Revision f7d0fe02
b/Makefile | ||
---|---|---|
68 | 68 |
BLOCK_OBJS=cutils.o cache-utils.o qemu-malloc.o qemu-option.o module.o |
69 | 69 |
BLOCK_OBJS+=block/cow.o block/qcow.o aes.o block/vmdk.o block/cloop.o |
70 | 70 |
BLOCK_OBJS+=block/dmg.o block/bochs.o block/vpc.o block/vvfat.o |
71 |
BLOCK_OBJS+=block/qcow2.o block/parallels.o block/nbd.o |
|
71 |
BLOCK_OBJS+=block/qcow2.o block/qcow2-refcount.o |
|
72 |
BLOCK_OBJS+=block/parallels.o block/nbd.o |
|
72 | 73 |
BLOCK_OBJS+=nbd.o block.o aio.o |
73 | 74 |
|
74 | 75 |
ifdef CONFIG_WIN32 |
b/block/qcow2-refcount.c | ||
---|---|---|
1 |
/* |
|
2 |
* Block driver for the QCOW version 2 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 |
|
|
25 |
#include "qemu-common.h" |
|
26 |
#include "block_int.h" |
|
27 |
#include "block/qcow2.h" |
|
28 |
|
|
29 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size); |
|
30 |
static int update_refcount(BlockDriverState *bs, |
|
31 |
int64_t offset, int64_t length, |
|
32 |
int addend); |
|
33 |
|
|
34 |
/*********************************************************/ |
|
35 |
/* refcount handling */ |
|
36 |
|
|
37 |
int refcount_init(BlockDriverState *bs) |
|
38 |
{ |
|
39 |
BDRVQcowState *s = bs->opaque; |
|
40 |
int ret, refcount_table_size2, i; |
|
41 |
|
|
42 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
|
43 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
|
44 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
|
45 |
if (s->refcount_table_size > 0) { |
|
46 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
|
47 |
s->refcount_table, refcount_table_size2); |
|
48 |
if (ret != refcount_table_size2) |
|
49 |
goto fail; |
|
50 |
for(i = 0; i < s->refcount_table_size; i++) |
|
51 |
be64_to_cpus(&s->refcount_table[i]); |
|
52 |
} |
|
53 |
return 0; |
|
54 |
fail: |
|
55 |
return -ENOMEM; |
|
56 |
} |
|
57 |
|
|
58 |
void refcount_close(BlockDriverState *bs) |
|
59 |
{ |
|
60 |
BDRVQcowState *s = bs->opaque; |
|
61 |
qemu_free(s->refcount_block_cache); |
|
62 |
qemu_free(s->refcount_table); |
|
63 |
} |
|
64 |
|
|
65 |
|
|
66 |
static int load_refcount_block(BlockDriverState *bs, |
|
67 |
int64_t refcount_block_offset) |
|
68 |
{ |
|
69 |
BDRVQcowState *s = bs->opaque; |
|
70 |
int ret; |
|
71 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
|
72 |
s->cluster_size); |
|
73 |
if (ret != s->cluster_size) |
|
74 |
return -EIO; |
|
75 |
s->refcount_block_cache_offset = refcount_block_offset; |
|
76 |
return 0; |
|
77 |
} |
|
78 |
|
|
79 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
|
80 |
{ |
|
81 |
BDRVQcowState *s = bs->opaque; |
|
82 |
int refcount_table_index, block_index; |
|
83 |
int64_t refcount_block_offset; |
|
84 |
|
|
85 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
86 |
if (refcount_table_index >= s->refcount_table_size) |
|
87 |
return 0; |
|
88 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
89 |
if (!refcount_block_offset) |
|
90 |
return 0; |
|
91 |
if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
92 |
/* better than nothing: return allocated if read error */ |
|
93 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
94 |
return 1; |
|
95 |
} |
|
96 |
block_index = cluster_index & |
|
97 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
98 |
return be16_to_cpu(s->refcount_block_cache[block_index]); |
|
99 |
} |
|
100 |
|
|
101 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
|
102 |
{ |
|
103 |
BDRVQcowState *s = bs->opaque; |
|
104 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret; |
|
105 |
uint64_t *new_table; |
|
106 |
int64_t table_offset; |
|
107 |
uint8_t data[12]; |
|
108 |
int old_table_size; |
|
109 |
int64_t old_table_offset; |
|
110 |
|
|
111 |
if (min_size <= s->refcount_table_size) |
|
112 |
return 0; |
|
113 |
/* compute new table size */ |
|
114 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); |
|
115 |
for(;;) { |
|
116 |
if (refcount_table_clusters == 0) { |
|
117 |
refcount_table_clusters = 1; |
|
118 |
} else { |
|
119 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
|
120 |
} |
|
121 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3); |
|
122 |
if (min_size <= new_table_size) |
|
123 |
break; |
|
124 |
} |
|
125 |
#ifdef DEBUG_ALLOC2 |
|
126 |
printf("grow_refcount_table from %d to %d\n", |
|
127 |
s->refcount_table_size, |
|
128 |
new_table_size); |
|
129 |
#endif |
|
130 |
new_table_size2 = new_table_size * sizeof(uint64_t); |
|
131 |
new_table = qemu_mallocz(new_table_size2); |
|
132 |
memcpy(new_table, s->refcount_table, |
|
133 |
s->refcount_table_size * sizeof(uint64_t)); |
|
134 |
for(i = 0; i < s->refcount_table_size; i++) |
|
135 |
cpu_to_be64s(&new_table[i]); |
|
136 |
/* Note: we cannot update the refcount now to avoid recursion */ |
|
137 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
|
138 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
|
139 |
if (ret != new_table_size2) |
|
140 |
goto fail; |
|
141 |
for(i = 0; i < s->refcount_table_size; i++) |
|
142 |
be64_to_cpus(&new_table[i]); |
|
143 |
|
|
144 |
cpu_to_be64w((uint64_t*)data, table_offset); |
|
145 |
cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters); |
|
146 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset), |
|
147 |
data, sizeof(data)) != sizeof(data)) |
|
148 |
goto fail; |
|
149 |
qemu_free(s->refcount_table); |
|
150 |
old_table_offset = s->refcount_table_offset; |
|
151 |
old_table_size = s->refcount_table_size; |
|
152 |
s->refcount_table = new_table; |
|
153 |
s->refcount_table_size = new_table_size; |
|
154 |
s->refcount_table_offset = table_offset; |
|
155 |
|
|
156 |
update_refcount(bs, table_offset, new_table_size2, 1); |
|
157 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); |
|
158 |
return 0; |
|
159 |
fail: |
|
160 |
free_clusters(bs, table_offset, new_table_size2); |
|
161 |
qemu_free(new_table); |
|
162 |
return -EIO; |
|
163 |
} |
|
164 |
|
|
165 |
|
|
166 |
static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index) |
|
167 |
{ |
|
168 |
BDRVQcowState *s = bs->opaque; |
|
169 |
int64_t offset, refcount_block_offset; |
|
170 |
int ret, refcount_table_index; |
|
171 |
uint64_t data64; |
|
172 |
|
|
173 |
/* Find L1 index and grow refcount table if needed */ |
|
174 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
175 |
if (refcount_table_index >= s->refcount_table_size) { |
|
176 |
ret = grow_refcount_table(bs, refcount_table_index + 1); |
|
177 |
if (ret < 0) |
|
178 |
return ret; |
|
179 |
} |
|
180 |
|
|
181 |
/* Load or allocate the refcount block */ |
|
