root / block / qcow.c @ 76ae317f
History | View | Annotate | Download (29.5 kB)
1 |
/*
|
---|---|
2 |
* Block driver for the QCOW format
|
3 |
*
|
4 |
* Copyright (c) 2004-2006 Fabrice Bellard
|
5 |
*
|
6 |
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
7 |
* of this software and associated documentation files (the "Software"), to deal
|
8 |
* in the Software without restriction, including without limitation the rights
|
9 |
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
10 |
* copies of the Software, and to permit persons to whom the Software is
|
11 |
* furnished to do so, subject to the following conditions:
|
12 |
*
|
13 |
* The above copyright notice and this permission notice shall be included in
|
14 |
* all copies or substantial portions of the Software.
|
15 |
*
|
16 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
17 |
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
18 |
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
19 |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
20 |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
21 |
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
22 |
* THE SOFTWARE.
|
23 |
*/
|
24 |
#include "qemu-common.h" |
25 |
#include "block_int.h" |
26 |
#include "module.h" |
27 |
#include <zlib.h> |
28 |
#include "aes.h" |
29 |
|
30 |
/**************************************************************/
|
31 |
/* QEMU COW block driver with compression and encryption support */
|
32 |
|
33 |
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
34 |
#define QCOW_VERSION 1 |
35 |
|
36 |
#define QCOW_CRYPT_NONE 0 |
37 |
#define QCOW_CRYPT_AES 1 |
38 |
|
39 |
#define QCOW_OFLAG_COMPRESSED (1LL << 63) |
40 |
|
41 |
typedef struct QCowHeader { |
42 |
uint32_t magic; |
43 |
uint32_t version; |
44 |
uint64_t backing_file_offset; |
45 |
uint32_t backing_file_size; |
46 |
uint32_t mtime; |
47 |
uint64_t size; /* in bytes */
|
48 |
uint8_t cluster_bits; |
49 |
uint8_t l2_bits; |
50 |
uint32_t crypt_method; |
51 |
uint64_t l1_table_offset; |
52 |
} QCowHeader; |
53 |
|
54 |
#define L2_CACHE_SIZE 16 |
55 |
|
56 |
typedef struct BDRVQcowState { |
57 |
BlockDriverState *hd; |
58 |
int cluster_bits;
|
59 |
int cluster_size;
|
60 |
int cluster_sectors;
|
61 |
int l2_bits;
|
62 |
int l2_size;
|
63 |
int l1_size;
|
64 |
uint64_t cluster_offset_mask; |
65 |
uint64_t l1_table_offset; |
66 |
uint64_t *l1_table; |
67 |
uint64_t *l2_cache; |
68 |
uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
69 |
uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
70 |
uint8_t *cluster_cache; |
71 |
uint8_t *cluster_data; |
72 |
uint64_t cluster_cache_offset; |
73 |
uint32_t crypt_method; /* current crypt method, 0 if no key yet */
|
74 |
uint32_t crypt_method_header; |
75 |
AES_KEY aes_encrypt_key; |
76 |
AES_KEY aes_decrypt_key; |
77 |
} BDRVQcowState; |
78 |
|
79 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
80 |
|
81 |
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
82 |
{ |
83 |
const QCowHeader *cow_header = (const void *)buf; |
84 |
|
85 |
if (buf_size >= sizeof(QCowHeader) && |
86 |
be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
87 |
be32_to_cpu(cow_header->version) == QCOW_VERSION) |
88 |
return 100; |
89 |
else
|
90 |
return 0; |
91 |
} |
92 |
|
93 |
static int qcow_open(BlockDriverState *bs, const char *filename, int flags) |
94 |
{ |
95 |
BDRVQcowState *s = bs->opaque; |
96 |
int len, i, shift, ret;
|
97 |
QCowHeader header; |
98 |
|
99 |
ret = bdrv_file_open(&s->hd, filename, flags); |
100 |
if (ret < 0) |
101 |
return ret;
|
102 |
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) |
103 |
goto fail;
|
104 |
be32_to_cpus(&header.magic); |
105 |
be32_to_cpus(&header.version); |
106 |
be64_to_cpus(&header.backing_file_offset); |
107 |
be32_to_cpus(&header.backing_file_size); |
108 |
be32_to_cpus(&header.mtime); |
109 |
be64_to_cpus(&header.size); |
110 |
be32_to_cpus(&header.crypt_method); |
111 |
be64_to_cpus(&header.l1_table_offset); |
112 |
|
113 |
if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
