root / block / qcow2-refcount.c @ 6c6ea921
History | View | Annotate | Download (36.8 kB)
1 | f7d0fe02 | Kevin Wolf | /*
|
---|---|---|---|
2 | f7d0fe02 | Kevin Wolf | * Block driver for the QCOW version 2 format
|
3 | f7d0fe02 | Kevin Wolf | *
|
4 | f7d0fe02 | Kevin Wolf | * Copyright (c) 2004-2006 Fabrice Bellard
|
5 | f7d0fe02 | Kevin Wolf | *
|
6 | f7d0fe02 | Kevin Wolf | * Permission is hereby granted, free of charge, to any person obtaining a copy
|
7 | f7d0fe02 | Kevin Wolf | * of this software and associated documentation files (the "Software"), to deal
|
8 | f7d0fe02 | Kevin Wolf | * in the Software without restriction, including without limitation the rights
|
9 | f7d0fe02 | Kevin Wolf | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
10 | f7d0fe02 | Kevin Wolf | * copies of the Software, and to permit persons to whom the Software is
|
11 | f7d0fe02 | Kevin Wolf | * furnished to do so, subject to the following conditions:
|
12 | f7d0fe02 | Kevin Wolf | *
|
13 | f7d0fe02 | Kevin Wolf | * The above copyright notice and this permission notice shall be included in
|
14 | f7d0fe02 | Kevin Wolf | * all copies or substantial portions of the Software.
|
15 | f7d0fe02 | Kevin Wolf | *
|
16 | f7d0fe02 | Kevin Wolf | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
17 | f7d0fe02 | Kevin Wolf | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
18 | f7d0fe02 | Kevin Wolf | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
19 | f7d0fe02 | Kevin Wolf | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
20 | f7d0fe02 | Kevin Wolf | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
21 | f7d0fe02 | Kevin Wolf | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
22 | f7d0fe02 | Kevin Wolf | * THE SOFTWARE.
|
23 | f7d0fe02 | Kevin Wolf | */
|
24 | f7d0fe02 | Kevin Wolf | |
25 | f7d0fe02 | Kevin Wolf | #include "qemu-common.h" |
26 | f7d0fe02 | Kevin Wolf | #include "block_int.h" |
27 | f7d0fe02 | Kevin Wolf | #include "block/qcow2.h" |
28 | f7d0fe02 | Kevin Wolf | |
29 | f7d0fe02 | Kevin Wolf | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size);
|
30 | 92dcb59f | Kevin Wolf | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
31 | f7d0fe02 | Kevin Wolf | int64_t offset, int64_t length, |
32 | f7d0fe02 | Kevin Wolf | int addend);
|
33 | f7d0fe02 | Kevin Wolf | |
34 | 3b88e52b | Kevin Wolf | |
35 | 3b88e52b | Kevin Wolf | static int cache_refcount_updates = 0; |
36 | 3b88e52b | Kevin Wolf | |
37 | 66f82cee | Kevin Wolf | static int write_refcount_block(BlockDriverState *bs) |
38 | 3b88e52b | Kevin Wolf | { |
39 | 66f82cee | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
40 | 3b88e52b | Kevin Wolf | size_t size = s->cluster_size; |
41 | 3b88e52b | Kevin Wolf | |
42 | 3b88e52b | Kevin Wolf | if (s->refcount_block_cache_offset == 0) { |
43 | 3b88e52b | Kevin Wolf | return 0; |
44 | 3b88e52b | Kevin Wolf | } |
45 | 3b88e52b | Kevin Wolf | |
46 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE); |
47 | 66f82cee | Kevin Wolf | if (bdrv_pwrite(bs->file, s->refcount_block_cache_offset,
|
48 | 3b88e52b | Kevin Wolf | s->refcount_block_cache, size) != size) |
49 | 3b88e52b | Kevin Wolf | { |
50 | 3b88e52b | Kevin Wolf | return -EIO;
|
51 | 3b88e52b | Kevin Wolf | } |
52 | 3b88e52b | Kevin Wolf | |
53 | 3b88e52b | Kevin Wolf | return 0; |
54 | 3b88e52b | Kevin Wolf | } |
55 | 3b88e52b | Kevin Wolf | |
56 | f7d0fe02 | Kevin Wolf | /*********************************************************/
|
57 | f7d0fe02 | Kevin Wolf | /* refcount handling */
|
58 | f7d0fe02 | Kevin Wolf | |
59 | ed6ccf0f | Kevin Wolf | int qcow2_refcount_init(BlockDriverState *bs)
|
60 | f7d0fe02 | Kevin Wolf | { |
61 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
62 | f7d0fe02 | Kevin Wolf | int ret, refcount_table_size2, i;
|
63 | f7d0fe02 | Kevin Wolf | |
64 | f7d0fe02 | Kevin Wolf | s->refcount_block_cache = qemu_malloc(s->cluster_size); |
65 | f7d0fe02 | Kevin Wolf | refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
|
66 | f7d0fe02 | Kevin Wolf | s->refcount_table = qemu_malloc(refcount_table_size2); |
67 | f7d0fe02 | Kevin Wolf | if (s->refcount_table_size > 0) { |
68 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_LOAD); |
69 | 66f82cee | Kevin Wolf | ret = bdrv_pread(bs->file, s->refcount_table_offset, |
70 | f7d0fe02 | Kevin Wolf | s->refcount_table, refcount_table_size2); |
71 | f7d0fe02 | Kevin Wolf | if (ret != refcount_table_size2)
|
72 | f7d0fe02 | Kevin Wolf | goto fail;
|
73 | f7d0fe02 | Kevin Wolf | for(i = 0; i < s->refcount_table_size; i++) |
74 | f7d0fe02 | Kevin Wolf | be64_to_cpus(&s->refcount_table[i]); |
75 | f7d0fe02 | Kevin Wolf | } |
76 | f7d0fe02 | Kevin Wolf | return 0; |
77 | f7d0fe02 | Kevin Wolf | fail:
|
78 | f7d0fe02 | Kevin Wolf | return -ENOMEM;
|
79 | f7d0fe02 | Kevin Wolf | } |
80 | f7d0fe02 | Kevin Wolf | |
81 | ed6ccf0f | Kevin Wolf | void qcow2_refcount_close(BlockDriverState *bs)
|
82 | f7d0fe02 | Kevin Wolf | { |
83 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
84 | f7d0fe02 | Kevin Wolf | qemu_free(s->refcount_block_cache); |
85 | f7d0fe02 | Kevin Wolf | qemu_free(s->refcount_table); |
86 | f7d0fe02 | Kevin Wolf | } |
87 | f7d0fe02 | Kevin Wolf | |
88 | f7d0fe02 | Kevin Wolf | |
89 | f7d0fe02 | Kevin Wolf | static int load_refcount_block(BlockDriverState *bs, |
90 | f7d0fe02 | Kevin Wolf | int64_t refcount_block_offset) |
91 | f7d0fe02 | Kevin Wolf | { |
92 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
93 | f7d0fe02 | Kevin Wolf | int ret;
|
94 | 3b88e52b | Kevin Wolf | |
95 | 3b88e52b | Kevin Wolf | if (cache_refcount_updates) {
|
96 | 66f82cee | Kevin Wolf | write_refcount_block(bs); |
97 | 3b88e52b | Kevin Wolf | } |
98 | 3b88e52b | Kevin Wolf | |
99 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_LOAD); |
100 | 66f82cee | Kevin Wolf | ret = bdrv_pread(bs->file, refcount_block_offset, s->refcount_block_cache, |
101 | f7d0fe02 | Kevin Wolf | s->cluster_size); |
102 | f7d0fe02 | Kevin Wolf | if (ret != s->cluster_size)
|
103 | f7d0fe02 | Kevin Wolf | return -EIO;
|
104 | f7d0fe02 | Kevin Wolf | s->refcount_block_cache_offset = refcount_block_offset; |
105 | f7d0fe02 | Kevin Wolf | return 0; |
106 | f7d0fe02 | Kevin Wolf | } |
107 | f7d0fe02 | Kevin Wolf | |
108 | f7d0fe02 | Kevin Wolf | static int get_refcount(BlockDriverState *bs, int64_t cluster_index) |
109 | f7d0fe02 | Kevin Wolf | { |
110 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
111 | f7d0fe02 | Kevin Wolf | int refcount_table_index, block_index;
|
112 | f7d0fe02 | Kevin Wolf | int64_t refcount_block_offset; |
113 | f7d0fe02 | Kevin Wolf | |
114 | f7d0fe02 | Kevin Wolf | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
115 | f7d0fe02 | Kevin Wolf | if (refcount_table_index >= s->refcount_table_size)
|
116 | f7d0fe02 | Kevin Wolf | return 0; |
117 | f7d0fe02 | Kevin Wolf | refcount_block_offset = s->refcount_table[refcount_table_index]; |
118 | f7d0fe02 | Kevin Wolf | if (!refcount_block_offset)
|
119 | f7d0fe02 | Kevin Wolf | return 0; |
120 | f7d0fe02 | Kevin Wolf | if (refcount_block_offset != s->refcount_block_cache_offset) {
|
121 | f7d0fe02 | Kevin Wolf | /* better than nothing: return allocated if read error */
|
122 | f7d0fe02 | Kevin Wolf | if (load_refcount_block(bs, refcount_block_offset) < 0) |
123 | f7d0fe02 | Kevin Wolf | return 1; |
124 | f7d0fe02 | Kevin Wolf | } |
125 | f7d0fe02 | Kevin Wolf | block_index = cluster_index & |
126 | f7d0fe02 | Kevin Wolf | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
127 | f7d0fe02 | Kevin Wolf | return be16_to_cpu(s->refcount_block_cache[block_index]);
|
128 | f7d0fe02 | Kevin Wolf | } |
129 | f7d0fe02 | Kevin Wolf | |
130 | 05121aed | Kevin Wolf | /*
|
131 | 05121aed | Kevin Wolf | * Rounds the refcount table size up to avoid growing the table for each single
|
132 | 05121aed | Kevin Wolf | * refcount block that is allocated.