182 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
183 |
if (!refcount_block_offset) { |
|
184 |
/* create a new refcount block */ |
|
185 |
/* Note: we cannot update the refcount now to avoid recursion */ |
|
186 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
|
187 |
memset(s->refcount_block_cache, 0, s->cluster_size); |
|
188 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
|
189 |
if (ret != s->cluster_size) |
|
190 |
return -EINVAL; |
|
191 |
s->refcount_table[refcount_table_index] = offset; |
|
192 |
data64 = cpu_to_be64(offset); |
|
193 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
|
194 |
refcount_table_index * sizeof(uint64_t), |
|
195 |
&data64, sizeof(data64)); |
|
196 |
if (ret != sizeof(data64)) |
|
197 |
return -EINVAL; |
|
198 |
|
|
199 |
refcount_block_offset = offset; |
|
200 |
s->refcount_block_cache_offset = offset; |
|
201 |
update_refcount(bs, offset, s->cluster_size, 1); |
|
202 |
} else { |
|
203 |
if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
204 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
205 |
return -EIO; |
|
206 |
} |
|
207 |
} |
|
208 |
|
|
209 |
return refcount_block_offset; |
|
210 |
} |
|
211 |
|
|
212 |
/* XXX: cache several refcount block clusters ? */ |
|
213 |
static int update_refcount(BlockDriverState *bs, |
|
214 |
int64_t offset, int64_t length, |
|
215 |
int addend) |
|
216 |
{ |
|
217 |
BDRVQcowState *s = bs->opaque; |
|
218 |
int64_t start, last, cluster_offset; |
|
219 |
int64_t refcount_block_offset = 0; |
|
220 |
int64_t table_index = -1, old_table_index; |
|
221 |
int first_index = -1, last_index = -1; |
|
222 |
|
|
223 |
#ifdef DEBUG_ALLOC2 |
|
224 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n", |
|
225 |
offset, length, addend); |
|
226 |
#endif |
|
227 |
if (length <= 0) |
|
228 |
return -EINVAL; |
|
229 |
start = offset & ~(s->cluster_size - 1); |
|
230 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
|
231 |
for(cluster_offset = start; cluster_offset <= last; |
|
232 |
cluster_offset += s->cluster_size) |
|
233 |
{ |
|
234 |
int block_index, refcount; |
|
235 |
int64_t cluster_index = cluster_offset >> s->cluster_bits; |
|
236 |
|
|
237 |
/* Only write refcount block to disk when we are done with it */ |
|
238 |
old_table_index = table_index; |
|
239 |
table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
240 |
if ((old_table_index >= 0) && (table_index != old_table_index)) { |
|
241 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT; |
|
242 |
if (bdrv_pwrite(s->hd, |
|
243 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
|
244 |
&s->refcount_block_cache[first_index], size) != size) |
|
245 |
{ |
|
246 |
return -EIO; |
|
247 |
} |
|
248 |
|
|
249 |
first_index = -1; |
|
250 |
last_index = -1; |
|
251 |
} |
|
252 |
|
|
253 |
/* Load the refcount block and allocate it if needed */ |
|
254 |
refcount_block_offset = alloc_refcount_block(bs, cluster_index); |
|
255 |
if (refcount_block_offset < 0) { |
|
256 |
return refcount_block_offset; |
|
257 |
} |
|
258 |
|
|
259 |
/* we can update the count and save it */ |
|
260 |
block_index = cluster_index & |
|
261 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
262 |
if (first_index == -1 || block_index < first_index) { |
|
263 |
first_index = block_index; |
|
264 |
} |
|
265 |
if (block_index > last_index) { |
|
266 |
last_index = block_index; |
|
267 |
} |
|
268 |
|
|
269 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
|
270 |
refcount += addend; |
|
271 |
if (refcount < 0 || refcount > 0xffff) |
|
272 |
return -EINVAL; |
|
273 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
|
274 |
s->free_cluster_index = cluster_index; |
|
275 |
} |
|
276 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
|
277 |
} |
|
278 |
|
|
279 |
/* Write last changed block to disk */ |
|
280 |
if (refcount_block_offset != 0) { |
|
281 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT; |
|
282 |
if (bdrv_pwrite(s->hd, |
|
283 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
|
284 |
&s->refcount_block_cache[first_index], size) != size) |
|
285 |
{ |
|
286 |
return -EIO; |
|
287 |
} |
|
288 |
} |
|
289 |
|
|
290 |
return 0; |
|
291 |
} |
|
292 |
|
|
293 |
/* addend must be 1 or -1 */ |
|
294 |
static int update_cluster_refcount(BlockDriverState *bs, |
|
295 |
int64_t cluster_index, |
|
296 |
int addend) |
|
297 |
{ |
|
298 |
BDRVQcowState *s = bs->opaque; |
|
299 |
int ret; |
|
300 |
|
|
301 |
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend); |
|
302 |
if (ret < 0) { |
|
303 |
return ret; |
|
304 |
} |
|
305 |
|
|
306 |
return get_refcount(bs, cluster_index); |
|
307 |
} |
|
308 |
|
|
309 |
|
|
310 |
|
|
311 |
/*********************************************************/ |
|
312 |
/* cluster allocation functions */ |
|
313 |
|
|
314 |
|
|
315 |
|
|
316 |
/* return < 0 if error */ |
|
317 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) |
|
318 |
{ |
|
319 |
BDRVQcowState *s = bs->opaque; |
|
320 |
int i, nb_clusters; |
|
321 |
|
|
322 |
nb_clusters = size_to_clusters(s, size); |
|
323 |
retry: |
|
324 |
for(i = 0; i < nb_clusters; i++) { |
|
325 |
int64_t i = s->free_cluster_index++; |
|
326 |
if (get_refcount(bs, i) != 0) |
|
327 |
goto retry; |
|
328 |
} |
|
329 |
#ifdef DEBUG_ALLOC2 |
|
330 |
printf("alloc_clusters: size=%lld -> %lld\n", |
|
331 |
size, |
|
332 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
|
333 |
#endif |
|
334 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits; |
|
335 |
} |
|
336 |
|
|
337 |
int64_t alloc_clusters(BlockDriverState *bs, int64_t size) |
|
338 |
{ |
|
339 |
int64_t offset; |
|
340 |
|
|
341 |
offset = alloc_clusters_noref(bs, size); |
|
342 |
update_refcount(bs, offset, size, 1); |
|
343 |
return offset; |
|
344 |
} |
|
345 |
|
|
346 |
/* only used to allocate compressed sectors. We try to allocate |
|
347 |
contiguous sectors. size must be <= cluster_size */ |
|
348 |
int64_t alloc_bytes(BlockDriverState *bs, int size) |
|
349 |
{ |
|
350 |
BDRVQcowState *s = bs->opaque; |
|
351 |
int64_t offset, cluster_offset; |
|
352 |
int free_in_cluster; |
|
353 |
|
|
354 |
assert(size > 0 && size <= s->cluster_size); |
|
355 |
if (s->free_byte_offset == 0) { |
|
356 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
|
357 |
} |
|
358 |
redo: |
|
359 |
free_in_cluster = s->cluster_size - |
|
360 |
(s->free_byte_offset & (s->cluster_size - 1)); |
|
361 |
if (size <= free_in_cluster) { |
|
362 |
/* enough space in current cluster */ |
|
363 |
offset = s->free_byte_offset; |
|
364 |
s->free_byte_offset += size; |