|
114 |
goto fail;
|
115 |
if (header.size <= 1 || header.cluster_bits < 9) |
116 |
goto fail;
|
117 |
if (header.crypt_method > QCOW_CRYPT_AES)
|
118 |
goto fail;
|
119 |
s->crypt_method_header = header.crypt_method; |
120 |
if (s->crypt_method_header)
|
121 |
bs->encrypted = 1;
|
122 |
s->cluster_bits = header.cluster_bits; |
123 |
s->cluster_size = 1 << s->cluster_bits;
|
124 |
s->cluster_sectors = 1 << (s->cluster_bits - 9); |
125 |
s->l2_bits = header.l2_bits; |
126 |
s->l2_size = 1 << s->l2_bits;
|
127 |
bs->total_sectors = header.size / 512;
|
128 |
s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; |
129 |
|
130 |
/* read the level 1 table */
|
131 |
shift = s->cluster_bits + s->l2_bits; |
132 |
s->l1_size = (header.size + (1LL << shift) - 1) >> shift; |
133 |
|
134 |
s->l1_table_offset = header.l1_table_offset; |
135 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
136 |
if (!s->l1_table)
|
137 |
goto fail;
|
138 |
if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
139 |
s->l1_size * sizeof(uint64_t))
|
140 |
goto fail;
|
141 |
for(i = 0;i < s->l1_size; i++) { |
142 |
be64_to_cpus(&s->l1_table[i]); |
143 |
} |
144 |
/* alloc L2 cache */
|
145 |
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
146 |
if (!s->l2_cache)
|
147 |
goto fail;
|
148 |
s->cluster_cache = qemu_malloc(s->cluster_size); |
149 |
if (!s->cluster_cache)
|
150 |
goto fail;
|
151 |
s->cluster_data = qemu_malloc(s->cluster_size); |
152 |
if (!s->cluster_data)
|
153 |
goto fail;
|
154 |
s->cluster_cache_offset = -1;
|
155 |
|
156 |
/* read the backing file name */
|
157 |
if (header.backing_file_offset != 0) { |
158 |
len = header.backing_file_size; |
159 |
if (len > 1023) |
160 |
len = 1023;
|
161 |
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
162 |
goto fail;
|
163 |
bs->backing_file[len] = '\0';
|
164 |
} |
165 |
return 0; |
166 |
|
167 |
fail:
|
168 |
qemu_free(s->l1_table); |
169 |
qemu_free(s->l2_cache); |
170 |
qemu_free(s->cluster_cache); |
171 |
qemu_free(s->cluster_data); |
172 |
bdrv_delete(s->hd); |
173 |
return -1; |
174 |
} |
175 |
|
176 |
static int qcow_set_key(BlockDriverState *bs, const char *key) |
177 |
{ |
178 |
BDRVQcowState *s = bs->opaque; |
179 |
uint8_t keybuf[16];
|
180 |
int len, i;
|
181 |
|
182 |
memset(keybuf, 0, 16); |
183 |
len = strlen(key); |
184 |
if (len > 16) |
185 |
len = 16;
|
186 |
/* XXX: we could compress the chars to 7 bits to increase
|
187 |
entropy */
|
188 |
for(i = 0;i < len;i++) { |
189 |
keybuf[i] = key[i]; |
190 |
} |
191 |
s->crypt_method = s->crypt_method_header; |
192 |
|
193 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
194 |
return -1; |
195 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
196 |
return -1; |
197 |
#if 0
|
198 |
/* test */
|
199 |
{
|
200 |
uint8_t in[16];
|
201 |
uint8_t out[16];
|
202 |
uint8_t tmp[16];
|
203 |
for(i=0;i<16;i++)
|
204 |
in[i] = i;
|
205 |
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
206 |
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
207 |
for(i = 0; i < 16; i++)
|
208 |
printf(" %02x", tmp[i]);
|
209 |
printf("\n");
|
210 |
for(i = 0; i < 16; i++)
|
211 |
printf(" %02x", out[i]);
|
212 |
printf("\n");
|
213 |
}
|
214 |
#endif
|
215 |
return 0; |
216 |
} |
217 |
|
218 |
/* The crypt function is compatible with the linux cryptoloop
|
219 |
algorithm for < 4 GB images. NOTE: out_buf == in_buf is
|
220 |
supported */
|
221 |
static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
222 |
uint8_t *out_buf, const uint8_t *in_buf,
|
223 |
int nb_sectors, int enc, |
224 |
const AES_KEY *key)
|
225 |
{ |
226 |
union {
|
227 |
uint64_t ll[2];
|
228 |
uint8_t b[16];
|
229 |
} ivec; |
230 |
int i;
|
231 |
|
232 |
for(i = 0; i < nb_sectors; i++) { |
233 |
ivec.ll[0] = cpu_to_le64(sector_num);
|
234 |
ivec.ll[1] = 0; |
235 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
236 |
ivec.b, enc); |
237 |
sector_num++; |
238 |
in_buf += 512;
|
239 |
out_buf += 512;
|
240 |
} |
241 |
} |
242 |
|
243 |
/* 'allocate' is:
|
244 |
*
|
245 |
* 0 to not allocate.
