyun 		_leave(" = OBSOLETE [len %hx != %zx]", buflen, sizeof(aux));
57*4882a593Smuzhiyun 		return FSCACHE_CHECKAUX_OBSOLETE;
58*4882a593Smuzhiyun 	}
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	if (vnode->status.data_version != aux.data_version) {
61*4882a593Smuzhiyun 		_leave(" = OBSOLETE [vers %llx != %llx]",
62*4882a593Smuzhiyun 		       aux.data_version, vnode->status.data_version);
63*4882a593Smuzhiyun 		return FSCACHE_CHECKAUX_OBSOLETE;
64*4882a593Smuzhiyun 	}
65*4882a593Smuzhiyun 
66*4882a593Smuzhiyun 	_leave(" = SUCCESS");
67*4882a593Smuzhiyun 	return FSCACHE_CHECKAUX_OKAY;
68*4882a593Smuzhiyun }
69