|
365 |
free_in_cluster -= size; |
|
366 |
if (free_in_cluster == 0) |
|
367 |
s->free_byte_offset = 0; |
|
368 |
if ((offset & (s->cluster_size - 1)) != 0) |
|
369 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
370 |
} else { |
|
371 |
offset = alloc_clusters(bs, s->cluster_size); |
|
372 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); |
|
373 |
if ((cluster_offset + s->cluster_size) == offset) { |
|
374 |
/* we are lucky: contiguous data */ |
|
375 |
offset = s->free_byte_offset; |
|
376 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
377 |
s->free_byte_offset += size; |
|
378 |
} else { |
|
379 |
s->free_byte_offset = offset; |
|
380 |
goto redo; |
|
381 |
} |
|
382 |
} |
|
383 |
return offset; |
|
384 |
} |
|
385 |
|
|
386 |
void free_clusters(BlockDriverState *bs, |
|
387 |
int64_t offset, int64_t size) |
|
388 |
{ |
|
389 |
update_refcount(bs, offset, size, -1); |
|
390 |
} |
|
391 |
|
|
392 |
|
|
393 |
|
|
394 |
/*********************************************************/ |
|
395 |
/* snapshots and image creation */ |
|
396 |
|
|
397 |
|
|
398 |
|
|
399 |
void create_refcount_update(QCowCreateState *s, int64_t offset, int64_t size) |
|
400 |
{ |
|
401 |
int refcount; |
|
402 |
int64_t start, last, cluster_offset; |
|
403 |
uint16_t *p; |
|
404 |
|
|
405 |
start = offset & ~(s->cluster_size - 1); |
|
406 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
|
407 |
for(cluster_offset = start; cluster_offset <= last; |
|
408 |
cluster_offset += s->cluster_size) { |
|
409 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
|
410 |
refcount = be16_to_cpu(*p); |
|
411 |
refcount++; |
|
412 |
*p = cpu_to_be16(refcount); |
|
413 |
} |
|
414 |
} |
|
415 |
|
|
416 |
/* update the refcounts of snapshots and the copied flag */ |
|
417 |
int update_snapshot_refcount(BlockDriverState *bs, |
|
418 |
int64_t l1_table_offset, |
|
419 |
int l1_size, |
|
420 |
int addend) |
|
421 |
{ |
|
422 |
BDRVQcowState *s = bs->opaque; |
|
423 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
|
424 |
int64_t old_offset, old_l2_offset; |
|
425 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount; |
|
426 |
|
|
427 |
l2_cache_reset(bs); |
|
428 |
|
|
429 |
l2_table = NULL; |
|
430 |
l1_table = NULL; |
|
431 |
l1_size2 = l1_size * sizeof(uint64_t); |
|
432 |
l1_allocated = 0; |
|
433 |
if (l1_table_offset != s->l1_table_offset) { |
|
434 |
l1_table = qemu_malloc(l1_size2); |
|
435 |
l1_allocated = 1; |
|
436 |
if (bdrv_pread(s->hd, l1_table_offset, |
|
437 |
l1_table, l1_size2) != l1_size2) |
|
438 |
goto fail; |
|
439 |
for(i = 0;i < l1_size; i++) |
|
440 |
be64_to_cpus(&l1_table[i]); |
|
441 |
} else { |
|
442 |
assert(l1_size == s->l1_size); |
|
443 |
l1_table = s->l1_table; |
|
444 |
l1_allocated = 0; |
|
445 |
} |
|
446 |
|
|
447 |
l2_size = s->l2_size * sizeof(uint64_t); |
|
448 |
l2_table = qemu_malloc(l2_size); |
|
449 |
l1_modified = 0; |
|
450 |
for(i = 0; i < l1_size; i++) { |
|
451 |
l2_offset = l1_table[i]; |
|
452 |
if (l2_offset) { |
|
453 |
old_l2_offset = l2_offset; |
|
454 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
|
455 |
l2_modified = 0; |
|
456 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) |
|
457 |
goto fail; |
|
458 |
for(j = 0; j < s->l2_size; j++) { |
|
459 |
offset = be64_to_cpu(l2_table[j]); |
|
460 |
if (offset != 0) { |
|
461 |
old_offset = offset; |
|
462 |
offset &= ~QCOW_OFLAG_COPIED; |
|
463 |
if (offset & QCOW_OFLAG_COMPRESSED) { |
|
464 |
nb_csectors = ((offset >> s->csize_shift) & |
|
465 |
s->csize_mask) + 1; |
|
466 |
if (addend != 0) |
|
467 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511, |
|
468 |
nb_csectors * 512, addend); |
|
469 |
/* compressed clusters are never modified */ |
|
470 |
refcount = 2; |
|
471 |
} else { |
|
472 |
if (addend != 0) { |
|
473 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
|
474 |
} else { |
|
475 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
|
476 |
} |
|
477 |
} |
|
478 |
|
|
479 |
if (refcount == 1) { |
|
480 |
offset |= QCOW_OFLAG_COPIED; |
|
481 |
} |
|
482 |
if (offset != old_offset) { |
|
483 |
l2_table[j] = cpu_to_be64(offset); |
|
484 |
l2_modified = 1; |
|
485 |
} |
|
486 |
} |
|
487 |
} |
|
488 |
if (l2_modified) { |
|
489 |
if (bdrv_pwrite(s->hd, |
|
490 |
l2_offset, l2_table, l2_size) != l2_size) |
|
491 |
goto fail; |
|
492 |
} |
|
493 |
|
|
494 |
if (addend != 0) { |
|
495 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
|
496 |
} else { |
|
497 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
|
498 |
} |
|
499 |
if (refcount == 1) { |
|
500 |
l2_offset |= QCOW_OFLAG_COPIED; |
|
501 |
} |
|
502 |
if (l2_offset != old_l2_offset) { |
|
503 |
l1_table[i] = l2_offset; |
|
504 |
l1_modified = 1; |
|
505 |
} |
|
506 |
} |
|
507 |
} |
|
508 |
if (l1_modified) { |
|
509 |
for(i = 0; i < l1_size; i++) |
|
510 |
cpu_to_be64s(&l1_table[i]); |
|
511 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table, |
|
512 |
l1_size2) != l1_size2) |
|
513 |
goto fail; |
|
514 |
for(i = 0; i < l1_size; i++) |
|
515 |
be64_to_cpus(&l1_table[i]); |
|
516 |
} |
|
517 |
if (l1_allocated) |
|
518 |
qemu_free(l1_table); |
|
519 |
qemu_free(l2_table); |
|
520 |
return 0; |
|
521 |
fail: |
|
522 |
if (l1_allocated) |
|
523 |
qemu_free(l1_table); |
|
524 |
qemu_free(l2_table); |
|
525 |
return -EIO; |
|
526 |
} |
|
527 |
|
|
528 |
|
|
529 |
|
|
530 |
|
|
531 |
/*********************************************************/ |
|
532 |
/* refcount checking functions */ |
|
533 |
|
|
534 |
|
|
535 |
|
|
536 |
/* |
|
537 |
* Increases the refcount for a range of clusters in a given refcount table. |
|
538 |
* This is used to construct a temporary refcount table out of L1 and L2 tables |
|
539 |
* which can be compared the the refcount table saved in the image. |
|
540 |
* |
|
541 |
* Returns the number of errors in the image that were found |
|
542 |
*/ |
|
543 |
static int inc_refcounts(BlockDriverState *bs, |
|
544 |
uint16_t *refcount_table, |
|
545 |
int refcount_table_size, |
|
546 |
int64_t offset, int64_t size) |
|
547 |
{ |
|
548 |
BDRVQcowState *s = bs->opaque; |
|
549 |
int64_t start, last, cluster_offset; |
|
550 |
int k; |
|
551 |
int errors = 0; |
|
552 |
|
|
553 |
if (size <= 0) |
|
554 |
return 0; |
|
555 |
|
|
556 |
start = offset & ~(s->cluster_size - 1); |
|
557 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
|
558 |
for(cluster_offset = start; cluster_offset <= last; |
|
559 |
cluster_offset += s->cluster_size) { |
|
560 |
k = cluster_offset >> s->cluster_bits; |
|
561 |