|
246 |
*
|
247 |
* 1 to allocate a normal cluster (for sector indexes 'n_start' to
|
248 |
* 'n_end')
|
249 |
*
|
250 |
* 2 to allocate a compressed cluster of size
|
251 |
* 'compressed_size'. 'compressed_size' must be > 0 and <
|
252 |
* cluster_size
|
253 |
*
|
254 |
* return 0 if not allocated.
|
255 |
*/
|
256 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
257 |
uint64_t offset, int allocate,
|
258 |
int compressed_size,
|
259 |
int n_start, int n_end) |
260 |
{ |
261 |
BDRVQcowState *s = bs->opaque; |
262 |
int min_index, i, j, l1_index, l2_index;
|
263 |
uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
264 |
uint32_t min_count; |
265 |
int new_l2_table;
|
266 |
|
267 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
268 |
l2_offset = s->l1_table[l1_index]; |
269 |
new_l2_table = 0;
|
270 |
if (!l2_offset) {
|
271 |
if (!allocate)
|
272 |
return 0; |
273 |
/* allocate a new l2 entry */
|
274 |
l2_offset = bdrv_getlength(s->hd); |
275 |
/* round to cluster size */
|
276 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
277 |
/* update the L1 entry */
|
278 |
s->l1_table[l1_index] = l2_offset; |
279 |
tmp = cpu_to_be64(l2_offset); |
280 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
281 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
282 |
return 0; |
283 |
new_l2_table = 1;
|
284 |
} |
285 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
286 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
287 |
/* increment the hit count */
|
288 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
289 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
290 |
s->l2_cache_counts[j] >>= 1;
|
291 |
} |
292 |
} |
293 |
l2_table = s->l2_cache + (i << s->l2_bits); |
294 |
goto found;
|
295 |
} |
296 |
} |
297 |
/* not found: load a new entry in the least used one */
|
298 |
min_index = 0;
|
299 |
min_count = 0xffffffff;
|
300 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
301 |
if (s->l2_cache_counts[i] < min_count) {
|
302 |
min_count = s->l2_cache_counts[i]; |
303 |
min_index = i; |
304 |
} |
305 |
} |
306 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
307 |
if (new_l2_table) {
|
308 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
309 |
if (bdrv_pwrite(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
310 |
s->l2_size * sizeof(uint64_t))
|
311 |
return 0; |
312 |
} else {
|
313 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
314 |
s->l2_size * sizeof(uint64_t))
|
315 |
return 0; |
316 |
} |
317 |
s->l2_cache_offsets[min_index] = l2_offset; |
318 |
s->l2_cache_counts[min_index] = 1;
|
319 |
found:
|
320 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
321 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
322 |
if (!cluster_offset ||
|
323 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
324 |
if (!allocate)
|
325 |
return 0; |
326 |
/* allocate a new cluster */
|
327 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
328 |
(n_end - n_start) < s->cluster_sectors) { |
329 |
/* if the cluster is already compressed, we must
|
330 |
decompress it in the case it is not completely
|
331 |
overwritten */
|
332 |
if (decompress_cluster(s, cluster_offset) < 0) |
333 |
return 0; |
334 |
cluster_offset = bdrv_getlength(s->hd); |
335 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
336 |
~(s->cluster_size - 1);
|
337 |
/* write the cluster content */
|
338 |
if (bdrv_pwrite(s->hd, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
339 |
s->cluster_size) |
340 |
return -1; |
341 |
} else {
|
342 |
cluster_offset = bdrv_getlength(s->hd); |
343 |
if (allocate == 1) { |
344 |
/* round to cluster size */
|
345 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
346 |
~(s->cluster_size - 1);
|
347 |