|
133 | 05121aed | Kevin Wolf | */
|
134 | 05121aed | Kevin Wolf | static unsigned int next_refcount_table_size(BDRVQcowState *s, |
135 | 05121aed | Kevin Wolf | unsigned int min_size) |
136 | 05121aed | Kevin Wolf | { |
137 | 05121aed | Kevin Wolf | unsigned int min_clusters = (min_size >> (s->cluster_bits - 3)) + 1; |
138 | 05121aed | Kevin Wolf | unsigned int refcount_table_clusters = |
139 | 05121aed | Kevin Wolf | MAX(1, s->refcount_table_size >> (s->cluster_bits - 3)); |
140 | 05121aed | Kevin Wolf | |
141 | 05121aed | Kevin Wolf | while (min_clusters > refcount_table_clusters) {
|
142 | 05121aed | Kevin Wolf | refcount_table_clusters = (refcount_table_clusters * 3 + 1) / 2; |
143 | 05121aed | Kevin Wolf | } |
144 | 05121aed | Kevin Wolf | |
145 | 05121aed | Kevin Wolf | return refcount_table_clusters << (s->cluster_bits - 3); |
146 | 05121aed | Kevin Wolf | } |
147 | 05121aed | Kevin Wolf | |
148 | 92dcb59f | Kevin Wolf | |
149 | 92dcb59f | Kevin Wolf | /* Checks if two offsets are described by the same refcount block */
|
150 | 92dcb59f | Kevin Wolf | static int in_same_refcount_block(BDRVQcowState *s, uint64_t offset_a, |
151 | 92dcb59f | Kevin Wolf | uint64_t offset_b) |
152 | 92dcb59f | Kevin Wolf | { |
153 | 92dcb59f | Kevin Wolf | uint64_t block_a = offset_a >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
|
154 | 92dcb59f | Kevin Wolf | uint64_t block_b = offset_b >> (2 * s->cluster_bits - REFCOUNT_SHIFT);
|
155 | 92dcb59f | Kevin Wolf | |
156 | 92dcb59f | Kevin Wolf | return (block_a == block_b);
|
157 | 92dcb59f | Kevin Wolf | } |
158 | 92dcb59f | Kevin Wolf | |
159 | 92dcb59f | Kevin Wolf | /*
|
160 | 92dcb59f | Kevin Wolf | * Loads a refcount block. If it doesn't exist yet, it is allocated first
|
161 | 92dcb59f | Kevin Wolf | * (including growing the refcount table if needed).
|
162 | 92dcb59f | Kevin Wolf | *
|
163 | 92dcb59f | Kevin Wolf | * Returns the offset of the refcount block on success or -errno in error case
|
164 | 92dcb59f | Kevin Wolf | */
|
165 | 92dcb59f | Kevin Wolf | static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
|
166 | f7d0fe02 | Kevin Wolf | { |
167 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
168 | 92dcb59f | Kevin Wolf | unsigned int refcount_table_index; |
169 | 92dcb59f | Kevin Wolf | int ret;
|
170 | 92dcb59f | Kevin Wolf | |
171 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC); |
172 | 8252278a | Kevin Wolf | |
173 | 92dcb59f | Kevin Wolf | /* Find the refcount block for the given cluster */
|
174 | 92dcb59f | Kevin Wolf | refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
175 | 92dcb59f | Kevin Wolf | |
176 | 92dcb59f | Kevin Wolf | if (refcount_table_index < s->refcount_table_size) {
|
177 | 92dcb59f | Kevin Wolf | |
178 | 92dcb59f | Kevin Wolf | uint64_t refcount_block_offset = |
179 | 92dcb59f | Kevin Wolf | s->refcount_table[refcount_table_index]; |
180 | 92dcb59f | Kevin Wolf | |
181 | 92dcb59f | Kevin Wolf | /* If it's already there, we're done */
|
182 | 92dcb59f | Kevin Wolf | if (refcount_block_offset) {
|
183 | 92dcb59f | Kevin Wolf | if (refcount_block_offset != s->refcount_block_cache_offset) {
|
184 | 92dcb59f | Kevin Wolf | ret = load_refcount_block(bs, refcount_block_offset); |
185 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
186 | 92dcb59f | Kevin Wolf | return ret;
|
187 | 92dcb59f | Kevin Wolf | } |
188 | 92dcb59f | Kevin Wolf | } |
189 | 92dcb59f | Kevin Wolf | return refcount_block_offset;
|
190 | 92dcb59f | Kevin Wolf | } |
191 | 92dcb59f | Kevin Wolf | } |
192 | 92dcb59f | Kevin Wolf | |
193 | 92dcb59f | Kevin Wolf | /*
|
194 | 92dcb59f | Kevin Wolf | * If we came here, we need to allocate something. Something is at least
|
195 | 92dcb59f | Kevin Wolf | * a cluster for the new refcount block. It may also include a new refcount
|
196 | 92dcb59f | Kevin Wolf | * table if the old refcount table is too small.
|
197 | 92dcb59f | Kevin Wolf | *
|
198 | 92dcb59f | Kevin Wolf | * Note that allocating clusters here needs some special care:
|
199 | 92dcb59f | Kevin Wolf | *
|
200 | 92dcb59f | Kevin Wolf | * - We can't use the normal qcow2_alloc_clusters(), it would try to
|
201 | 92dcb59f | Kevin Wolf | * increase the refcount and very likely we would end up with an endless
|
202 | 92dcb59f | Kevin Wolf | * recursion. Instead we must place the refcount blocks in a way that
|
203 | 92dcb59f | Kevin Wolf | * they can describe them themselves.
|
204 | 92dcb59f | Kevin Wolf | *
|
205 | 92dcb59f | Kevin Wolf | * - We need to consider that at this point we are inside update_refcounts
|
206 | 92dcb59f | Kevin Wolf | * and doing the initial refcount increase. This means that some clusters
|
207 | 92dcb59f | Kevin Wolf | * have already been allocated by the caller, but their refcount isn't
|
208 | 92dcb59f | Kevin Wolf | * accurate yet. free_cluster_index tells us where this allocation ends
|
209 | 92dcb59f | Kevin Wolf | * as long as we don't overwrite it by freeing clusters.
|
210 | 92dcb59f | Kevin Wolf | *
|
211 | 92dcb59f | Kevin Wolf | * - alloc_clusters_noref and qcow2_free_clusters may load a different
|
212 | 92dcb59f | Kevin Wolf | * refcount block into the cache
|
213 | 92dcb59f | Kevin Wolf | */
|
214 | 92dcb59f | Kevin Wolf | |
215 | 92dcb59f | Kevin Wolf | if (cache_refcount_updates) {
|
216 | 66f82cee | Kevin Wolf | ret = write_refcount_block(bs); |
217 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
218 | 92dcb59f | Kevin Wolf | return ret;
|
219 | 92dcb59f | Kevin Wolf | } |
220 | 92dcb59f | Kevin Wolf | } |
221 | 92dcb59f | Kevin Wolf | |
222 | 92dcb59f | Kevin Wolf | /* Allocate the refcount block itself and mark it as used */
|
223 | 92dcb59f | Kevin Wolf | uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size); |
224 | f7d0fe02 | Kevin Wolf | |
225 | f7d0fe02 | Kevin Wolf | #ifdef DEBUG_ALLOC2
|
226 | 92dcb59f | Kevin Wolf | fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
|
227 | 92dcb59f | Kevin Wolf | " at %" PRIx64 "\n", |
228 | 92dcb59f | Kevin Wolf | refcount_table_index, cluster_index << s->cluster_bits, new_block); |
229 | f7d0fe02 | Kevin Wolf | #endif
|
230 | 92dcb59f | Kevin Wolf | |
231 | 92dcb59f | Kevin Wolf | if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) {
|
232 | 25408c09 | Kevin Wolf | /* Zero the new refcount block before updating it */
|
233 | 25408c09 | Kevin Wolf | memset(s->refcount_block_cache, 0, s->cluster_size);
|
234 | 25408c09 | Kevin Wolf | s->refcount_block_cache_offset = new_block; |
235 | 25408c09 | Kevin Wolf | |
236 | 92dcb59f | Kevin Wolf | /* The block describes itself, need to update the cache */
|
237 | 92dcb59f | Kevin Wolf | int block_index = (new_block >> s->cluster_bits) &
|
238 | 92dcb59f | Kevin Wolf | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
239 | 92dcb59f | Kevin Wolf | s->refcount_block_cache[block_index] = cpu_to_be16(1);
|
240 | 92dcb59f | Kevin Wolf | } else {
|
241 | 92dcb59f | Kevin Wolf | /* Described somewhere else. This can recurse at most twice before we
|
242 | 92dcb59f | Kevin Wolf | * arrive at a block that describes itself. */
|
243 | 92dcb59f | Kevin Wolf | ret = update_refcount(bs, new_block, s->cluster_size, 1);
|
244 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
245 | 92dcb59f | Kevin Wolf | goto fail_block;
|
246 | 92dcb59f | Kevin Wolf | } |
247 | 25408c09 | Kevin Wolf | |
248 | 25408c09 | Kevin Wolf | /* Initialize the new refcount block only after updating its refcount,
|
249 | 25408c09 | Kevin Wolf | * update_refcount uses the refcount cache itself */
|
250 | 25408c09 | Kevin Wolf | memset(s->refcount_block_cache, 0, s->cluster_size);
|
251 | 25408c09 | Kevin Wolf | s->refcount_block_cache_offset = new_block; |
252 | 92dcb59f | Kevin Wolf | } |
253 | 92dcb59f | Kevin Wolf | |
254 | 92dcb59f | Kevin Wolf | /* Now the new refcount block needs to be written to disk */
|
255 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE); |
256 | 66f82cee | Kevin Wolf | ret = bdrv_pwrite(bs->file, new_block, s->refcount_block_cache, |
257 | 92dcb59f | Kevin Wolf | s->cluster_size); |
258 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
259 | 92dcb59f | Kevin Wolf | goto fail_block;
|
260 | 92dcb59f | Kevin Wolf | } |
261 | 92dcb59f | Kevin Wolf | |
262 | 92dcb59f | Kevin Wolf | /* If the refcount table is big enough, just hook the block up there */
|
263 | 92dcb59f | Kevin Wolf | if (refcount_table_index < s->refcount_table_size) {
|
264 | 92dcb59f | Kevin Wolf | uint64_t data64 = cpu_to_be64(new_block); |
265 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_HOOKUP); |
266 | 66f82cee | Kevin Wolf | ret = bdrv_pwrite(bs->file, |
267 | 92dcb59f | Kevin Wolf | s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
|
268 | 92dcb59f | Kevin Wolf | &data64, sizeof(data64));
|
269 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
270 | 92dcb59f | Kevin Wolf | goto fail_block;
|
271 | 92dcb59f | Kevin Wolf | } |
272 | 92dcb59f | Kevin Wolf | |
273 | 92dcb59f | Kevin Wolf | s->refcount_table[refcount_table_index] = new_block; |
274 | 92dcb59f | Kevin Wolf | return new_block;
|
275 | 92dcb59f | Kevin Wolf | } |
276 | 92dcb59f | Kevin Wolf | |
277 | 92dcb59f | Kevin Wolf | /*
|
278 | 92dcb59f | Kevin Wolf | * If we come here, we need to grow the refcount table. Again, a new
|
279 | 92dcb59f | Kevin Wolf | * refcount table needs some space and we can't simply allocate to avoid
|
280 | 92dcb59f | Kevin Wolf | * endless recursion.
