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 */
27 struct fscache_netfs cifs_fscache_netfs = {
28 .name = "cifs",
29 .version = 0,
30 };
31
32 /*
33 * Register CIFS for caching with FS-Cache
34 */
cifs_fscache_register(void)35 int cifs_fscache_register(void)
36 {
37 return fscache_register_netfs(&cifs_fscache_netfs);
38 }
39
40 /*
41 * Unregister CIFS for caching
42 */
cifs_fscache_unregister(void)43 void cifs_fscache_unregister(void)
44 {
45 fscache_unregister_netfs(&cifs_fscache_netfs);
46 }
47
48 /*
49 * Key layout of CIFS server cache index object
50 */
51 struct cifs_server_key {
52 uint16_t family; /* address family */
53 __be16 port; /* IP port */
54 union {
55 struct in_addr ipv4_addr;
56 struct in6_addr ipv6_addr;
57 } addr[0];
58 };
59
60 /*
61 * Server object keyed by {IPaddress,port,family} tuple
62 */
cifs_server_get_key(const void * cookie_netfs_data,void * buffer,uint16_t maxbuf)63 static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
64 void *buffer, uint16_t maxbuf)
65 {
66 const struct TCP_Server_Info *server = cookie_netfs_data;
67 const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
68 const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
69 const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
70 struct cifs_server_key *key = buffer;
71 uint16_t key_len = sizeof(struct cifs_server_key);
72
73 memset(key, 0, key_len);
74
75 /*
76 * Should not be a problem as sin_family/sin6_family overlays
77 * sa_family field
78 */
79 switch (sa->sa_family) {
80 case AF_INET:
81 key->family = sa->sa_family;
82 key->port = addr->sin_port;
83 key->addr[0].ipv4_addr = addr->sin_addr;
84 key_len += sizeof(key->addr[0].ipv4_addr);
85 break;
86
87 case AF_INET6:
88 key->family = sa->sa_family;
89 key->port = addr6->sin6_port;
90 key->addr[0].ipv6_addr = addr6->sin6_addr;
91 key_len += sizeof(key->addr[0].ipv6_addr);
92 break;
93
94 default:
95 cERROR(1, "CIFS: Unknown network family '%d'", sa->sa_family);
96 key_len = 0;
97 break;
98 }
99
100 return key_len;
101 }
102
103 /*
104 * Server object for FS-Cache
105 */
106 const struct fscache_cookie_def cifs_fscache_server_index_def = {
107 .name = "CIFS.server",
108 .type = FSCACHE_COOKIE_TYPE_INDEX,
109 .get_key = cifs_server_get_key,
110 };
111
112 /*
113 * Auxiliary data attached to CIFS superblock within the cache
114 */
115 struct cifs_fscache_super_auxdata {
116 u64 resource_id; /* unique server resource id */
117 };
118
extract_sharename(const char * treename)119 static char *extract_sharename(const char *treename)
120 {
121 const char *src;
122 char *delim, *dst;
123 int len;
124
125 /* skip double chars at the beginning */
126 src = treename + 2;
127
128 /* share name is always preceded by '\\' now */
129 delim = strchr(src, '\\');
130 if (!delim)
131 return ERR_PTR(-EINVAL);
132 delim++;
133 len = strlen(delim);
134
135 /* caller has to free the memory */
136 dst = kstrndup(delim, len, GFP_KERNEL);
137 if (!dst)
138 return ERR_PTR(-ENOMEM);
139
140 return dst;
141 }
142
143 /*
144 * Superblock object currently keyed by share name
145 */
cifs_super_get_key(const void * cookie_netfs_data,void * buffer,uint16_t maxbuf)146 static uint16_t cifs_super_get_key(const void *cookie_netfs_data, void *buffer,
147 uint16_t maxbuf)
148 {
149 const struct cifsTconInfo *tcon = cookie_netfs_data;
150 char *sharename;
151 uint16_t len;
152
153 sharename = extract_sharename(tcon->treeName);
154 if (IS_ERR(sharename)) {
155 cFYI(1, "CIFS: couldn't extract sharename\n");
156 sharename = NULL;
157 return 0;
158 }
159
160 len = strlen(sharename);
161 if (len > maxbuf)
162 return 0;
163
164 memcpy(buffer, sharename, len);
165
166 kfree(sharename);
167
168 return len;
169 }
170
171 static uint16_t
cifs_fscache_super_get_aux(const void * cookie_netfs_data,void * buffer,uint16_t maxbuf)172 cifs_fscache_super_get_aux(const void *cookie_netfs_data, void *buffer,
173 uint16_t maxbuf)
174 {
175 struct cifs_fscache_super_auxdata auxdata;
176 const struct cifsTconInfo *tcon = cookie_netfs_data;
177
178 memset(&auxdata, 0, sizeof(auxdata));
179 auxdata.resource_id = tcon->resource_id;
180
181 if (maxbuf > sizeof(auxdata))
182 maxbuf = sizeof(auxdata);
183
184 memcpy(buffer, &auxdata, maxbuf);
185
186 return maxbuf;
187 }
188
189 static enum
cifs_fscache_super_check_aux(void * cookie_netfs_data,const void * data,uint16_t datalen)190 fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