bdrv_truncate(s->hd, cluster_offset + s->cluster_size); |
348 |
/* if encrypted, we must initialize the cluster
|
349 |
content which won't be written */
|
350 |
if (s->crypt_method &&
|
351 |
(n_end - n_start) < s->cluster_sectors) { |
352 |
uint64_t start_sect; |
353 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
354 |
memset(s->cluster_data + 512, 0x00, 512); |
355 |
for(i = 0; i < s->cluster_sectors; i++) { |
356 |
if (i < n_start || i >= n_end) {
|
357 |
encrypt_sectors(s, start_sect + i, |
358 |
s->cluster_data, |
359 |
s->cluster_data + 512, 1, 1, |
360 |
&s->aes_encrypt_key); |
361 |
if (bdrv_pwrite(s->hd, cluster_offset + i * 512, |
362 |
s->cluster_data, 512) != 512) |
363 |
return -1; |
364 |
} |
365 |
} |
366 |
} |
367 |
} else if (allocate == 2) { |
368 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
369 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
370 |
} |
371 |
} |
372 |
/* update L2 table */
|
373 |
tmp = cpu_to_be64(cluster_offset); |
374 |
l2_table[l2_index] = tmp; |
375 |
if (bdrv_pwrite(s->hd,
|
376 |
l2_offset + l2_index * sizeof(tmp), &tmp, sizeof(tmp)) != sizeof(tmp)) |
377 |
return 0; |
378 |
} |
379 |
return cluster_offset;
|
380 |
} |
381 |
|
382 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
383 |
int nb_sectors, int *pnum) |
384 |
{ |
385 |
BDRVQcowState *s = bs->opaque; |
386 |
int index_in_cluster, n;
|
387 |
uint64_t cluster_offset; |
388 |
|
389 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
390 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
391 |
n = s->cluster_sectors - index_in_cluster; |
392 |
if (n > nb_sectors)
|
393 |
n = nb_sectors; |
394 |
*pnum = n; |
395 |
return (cluster_offset != 0); |
396 |
} |
397 |
|
398 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
399 |
const uint8_t *buf, int buf_size) |
400 |
{ |
401 |
z_stream strm1, *strm = &strm1; |
402 |
int ret, out_len;
|
403 |
|
404 |
memset(strm, 0, sizeof(*strm)); |
405 |
|
406 |
strm->next_in = (uint8_t *)buf; |
407 |
strm->avail_in = buf_size; |
408 |
strm->next_out = out_buf; |
409 |
strm->avail_out = out_buf_size; |
410 |
|
411 |
ret = inflateInit2(strm, -12);
|
412 |
if (ret != Z_OK)
|
413 |
return -1; |
414 |
ret = inflate(strm, Z_FINISH); |
415 |
out_len = strm->next_out - out_buf; |
416 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
417 |
out_len != out_buf_size) { |
418 |
inflateEnd(strm); |
419 |
return -1; |
420 |
} |
421 |
inflateEnd(strm); |
422 |
return 0; |
423 |
} |
424 |
|
425 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
426 |
{ |
427 |
int ret, csize;
|
428 |
uint64_t coffset; |
429 |
|
430 |
coffset = cluster_offset & s->cluster_offset_mask; |
431 |
if (s->cluster_cache_offset != coffset) {
|
432 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
433 |
csize &= (s->cluster_size - 1);
|
434 |
ret = bdrv_pread(s->hd, coffset, s->cluster_data, csize); |
435 |
if (ret != csize)
|
436 |
return -1; |
437 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
438 |
s->cluster_data, csize) < 0) {
|
439 |
return -1; |
440 |
} |
441 |
s->cluster_cache_offset = coffset; |
442 |
} |
443 |
return 0; |
444 |
} |
445 |
|
446 |
#if 0
|
447 |
|
448 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num,
|
449 |
uint8_t *buf, int nb_sectors)
|
450 |
{
|
451 |
BDRVQcowState *s = bs->opaque;
|
452 |
int ret, index_in_cluster, n;
|
453 |
uint64_t cluster_offset;
|
454 |
|
455 |
while (nb_sectors > 0) {
|
456 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
|
457 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
458 |
n = s->cluster_sectors - index_in_cluster;
|
459 |
if (n > nb_sectors)
|
460 |
n = nb_sectors;
|
461 |
if (!cluster_offset) {
|
462 |
if (bs->backing_hd) {
|
463 |
/* read from the base image */
|