|
281 | 92dcb59f | Kevin Wolf | *
|
282 | 92dcb59f | Kevin Wolf | * Therefore let's grab new refcount blocks at the end of the image, which
|
283 | 92dcb59f | Kevin Wolf | * will describe themselves and the new refcount table. This way we can
|
284 | 92dcb59f | Kevin Wolf | * reference them only in the new table and do the switch to the new
|
285 | 92dcb59f | Kevin Wolf | * refcount table at once without producing an inconsistent state in
|
286 | 92dcb59f | Kevin Wolf | * between.
|
287 | 92dcb59f | Kevin Wolf | */
|
288 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_GROW); |
289 | 8252278a | Kevin Wolf | |
290 | 92dcb59f | Kevin Wolf | /* Calculate the number of refcount blocks needed so far */
|
291 | 92dcb59f | Kevin Wolf | uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
|
292 | 92dcb59f | Kevin Wolf | uint64_t blocks_used = (s->free_cluster_index + |
293 | 92dcb59f | Kevin Wolf | refcount_block_clusters - 1) / refcount_block_clusters;
|
294 | 92dcb59f | Kevin Wolf | |
295 | 92dcb59f | Kevin Wolf | /* And now we need at least one block more for the new metadata */
|
296 | 92dcb59f | Kevin Wolf | uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
|
297 | 92dcb59f | Kevin Wolf | uint64_t last_table_size; |
298 | 92dcb59f | Kevin Wolf | uint64_t blocks_clusters; |
299 | 92dcb59f | Kevin Wolf | do {
|
300 | 92dcb59f | Kevin Wolf | uint64_t table_clusters = size_to_clusters(s, table_size); |
301 | 92dcb59f | Kevin Wolf | blocks_clusters = 1 +
|
302 | 92dcb59f | Kevin Wolf | ((table_clusters + refcount_block_clusters - 1)
|
303 | 92dcb59f | Kevin Wolf | / refcount_block_clusters); |
304 | 92dcb59f | Kevin Wolf | uint64_t meta_clusters = table_clusters + blocks_clusters; |
305 | 92dcb59f | Kevin Wolf | |
306 | 92dcb59f | Kevin Wolf | last_table_size = table_size; |
307 | 92dcb59f | Kevin Wolf | table_size = next_refcount_table_size(s, blocks_used + |
308 | 92dcb59f | Kevin Wolf | ((meta_clusters + refcount_block_clusters - 1)
|
309 | 92dcb59f | Kevin Wolf | / refcount_block_clusters)); |
310 | 92dcb59f | Kevin Wolf | |
311 | 92dcb59f | Kevin Wolf | } while (last_table_size != table_size);
|
312 | 92dcb59f | Kevin Wolf | |
313 | 92dcb59f | Kevin Wolf | #ifdef DEBUG_ALLOC2
|
314 | 92dcb59f | Kevin Wolf | fprintf(stderr, "qcow2: Grow refcount table %" PRId32 " => %" PRId64 "\n", |
315 | 92dcb59f | Kevin Wolf | s->refcount_table_size, table_size); |
316 | 92dcb59f | Kevin Wolf | #endif
|
317 | 92dcb59f | Kevin Wolf | |
318 | 92dcb59f | Kevin Wolf | /* Create the new refcount table and blocks */
|
319 | 92dcb59f | Kevin Wolf | uint64_t meta_offset = (blocks_used * refcount_block_clusters) * |
320 | 92dcb59f | Kevin Wolf | s->cluster_size; |
321 | 92dcb59f | Kevin Wolf | uint64_t table_offset = meta_offset + blocks_clusters * s->cluster_size; |
322 | 92dcb59f | Kevin Wolf | uint16_t *new_blocks = qemu_mallocz(blocks_clusters * s->cluster_size); |
323 | 92dcb59f | Kevin Wolf | uint64_t *new_table = qemu_mallocz(table_size * sizeof(uint64_t));
|
324 | 92dcb59f | Kevin Wolf | |
325 | 92dcb59f | Kevin Wolf | assert(meta_offset >= (s->free_cluster_index * s->cluster_size)); |
326 | 92dcb59f | Kevin Wolf | |
327 | 92dcb59f | Kevin Wolf | /* Fill the new refcount table */
|
328 | f7d0fe02 | Kevin Wolf | memcpy(new_table, s->refcount_table, |
329 | 92dcb59f | Kevin Wolf | s->refcount_table_size * sizeof(uint64_t));
|
330 | 92dcb59f | Kevin Wolf | new_table[refcount_table_index] = new_block; |
331 | 92dcb59f | Kevin Wolf | |
332 | 92dcb59f | Kevin Wolf | int i;
|
333 | 92dcb59f | Kevin Wolf | for (i = 0; i < blocks_clusters; i++) { |
334 | 92dcb59f | Kevin Wolf | new_table[blocks_used + i] = meta_offset + (i * s->cluster_size); |
335 | 92dcb59f | Kevin Wolf | } |
336 | 92dcb59f | Kevin Wolf | |
337 | 92dcb59f | Kevin Wolf | /* Fill the refcount blocks */
|
338 | 92dcb59f | Kevin Wolf | uint64_t table_clusters = size_to_clusters(s, table_size * sizeof(uint64_t));
|
339 | 92dcb59f | Kevin Wolf | int block = 0; |
340 | 92dcb59f | Kevin Wolf | for (i = 0; i < table_clusters + blocks_clusters; i++) { |
341 | 92dcb59f | Kevin Wolf | new_blocks[block++] = cpu_to_be16(1);
|
342 | 92dcb59f | Kevin Wolf | } |
343 | 92dcb59f | Kevin Wolf | |
344 | 92dcb59f | Kevin Wolf | /* Write refcount blocks to disk */
|
345 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS); |
346 | 66f82cee | Kevin Wolf | ret = bdrv_pwrite(bs->file, meta_offset, new_blocks, |
347 | 92dcb59f | Kevin Wolf | blocks_clusters * s->cluster_size); |
348 | 92dcb59f | Kevin Wolf | qemu_free(new_blocks); |
349 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
350 | 92dcb59f | Kevin Wolf | goto fail_table;
|
351 | 92dcb59f | Kevin Wolf | } |
352 | 92dcb59f | Kevin Wolf | |
353 | 92dcb59f | Kevin Wolf | /* Write refcount table to disk */
|
354 | 92dcb59f | Kevin Wolf | for(i = 0; i < table_size; i++) { |
355 | 92dcb59f | Kevin Wolf | cpu_to_be64s(&new_table[i]); |
356 | 92dcb59f | Kevin Wolf | } |
357 | 92dcb59f | Kevin Wolf | |
358 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE); |
359 | 66f82cee | Kevin Wolf | ret = bdrv_pwrite(bs->file, table_offset, new_table, |
360 | 92dcb59f | Kevin Wolf | table_size * sizeof(uint64_t));
|
361 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
362 | 92dcb59f | Kevin Wolf | goto fail_table;
|
363 | 92dcb59f | Kevin Wolf | } |
364 | 92dcb59f | Kevin Wolf | |
365 | 92dcb59f | Kevin Wolf | for(i = 0; i < table_size; i++) { |
366 | f7d0fe02 | Kevin Wolf | cpu_to_be64s(&new_table[i]); |
367 | 92dcb59f | Kevin Wolf | } |
368 | f7d0fe02 | Kevin Wolf | |
369 | 92dcb59f | Kevin Wolf | /* Hook up the new refcount table in the qcow2 header */
|
370 | 92dcb59f | Kevin Wolf | uint8_t data[12];
|
371 | f7d0fe02 | Kevin Wolf | cpu_to_be64w((uint64_t*)data, table_offset); |
372 | 92dcb59f | Kevin Wolf | cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
|
373 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE); |
374 | 66f82cee | Kevin Wolf | ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, refcount_table_offset), |
375 | 92dcb59f | Kevin Wolf | data, sizeof(data));
|
376 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
377 | 92dcb59f | Kevin Wolf | goto fail_table;
|
378 | f2b7c8b3 | Kevin Wolf | } |
379 | f2b7c8b3 | Kevin Wolf | |
380 | 92dcb59f | Kevin Wolf | /* And switch it in memory */
|
381 | 92dcb59f | Kevin Wolf | uint64_t old_table_offset = s->refcount_table_offset; |