if (k < 0 || k >= refcount_table_size) { |
|
562 |
fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
|
563 |
cluster_offset); |
|
564 |
errors++; |
|
565 |
} else { |
|
566 |
if (++refcount_table[k] == 0) { |
|
567 |
fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64 |
|
568 |
"\n", cluster_offset); |
|
569 |
errors++; |
|
570 |
} |
|
571 |
} |
|
572 |
} |
|
573 |
|
|
574 |
return errors; |
|
575 |
} |
|
576 |
|
|
577 |
/* |
|
578 |
* Increases the refcount in the given refcount table for the all clusters |
|
579 |
* referenced in the L2 table. While doing so, performs some checks on L2 |
|
580 |
* entries. |
|
581 |
* |
|
582 |
* Returns the number of errors found by the checks or -errno if an internal |
|
583 |
* error occurred. |
|
584 |
*/ |
|
585 |
static int check_refcounts_l2(BlockDriverState *bs, |
|
586 |
uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset, |
|
587 |
int check_copied) |
|
588 |
{ |
|
589 |
BDRVQcowState *s = bs->opaque; |
|
590 |
uint64_t *l2_table, offset; |
|
591 |
int i, l2_size, nb_csectors, refcount; |
|
592 |
int errors = 0; |
|
593 |
|
|
594 |
/* Read L2 table from disk */ |
|
595 |
l2_size = s->l2_size * sizeof(uint64_t); |
|
596 |
l2_table = qemu_malloc(l2_size); |
|
597 |
|
|
598 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) |
|
599 |
goto fail; |
|
600 |
|
|
601 |
/* Do the actual checks */ |
|
602 |
for(i = 0; i < s->l2_size; i++) { |
|
603 |
offset = be64_to_cpu(l2_table[i]); |
|
604 |
if (offset != 0) { |
|
605 |
if (offset & QCOW_OFLAG_COMPRESSED) { |
|
606 |
/* Compressed clusters don't have QCOW_OFLAG_COPIED */ |
|
607 |
if (offset & QCOW_OFLAG_COPIED) { |
|
608 |
fprintf(stderr, "ERROR: cluster %" PRId64 ": " |
|
609 |
"copied flag must never be set for compressed " |
|
610 |
"clusters\n", offset >> s->cluster_bits); |
|
611 |
offset &= ~QCOW_OFLAG_COPIED; |
|
612 |
errors++; |
|
613 |
} |
|
614 |
|
|
615 |
/* Mark cluster as used */ |
|
616 |
nb_csectors = ((offset >> s->csize_shift) & |
|
617 |
s->csize_mask) + 1; |
|
618 |
offset &= s->cluster_offset_mask; |
|
619 |
errors += inc_refcounts(bs, refcount_table, |
|
620 |
refcount_table_size, |
|
621 |
offset & ~511, nb_csectors * 512); |
|
622 |
} else { |
|
623 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ |
|
624 |
if (check_copied) { |
|
625 |
uint64_t entry = offset; |
|
626 |
offset &= ~QCOW_OFLAG_COPIED; |
|
627 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
|
628 |
if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) { |
|
629 |
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%" |
|
630 |
PRIx64 " refcount=%d\n", entry, refcount); |
|
631 |
errors++; |
|
632 |
} |
|
633 |
} |
|
634 |
|
|
635 |
/* Mark cluster as used */ |
|
636 |
offset &= ~QCOW_OFLAG_COPIED; |
|
637 |
errors += inc_refcounts(bs, refcount_table, |
|
638 |
refcount_table_size, |
|
639 |
offset, s->cluster_size); |
|
640 |
|
|
641 |
/* Correct offsets are cluster aligned */ |
|
642 |
if (offset & (s->cluster_size - 1)) { |
|
643 |
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
|
644 |
"properly aligned; L2 entry corrupted.\n", offset); |
|
645 |
errors++; |
|
646 |
} |
|
647 |
} |
|
648 |
} |
|
649 |
} |
|
650 |
|
|
651 |
qemu_free(l2_table); |
|
652 |
return errors; |
|
653 |
|
|
654 |
fail: |
|
655 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); |
|
656 |
qemu_free(l2_table); |
|
657 |
return -EIO; |
|
658 |
} |
|
659 |
|
|
660 |
/* |
|
661 |
* Increases the refcount for the L1 table, its L2 tables and all referenced |
|
662 |
* clusters in the given refcount table. While doing so, performs some checks |
|
663 |
* on L1 and L2 entries. |
|
664 |
* |
|
665 |
* Returns the number of errors found by the checks or -errno if an internal |
|
666 |
* error occurred. |
|
667 |
*/ |
|
668 |
static int check_refcounts_l1(BlockDriverState *bs, |
|
669 |
uint16_t *refcount_table, |
|
670 |
int refcount_table_size, |
|
671 |
int64_t l1_table_offset, int l1_size, |
|
672 |
int check_copied) |
|
673 |
{ |
|
674 |
BDRVQcowState *s = bs->opaque; |
|
675 |
uint64_t *l1_table, l2_offset, l1_size2; |
|
676 |
int i, refcount, ret; |
|
677 |
int errors = 0; |
|
678 |
|
|
679 |
l1_size2 = l1_size * sizeof(uint64_t); |
|
680 |
|
|
681 |
/* Mark L1 table as used */ |
|
682 |
errors += inc_refcounts(bs, refcount_table, refcount_table_size, |
|
683 |
l1_table_offset, l1_size2); |
|
684 |
|
|
685 |
/* Read L1 table entries from disk */ |
|
686 |
l1_table = qemu_malloc(l1_size2); |
|
687 |
if (bdrv_pread(s->hd, l1_table_offset, |
|
688 |
l1_table, l1_size2) != l1_size2) |
|
689 |
goto fail; |
|
690 |
for(i = 0;i < l1_size; i++) |
|
691 |
be64_to_cpus(&l1_table[i]); |
|
692 |
|
|
693 |
/* Do the actual checks */ |
|
694 |
for(i = 0; i < l1_size; i++) { |
|
695 |
l2_offset = l1_table[i]; |
|
696 |
if (l2_offset) { |
|
697 |
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */ |
|
698 |
if (check_copied) { |
|
699 |
refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
|
700 |
>> s->cluster_bits); |
|
701 |
if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
|
702 |
fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64 |
|
703 |
" refcount=%d\n", l2_offset, refcount); |
|
704 |
errors++; |
|
705 |
} |
|
706 |
} |
|
707 |
|
|
708 |
/* Mark L2 table as used */ |
|
709 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
|
710 |
errors += inc_refcounts(bs, refcount_table, |
|
711 |
refcount_table_size, |
|
712 |
l2_offset, |
|
713 |
s->cluster_size); |
|
714 |
|
|
715 |
/* L2 tables are cluster aligned */ |
|
716 |
if (l2_offset & (s->cluster_size - 1)) { |
|
717 |
fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
|
718 |
"cluster aligned; L1 entry corrupted\n", l2_offset); |
|
719 |
errors++; |
|
720 |
} |
|
721 |
|
|
722 |
/* Process and check L2 entries */ |
|
723 |
ret = check_refcounts_l2(bs, refcount_table, refcount_table_size, |
|
724 |
l2_offset, check_copied); |
|
725 |
if (ret < 0) { |
|
726 |
goto fail; |
|
727 |
} |
|
728 |
errors += ret; |
|
729 |
} |
|
730 |
} |
|
731 |
qemu_free(l1_table); |
|
732 |
return errors; |
|
733 |
|
|
734 |
fail: |
|
735 |
fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n"); |
|
736 |
qemu_free(l1_table); |
|
737 |
return -EIO; |
|
738 |
} |
|
739 |
|
|
740 |
/* |
|
741 |
* Checks an image for refcount consistency. |
|
742 |
* |
|
743 |
* Returns 0 if no errors are found, the number of errors in case the image is |
|
744 |
* detected as corrupted, and -errno when an internal error occured. |
|
745 |
*/ |
|
746 |
int check_refcounts(BlockDriverState *bs) |