464 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
|
465 |
if (ret < 0)
|
466 |
return -1;
|
467 |
} else {
|
468 |
memset(buf, 0, 512 * n);
|
469 |
}
|
470 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
471 |
if (decompress_cluster(s, cluster_offset) < 0)
|
472 |
return -1;
|
473 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
|
474 |
} else {
|
475 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512);
|
476 |
if (ret != n * 512)
|
477 |
return -1;
|
478 |
if (s->crypt_method) {
|
479 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
480 |
&s->aes_decrypt_key);
|
481 |
}
|
482 |
}
|
483 |
nb_sectors -= n;
|
484 |
sector_num += n;
|
485 |
buf += n * 512;
|
486 |
}
|
487 |
return 0;
|
488 |
}
|
489 |
#endif
|
490 |
|
491 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
492 |
const uint8_t *buf, int nb_sectors) |
493 |
{ |
494 |
BDRVQcowState *s = bs->opaque; |
495 |
int ret, index_in_cluster, n;
|
496 |
uint64_t cluster_offset; |
497 |
|
498 |
while (nb_sectors > 0) { |
499 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
500 |
n = s->cluster_sectors - index_in_cluster; |
501 |
if (n > nb_sectors)
|
502 |
n = nb_sectors; |
503 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
504 |
index_in_cluster, |
505 |
index_in_cluster + n); |
506 |
if (!cluster_offset)
|
507 |
return -1; |
508 |
if (s->crypt_method) {
|
509 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
510 |
&s->aes_encrypt_key); |
511 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
512 |
s->cluster_data, n * 512);
|
513 |
} else {
|
514 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
515 |
} |
516 |
if (ret != n * 512) |
517 |
return -1; |
518 |
nb_sectors -= n; |
519 |
sector_num += n; |
520 |
buf += n * 512;
|
521 |
} |
522 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
523 |
return 0; |
524 |
} |
525 |
|
526 |
typedef struct QCowAIOCB { |
527 |
BlockDriverAIOCB common; |
528 |
int64_t sector_num; |
529 |
QEMUIOVector *qiov; |
530 |
uint8_t *buf; |
531 |
void *orig_buf;
|
532 |
int nb_sectors;
|
533 |
int n;
|
534 |
uint64_t cluster_offset; |
535 |
uint8_t *cluster_data; |
536 |
struct iovec hd_iov;
|
537 |
QEMUIOVector hd_qiov; |
538 |
BlockDriverAIOCB *hd_aiocb; |
539 |
} QCowAIOCB; |
540 |
|
541 |
static void qcow_aio_read_cb(void *opaque, int ret) |
542 |
{ |
543 |
QCowAIOCB *acb = opaque; |
544 |
BlockDriverState *bs = acb->common.bs; |
545 |
BDRVQcowState *s = bs->opaque; |
546 |
int index_in_cluster;
|
547 |
|
548 |
acb->hd_aiocb = NULL;
|
549 |
if (ret < 0) |
550 |
goto done;
|
551 |
|
552 |
redo:
|
553 |
/* post process the read buffer */
|
554 |
if (!acb->cluster_offset) {
|
555 |
/* nothing to do */
|
556 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
557 |
/* nothing to do */
|
558 |
} else {
|
559 |
if (s->crypt_method) {
|
560 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
561 |
acb->n, 0,
|
562 |
&s->aes_decrypt_key); |
563 |
} |
564 |
} |
565 |
|
566 |
acb->nb_sectors -= acb->n; |
567 |
acb->sector_num += acb->n; |
568 |
acb->buf += acb->n * 512;
|
569 |
|
570 |
if (acb->nb_sectors == 0) { |
571 |
/* request completed */
|
572 |
ret = 0;
|
573 |
goto done;
|
574 |
} |
575 |
|
576 |
/* prepare next AIO request */
|
577 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
|
578 |
0, 0, 0, 0); |
579 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
580 |
acb->n = s->cluster_sectors - index_in_cluster; |
581 |
if (acb->n > acb->nb_sectors)
|
582 |
acb->n = acb->nb_sectors; |
583 |
|
584 |
if (!acb->cluster_offset) {
|
585 |
if (bs->backing_hd) {
|
586 |
/* read from the base image */
|
587 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
588 |
acb->hd_iov.iov_len = acb->n * 512;
|
589 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