382 | 92dcb59f | Kevin Wolf | uint64_t old_table_size = s->refcount_table_size; |
383 | 92dcb59f | Kevin Wolf | |
384 | f7d0fe02 | Kevin Wolf | qemu_free(s->refcount_table); |
385 | f7d0fe02 | Kevin Wolf | s->refcount_table = new_table; |
386 | 92dcb59f | Kevin Wolf | s->refcount_table_size = table_size; |
387 | f7d0fe02 | Kevin Wolf | s->refcount_table_offset = table_offset; |
388 | f7d0fe02 | Kevin Wolf | |
389 | 92dcb59f | Kevin Wolf | /* Free old table. Remember, we must not change free_cluster_index */
|
390 | 92dcb59f | Kevin Wolf | uint64_t old_free_cluster_index = s->free_cluster_index; |
391 | ed6ccf0f | Kevin Wolf | qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
|
392 | 92dcb59f | Kevin Wolf | s->free_cluster_index = old_free_cluster_index; |
393 | f7d0fe02 | Kevin Wolf | |
394 | 92dcb59f | Kevin Wolf | ret = load_refcount_block(bs, new_block); |
395 | 92dcb59f | Kevin Wolf | if (ret < 0) { |
396 | 92dcb59f | Kevin Wolf | goto fail_block;
|
397 | f7d0fe02 | Kevin Wolf | } |
398 | f7d0fe02 | Kevin Wolf | |
399 | 92dcb59f | Kevin Wolf | return new_block;
|
400 | f7d0fe02 | Kevin Wolf | |
401 | 92dcb59f | Kevin Wolf | fail_table:
|
402 | 92dcb59f | Kevin Wolf | qemu_free(new_table); |
403 | 92dcb59f | Kevin Wolf | fail_block:
|
404 | 92dcb59f | Kevin Wolf | s->refcount_block_cache_offset = 0;
|
405 | 92dcb59f | Kevin Wolf | return ret;
|
406 | f7d0fe02 | Kevin Wolf | } |
407 | f7d0fe02 | Kevin Wolf | |
408 | 9923e05e | Kevin Wolf | #define REFCOUNTS_PER_SECTOR (512 >> REFCOUNT_SHIFT) |
409 | 66f82cee | Kevin Wolf | static int write_refcount_block_entries(BlockDriverState *bs, |
410 | 9923e05e | Kevin Wolf | int64_t refcount_block_offset, int first_index, int last_index) |
411 | 9923e05e | Kevin Wolf | { |
412 | 66f82cee | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
413 | 9923e05e | Kevin Wolf | size_t size; |
414 | ed0df867 | Kevin Wolf | int ret;
|
415 | 9923e05e | Kevin Wolf | |
416 | 3b88e52b | Kevin Wolf | if (cache_refcount_updates) {
|
417 | 3b88e52b | Kevin Wolf | return 0; |
418 | 3b88e52b | Kevin Wolf | } |
419 | 3b88e52b | Kevin Wolf | |
420 | 86fa8da8 | Kevin Wolf | if (first_index < 0) { |
421 | 86fa8da8 | Kevin Wolf | return 0; |
422 | 86fa8da8 | Kevin Wolf | } |
423 | 86fa8da8 | Kevin Wolf | |
424 | 9923e05e | Kevin Wolf | first_index &= ~(REFCOUNTS_PER_SECTOR - 1);
|
425 | 9923e05e | Kevin Wolf | last_index = (last_index + REFCOUNTS_PER_SECTOR) |
426 | 9923e05e | Kevin Wolf | & ~(REFCOUNTS_PER_SECTOR - 1);
|
427 | 9923e05e | Kevin Wolf | |
428 | 9923e05e | Kevin Wolf | size = (last_index - first_index) << REFCOUNT_SHIFT; |
429 | ed0df867 | Kevin Wolf | |
430 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART); |
431 | ed0df867 | Kevin Wolf | ret = bdrv_pwrite(bs->file, |
432 | 9923e05e | Kevin Wolf | refcount_block_offset + (first_index << REFCOUNT_SHIFT), |
433 | ed0df867 | Kevin Wolf | &s->refcount_block_cache[first_index], size); |
434 | ed0df867 | Kevin Wolf | if (ret < 0) { |
435 | ed0df867 | Kevin Wolf | return ret;
|
436 | 9923e05e | Kevin Wolf | } |
437 | 9923e05e | Kevin Wolf | |
438 | 9923e05e | Kevin Wolf | return 0; |
439 | 9923e05e | Kevin Wolf | } |
440 | 9923e05e | Kevin Wolf | |
441 | f7d0fe02 | Kevin Wolf | /* XXX: cache several refcount block clusters ? */
|
442 | db3a964f | Kevin Wolf | static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, |
443 | db3a964f | Kevin Wolf | int64_t offset, int64_t length, int addend)
|
444 | f7d0fe02 | Kevin Wolf | { |
445 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
446 | f7d0fe02 | Kevin Wolf | int64_t start, last, cluster_offset; |
447 | f7d0fe02 | Kevin Wolf | int64_t refcount_block_offset = 0;
|
448 | f7d0fe02 | Kevin Wolf | int64_t table_index = -1, old_table_index;
|
449 | f7d0fe02 | Kevin Wolf | int first_index = -1, last_index = -1; |
450 | 09508d13 | Kevin Wolf | int ret;
|
451 | f7d0fe02 | Kevin Wolf | |
452 | f7d0fe02 | Kevin Wolf | #ifdef DEBUG_ALLOC2
|
453 | 0bf9e31a | Blue Swirl | printf("update_refcount: offset=%" PRId64 " size=%" PRId64 " addend=%d\n", |
454 | f7d0fe02 | Kevin Wolf | offset, length, addend); |
455 | f7d0fe02 | Kevin Wolf | #endif
|
456 | 7322afe7 | Kevin Wolf | if (length < 0) { |
457 | f7d0fe02 | Kevin Wolf | return -EINVAL;
|
458 | 7322afe7 | Kevin Wolf | } else if (length == 0) { |
459 | 7322afe7 | Kevin Wolf | return 0; |
460 | 7322afe7 | Kevin Wolf | } |
461 | 7322afe7 | Kevin Wolf | |
462 | f7d0fe02 | Kevin Wolf | start = offset & ~(s->cluster_size - 1);
|
463 | f7d0fe02 | Kevin Wolf | last = (offset + length - 1) & ~(s->cluster_size - 1); |
464 | f7d0fe02 | Kevin Wolf | for(cluster_offset = start; cluster_offset <= last;
|
465 | f7d0fe02 | Kevin Wolf | cluster_offset += s->cluster_size) |
466 | f7d0fe02 | Kevin Wolf | { |
467 | f7d0fe02 | Kevin Wolf | int block_index, refcount;
|
468 | f7d0fe02 | Kevin Wolf | int64_t cluster_index = cluster_offset >> s->cluster_bits; |
469 | 09508d13 | Kevin Wolf | int64_t new_block; |
470 | f7d0fe02 | Kevin Wolf | |
471 | f7d0fe02 | Kevin Wolf | /* Only write refcount block to disk when we are done with it */
|
472 | f7d0fe02 | Kevin Wolf | old_table_index = table_index; |
473 | f7d0fe02 | Kevin Wolf | table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT); |
474 | f7d0fe02 | Kevin Wolf | if ((old_table_index >= 0) && (table_index != old_table_index)) { |
475 | 9923e05e | Kevin Wolf | |
476 | ed0df867 | Kevin Wolf | ret = write_refcount_block_entries(bs, refcount_block_offset, |
477 | ed0df867 | Kevin Wolf | first_index, last_index); |
478 | ed0df867 | Kevin Wolf | if (ret < 0) { |
479 | ed0df867 | Kevin Wolf | return ret;
|
480 | f7d0fe02 | Kevin Wolf | } |
481 | f7d0fe02 | Kevin Wolf | |
482 | f7d0fe02 | Kevin Wolf | first_index = -1;
|
483 | f7d0fe02 | Kevin Wolf | last_index = -1;
|
484 | f7d0fe02 | Kevin Wolf | } |
485 | f7d0fe02 | Kevin Wolf | |
486 | f7d0fe02 | Kevin Wolf | /* Load the refcount block and allocate it if needed */
|
487 | 09508d13 | Kevin Wolf | new_block = alloc_refcount_block(bs, cluster_index); |
488 | 09508d13 | Kevin Wolf | if (new_block < 0) { |
489 | 09508d13 | Kevin Wolf | ret = new_block; |
490 | 09508d13 | Kevin Wolf | goto fail;
|
491 | f7d0fe02 | Kevin Wolf | } |
492 | 09508d13 | Kevin Wolf | refcount_block_offset = new_block; |
493 | f7d0fe02 | Kevin Wolf | |
494 | f7d0fe02 | Kevin Wolf | /* we can update the count and save it */
|
495 | f7d0fe02 | Kevin Wolf | block_index = cluster_index & |