|
747 |
{ |
|
748 |
BDRVQcowState *s = bs->opaque; |
|
749 |
int64_t size; |
|
750 |
int nb_clusters, refcount1, refcount2, i; |
|
751 |
QCowSnapshot *sn; |
|
752 |
uint16_t *refcount_table; |
|
753 |
int ret, errors = 0; |
|
754 |
|
|
755 |
size = bdrv_getlength(s->hd); |
|
756 |
nb_clusters = size_to_clusters(s, size); |
|
757 |
refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t)); |
|
758 |
|
|
759 |
/* header */ |
|
760 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
|
761 |
0, s->cluster_size); |
|
762 |
|
|
763 |
/* current L1 table */ |
|
764 |
ret = check_refcounts_l1(bs, refcount_table, nb_clusters, |
|
765 |
s->l1_table_offset, s->l1_size, 1); |
|
766 |
if (ret < 0) { |
|
767 |
return ret; |
|
768 |
} |
|
769 |
errors += ret; |
|
770 |
|
|
771 |
/* snapshots */ |
|
772 |
for(i = 0; i < s->nb_snapshots; i++) { |
|
773 |
sn = s->snapshots + i; |
|
774 |
check_refcounts_l1(bs, refcount_table, nb_clusters, |
|
775 |
sn->l1_table_offset, sn->l1_size, 0); |
|
776 |
} |
|
777 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
|
778 |
s->snapshots_offset, s->snapshots_size); |
|
779 |
|
|
780 |
/* refcount data */ |
|
781 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
|
782 |
s->refcount_table_offset, |
|
783 |
s->refcount_table_size * sizeof(uint64_t)); |
|
784 |
for(i = 0; i < s->refcount_table_size; i++) { |
|
785 |
int64_t offset; |
|
786 |
offset = s->refcount_table[i]; |
|
787 |
if (offset != 0) { |
|
788 |
errors += inc_refcounts(bs, refcount_table, nb_clusters, |
|
789 |
offset, s->cluster_size); |
|
790 |
} |
|
791 |
} |
|
792 |
|
|
793 |
/* compare ref counts */ |
|
794 |
for(i = 0; i < nb_clusters; i++) { |
|
795 |
refcount1 = get_refcount(bs, i); |
|
796 |
refcount2 = refcount_table[i]; |
|
797 |
if (refcount1 != refcount2) { |
|
798 |
fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n", |
|
799 |
i, refcount1, refcount2); |
|
800 |
errors++; |
|
801 |
} |
|
802 |
} |
|
803 |
|
|
804 |
qemu_free(refcount_table); |
|
805 |
|
|
806 |
return errors; |
|
807 |
} |
|
808 |
|
b/block/qcow2.c | ||
---|---|---|
26 | 26 |
#include "module.h" |
27 | 27 |
#include <zlib.h> |
28 | 28 |
#include "aes.h" |
29 |
#include "block/qcow2.h" |
|
29 | 30 |
|
30 | 31 |
/* |
31 | 32 |
Differences with QCOW: |
... | ... | |
47 | 48 |
//#define DEBUG_ALLOC2 |
48 | 49 |
//#define DEBUG_EXT |
49 | 50 |
|
50 |
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
|
51 |
#define QCOW_VERSION 2 |
|
52 |
|
|
53 |
#define QCOW_CRYPT_NONE 0 |
|
54 |
#define QCOW_CRYPT_AES 1 |
|
55 |
|
|
56 |
#define QCOW_MAX_CRYPT_CLUSTERS 32 |
|
57 |
|
|
58 |
/* indicate that the refcount of the referenced cluster is exactly one. */ |
|
59 |
#define QCOW_OFLAG_COPIED (1LL << 63) |
|
60 |
/* indicate that the cluster is compressed (they never have the copied flag) */ |
|
61 |
#define QCOW_OFLAG_COMPRESSED (1LL << 62) |
|
62 |
|
|
63 |
#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ |
|
64 |
|
|
65 |
#define MIN_CLUSTER_BITS 9 |
|
66 |
#define MAX_CLUSTER_BITS 16 |
|
67 |
|
|
68 |
typedef struct QCowHeader { |
|
69 |
uint32_t magic; |
|
70 |
uint32_t version; |
|
71 |
uint64_t backing_file_offset; |
|
72 |
uint32_t backing_file_size; |
|
73 |
uint32_t cluster_bits; |
|
74 |
uint64_t size; /* in bytes */ |
|
75 |
uint32_t crypt_method; |
|
76 |
uint32_t l1_size; /* XXX: save number of clusters instead ? */ |
|
77 |
uint64_t l1_table_offset; |
|
78 |
uint64_t refcount_table_offset; |
|
79 |
uint32_t refcount_table_clusters; |
|
80 |
uint32_t nb_snapshots; |
|
81 |
uint64_t snapshots_offset; |
|
82 |
} QCowHeader; |
|
83 |
|
|
84 | 51 |
|
85 | 52 |
typedef struct { |
86 | 53 |
uint32_t magic; |
... | ... | |
110 | 77 |
/* name follows */ |
111 | 78 |
} QCowSnapshotHeader; |
112 | 79 |
|
113 |
#define L2_CACHE_SIZE 16 |
|
114 |
|
|
115 |
typedef struct QCowSnapshot { |
|
116 |
uint64_t l1_table_offset; |
|
117 |
uint32_t l1_size; |
|
118 |
char *id_str; |
|
119 |
char *name; |
|
120 |
uint32_t vm_state_size; |
|
121 |
uint32_t date_sec; |
|
122 |
uint32_t date_nsec; |
|
123 |
uint64_t vm_clock_nsec; |
|
124 |
} QCowSnapshot; |
|
125 |
|
|
126 |
typedef struct BDRVQcowState { |
|
127 |
BlockDriverState *hd; |
|
128 |
int cluster_bits; |
|
129 |
int cluster_size; |
|
130 |
int cluster_sectors; |
|
131 |
int l2_bits; |
|
132 |
int l2_size; |
|
133 |
int l1_size; |
|
134 |
int l1_vm_state_index; |
|
135 |
int csize_shift; |
|
136 |
int csize_mask; |
|
137 |
uint64_t cluster_offset_mask; |
|
138 |
uint64_t l1_table_offset; |
|
139 |
uint64_t *l1_table; |
|
140 |
uint64_t *l2_cache; |
|
141 |
uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
|
142 |
uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
|
143 |
uint8_t *cluster_cache; |
|
144 |
uint8_t *cluster_data; |
|
145 |
uint64_t cluster_cache_offset; |
|
146 |
|
|
147 |
uint64_t *refcount_table; |
|
148 |
uint64_t refcount_table_offset; |
|
149 |
uint32_t refcount_table_size; |
|
150 |
uint64_t refcount_block_cache_offset; |
|
151 |
uint16_t *refcount_block_cache; |
|
152 |
int64_t free_cluster_index; |
|
153 |
int64_t free_byte_offset; |
|
154 |
|
|
155 |
uint32_t crypt_method; /* current crypt method, 0 if no key yet */ |
|
156 |
uint32_t crypt_method_header; |
|
157 |
AES_KEY aes_encrypt_key; |
|
158 |
AES_KEY aes_decrypt_key; |
|
159 |
uint64_t snapshots_offset; |
|
160 |
int snapshots_size; |
|
161 |
int nb_snapshots; |
|
162 |
QCowSnapshot *snapshots; |
|
163 |
} BDRVQcowState; |
|
164 | 80 |
|
165 | 81 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
166 | 82 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
167 | 83 |
uint8_t *buf, int nb_sectors); |
168 | 84 |
static int qcow_read_snapshots(BlockDriverState *bs); |
169 | 85 |
static void qcow_free_snapshots(BlockDriverState *bs); |
170 |
static int refcount_init(BlockDriverState *bs); |
|
171 |
static void refcount_close(BlockDriverState *bs); |
|
172 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index); |
|
173 |
static int update_cluster_refcount(BlockDriverState *bs, |
|
174 |
int64_t cluster_index, |
|
175 |
int addend); |
|
176 |
static int update_refcount(BlockDriverState *bs, |
|
177 |
int64_t offset, int64_t length, |
|
178 |
int addend); |
|
179 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size); |
|
180 |
static int64_t alloc_bytes(BlockDriverState *bs, int size); |
|
181 |
static void free_clusters(BlockDriverState *bs, |
|
182 |
int64_t offset, int64_t size); |
|
183 |
static int check_refcounts(BlockDriverState *bs); |
|
184 | 86 |
|
185 | 87 |
