Linux kernel mirror (for testing)
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linux
1/*
2 * fs/cifs/cache.c - CIFS filesystem cache index structure definitions
3 *
4 * Copyright (c) 2010 Novell, Inc.
5 * Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21#include "fscache.h"
22#include "cifs_debug.h"
23
24/*
25 * CIFS filesystem definition for FS-Cache
26 */
27struct fscache_netfs cifs_fscache_netfs = {
28 .name = "cifs",
29 .version = 0,
30};
31
32/*
33 * Register CIFS for caching with FS-Cache
34 */
35int cifs_fscache_register(void)
36{
37 return fscache_register_netfs(&cifs_fscache_netfs);
38}
39
40/*
41 * Unregister CIFS for caching
42 */
43void cifs_fscache_unregister(void)
44{
45 fscache_unregister_netfs(&cifs_fscache_netfs);
46}
47
48/*
49 * Server object for FS-Cache
50 */
51const struct fscache_cookie_def cifs_fscache_server_index_def = {
52 .name = "CIFS.server",
53 .type = FSCACHE_COOKIE_TYPE_INDEX,
54};
55
56/*
57 * Auxiliary data attached to CIFS superblock within the cache
58 */
59struct cifs_fscache_super_auxdata {
60 u64 resource_id; /* unique server resource id */
61};
62
63char *extract_sharename(const char *treename)
64{
65 const char *src;
66 char *delim, *dst;
67 int len;
68
69 /* skip double chars at the beginning */
70 src = treename + 2;
71
72 /* share name is always preceded by '\\' now */
73 delim = strchr(src, '\\');
74 if (!delim)
75 return ERR_PTR(-EINVAL);
76 delim++;
77 len = strlen(delim);
78
79 /* caller has to free the memory */
80 dst = kstrndup(delim, len, GFP_KERNEL);
81 if (!dst)
82 return ERR_PTR(-ENOMEM);
83
84 return dst;
85}
86
87static enum
88fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
89 const void *data,
90 uint16_t datalen,
91 loff_t object_size)
92{
93 struct cifs_fscache_super_auxdata auxdata;
94 const struct cifs_tcon *tcon = cookie_netfs_data;
95
96 if (datalen != sizeof(auxdata))
97 return FSCACHE_CHECKAUX_OBSOLETE;
98
99 memset(&auxdata, 0, sizeof(auxdata));
100 auxdata.resource_id = tcon->resource_id;
101
102 if (memcmp(data, &auxdata, datalen) != 0)
103 return FSCACHE_CHECKAUX_OBSOLETE;
104
105 return FSCACHE_CHECKAUX_OKAY;
106}
107
108/*
109 * Superblock object for FS-Cache
110 */
111const struct fscache_cookie_def cifs_fscache_super_index_def = {
112 .name = "CIFS.super",
113 .type = FSCACHE_COOKIE_TYPE_INDEX,
114 .check_aux = cifs_fscache_super_check_aux,
115};
116
117static enum
118fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
119 const void *data,
120 uint16_t datalen,
121 loff_t object_size)
122{
123 struct cifs_fscache_inode_auxdata auxdata;
124 struct cifsInodeInfo *cifsi = cookie_netfs_data;
125
126 if (datalen != sizeof(auxdata))
127 return FSCACHE_CHECKAUX_OBSOLETE;
128
129 memset(&auxdata, 0, sizeof(auxdata));
130 auxdata.eof = cifsi->server_eof;
131 auxdata.last_write_time_sec = cifsi->vfs_inode.i_mtime.tv_sec;
132 auxdata.last_change_time_sec = cifsi->vfs_inode.i_ctime.tv_sec;
133 auxdata.last_write_time_nsec = cifsi->vfs_inode.i_mtime.tv_nsec;
134 auxdata.last_change_time_nsec = cifsi->vfs_inode.i_ctime.tv_nsec;
135
136 if (memcmp(data, &auxdata, datalen) != 0)
137 return FSCACHE_CHECKAUX_OBSOLETE;
138
139 return FSCACHE_CHECKAUX_OKAY;
140}
141
142const struct fscache_cookie_def cifs_fscache_inode_object_def = {
143 .name = "CIFS.uniqueid",
144 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
145 .check_aux = cifs_fscache_inode_check_aux,
146};