496 | f7d0fe02 | Kevin Wolf | ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1); |
497 | f7d0fe02 | Kevin Wolf | if (first_index == -1 || block_index < first_index) { |
498 | f7d0fe02 | Kevin Wolf | first_index = block_index; |
499 | f7d0fe02 | Kevin Wolf | } |
500 | f7d0fe02 | Kevin Wolf | if (block_index > last_index) {
|
501 | f7d0fe02 | Kevin Wolf | last_index = block_index; |
502 | f7d0fe02 | Kevin Wolf | } |
503 | f7d0fe02 | Kevin Wolf | |
504 | f7d0fe02 | Kevin Wolf | refcount = be16_to_cpu(s->refcount_block_cache[block_index]); |
505 | f7d0fe02 | Kevin Wolf | refcount += addend; |
506 | 09508d13 | Kevin Wolf | if (refcount < 0 || refcount > 0xffff) { |
507 | 09508d13 | Kevin Wolf | ret = -EINVAL; |
508 | 09508d13 | Kevin Wolf | goto fail;
|
509 | 09508d13 | Kevin Wolf | } |
510 | f7d0fe02 | Kevin Wolf | if (refcount == 0 && cluster_index < s->free_cluster_index) { |
511 | f7d0fe02 | Kevin Wolf | s->free_cluster_index = cluster_index; |
512 | f7d0fe02 | Kevin Wolf | } |
513 | f7d0fe02 | Kevin Wolf | s->refcount_block_cache[block_index] = cpu_to_be16(refcount); |
514 | f7d0fe02 | Kevin Wolf | } |
515 | f7d0fe02 | Kevin Wolf | |
516 | 09508d13 | Kevin Wolf | ret = 0;
|
517 | 09508d13 | Kevin Wolf | fail:
|
518 | 09508d13 | Kevin Wolf | |
519 | f7d0fe02 | Kevin Wolf | /* Write last changed block to disk */
|
520 | f7d0fe02 | Kevin Wolf | if (refcount_block_offset != 0) { |
521 | ed0df867 | Kevin Wolf | int wret;
|
522 | ed0df867 | Kevin Wolf | wret = write_refcount_block_entries(bs, refcount_block_offset, |
523 | ed0df867 | Kevin Wolf | first_index, last_index); |
524 | ed0df867 | Kevin Wolf | if (wret < 0) { |
525 | ed0df867 | Kevin Wolf | return ret < 0 ? ret : wret; |
526 | f7d0fe02 | Kevin Wolf | } |
527 | f7d0fe02 | Kevin Wolf | } |
528 | f7d0fe02 | Kevin Wolf | |
529 | 09508d13 | Kevin Wolf | /*
|
530 | 09508d13 | Kevin Wolf | * Try do undo any updates if an error is returned (This may succeed in
|
531 | 09508d13 | Kevin Wolf | * some cases like ENOSPC for allocating a new refcount block)
|
532 | 09508d13 | Kevin Wolf | */
|
533 | 09508d13 | Kevin Wolf | if (ret < 0) { |
534 | 09508d13 | Kevin Wolf | int dummy;
|
535 | 09508d13 | Kevin Wolf | dummy = update_refcount(bs, offset, cluster_offset - offset, -addend); |
536 | 09508d13 | Kevin Wolf | } |
537 | 09508d13 | Kevin Wolf | |
538 | 09508d13 | Kevin Wolf | return ret;
|
539 | f7d0fe02 | Kevin Wolf | } |
540 | f7d0fe02 | Kevin Wolf | |
541 | f7d0fe02 | Kevin Wolf | /* addend must be 1 or -1 */
|
542 | f7d0fe02 | Kevin Wolf | static int update_cluster_refcount(BlockDriverState *bs, |
543 | f7d0fe02 | Kevin Wolf | int64_t cluster_index, |
544 | f7d0fe02 | Kevin Wolf | int addend)
|
545 | f7d0fe02 | Kevin Wolf | { |
546 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
547 | f7d0fe02 | Kevin Wolf | int ret;
|
548 | f7d0fe02 | Kevin Wolf | |
549 | f7d0fe02 | Kevin Wolf | ret = update_refcount(bs, cluster_index << s->cluster_bits, 1, addend);
|
550 | f7d0fe02 | Kevin Wolf | if (ret < 0) { |
551 | f7d0fe02 | Kevin Wolf | return ret;
|
552 | f7d0fe02 | Kevin Wolf | } |
553 | f7d0fe02 | Kevin Wolf | |
554 | f7d0fe02 | Kevin Wolf | return get_refcount(bs, cluster_index);
|
555 | f7d0fe02 | Kevin Wolf | } |
556 | f7d0fe02 | Kevin Wolf | |
557 | f7d0fe02 | Kevin Wolf | |
558 | f7d0fe02 | Kevin Wolf | |
559 | f7d0fe02 | Kevin Wolf | /*********************************************************/
|
560 | f7d0fe02 | Kevin Wolf | /* cluster allocation functions */
|
561 | f7d0fe02 | Kevin Wolf | |
562 | f7d0fe02 | Kevin Wolf | |
563 | f7d0fe02 | Kevin Wolf | |
564 | f7d0fe02 | Kevin Wolf | /* return < 0 if error */
|
565 | f7d0fe02 | Kevin Wolf | static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
|
566 | f7d0fe02 | Kevin Wolf | { |
567 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
568 | f7d0fe02 | Kevin Wolf | int i, nb_clusters;
|
569 | f7d0fe02 | Kevin Wolf | |
570 | f7d0fe02 | Kevin Wolf | nb_clusters = size_to_clusters(s, size); |
571 | f7d0fe02 | Kevin Wolf | retry:
|
572 | f7d0fe02 | Kevin Wolf | for(i = 0; i < nb_clusters; i++) { |
573 | 508e0893 | Stefan Hajnoczi | int64_t next_cluster_index = s->free_cluster_index++; |
574 | 508e0893 | Stefan Hajnoczi | if (get_refcount(bs, next_cluster_index) != 0) |
575 | f7d0fe02 | Kevin Wolf | goto retry;
|
576 | f7d0fe02 | Kevin Wolf | } |
577 | f7d0fe02 | Kevin Wolf | #ifdef DEBUG_ALLOC2
|
578 | 0bf9e31a | Blue Swirl | printf("alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n", |
579 | f7d0fe02 | Kevin Wolf | size, |
580 | f7d0fe02 | Kevin Wolf | (s->free_cluster_index - nb_clusters) << s->cluster_bits); |
581 | f7d0fe02 | Kevin Wolf | #endif
|
582 | f7d0fe02 | Kevin Wolf | return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
|
583 | f7d0fe02 | Kevin Wolf | } |
584 | f7d0fe02 | Kevin Wolf | |
585 | ed6ccf0f | Kevin Wolf | int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) |
586 | f7d0fe02 | Kevin Wolf | { |
587 | f7d0fe02 | Kevin Wolf | int64_t offset; |
588 | db3a964f | Kevin Wolf | int ret;
|
589 | f7d0fe02 | Kevin Wolf | |
590 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC); |
591 | f7d0fe02 | Kevin Wolf | offset = alloc_clusters_noref(bs, size); |
592 | db3a964f | Kevin Wolf | ret = update_refcount(bs, offset, size, 1);
|
593 | db3a964f | Kevin Wolf | if (ret < 0) { |
594 | db3a964f | Kevin Wolf | return ret;
|
595 | db3a964f | Kevin Wolf | } |
596 | f7d0fe02 | Kevin Wolf | return offset;
|
597 | f7d0fe02 | Kevin Wolf | } |
598 | f7d0fe02 | Kevin Wolf | |
599 | f7d0fe02 | Kevin Wolf | /* only used to allocate compressed sectors. We try to allocate
|
600 | f7d0fe02 | Kevin Wolf | contiguous sectors. size must be <= cluster_size */
|
601 | ed6ccf0f | Kevin Wolf | int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
|
602 | f7d0fe02 | Kevin Wolf | { |
603 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
604 | f7d0fe02 | Kevin Wolf | int64_t offset, cluster_offset; |
605 | f7d0fe02 | Kevin Wolf | int free_in_cluster;
|
606 | f7d0fe02 | Kevin Wolf | |
607 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_BYTES); |
608 | f7d0fe02 | Kevin Wolf | assert(size > 0 && size <= s->cluster_size);
|
609 | f7d0fe02 | Kevin Wolf | if (s->free_byte_offset == 0) { |
610 | ed6ccf0f | Kevin Wolf | s->free_byte_offset = qcow2_alloc_clusters(bs, s->cluster_size); |
611 | 5d757b56 | Kevin Wolf | if (s->free_byte_offset < 0) { |