191 const void *data,
192 uint16_t datalen)
193 {
194 struct cifs_fscache_super_auxdata auxdata;
195 const struct cifsTconInfo *tcon = cookie_netfs_data;
196
197 if (datalen != sizeof(auxdata))
198 return FSCACHE_CHECKAUX_OBSOLETE;
199
200 memset(&auxdata, 0, sizeof(auxdata));
201 auxdata.resource_id = tcon->resource_id;
202
203 if (memcmp(data, &auxdata, datalen) != 0)
204 return FSCACHE_CHECKAUX_OBSOLETE;
205
206 return FSCACHE_CHECKAUX_OKAY;
207 }
208
209 /*
210 * Superblock object for FS-Cache
211 */
212 const struct fscache_cookie_def cifs_fscache_super_index_def = {
213 .name = "CIFS.super",
214 .type = FSCACHE_COOKIE_TYPE_INDEX,
215 .get_key = cifs_super_get_key,
216 .get_aux = cifs_fscache_super_get_aux,
217 .check_aux = cifs_fscache_super_check_aux,
218 };
219
220 /*
221 * Auxiliary data attached to CIFS inode within the cache
222 */
223 struct cifs_fscache_inode_auxdata {
224 struct timespec last_write_time;
225 struct timespec last_change_time;
226 u64 eof;
227 };
228
cifs_fscache_inode_get_key(const void * cookie_netfs_data,void * buffer,uint16_t maxbuf)229 static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
230 void *buffer, uint16_t maxbuf)
231 {
232 const struct cifsInodeInfo *cifsi = cookie_netfs_data;
233 uint16_t keylen;
234
235 /* use the UniqueId as the key */
236 keylen = sizeof(cifsi->uniqueid);
237 if (keylen > maxbuf)
238 keylen = 0;
239 else
240 memcpy(buffer, &cifsi->uniqueid, keylen);
241
242 return keylen;
243 }
244
245 static void
cifs_fscache_inode_get_attr(const void * cookie_netfs_data,uint64_t * size)246 cifs_fscache_inode_get_attr(const void *cookie_netfs_data, uint64_t *size)
247 {
248 const struct cifsInodeInfo *cifsi = cookie_netfs_data;
249
250 *size = cifsi->vfs_inode.i_size;
251 }
252
253 static uint16_t
cifs_fscache_inode_get_aux(const void * cookie_netfs_data,void * buffer,uint16_t maxbuf)254 cifs_fscache_inode_get_aux(const void *cookie_netfs_data, void *buffer,
255 uint16_t maxbuf)
256 {
257 struct cifs_fscache_inode_auxdata auxdata;
258 const struct cifsInodeInfo *cifsi = cookie_netfs_data;
259
260 memset(&auxdata, 0, sizeof(auxdata));
261 auxdata.eof = cifsi->server_eof;
262 auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
263 auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
264
265 if (maxbuf > sizeof(auxdata))
266 maxbuf = sizeof(auxdata);
267
268 memcpy(buffer, &auxdata, maxbuf);
269
270 return maxbuf;
271 }
272
273 static enum
cifs_fscache_inode_check_aux(void * cookie_netfs_data,const void * data,uint16_t datalen)274 fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
275 const void *data,
276 uint16_t datalen)
277 {
278 struct cifs_fscache_inode_auxdata auxdata;
279 struct cifsInodeInfo *cifsi = cookie_netfs_data;
280
281 if (datalen != sizeof(auxdata))
282 return FSCACHE_CHECKAUX_OBSOLETE;
283
284 memset(&auxdata, 0, sizeof(auxdata));
285 auxdata.eof = cifsi->server_eof;
286 auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
287 auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
288
289 if (memcmp(data, &auxdata, datalen) != 0)
290 return FSCACHE_CHECKAUX_OBSOLETE;
291
292 return FSCACHE_CHECKAUX_OKAY;
293 }
294
cifs_fscache_inode_now_uncached(void * cookie_netfs_data)295 static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
296 {
297 struct cifsInodeInfo *cifsi = cookie_netfs_data;
298 struct pagevec pvec;
299 pgoff_t first;
300 int loop, nr_pages;
301
302 pagevec_init(&pvec, 0);
303 first = 0;
304
305 cFYI(1, "cifs inode 0x%p now uncached", cifsi);
306
307 for (;;) {
308 nr_pages = pagevec_lookup(&pvec,
309 cifsi->vfs_inode.i_mapping, first,
310 PAGEVEC_SIZE - pagevec_count(&pvec));
311 if (!nr_pages)
312 break;
313
314 for (loop = 0; loop < nr_pages; loop++)
315 ClearPageFsCache(pvec.pages[loop]);
316
317 first = pvec.pages[nr_pages - 1]->index + 1;
318
319 pvec.nr = nr_pages;
320 pagevec_release(&pvec);
321 cond_resched();
322 }
323 }
324
325 const struct fscache_cookie_def cifs_fscache_inode_object_def = {
326 .name = "CIFS.uniqueid",
327 .type = FSCACHE_COOKIE_TYPE_DATAFILE,
328 .get_key = cifs_fscache_inode_get_key,
329 .get_attr = cifs_fscache_inode_get_attr,
330 .get_aux = cifs_fscache_inode_get_aux,
331 .check_aux = cifs_fscache_inode_check_aux,
332 .now_uncached = cifs_fscache_inode_now_uncached,
333 };
334