summaryrefslogtreecommitdiffstats
path: root/fs/afs/cache.c
blob: 1fe855191261fce57a85be27f59690743957ecd6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
/* AFS caching stuff
 *
 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/sched.h>
#include "internal.h"

static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
				       void *buffer, uint16_t buflen);
static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
				       void *buffer, uint16_t buflen);
static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
						      const void *buffer,
						      uint16_t buflen);

static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
					    void *buffer, uint16_t buflen);
static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
					    void *buffer, uint16_t buflen);
static enum fscache_checkaux afs_vlocation_cache_check_aux(
	void *cookie_netfs_data, const void *buffer, uint16_t buflen);

static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
					 void *buffer, uint16_t buflen);

static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
					void *buffer, uint16_t buflen);
static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
				     uint64_t *size);
static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
					void *buffer, uint16_t buflen);
static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
						       const void *buffer,
						       uint16_t buflen);

struct fscache_netfs afs_cache_netfs = {
	.name			= "afs",
	.version		= 0,
};

struct fscache_cookie_def afs_cell_cache_index_def = {
	.name		= "AFS.cell",
	.type		= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key	= afs_cell_cache_get_key,
	.get_aux	= afs_cell_cache_get_aux,
	.check_aux	= afs_cell_cache_check_aux,
};

struct fscache_cookie_def afs_vlocation_cache_index_def = {
	.name			= "AFS.vldb",
	.type			= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key		= afs_vlocation_cache_get_key,
	.get_aux		= afs_vlocation_cache_get_aux,
	.check_aux		= afs_vlocation_cache_check_aux,
};

struct fscache_cookie_def afs_volume_cache_index_def = {
	.name		= "AFS.volume",
	.type		= FSCACHE_COOKIE_TYPE_INDEX,
	.get_key	= afs_volume_cache_get_key,
};

struct fscache_cookie_def afs_vnode_cache_index_def = {
	.name			= "AFS.vnode",
	.type			= FSCACHE_COOKIE_TYPE_DATAFILE,
	.get_key		= afs_vnode_cache_get_key,
	.get_attr		= afs_vnode_cache_get_attr,
	.get_aux		= afs_vnode_cache_get_aux,
	.check_aux		= afs_vnode_cache_check_aux,
};

/*
 * set the key for the index entry
 */
static uint16_t afs_cell_cache_get_key(const void *cookie_netfs_data,
				       void *buffer, uint16_t bufmax)
{
	const struct afs_cell *cell = cookie_netfs_data;
	uint16_t klen;

	_enter("%p,%p,%u", cell, buffer, bufmax);

	klen = strlen(cell->name);
	if (klen > bufmax)
		return 0;

	memcpy(buffer, cell->name, klen);
	return klen;
}

/*
 * provide new auxiliary cache data
 */
static uint16_t afs_cell_cache_get_aux(const void *cookie_netfs_data,
				       void *buffer, uint16_t bufmax)
{
	const struct afs_cell *cell = cookie_netfs_data;
	uint16_t dlen;

	_enter("%p,%p,%u", cell, buffer, bufmax);

	dlen = cell->vl_naddrs * sizeof(cell->vl_addrs[0]);
	dlen = min(dlen, bufmax);
	dlen &= ~(sizeof(cell->vl_addrs[0]) - 1);

	memcpy(buffer, cell->vl_addrs, dlen);
	return dlen;
}

/*
 * check that the auxiliary data indicates that the entry is still valid
 */
static enum fscache_checkaux afs_cell_cache_check_aux(void *cookie_netfs_data,
						      const void *buffer,
						      uint16_t buflen)
{
	_leave(" = OKAY");
	return FSCACHE_CHECKAUX_OKAY;
}

/*****************************************************************************/
/*
 * set the key for the index entry
 */
static uint16_t afs_vlocation_cache_get_key(const void *cookie_netfs_data,
					    void *buffer, uint16_t bufmax)
{
	const struct afs_vlocation *vlocation = cookie_netfs_data;
	uint16_t klen;

	_enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);

	klen = strnlen(vlocation->vldb.name, sizeof(vlocation->vldb.name));
	if (klen > bufmax)
		return 0;

	memcpy(buffer, vlocation->vldb.name, klen);

	_leave(" = %u", klen);
	return klen;
}

/*
 * provide new auxiliary cache data
 */
static uint16_t afs_vlocation_cache_get_aux(const void *cookie_netfs_data,
					    void *buffer, uint16_t bufmax)
{
	const struct afs_vlocation *vlocation = cookie_netfs_data;
	uint16_t dlen;

	_enter("{%s},%p,%u", vlocation->vldb.name, buffer, bufmax);

	dlen = sizeof(struct afs_cache_vlocation);
	dlen -= offsetof(struct afs_cache_vlocation, nservers);
	if (dlen > bufmax)
		return 0;

	memcpy(buffer, (uint8_t *)&vlocation->vldb.nservers, dlen);

	_leave(" = %u", dlen);
	return dlen;
}

/*
 * check that the auxiliary data indicates that the entry is still valid
 */
static
enum fscache_checkaux afs_vlocation_cache_check_aux(void *cookie_netfs_data,
						    const void *buffer,
						    uint16_t buflen)
{
	const struct afs_cache_vlocation *cvldb;
	struct afs_vlocation *vlocation = cookie_netfs_data;
	uint16_t dlen;

	_enter("{%s},%p,%u", vlocation->vldb.name, buffer, buflen);