612 | 5d757b56 | Kevin Wolf | return s->free_byte_offset;
|
613 | 5d757b56 | Kevin Wolf | } |
614 | f7d0fe02 | Kevin Wolf | } |
615 | f7d0fe02 | Kevin Wolf | redo:
|
616 | f7d0fe02 | Kevin Wolf | free_in_cluster = s->cluster_size - |
617 | f7d0fe02 | Kevin Wolf | (s->free_byte_offset & (s->cluster_size - 1));
|
618 | f7d0fe02 | Kevin Wolf | if (size <= free_in_cluster) {
|
619 | f7d0fe02 | Kevin Wolf | /* enough space in current cluster */
|
620 | f7d0fe02 | Kevin Wolf | offset = s->free_byte_offset; |
621 | f7d0fe02 | Kevin Wolf | s->free_byte_offset += size; |
622 | f7d0fe02 | Kevin Wolf | free_in_cluster -= size; |
623 | f7d0fe02 | Kevin Wolf | if (free_in_cluster == 0) |
624 | f7d0fe02 | Kevin Wolf | s->free_byte_offset = 0;
|
625 | f7d0fe02 | Kevin Wolf | if ((offset & (s->cluster_size - 1)) != 0) |
626 | f7d0fe02 | Kevin Wolf | update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
627 | f7d0fe02 | Kevin Wolf | } else {
|
628 | ed6ccf0f | Kevin Wolf | offset = qcow2_alloc_clusters(bs, s->cluster_size); |
629 | 5d757b56 | Kevin Wolf | if (offset < 0) { |
630 | 5d757b56 | Kevin Wolf | return offset;
|
631 | 5d757b56 | Kevin Wolf | } |
632 | f7d0fe02 | Kevin Wolf | cluster_offset = s->free_byte_offset & ~(s->cluster_size - 1);
|
633 | f7d0fe02 | Kevin Wolf | if ((cluster_offset + s->cluster_size) == offset) {
|
634 | f7d0fe02 | Kevin Wolf | /* we are lucky: contiguous data */
|
635 | f7d0fe02 | Kevin Wolf | offset = s->free_byte_offset; |
636 | f7d0fe02 | Kevin Wolf | update_cluster_refcount(bs, offset >> s->cluster_bits, 1);
|
637 | f7d0fe02 | Kevin Wolf | s->free_byte_offset += size; |
638 | f7d0fe02 | Kevin Wolf | } else {
|
639 | f7d0fe02 | Kevin Wolf | s->free_byte_offset = offset; |
640 | f7d0fe02 | Kevin Wolf | goto redo;
|
641 | f7d0fe02 | Kevin Wolf | } |
642 | f7d0fe02 | Kevin Wolf | } |
643 | f7d0fe02 | Kevin Wolf | return offset;
|
644 | f7d0fe02 | Kevin Wolf | } |
645 | f7d0fe02 | Kevin Wolf | |
646 | ed6ccf0f | Kevin Wolf | void qcow2_free_clusters(BlockDriverState *bs,
|
647 | f7d0fe02 | Kevin Wolf | int64_t offset, int64_t size) |
648 | f7d0fe02 | Kevin Wolf | { |
649 | db3a964f | Kevin Wolf | int ret;
|
650 | db3a964f | Kevin Wolf | |
651 | 66f82cee | Kevin Wolf | BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_FREE); |
652 | db3a964f | Kevin Wolf | ret = update_refcount(bs, offset, size, -1);
|
653 | db3a964f | Kevin Wolf | if (ret < 0) { |
654 | db3a964f | Kevin Wolf | fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret));
|
655 | 003fad6e | Kevin Wolf | /* TODO Remember the clusters to free them later and avoid leaking */
|
656 | db3a964f | Kevin Wolf | } |
657 | f7d0fe02 | Kevin Wolf | } |
658 | f7d0fe02 | Kevin Wolf | |
659 | 45aba42f | Kevin Wolf | /*
|
660 | 45aba42f | Kevin Wolf | * free_any_clusters
|
661 | 45aba42f | Kevin Wolf | *
|
662 | 45aba42f | Kevin Wolf | * free clusters according to its type: compressed or not
|
663 | 45aba42f | Kevin Wolf | *
|
664 | 45aba42f | Kevin Wolf | */
|
665 | 45aba42f | Kevin Wolf | |
666 | ed6ccf0f | Kevin Wolf | void qcow2_free_any_clusters(BlockDriverState *bs,
|
667 | 45aba42f | Kevin Wolf | uint64_t cluster_offset, int nb_clusters)
|
668 | 45aba42f | Kevin Wolf | { |
669 | 45aba42f | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
670 | 45aba42f | Kevin Wolf | |
671 | 45aba42f | Kevin Wolf | /* free the cluster */
|
672 | 45aba42f | Kevin Wolf | |
673 | 45aba42f | Kevin Wolf | if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
674 | 45aba42f | Kevin Wolf | int nb_csectors;
|
675 | 45aba42f | Kevin Wolf | nb_csectors = ((cluster_offset >> s->csize_shift) & |
676 | 45aba42f | Kevin Wolf | s->csize_mask) + 1;
|
677 | ed6ccf0f | Kevin Wolf | qcow2_free_clusters(bs, |
678 | ed6ccf0f | Kevin Wolf | (cluster_offset & s->cluster_offset_mask) & ~511,
|
679 | ed6ccf0f | Kevin Wolf | nb_csectors * 512);
|
680 | 45aba42f | Kevin Wolf | return;
|
681 | 45aba42f | Kevin Wolf | } |
682 | 45aba42f | Kevin Wolf | |
683 | ed6ccf0f | Kevin Wolf | qcow2_free_clusters(bs, cluster_offset, nb_clusters << s->cluster_bits); |
684 | 45aba42f | Kevin Wolf | |
685 | 45aba42f | Kevin Wolf | return;
|
686 | 45aba42f | Kevin Wolf | } |
687 | 45aba42f | Kevin Wolf | |
688 | f7d0fe02 | Kevin Wolf | |
689 | f7d0fe02 | Kevin Wolf | |
690 | f7d0fe02 | Kevin Wolf | /*********************************************************/
|
691 | f7d0fe02 | Kevin Wolf | /* snapshots and image creation */
|
692 | f7d0fe02 | Kevin Wolf | |
693 | f7d0fe02 | Kevin Wolf | |
694 | f7d0fe02 | Kevin Wolf | |
695 | ed6ccf0f | Kevin Wolf | void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset,
|
696 | ed6ccf0f | Kevin Wolf | int64_t size) |
697 | f7d0fe02 | Kevin Wolf | { |
698 | f7d0fe02 | Kevin Wolf | int refcount;
|
699 | f7d0fe02 | Kevin Wolf | int64_t start, last, cluster_offset; |
700 | f7d0fe02 | Kevin Wolf | uint16_t *p; |
701 | f7d0fe02 | Kevin Wolf | |
702 | f7d0fe02 | Kevin Wolf | start = offset & ~(s->cluster_size - 1);
|
703 | f7d0fe02 | Kevin Wolf | last = (offset + size - 1) & ~(s->cluster_size - 1); |
704 | f7d0fe02 | Kevin Wolf | for(cluster_offset = start; cluster_offset <= last;
|
705 | f7d0fe02 | Kevin Wolf | cluster_offset += s->cluster_size) { |
706 | f7d0fe02 | Kevin Wolf | p = &s->refcount_block[cluster_offset >> s->cluster_bits]; |
707 | f7d0fe02 | Kevin Wolf | refcount = be16_to_cpu(*p); |
708 | f7d0fe02 | Kevin Wolf | refcount++; |
709 | f7d0fe02 | Kevin Wolf | *p = cpu_to_be16(refcount); |
710 | f7d0fe02 | Kevin Wolf | } |
711 | f7d0fe02 | Kevin Wolf | } |
712 | f7d0fe02 | Kevin Wolf | |
713 | f7d0fe02 | Kevin Wolf | /* update the refcounts of snapshots and the copied flag */
|
714 | ed6ccf0f | Kevin Wolf | int qcow2_update_snapshot_refcount(BlockDriverState *bs,
|
715 | ed6ccf0f | Kevin Wolf | int64_t l1_table_offset, int l1_size, int addend) |
716 | f7d0fe02 | Kevin Wolf | { |
717 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
718 | f7d0fe02 | Kevin Wolf | uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2, l1_allocated; |
719 | f7d0fe02 | Kevin Wolf | int64_t old_offset, old_l2_offset; |
720 | f7d0fe02 | Kevin Wolf | int l2_size, i, j, l1_modified, l2_modified, nb_csectors, refcount;
|
721 | f7d0fe02 | Kevin Wolf | |
722 | ed6ccf0f | Kevin Wolf | qcow2_l2_cache_reset(bs); |
723 | 3b88e52b | Kevin Wolf | cache_refcount_updates = 1;
|
724 | f7d0fe02 | Kevin Wolf | |
725 | f7d0fe02 | Kevin Wolf | l2_table = NULL;
|
726 | f7d0fe02 | Kevin Wolf | l1_table = NULL;