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
186 | 88 |
{ |
... | ... | |
482 | 384 |
return 0; |
483 | 385 |
} |
484 | 386 |
|
485 |
static void l2_cache_reset(BlockDriverState *bs)
|
|
387 |
void l2_cache_reset(BlockDriverState *bs) |
|
486 | 388 |
{ |
487 | 389 |
BDRVQcowState *s = bs->opaque; |
488 | 390 |
|
... | ... | |
691 | 593 |
return l2_table; |
692 | 594 |
} |
693 | 595 |
|
694 |
static int size_to_clusters(BDRVQcowState *s, int64_t size) |
|
695 |
{ |
|
696 |
return (size + (s->cluster_size - 1)) >> s->cluster_bits; |
|
697 |
} |
|
698 |
|
|
699 | 596 |
static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size, |
700 | 597 |
uint64_t *l2_table, uint64_t start, uint64_t mask) |
701 | 598 |
{ |
... | ... | |
1522 | 1419 |
bdrv_delete(s->hd); |
1523 | 1420 |
} |
1524 | 1421 |
|
1525 |
/* XXX: use std qcow open function ? */ |
|
1526 |
typedef struct QCowCreateState { |
|
1527 |
int cluster_size; |
|
1528 |
int cluster_bits; |
|
1529 |
uint16_t *refcount_block; |
|
1530 |
uint64_t *refcount_table; |
|
1531 |
int64_t l1_table_offset; |
|
1532 |
int64_t refcount_table_offset; |
|
1533 |
int64_t refcount_block_offset; |
|
1534 |
} QCowCreateState; |
|
1535 |
|
|
1536 |
static void create_refcount_update(QCowCreateState *s, |
|
1537 |
int64_t offset, int64_t size) |
|
1538 |
{ |
|
1539 |
int refcount; |
|
1540 |
int64_t start, last, cluster_offset; |
|
1541 |
uint16_t *p; |
|
1542 |
|
|
1543 |
start = offset & ~(s->cluster_size - 1); |
|
1544 |
last = (offset + size - 1) & ~(s->cluster_size - 1); |
|
1545 |
for(cluster_offset = start; cluster_offset <= last; |
|
1546 |
cluster_offset += s->cluster_size) { |
|
1547 |
p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
|
1548 |
refcount = be16_to_cpu(*p); |
|
1549 |
refcount++; |
|
1550 |
*p = cpu_to_be16(refcount); |
|
1551 |
} |
|
1552 |
} |
|
1553 |
|
|
1554 | 1422 |
static int get_bits_from_size(size_t size) |
1555 | 1423 |
{ |
1556 | 1424 |
int res = 0; |
... | ... | |
1834 | 1702 |
/*********************************************************/ |
1835 | 1703 |
/* snapshot support */ |
1836 | 1704 |
|
1837 |
/* update the refcounts of snapshots and the copied flag */ |
|
1838 |
static int update_snapshot_refcount(BlockDriverState *bs, |
|
1839 |
int64_t l1_table_offset, |
|
1840 |
int l1_size, |
|
1841 |
int addend) |
|
1842 |
{ |
|
1843 |
BDRVQcowState *s = bs->opaque; |
|
1844 |
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
|
1845 |
int64_t old_offset, old_l2_offset; |
|
1846 |
int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount; |
|
1847 |
|
|
1848 |
l2_cache_reset(bs); |
|
1849 |
|
|
1850 |
l2_table = NULL; |
|
1851 |
l1_table = NULL; |
|
1852 |
l1_size2 = l1_size * sizeof(uint64_t); |
|
1853 |
l1_allocated = 0; |
|
1854 |
if (l1_table_offset != s->l1_table_offset) { |
|
1855 |
l1_table = qemu_malloc(l1_size2); |
|
1856 |
l1_allocated = 1; |
|
1857 |
if (bdrv_pread(s->hd, l1_table_offset, |
|
1858 |
l1_table, l1_size2) != l1_size2) |
|
1859 |
goto fail; |
|
1860 |
for(i = 0;i < l1_size; i++) |
|
1861 |
be64_to_cpus(&l1_table[i]); |
|
1862 |
} else { |
|
1863 |
assert(l1_size == s->l1_size); |
|
1864 |
l1_table = s->l1_table; |
|
1865 |
l1_allocated = 0; |
|
1866 |
} |
|
1867 |
|
|
1868 |
l2_size = s->l2_size * sizeof(uint64_t); |
|
1869 |
l2_table = qemu_malloc(l2_size); |
|
1870 |
l1_modified = 0; |
|
1871 |
for(i = 0; i < l1_size; i++) { |
|
1872 |
l2_offset = l1_table[i]; |
|
1873 |
if (l2_offset) { |
|
1874 |
old_l2_offset = l2_offset; |
|
1875 |
l2_offset &= ~QCOW_OFLAG_COPIED; |
|
1876 |
l2_modified = 0; |
|
1877 |
if (bdrv_pread(s->hd, l2_offset, l2_table, l2_size) != l2_size) |
|
1878 |
goto fail; |
|
1879 |
for(j = 0; j < s->l2_size; j++) { |
|
1880 |
offset = be64_to_cpu(l2_table[j]); |
|
1881 |
if (offset != 0) { |
|
1882 |
old_offset = offset; |
|
1883 |
offset &= ~QCOW_OFLAG_COPIED; |
|
1884 |
if (offset & QCOW_OFLAG_COMPRESSED) { |
|
1885 |
nb_csectors = ((offset >> s->csize_shift) & |
|
1886 |
s->csize_mask) + 1; |
|
1887 |
if (addend != 0) |
|
1888 |
update_refcount(bs, (offset & s->cluster_offset_mask) & ~511, |
|
1889 |
nb_csectors * 512, addend); |
|
1890 |
/* compressed clusters are never modified */ |
|
1891 |
refcount = 2; |
|
1892 |
} else { |
|
1893 |
if (addend != 0) { |
|
1894 |
refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
|
1895 |
} else { |
|
1896 |
refcount = get_refcount(bs, offset >> s->cluster_bits); |
|
1897 |
} |
|
1898 |
} |
|
1899 |
|
|
1900 |
if (refcount == 1) { |
|
1901 |
offset |= QCOW_OFLAG_COPIED; |
|
1902 |
} |
|
1903 |
if (offset != old_offset) { |
|
1904 |
l2_table[j] = cpu_to_be64(offset); |
|
1905 |
l2_modified = 1; |
|
1906 |
} |
|
1907 |
} |
|
1908 |
} |
|
1909 |
if (l2_modified) { |
|
1910 |
if (bdrv_pwrite(s->hd, |
|
1911 |
l2_offset, l2_table, l2_size) != l2_size) |
|
1912 |
goto fail; |
|
1913 |
} |
|
1914 |
|
|
1915 |
if (addend != 0) { |
|
1916 |
refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
|
1917 |
} else { |
|
1918 |
refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
|
1919 |
} |
|
1920 |
if (refcount == 1) { |
|
1921 |
l2_offset |= QCOW_OFLAG_COPIED; |
|
1922 |
} |
|
1923 |
if (l2_offset != old_l2_offset) { |
|
1924 |
l1_table[i] = l2_offset; |
|
1925 |
l1_modified = 1; |
|
1926 |
} |
|
1927 |
} |
|
1928 |
} |
|
1929 |
if (l1_modified) { |
|
1930 |
for(i = 0; i < l1_size; i++) |
|
1931 |
cpu_to_be64s(&l1_table[i]); |
|
1932 |
if (bdrv_pwrite(s->hd, l1_table_offset, l1_table, |
|
1933 |
l1_size2) != l1_size2) |
|
1934 |
goto fail; |
|
1935 |
for(i = 0; i < l1_size; i++) |
|
1936 |
be64_to_cpus(&l1_table[i]); |
|
1937 |
} |
|
1938 |
if (l1_allocated) |
|
1939 |
qemu_free(l1_table); |
|
1940 |
qemu_free(l2_table); |
|
1941 |
return 0; |
|
1942 |
fail: |
|
1943 |
if (l1_allocated) |
|
1944 |
qemu_free(l1_table); |
|
1945 |
qemu_free(l2_table); |
|
1946 |
return -EIO; |
|
1947 |
} |
|
1948 | 1705 |
|
1949 | 1706 |
static void qcow_free_snapshots(BlockDriverState *bs) |
1950 | 1707 |
{ |
... | ... | |
2306 | 2063 |
return s->nb_snapshots; |
2307 | 2064 |
} |
2308 | 2065 |
|
2309 |
/*********************************************************/ |
|
2310 |
/* refcount handling */ |
|
2311 |
|
|
2312 |
static int refcount_init(BlockDriverState *bs) |
|
2313 |
{ |
|
2314 |
BDRVQcowState *s = bs->opaque; |
|
2315 |
int ret, refcount_table_size2, i; |
|
2316 |
|
|
2317 |
s->refcount_block_cache = qemu_malloc(s->cluster_size); |
|
2318 |
refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); |
|
2319 |
s->refcount_table = qemu_malloc(refcount_table_size2); |
|