590 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
591 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
592 |
if (acb->hd_aiocb == NULL) |
593 |
goto done;
|
594 |
} else {
|
595 |
/* Note: in this case, no need to wait */
|
596 |
memset(acb->buf, 0, 512 * acb->n); |
597 |
goto redo;
|
598 |
} |
599 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
600 |
/* add AIO support for compressed blocks ? */
|
601 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
602 |
goto done;
|
603 |
memcpy(acb->buf, |
604 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
605 |
goto redo;
|
606 |
} else {
|
607 |
if ((acb->cluster_offset & 511) != 0) { |
608 |
ret = -EIO; |
609 |
goto done;
|
610 |
} |
611 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
612 |
acb->hd_iov.iov_len = acb->n * 512;
|
613 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
614 |
acb->hd_aiocb = bdrv_aio_readv(s->hd, |
615 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
616 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
617 |
if (acb->hd_aiocb == NULL) |
618 |
goto done;
|
619 |
} |
620 |
|
621 |
return;
|
622 |
|
623 |
done:
|
624 |
if (acb->qiov->niov > 1) { |
625 |
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); |
626 |
qemu_vfree(acb->orig_buf); |
627 |
} |
628 |
acb->common.cb(acb->common.opaque, ret); |
629 |
qemu_aio_release(acb); |
630 |
} |
631 |
|
632 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
633 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
634 |
BlockDriverCompletionFunc *cb, void *opaque)
|
635 |
{ |
636 |
QCowAIOCB *acb; |
637 |
|
638 |
acb = qemu_aio_get(bs, cb, opaque); |
639 |
if (!acb)
|
640 |
return NULL; |
641 |
acb->hd_aiocb = NULL;
|
642 |
acb->sector_num = sector_num; |
643 |
acb->qiov = qiov; |
644 |
if (qiov->niov > 1) |
645 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
646 |
else
|
647 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
648 |
acb->nb_sectors = nb_sectors; |
649 |
acb->n = 0;
|
650 |
acb->cluster_offset = 0;
|
651 |
|
652 |
qcow_aio_read_cb(acb, 0);
|
653 |
return &acb->common;
|
654 |
} |
655 |
|
656 |
static void qcow_aio_write_cb(void *opaque, int ret) |
657 |
{ |
658 |
QCowAIOCB *acb = opaque; |
659 |
BlockDriverState *bs = acb->common.bs; |
660 |
BDRVQcowState *s = bs->opaque; |
661 |
int index_in_cluster;
|
662 |
uint64_t cluster_offset; |
663 |
const uint8_t *src_buf;
|
664 |
|
665 |
acb->hd_aiocb = NULL;
|
666 |
|
667 |
if (ret < 0) |
668 |
goto done;
|
669 |
|
670 |
acb->nb_sectors -= acb->n; |
671 |
acb->sector_num += acb->n; |
672 |
acb->buf += acb->n * 512;
|
673 |
|
674 |
if (acb->nb_sectors == 0) { |
675 |
/* request completed */
|
676 |
ret = 0;
|
677 |
goto done;
|
678 |
} |
679 |
|
680 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
681 |
acb->n = s->cluster_sectors - index_in_cluster; |
682 |
if (acb->n > acb->nb_sectors)
|
683 |
acb->n = acb->nb_sectors; |
684 |
cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0, |
685 |
index_in_cluster, |
686 |
index_in_cluster + acb->n); |
687 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
688 |
ret = -EIO; |
689 |
goto done;
|
690 |
} |
691 |
if (s->crypt_method) {
|
692 |
if (!acb->cluster_data) {
|
693 |
acb->cluster_data = qemu_mallocz(s->cluster_size); |
694 |
if (!acb->cluster_data) {
|
695 |
ret = -ENOMEM; |
696 |
goto done;
|
697 |
} |
698 |
} |
699 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
700 |
acb->n, 1, &s->aes_encrypt_key);
|
701 |
src_buf = acb->cluster_data; |
702 |
} else {
|
703 |
src_buf = acb->buf; |
704 |
} |
705 |
|
706 |
acb->hd_iov.iov_base = (void *)src_buf;
|
707 |
acb->hd_iov.iov_len = acb->n * 512;
|
708 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
709 |
acb->hd_aiocb = bdrv_aio_writev(s->hd, |