|
727 | f7d0fe02 | Kevin Wolf | l1_size2 = l1_size * sizeof(uint64_t);
|
728 | f7d0fe02 | Kevin Wolf | if (l1_table_offset != s->l1_table_offset) {
|
729 | 702ef63f | Kevin Wolf | if (l1_size2 != 0) { |
730 | 702ef63f | Kevin Wolf | l1_table = qemu_mallocz(align_offset(l1_size2, 512));
|
731 | 702ef63f | Kevin Wolf | } else {
|
732 | 702ef63f | Kevin Wolf | l1_table = NULL;
|
733 | 702ef63f | Kevin Wolf | } |
734 | f7d0fe02 | Kevin Wolf | l1_allocated = 1;
|
735 | 66f82cee | Kevin Wolf | if (bdrv_pread(bs->file, l1_table_offset,
|
736 | f7d0fe02 | Kevin Wolf | l1_table, l1_size2) != l1_size2) |
737 | f7d0fe02 | Kevin Wolf | goto fail;
|
738 | f7d0fe02 | Kevin Wolf | for(i = 0;i < l1_size; i++) |
739 | f7d0fe02 | Kevin Wolf | be64_to_cpus(&l1_table[i]); |
740 | f7d0fe02 | Kevin Wolf | } else {
|
741 | f7d0fe02 | Kevin Wolf | assert(l1_size == s->l1_size); |
742 | f7d0fe02 | Kevin Wolf | l1_table = s->l1_table; |
743 | f7d0fe02 | Kevin Wolf | l1_allocated = 0;
|
744 | f7d0fe02 | Kevin Wolf | } |
745 | f7d0fe02 | Kevin Wolf | |
746 | f7d0fe02 | Kevin Wolf | l2_size = s->l2_size * sizeof(uint64_t);
|
747 | f7d0fe02 | Kevin Wolf | l2_table = qemu_malloc(l2_size); |
748 | f7d0fe02 | Kevin Wolf | l1_modified = 0;
|
749 | f7d0fe02 | Kevin Wolf | for(i = 0; i < l1_size; i++) { |
750 | f7d0fe02 | Kevin Wolf | l2_offset = l1_table[i]; |
751 | f7d0fe02 | Kevin Wolf | if (l2_offset) {
|
752 | f7d0fe02 | Kevin Wolf | old_l2_offset = l2_offset; |
753 | f7d0fe02 | Kevin Wolf | l2_offset &= ~QCOW_OFLAG_COPIED; |
754 | f7d0fe02 | Kevin Wolf | l2_modified = 0;
|
755 | 66f82cee | Kevin Wolf | if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size)
|
756 | f7d0fe02 | Kevin Wolf | goto fail;
|
757 | f7d0fe02 | Kevin Wolf | for(j = 0; j < s->l2_size; j++) { |
758 | f7d0fe02 | Kevin Wolf | offset = be64_to_cpu(l2_table[j]); |
759 | f7d0fe02 | Kevin Wolf | if (offset != 0) { |
760 | f7d0fe02 | Kevin Wolf | old_offset = offset; |
761 | f7d0fe02 | Kevin Wolf | offset &= ~QCOW_OFLAG_COPIED; |
762 | f7d0fe02 | Kevin Wolf | if (offset & QCOW_OFLAG_COMPRESSED) {
|
763 | f7d0fe02 | Kevin Wolf | nb_csectors = ((offset >> s->csize_shift) & |
764 | f7d0fe02 | Kevin Wolf | s->csize_mask) + 1;
|
765 | db3a964f | Kevin Wolf | if (addend != 0) { |
766 | db3a964f | Kevin Wolf | int ret;
|
767 | db3a964f | Kevin Wolf | ret = update_refcount(bs, |
768 | db3a964f | Kevin Wolf | (offset & s->cluster_offset_mask) & ~511,
|
769 | db3a964f | Kevin Wolf | nb_csectors * 512, addend);
|
770 | db3a964f | Kevin Wolf | if (ret < 0) { |
771 | db3a964f | Kevin Wolf | goto fail;
|
772 | db3a964f | Kevin Wolf | } |
773 | db3a964f | Kevin Wolf | } |
774 | f7d0fe02 | Kevin Wolf | /* compressed clusters are never modified */
|
775 | f7d0fe02 | Kevin Wolf | refcount = 2;
|
776 | f7d0fe02 | Kevin Wolf | } else {
|
777 | f7d0fe02 | Kevin Wolf | if (addend != 0) { |
778 | f7d0fe02 | Kevin Wolf | refcount = update_cluster_refcount(bs, offset >> s->cluster_bits, addend); |
779 | f7d0fe02 | Kevin Wolf | } else {
|
780 | f7d0fe02 | Kevin Wolf | refcount = get_refcount(bs, offset >> s->cluster_bits); |
781 | f7d0fe02 | Kevin Wolf | } |
782 | f7d0fe02 | Kevin Wolf | } |
783 | f7d0fe02 | Kevin Wolf | |
784 | f7d0fe02 | Kevin Wolf | if (refcount == 1) { |
785 | f7d0fe02 | Kevin Wolf | offset |= QCOW_OFLAG_COPIED; |
786 | f7d0fe02 | Kevin Wolf | } |
787 | f7d0fe02 | Kevin Wolf | if (offset != old_offset) {
|
788 | f7d0fe02 | Kevin Wolf | l2_table[j] = cpu_to_be64(offset); |
789 | f7d0fe02 | Kevin Wolf | l2_modified = 1;
|
790 | f7d0fe02 | Kevin Wolf | } |
791 | f7d0fe02 | Kevin Wolf | } |
792 | f7d0fe02 | Kevin Wolf | } |
793 | f7d0fe02 | Kevin Wolf | if (l2_modified) {
|
794 | 66f82cee | Kevin Wolf | if (bdrv_pwrite(bs->file,
|
795 | f7d0fe02 | Kevin Wolf | l2_offset, l2_table, l2_size) != l2_size) |
796 | f7d0fe02 | Kevin Wolf | goto fail;
|
797 | f7d0fe02 | Kevin Wolf | } |
798 | f7d0fe02 | Kevin Wolf | |
799 | f7d0fe02 | Kevin Wolf | if (addend != 0) { |
800 | f7d0fe02 | Kevin Wolf | refcount = update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend); |
801 | f7d0fe02 | Kevin Wolf | } else {
|
802 | f7d0fe02 | Kevin Wolf | refcount = get_refcount(bs, l2_offset >> s->cluster_bits); |
803 | f7d0fe02 | Kevin Wolf | } |
804 | f7d0fe02 | Kevin Wolf | if (refcount == 1) { |
805 | f7d0fe02 | Kevin Wolf | l2_offset |= QCOW_OFLAG_COPIED; |
806 | f7d0fe02 | Kevin Wolf | } |
807 | f7d0fe02 | Kevin Wolf | if (l2_offset != old_l2_offset) {
|
808 | f7d0fe02 | Kevin Wolf | l1_table[i] = l2_offset; |
809 | f7d0fe02 | Kevin Wolf | l1_modified = 1;
|
810 | f7d0fe02 | Kevin Wolf | } |
811 | f7d0fe02 | Kevin Wolf | } |
812 | f7d0fe02 | Kevin Wolf | } |
813 | f7d0fe02 | Kevin Wolf | if (l1_modified) {
|
814 | f7d0fe02 | Kevin Wolf | for(i = 0; i < l1_size; i++) |
815 | f7d0fe02 | Kevin Wolf | cpu_to_be64s(&l1_table[i]); |
816 | 66f82cee | Kevin Wolf | if (bdrv_pwrite(bs->file, l1_table_offset, l1_table,
|
817 | f7d0fe02 | Kevin Wolf | l1_size2) != l1_size2) |
818 | f7d0fe02 | Kevin Wolf | goto fail;
|
819 | f7d0fe02 | Kevin Wolf | for(i = 0; i < l1_size; i++) |
820 | f7d0fe02 | Kevin Wolf | be64_to_cpus(&l1_table[i]); |
821 | f7d0fe02 | Kevin Wolf | } |
822 | f7d0fe02 | Kevin Wolf | if (l1_allocated)
|
823 | f7d0fe02 | Kevin Wolf | qemu_free(l1_table); |
824 | f7d0fe02 | Kevin Wolf | qemu_free(l2_table); |
825 | 3b88e52b | Kevin Wolf | cache_refcount_updates = 0;
|
826 | 66f82cee | Kevin Wolf | write_refcount_block(bs); |
827 | f7d0fe02 | Kevin Wolf | return 0; |
828 | f7d0fe02 | Kevin Wolf | fail:
|
829 | f7d0fe02 | Kevin Wolf | if (l1_allocated)
|
830 | f7d0fe02 | Kevin Wolf | qemu_free(l1_table); |
831 | f7d0fe02 | Kevin Wolf | qemu_free(l2_table); |
832 | 3b88e52b | Kevin Wolf | cache_refcount_updates = 0;
|
833 | 66f82cee | Kevin Wolf | write_refcount_block(bs); |
834 | f7d0fe02 | Kevin Wolf | return -EIO;
|
835 | f7d0fe02 | Kevin Wolf | } |
836 | f7d0fe02 | Kevin Wolf | |
837 | f7d0fe02 | Kevin Wolf | |
838 | f7d0fe02 | Kevin Wolf | |
839 | f7d0fe02 | Kevin Wolf | |
840 | f7d0fe02 | Kevin Wolf | /*********************************************************/
|
841 | f7d0fe02 | Kevin Wolf | /* refcount checking functions */
|
842 | f7d0fe02 | Kevin Wolf | |
843 | f7d0fe02 | Kevin Wolf | |
844 | f7d0fe02 | Kevin Wolf | |
845 | f7d0fe02 | Kevin Wolf | /*
|
846 | f7d0fe02 | Kevin Wolf | * Increases the refcount for a range of clusters in a given refcount table.