	/* check the size of the data is what we're expecting */
	dlen = sizeof(struct afs_cache_vlocation);
	dlen -= offsetof(struct afs_cache_vlocation, nservers);
	if (dlen != buflen)
		return FSCACHE_CHECKAUX_OBSOLETE;

	cvldb = container_of(buffer, struct afs_cache_vlocation, nservers);

	/* if what's on disk is more valid than what's in memory, then use the
	 * VL record from the cache */
	if (!vlocation->valid || vlocation->vldb.rtime == cvldb->rtime) {
		memcpy((uint8_t *)&vlocation->vldb.nservers, buffer, dlen);
		vlocation->valid = 1;
		_leave(" = SUCCESS [c->m]");
		return FSCACHE_CHECKAUX_OKAY;
	}

	/* need to update the cache if the cached info differs */
	if (memcmp(&vlocation->vldb, buffer, dlen) != 0) {
		/* delete if the volume IDs for this name differ */
		if (memcmp(&vlocation->vldb.vid, &cvldb->vid,
			   sizeof(cvldb->vid)) != 0
		    ) {
			_leave(" = OBSOLETE");
			return FSCACHE_CHECKAUX_OBSOLETE;
		}

		_leave(" = UPDATE");
		return FSCACHE_CHECKAUX_NEEDS_UPDATE;
	}

	_leave(" = OKAY");
	return FSCACHE_CHECKAUX_OKAY;
}

/*****************************************************************************/
/*
 * set the key for the volume index entry
 */
static uint16_t afs_volume_cache_get_key(const void *cookie_netfs_data,
					void *buffer, uint16_t bufmax)
{
	const struct afs_volume *volume = cookie_netfs_data;
	uint16_t klen;

	_enter("{%u},%p,%u", volume->type, buffer, bufmax);

	klen = sizeof(volume->type);
	if (klen > bufmax)
		return 0;

	memcpy(buffer, &volume->type, sizeof(volume->type));

	_leave(" = %u", klen);
	return klen;

}

/*****************************************************************************/
/*
 * set the key for the index entry
 */
static uint16_t afs_vnode_cache_get_key(const void *cookie_netfs_data,
					void *buffer, uint16_t bufmax)
{
	const struct afs_vnode *vnode = cookie_netfs_data;
	uint16_t klen;

	_enter("{%x,%x,%llx},%p,%u",
	       vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
	       buffer, bufmax);

	klen = sizeof(vnode->fid.vnode);
	if (klen > bufmax)
		return 0;

	memcpy(buffer, &vnode->fid.vnode, sizeof(vnode->fid.vnode));

	_leave(" = %u", klen);
	return klen;
}

/*
 * provide updated file attributes
 */
static void afs_vnode_cache_get_attr(const void *cookie_netfs_data,
				     uint64_t *size)
{
	const struct afs_vnode *vnode = cookie_netfs_data;

	_enter("{%x,%x,%llx},",
	       vnode->fid.vnode, vnode->fid.unique,
	       vnode->status.data_version);

	*size = vnode->status.size;
}

/*
 * provide new auxiliary cache data
 */
static uint16_t afs_vnode_cache_get_aux(const void *cookie_netfs_data,
					void *buffer, uint16_t bufmax)
{
	const struct afs_vnode *vnode = cookie_netfs_data;
	uint16_t dlen;

	_enter("{%x,%x,%Lx},%p,%u",
	       vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
	       buffer, bufmax);

	dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
	if (dlen > bufmax)
		return 0;

	memcpy(buffer, &vnode->fid.unique, sizeof(vnode->fid.unique));
	buffer += sizeof(vnode->fid.unique);
	memcpy(buffer, &vnode->status.data_version,
	       sizeof(vnode->status.data_version));

	_leave(" = %u", dlen);
	return dlen;
}

/*
 * check that the auxiliary data indicates that the entry is still valid
 */
static enum fscache_checkaux afs_vnode_cache_check_aux(void *cookie_netfs_data,
						       const void *buffer,
						       uint16_t buflen)
{
	struct afs_vnode *vnode = cookie_netfs_data;
	uint16_t dlen;

	_enter("{%x,%x,%llx},%p,%u",
	       vnode->fid.vnode, vnode->fid.unique, vnode->status.data_version,
	       buffer, buflen);

	/* check the size of the data is what we're expecting */
	dlen = sizeof(vnode->fid.unique) + sizeof(vnode->status.data_version);
	if (dlen != buflen) {
		_leave(" = OBSOLETE [len %hx != %hx]", dlen, buflen);
		return FSCACHE_CHECKAUX_OBSOLETE;
	}

	if (memcmp(buffer,
		   &vnode->fid.unique,
		   sizeof(vnode->fid.unique)
		   ) != 0) {
		unsigned unique;

		memcpy(&unique, buffer, sizeof(unique));

		_leave(" = OBSOLETE [uniq %x != %x]",
		       unique, vnode->fid.unique);
		return FSCACHE_CHECKAUX_OBSOLETE;
	}

	if (memcmp(buffer + sizeof(vnode->fid.unique),
		   &vnode->status.data_version,
		   sizeof(vnode->status.data_version)
		   ) != 0) {
		afs_dataversion_t version;

		memcpy(&version, buffer + sizeof(vnode->fid.unique),
		       sizeof(version));

		_leave(" = OBSOLETE [vers %llx != %llx]",
		       version, vnode->status.data_version);
		return FSCACHE_CHECKAUX_OBSOLETE;
	}

	_leave(" = SUCCESS");
	return FSCACHE_CHECKAUX_OKAY;
}