710 |
(cluster_offset >> 9) + index_in_cluster,
|
711 |
&acb->hd_qiov, acb->n, |
712 |
qcow_aio_write_cb, acb); |
713 |
if (acb->hd_aiocb == NULL) |
714 |
goto done;
|
715 |
return;
|
716 |
|
717 |
done:
|
718 |
if (acb->qiov->niov > 1) |
719 |
qemu_vfree(acb->orig_buf); |
720 |
acb->common.cb(acb->common.opaque, ret); |
721 |
qemu_aio_release(acb); |
722 |
} |
723 |
|
724 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
725 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
726 |
BlockDriverCompletionFunc *cb, void *opaque)
|
727 |
{ |
728 |
BDRVQcowState *s = bs->opaque; |
729 |
QCowAIOCB *acb; |
730 |
|
731 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
732 |
|
733 |
acb = qemu_aio_get(bs, cb, opaque); |
734 |
if (!acb)
|
735 |
return NULL; |
736 |
acb->hd_aiocb = NULL;
|
737 |
acb->sector_num = sector_num; |
738 |
acb->qiov = qiov; |
739 |
if (qiov->niov > 1) { |
740 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
741 |
qemu_iovec_to_buffer(qiov, acb->buf); |
742 |
} else {
|
743 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
744 |
} |
745 |
acb->nb_sectors = nb_sectors; |
746 |
acb->n = 0;
|
747 |
|
748 |
qcow_aio_write_cb(acb, 0);
|
749 |
return &acb->common;
|
750 |
} |
751 |
|
752 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
753 |
{ |
754 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
755 |
if (acb->hd_aiocb)
|
756 |
bdrv_aio_cancel(acb->hd_aiocb); |
757 |
qemu_aio_release(acb); |
758 |
} |
759 |
|
760 |
static void qcow_close(BlockDriverState *bs) |
761 |
{ |
762 |
BDRVQcowState *s = bs->opaque; |
763 |
qemu_free(s->l1_table); |
764 |
qemu_free(s->l2_cache); |
765 |
qemu_free(s->cluster_cache); |
766 |
qemu_free(s->cluster_data); |
767 |
bdrv_delete(s->hd); |
768 |
} |
769 |
|
770 |
static int qcow_create(const char *filename, int64_t total_size, |
771 |
const char *backing_file, int flags) |
772 |
{ |
773 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
774 |
QCowHeader header; |
775 |
uint64_t tmp; |
776 |
|
777 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
778 |
if (fd < 0) |
779 |
return -1; |
780 |
memset(&header, 0, sizeof(header)); |
781 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
782 |
header.version = cpu_to_be32(QCOW_VERSION); |
783 |
header.size = cpu_to_be64(total_size * 512);
|
784 |
header_size = sizeof(header);
|
785 |
backing_filename_len = 0;
|
786 |
if (backing_file) {
|
787 |
if (strcmp(backing_file, "fat:")) { |
788 |
header.backing_file_offset = cpu_to_be64(header_size); |
789 |
backing_filename_len = strlen(backing_file); |
790 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
791 |
header_size += backing_filename_len; |
792 |
} else {
|
793 |
/* special backing file for vvfat */
|
794 |
backing_file = NULL;
|
795 |
} |
796 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
797 |
unmodifyed sectors */
|
798 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
799 |
} else {
|
800 |
header.cluster_bits = 12; /* 4 KB clusters */ |
801 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
802 |
} |
803 |
header_size = (header_size + 7) & ~7; |
804 |
shift = header.cluster_bits + header.l2_bits; |
805 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
806 |
|
807 |
header.l1_table_offset = cpu_to_be64(header_size); |
808 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
809 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
810 |
} else {
|
811 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
812 |
} |
813 |
|
814 |
/* write all the data */
|
815 |
write(fd, &header, sizeof(header));
|
816 |
if (backing_file) {
|
817 |
write(fd, backing_file, backing_filename_len); |
818 |
} |
819 |
lseek(fd, header_size, SEEK_SET); |
820 |
tmp = 0;
|
821 |
for(i = 0;i < l1_size; i++) { |