2320 |
if (s->refcount_table_size > 0) { |
|
2321 |
ret = bdrv_pread(s->hd, s->refcount_table_offset, |
|
2322 |
s->refcount_table, refcount_table_size2); |
|
2323 |
if (ret != refcount_table_size2) |
|
2324 |
goto fail; |
|
2325 |
for(i = 0; i < s->refcount_table_size; i++) |
|
2326 |
be64_to_cpus(&s->refcount_table[i]); |
|
2327 |
} |
|
2328 |
return 0; |
|
2329 |
fail: |
|
2330 |
return -ENOMEM; |
|
2331 |
} |
|
2332 |
|
|
2333 |
static void refcount_close(BlockDriverState *bs) |
|
2334 |
{ |
|
2335 |
BDRVQcowState *s = bs->opaque; |
|
2336 |
qemu_free(s->refcount_block_cache); |
|
2337 |
qemu_free(s->refcount_table); |
|
2338 |
} |
|
2339 |
|
|
2340 |
|
|
2341 |
static int load_refcount_block(BlockDriverState *bs, |
|
2342 |
int64_t refcount_block_offset) |
|
2343 |
{ |
|
2344 |
BDRVQcowState *s = bs->opaque; |
|
2345 |
int ret; |
|
2346 |
ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache, |
|
2347 |
s->cluster_size); |
|
2348 |
if (ret != s->cluster_size) |
|
2349 |
return -EIO; |
|
2350 |
s->refcount_block_cache_offset = refcount_block_offset; |
|
2351 |
return 0; |
|
2352 |
} |
|
2353 |
|
|
2354 |
static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
|
2355 |
{ |
|
2356 |
BDRVQcowState *s = bs->opaque; |
|
2357 |
int refcount_table_index, block_index; |
|
2358 |
int64_t refcount_block_offset; |
|
2359 |
|
|
2360 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
2361 |
if (refcount_table_index >= s->refcount_table_size) |
|
2362 |
return 0; |
|
2363 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
2364 |
if (!refcount_block_offset) |
|
2365 |
return 0; |
|
2366 |
if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
2367 |
/* better than nothing: return allocated if read error */ |
|
2368 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
2369 |
return 1; |
|
2370 |
} |
|
2371 |
block_index = cluster_index & |
|
2372 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
2373 |
return be16_to_cpu(s->refcount_block_cache[block_index]); |
|
2374 |
} |
|
2375 |
|
|
2376 |
/* return < 0 if error */ |
|
2377 |
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size) |
|
2378 |
{ |
|
2379 |
BDRVQcowState *s = bs->opaque; |
|
2380 |
int i, nb_clusters; |
|
2381 |
|
|
2382 |
nb_clusters = size_to_clusters(s, size); |
|
2383 |
retry: |
|
2384 |
for(i = 0; i < nb_clusters; i++) { |
|
2385 |
int64_t i = s->free_cluster_index++; |
|
2386 |
if (get_refcount(bs, i) != 0) |
|
2387 |
goto retry; |
|
2388 |
} |
|
2389 |
#ifdef DEBUG_ALLOC2 |
|
2390 |
printf("alloc_clusters: size=%lld -> %lld\n", |
|
2391 |
size, |
|
2392 |
(s->free_cluster_index - nb_clusters) << s->cluster_bits); |
|
2393 |
#endif |
|
2394 |
return (s->free_cluster_index - nb_clusters) << s->cluster_bits; |
|
2395 |
} |
|
2396 |
|
|
2397 |
static int64_t alloc_clusters(BlockDriverState *bs, int64_t size) |
|
2398 |
{ |
|
2399 |
int64_t offset; |
|
2400 |
|
|
2401 |
offset = alloc_clusters_noref(bs, size); |
|
2402 |
update_refcount(bs, offset, size, 1); |
|
2403 |
return offset; |
|
2404 |
} |
|
2405 |
|
|
2406 |
/* only used to allocate compressed sectors. We try to allocate |
|
2407 |
contiguous sectors. size must be <= cluster_size */ |
|
2408 |
static int64_t alloc_bytes(BlockDriverState *bs, int size) |
|
2409 |
{ |
|
2410 |
BDRVQcowState *s = bs->opaque; |
|
2411 |
int64_t offset, cluster_offset; |
|
2412 |
int free_in_cluster; |
|
2413 |
|
|
2414 |
assert(size > 0 && size <= s->cluster_size); |
|
2415 |
if (s->free_byte_offset == 0) { |
|
2416 |
s->free_byte_offset = alloc_clusters(bs, s->cluster_size); |
|
2417 |
} |
|
2418 |
redo: |
|
2419 |
free_in_cluster = s->cluster_size - |
|
2420 |
(s->free_byte_offset & (s->cluster_size - 1)); |
|
2421 |
if (size <= free_in_cluster) { |
|
2422 |
/* enough space in current cluster */ |
|
2423 |
offset = s->free_byte_offset; |
|
2424 |
s->free_byte_offset += size; |
|
2425 |
free_in_cluster -= size; |
|
2426 |
if (free_in_cluster == 0) |
|
2427 |
s->free_byte_offset = 0; |
|
2428 |
if ((offset & (s->cluster_size - 1)) != 0) |
|
2429 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
2430 |
} else { |
|
2431 |
offset = alloc_clusters(bs, s->cluster_size); |
|
2432 |
cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1); |
|
2433 |
if ((cluster_offset + s->cluster_size) == offset) { |
|
2434 |
/* we are lucky: contiguous data */ |
|
2435 |
offset = s->free_byte_offset; |
|
2436 |
update_cluster_refcount(bs, offset >> s->cluster_bits, 1); |
|
2437 |
s->free_byte_offset += size; |
|
2438 |
} else { |
|
2439 |
s->free_byte_offset = offset; |
|
2440 |
goto redo; |
|
2441 |
} |
|
2442 |
} |
|
2443 |
return offset; |
|
2444 |
} |
|
2445 |
|
|
2446 |
static void free_clusters(BlockDriverState *bs, |
|
2447 |
int64_t offset, int64_t size) |
|
2448 |
{ |
|
2449 |
update_refcount(bs, offset, size, -1); |
|
2450 |
} |
|
2451 |
|
|
2452 |
static int grow_refcount_table(BlockDriverState *bs, int min_size) |
|
2453 |
{ |
|
2454 |
BDRVQcowState *s = bs->opaque; |
|
2455 |
int new_table_size, new_table_size2, refcount_table_clusters, i, ret; |
|
2456 |
uint64_t *new_table; |
|
2457 |
int64_t table_offset; |
|
2458 |
uint8_t data[12]; |
|
2459 |
int old_table_size; |
|
2460 |
int64_t old_table_offset; |
|
2461 |
|
|
2462 |
if (min_size <= s->refcount_table_size) |
|
2463 |
return 0; |
|
2464 |
/* compute new table size */ |
|
2465 |
refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3); |
|
2466 |
for(;;) { |
|
2467 |
if (refcount_table_clusters == 0) { |
|
2468 |
refcount_table_clusters = 1; |
|
2469 |
} else { |
|
2470 |
refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
|
2471 |
} |
|
2472 |
new_table_size = refcount_table_clusters << (s->cluster_bits - 3); |
|
2473 |
if (min_size <= new_table_size) |
|
2474 |
break; |
|
2475 |
} |
|
2476 |
#ifdef DEBUG_ALLOC2 |
|
2477 |
printf("grow_refcount_table from %d to %d\n", |
|
2478 |
s->refcount_table_size, |
|
2479 |
new_table_size); |
|
2480 |
#endif |
|
2481 |
new_table_size2 = new_table_size * sizeof(uint64_t); |
|
2482 |
new_table = qemu_mallocz(new_table_size2); |
|
2483 |
memcpy(new_table, s->refcount_table, |
|
2484 |
s->refcount_table_size * sizeof(uint64_t)); |
|
2485 |
for(i = 0; i < s->refcount_table_size; i++) |
|
2486 |
cpu_to_be64s(&new_table[i]); |
|
2487 |
/* Note: we cannot update the refcount now to avoid recursion */ |
|
2488 |
table_offset = alloc_clusters_noref(bs, new_table_size2); |
|
2489 |
ret = bdrv_pwrite(s->hd, table_offset, new_table, new_table_size2); |
|
2490 |
if (ret != new_table_size2) |
|
2491 |
goto fail; |
|
2492 |
for(i = 0; i < s->refcount_table_size; i++) |
|
2493 |
be64_to_cpus(&new_table[i]); |
|
2494 |
|
|
2495 |
cpu_to_be64w((uint64_t*)data, table_offset); |
|
2496 |
cpu_to_be32w((uint32_t*)(data + 8), refcount_table_clusters); |
|
2497 |
if (bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset), |
|
2498 |
data, sizeof(data)) != sizeof(data)) |
|
2499 |
goto fail; |
|
2500 |
qemu_free(s->refcount_table); |
|
2501 |
old_table_offset = s->refcount_table_offset; |
|
2502 |
old_table_size = s->refcount_table_size; |
|
2503 |
s->refcount_table = new_table; |
|
2504 |
s->refcount_table_size = new_table_size; |
|
2505 |
s->refcount_table_offset = table_offset; |
|
2506 |
|
|
2507 |
update_refcount(bs, table_offset, new_table_size2, 1); |
|
2508 |
free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t)); |
|
2509 |
return 0; |
|
2510 |
fail: |
|
2511 |
free_clusters(bs, table_offset, new_table_size2); |
|
2512 |
qemu_free(new_table); |
|
2513 |
return -EIO; |
|
2514 |
} |
|
2515 |
|
|
2516 |
|
|
2517 |
static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index) |
|
2518 |
{ |
|
2519 |
BDRVQcowState *s = bs->opaque; |
|
2520 |
int64_t offset, refcount_block_offset; |
|
2521 |
int ret, refcount_table_index; |
|
2522 |
uint64_t data64; |
|
2523 |
|
|
2524 |
/* Find L1 index and grow refcount table if needed */ |
|
2525 |
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
2526 |
if (refcount_table_index >= s->refcount_table_size) { |
|
2527 |
ret = grow_refcount_table(bs, refcount_table_index + 1); |
|
2528 |
if (ret < 0) |
|
2529 |
return ret; |
|
2530 |
} |
|
2531 |
|
|
2532 |
/* Load or allocate the refcount block */ |
|
2533 |
refcount_block_offset = s->refcount_table[refcount_table_index]; |
|
2534 |
if (!refcount_block_offset) { |
|
2535 |
/* create a new refcount block */ |
|
2536 |
/* Note: we cannot update the refcount now to avoid recursion */ |
|
2537 |
offset = alloc_clusters_noref(bs, s->cluster_size); |
|
2538 |
memset(s->refcount_block_cache, 0, s->cluster_size); |
|
2539 |
ret = bdrv_pwrite(s->hd, offset, s->refcount_block_cache, s->cluster_size); |
|
2540 |
if (ret != s->cluster_size) |
|
2541 |
return -EINVAL; |
|
2542 |
s->refcount_table[refcount_table_index] = offset; |
|
2543 |
data64 = cpu_to_be64(offset); |
|
2544 |
ret = bdrv_pwrite(s->hd, s->refcount_table_offset + |
|
2545 |
refcount_table_index * sizeof(uint64_t), |
|
2546 |
&data64, sizeof(data64)); |
|
2547 |
if (ret != sizeof(data64)) |
|
2548 |
return -EINVAL; |
|
2549 |
|
|
2550 |
refcount_block_offset = offset; |
|
2551 |
s->refcount_block_cache_offset = offset; |
|
2552 |
update_refcount(bs, offset, s->cluster_size, 1); |
|
2553 |
} else { |
|
2554 |
if (refcount_block_offset != s->refcount_block_cache_offset) { |
|
2555 |
if (load_refcount_block(bs, refcount_block_offset) < 0) |
|
2556 |
return -EIO; |
|
2557 |
} |
|
2558 |
} |
|
2559 |
|
|
2560 |
return refcount_block_offset; |
|
2561 |
} |
|
2562 |
|
|
2563 |
/* addend must be 1 or -1 */ |
|
2564 |
static int update_cluster_refcount(BlockDriverState *bs, |
|
2565 |
int64_t cluster_index, |
|
2566 |
int addend) |
|
2567 |
{ |
|
2568 |
BDRVQcowState *s = bs->opaque; |
|
2569 |
int ret; |
|
2570 |
|
|
2571 |
ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend); |
|
2572 |
if (ret < 0) { |
|
2573 |
return ret; |
|
2574 |
} |
|
2575 |
|
|
2576 |
return get_refcount(bs, cluster_index); |
|
2577 |
} |
|
2578 |
|
|
2579 |
/* XXX: cache several refcount block clusters ? */ |
|
2580 |
static int update_refcount(BlockDriverState *bs, |
|
2581 |
int64_t offset, int64_t length, |
|
2582 |
int addend) |
|
2583 |
{ |
|
2584 |
BDRVQcowState *s = bs->opaque; |
|
2585 |
int64_t start, last, cluster_offset; |
|
2586 |
int64_t refcount_block_offset = 0; |
|
2587 |
int64_t table_index = -1, old_table_index; |
|
2588 |
int first_index = -1, last_index = -1; |
|
2589 |
|
|
2590 |
#ifdef DEBUG_ALLOC2 |
|
2591 |
printf("update_refcount: offset=%lld size=%lld addend=%d\n", |
|
2592 |
offset, length, addend); |
|
2593 |
#endif |
|
2594 |
if (length <= 0) |
|
2595 |
return -EINVAL; |
|
2596 |
start = offset & ~(s->cluster_size - 1); |
|
2597 |
last = (offset + length - 1) & ~(s->cluster_size - 1); |
|
2598 |
for(cluster_offset = start; cluster_offset <= last; |
|
2599 |
cluster_offset += s->cluster_size) |
|
2600 |
{ |
|
2601 |
int block_index, refcount; |
|
2602 |
int64_t cluster_index = cluster_offset >> s->cluster_bits; |
|
2603 |
|
|
2604 |
/* Only write refcount block to disk when we are done with it */ |
|
2605 |
old_table_index = table_index; |
|
2606 |
table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
|
2607 |
if ((old_table_index >= 0) && (table_index != old_table_index)) { |
|
2608 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT; |
|
2609 |
if (bdrv_pwrite(s->hd, |
|
2610 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
|
2611 |
&s->refcount_block_cache[first_index], size) != size) |
|
2612 |
{ |
|
2613 |
return -EIO; |
|
2614 |
} |
|
2615 |
|
|
2616 |
first_index = -1; |
|
2617 |
last_index = -1; |
|
2618 |
} |
|
2619 |
|
|
2620 |
/* Load the refcount block and allocate it if needed */ |
|
2621 |
refcount_block_offset = alloc_refcount_block(bs, cluster_index); |
|
2622 |
if (refcount_block_offset < 0) { |
|
2623 |
return refcount_block_offset; |
|
2624 |
} |
|
2625 |
|
|
2626 |
/* we can update the count and save it */ |
|
2627 |
block_index = cluster_index & |
|
2628 |
((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
|
2629 |
if (first_index == -1 || block_index < first_index) { |
|
2630 |
first_index = block_index; |
|
2631 |
} |
|
2632 |
if (block_index > last_index) { |
|
2633 |
last_index = block_index; |
|
2634 |
} |
|
2635 |
|
|
2636 |
refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
|
2637 |
refcount += addend; |
|
2638 |
if (refcount < 0 || refcount > 0xffff) |
|
2639 |
return -EINVAL; |
|
2640 |
if (refcount == 0 && cluster_index < s->free_cluster_index) { |
|
2641 |
s->free_cluster_index = cluster_index; |
|
2642 |
} |
|
2643 |
s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
|
2644 |
} |
|
2645 |
|
|
2646 |
/* Write last changed block to disk */ |
|
2647 |
if (refcount_block_offset != 0) { |
|
2648 |
size_t size = (last_index - first_index + 1) << REFCOUNT_SHIFT; |
|
2649 |
if (bdrv_pwrite(s->hd, |
|
2650 |
refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
|
2651 |
&s->refcount_block_cache[first_index], size) != size) |
|
2652 |
{ |
|
2653 |
return -EIO; |
|
2654 |
} |
|
2655 |
} |
Also available in: Unified diff