822 |
write(fd, &tmp, sizeof(tmp));
|
823 |
} |
824 |
close(fd); |
825 |
return 0; |
826 |
} |
827 |
|
828 |
static int qcow_make_empty(BlockDriverState *bs) |
829 |
{ |
830 |
BDRVQcowState *s = bs->opaque; |
831 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
832 |
int ret;
|
833 |
|
834 |
memset(s->l1_table, 0, l1_length);
|
835 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) |
836 |
return -1; |
837 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); |
838 |
if (ret < 0) |
839 |
return ret;
|
840 |
|
841 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
842 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
843 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
844 |
|
845 |
return 0; |
846 |
} |
847 |
|
848 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
849 |
tables to avoid losing bytes in alignment */
|
850 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
851 |
const uint8_t *buf, int nb_sectors) |
852 |
{ |
853 |
BDRVQcowState *s = bs->opaque; |
854 |
z_stream strm; |
855 |
int ret, out_len;
|
856 |
uint8_t *out_buf; |
857 |
uint64_t cluster_offset; |
858 |
|
859 |
if (nb_sectors != s->cluster_sectors)
|
860 |
return -EINVAL;
|
861 |
|
862 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
863 |
if (!out_buf)
|
864 |
return -1; |
865 |
|
866 |
/* best compression, small window, no zlib header */
|
867 |
memset(&strm, 0, sizeof(strm)); |
868 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
869 |
Z_DEFLATED, -12,
|
870 |
9, Z_DEFAULT_STRATEGY);
|
871 |
if (ret != 0) { |
872 |
qemu_free(out_buf); |
873 |
return -1; |
874 |
} |
875 |
|
876 |
strm.avail_in = s->cluster_size; |
877 |
strm.next_in = (uint8_t *)buf; |
878 |
strm.avail_out = s->cluster_size; |
879 |
strm.next_out = out_buf; |
880 |
|
881 |
ret = deflate(&strm, Z_FINISH); |
882 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
883 |
qemu_free(out_buf); |
884 |
deflateEnd(&strm); |
885 |
return -1; |
886 |
} |
887 |
out_len = strm.next_out - out_buf; |
888 |
|
889 |
deflateEnd(&strm); |
890 |
|
891 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
892 |
/* could not compress: write normal cluster */
|
893 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
894 |
} else {
|
895 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
896 |
out_len, 0, 0); |
897 |
cluster_offset &= s->cluster_offset_mask; |
898 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
899 |
qemu_free(out_buf); |
900 |
return -1; |
901 |
} |
902 |
} |
903 |
|
904 |
qemu_free(out_buf); |
905 |
return 0; |
906 |
} |
907 |
|
908 |
static void qcow_flush(BlockDriverState *bs) |
909 |
{ |
910 |
BDRVQcowState *s = bs->opaque; |
911 |
bdrv_flush(s->hd); |
912 |
} |
913 |
|
914 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
915 |
{ |
916 |
BDRVQcowState *s = bs->opaque; |
917 |
bdi->cluster_size = s->cluster_size; |
918 |
return 0; |
919 |
} |
920 |
|
921 |
static BlockDriver bdrv_qcow = {
|
922 |
.format_name = "qcow",
|
923 |
.instance_size = sizeof(BDRVQcowState),
|
924 |
.bdrv_probe = qcow_probe, |
925 |
.bdrv_open = qcow_open, |
926 |
.bdrv_close = qcow_close, |
927 |
.bdrv_create = qcow_create, |
928 |
.bdrv_flush = qcow_flush, |
929 |
.bdrv_is_allocated = qcow_is_allocated, |
930 |
.bdrv_set_key = qcow_set_key, |
931 |
.bdrv_make_empty = qcow_make_empty, |
932 |
.bdrv_aio_readv = qcow_aio_readv, |
933 |
.bdrv_aio_writev = qcow_aio_writev, |
934 |
.bdrv_aio_cancel = qcow_aio_cancel, |
935 |
.aiocb_size = sizeof(QCowAIOCB),
|
936 |
.bdrv_write_compressed = qcow_write_compressed, |
937 |
.bdrv_get_info = qcow_get_info, |
938 |
}; |
939 |
|
940 |
static void bdrv_qcow_init(void) |
941 |
{ |
942 |
bdrv_register(&bdrv_qcow); |
943 |
} |
944 |
|
945 |
block_init(bdrv_qcow_init); |