|
847 | f7d0fe02 | Kevin Wolf | * This is used to construct a temporary refcount table out of L1 and L2 tables
|
848 | f7d0fe02 | Kevin Wolf | * which can be compared the the refcount table saved in the image.
|
849 | f7d0fe02 | Kevin Wolf | *
|
850 | f7d0fe02 | Kevin Wolf | * Returns the number of errors in the image that were found
|
851 | f7d0fe02 | Kevin Wolf | */
|
852 | f7d0fe02 | Kevin Wolf | static int inc_refcounts(BlockDriverState *bs, |
853 | f7d0fe02 | Kevin Wolf | uint16_t *refcount_table, |
854 | f7d0fe02 | Kevin Wolf | int refcount_table_size,
|
855 | f7d0fe02 | Kevin Wolf | int64_t offset, int64_t size) |
856 | f7d0fe02 | Kevin Wolf | { |
857 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
858 | f7d0fe02 | Kevin Wolf | int64_t start, last, cluster_offset; |
859 | f7d0fe02 | Kevin Wolf | int k;
|
860 | f7d0fe02 | Kevin Wolf | int errors = 0; |
861 | f7d0fe02 | Kevin Wolf | |
862 | f7d0fe02 | Kevin Wolf | if (size <= 0) |
863 | f7d0fe02 | Kevin Wolf | return 0; |
864 | f7d0fe02 | Kevin Wolf | |
865 | f7d0fe02 | Kevin Wolf | start = offset & ~(s->cluster_size - 1);
|
866 | f7d0fe02 | Kevin Wolf | last = (offset + size - 1) & ~(s->cluster_size - 1); |
867 | f7d0fe02 | Kevin Wolf | for(cluster_offset = start; cluster_offset <= last;
|
868 | f7d0fe02 | Kevin Wolf | cluster_offset += s->cluster_size) { |
869 | f7d0fe02 | Kevin Wolf | k = cluster_offset >> s->cluster_bits; |
870 | f7d0fe02 | Kevin Wolf | if (k < 0 || k >= refcount_table_size) { |
871 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR: invalid cluster offset=0x%" PRIx64 "\n", |
872 | f7d0fe02 | Kevin Wolf | cluster_offset); |
873 | f7d0fe02 | Kevin Wolf | errors++; |
874 | f7d0fe02 | Kevin Wolf | } else {
|
875 | f7d0fe02 | Kevin Wolf | if (++refcount_table[k] == 0) { |
876 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR: overflow cluster offset=0x%" PRIx64
|
877 | f7d0fe02 | Kevin Wolf | "\n", cluster_offset);
|
878 | f7d0fe02 | Kevin Wolf | errors++; |
879 | f7d0fe02 | Kevin Wolf | } |
880 | f7d0fe02 | Kevin Wolf | } |
881 | f7d0fe02 | Kevin Wolf | } |
882 | f7d0fe02 | Kevin Wolf | |
883 | f7d0fe02 | Kevin Wolf | return errors;
|
884 | f7d0fe02 | Kevin Wolf | } |
885 | f7d0fe02 | Kevin Wolf | |
886 | f7d0fe02 | Kevin Wolf | /*
|
887 | f7d0fe02 | Kevin Wolf | * Increases the refcount in the given refcount table for the all clusters
|
888 | f7d0fe02 | Kevin Wolf | * referenced in the L2 table. While doing so, performs some checks on L2
|
889 | f7d0fe02 | Kevin Wolf | * entries.
|
890 | f7d0fe02 | Kevin Wolf | *
|
891 | f7d0fe02 | Kevin Wolf | * Returns the number of errors found by the checks or -errno if an internal
|
892 | f7d0fe02 | Kevin Wolf | * error occurred.
|
893 | f7d0fe02 | Kevin Wolf | */
|
894 | f7d0fe02 | Kevin Wolf | static int check_refcounts_l2(BlockDriverState *bs, |
895 | f7d0fe02 | Kevin Wolf | uint16_t *refcount_table, int refcount_table_size, int64_t l2_offset,
|
896 | f7d0fe02 | Kevin Wolf | int check_copied)
|
897 | f7d0fe02 | Kevin Wolf | { |
898 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
899 | f7d0fe02 | Kevin Wolf | uint64_t *l2_table, offset; |
900 | f7d0fe02 | Kevin Wolf | int i, l2_size, nb_csectors, refcount;
|
901 | f7d0fe02 | Kevin Wolf | int errors = 0; |
902 | f7d0fe02 | Kevin Wolf | |
903 | f7d0fe02 | Kevin Wolf | /* Read L2 table from disk */
|
904 | f7d0fe02 | Kevin Wolf | l2_size = s->l2_size * sizeof(uint64_t);
|
905 | f7d0fe02 | Kevin Wolf | l2_table = qemu_malloc(l2_size); |
906 | f7d0fe02 | Kevin Wolf | |
907 | 66f82cee | Kevin Wolf | if (bdrv_pread(bs->file, l2_offset, l2_table, l2_size) != l2_size)
|
908 | f7d0fe02 | Kevin Wolf | goto fail;
|
909 | f7d0fe02 | Kevin Wolf | |
910 | f7d0fe02 | Kevin Wolf | /* Do the actual checks */
|
911 | f7d0fe02 | Kevin Wolf | for(i = 0; i < s->l2_size; i++) { |
912 | f7d0fe02 | Kevin Wolf | offset = be64_to_cpu(l2_table[i]); |
913 | f7d0fe02 | Kevin Wolf | if (offset != 0) { |
914 | f7d0fe02 | Kevin Wolf | if (offset & QCOW_OFLAG_COMPRESSED) {
|
915 | f7d0fe02 | Kevin Wolf | /* Compressed clusters don't have QCOW_OFLAG_COPIED */
|
916 | f7d0fe02 | Kevin Wolf | if (offset & QCOW_OFLAG_COPIED) {
|
917 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR: cluster %" PRId64 ": " |
918 | f7d0fe02 | Kevin Wolf | "copied flag must never be set for compressed "
|
919 | f7d0fe02 | Kevin Wolf | "clusters\n", offset >> s->cluster_bits);
|
920 | f7d0fe02 | Kevin Wolf | offset &= ~QCOW_OFLAG_COPIED; |
921 | f7d0fe02 | Kevin Wolf | errors++; |
922 | f7d0fe02 | Kevin Wolf | } |
923 | f7d0fe02 | Kevin Wolf | |
924 | f7d0fe02 | Kevin Wolf | /* Mark cluster as used */
|
925 | f7d0fe02 | Kevin Wolf | nb_csectors = ((offset >> s->csize_shift) & |
926 | f7d0fe02 | Kevin Wolf | s->csize_mask) + 1;
|
927 | f7d0fe02 | Kevin Wolf | offset &= s->cluster_offset_mask; |
928 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, |
929 | f7d0fe02 | Kevin Wolf | refcount_table_size, |
930 | f7d0fe02 | Kevin Wolf | offset & ~511, nb_csectors * 512); |
931 | f7d0fe02 | Kevin Wolf | } else {
|
932 | f7d0fe02 | Kevin Wolf | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
933 | f7d0fe02 | Kevin Wolf | if (check_copied) {
|
934 | f7d0fe02 | Kevin Wolf | uint64_t entry = offset; |
935 | f7d0fe02 | Kevin Wolf | offset &= ~QCOW_OFLAG_COPIED; |
936 | f7d0fe02 | Kevin Wolf | refcount = get_refcount(bs, offset >> s->cluster_bits); |
937 | f7d0fe02 | Kevin Wolf | if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) { |
938 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
|
939 | f7d0fe02 | Kevin Wolf | PRIx64 " refcount=%d\n", entry, refcount);
|
940 | f7d0fe02 | Kevin Wolf | errors++; |
941 | f7d0fe02 | Kevin Wolf | } |
942 | f7d0fe02 | Kevin Wolf | } |
943 | f7d0fe02 | Kevin Wolf | |
944 | f7d0fe02 | Kevin Wolf | /* Mark cluster as used */
|
945 | f7d0fe02 | Kevin Wolf | offset &= ~QCOW_OFLAG_COPIED; |
946 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, |
947 | f7d0fe02 | Kevin Wolf | refcount_table_size, |
948 | f7d0fe02 | Kevin Wolf | offset, s->cluster_size); |
949 | f7d0fe02 | Kevin Wolf | |
950 | f7d0fe02 | Kevin Wolf | /* Correct offsets are cluster aligned */
|
951 | f7d0fe02 | Kevin Wolf | if (offset & (s->cluster_size - 1)) { |
952 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not " |
953 | f7d0fe02 | Kevin Wolf | "properly aligned; L2 entry corrupted.\n", offset);
|
954 | f7d0fe02 | Kevin Wolf | errors++; |
955 | f7d0fe02 | Kevin Wolf | } |
956 | f7d0fe02 | Kevin Wolf | } |
957 | f7d0fe02 | Kevin Wolf | } |
958 | f7d0fe02 | Kevin Wolf | } |
959 | f7d0fe02 | Kevin Wolf | |
960 | f7d0fe02 | Kevin Wolf | qemu_free(l2_table); |
961 | f7d0fe02 | Kevin Wolf | return errors;
|
962 | f7d0fe02 | Kevin Wolf | |
963 | f7d0fe02 | Kevin Wolf | fail:
|
964 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
965 | f7d0fe02 | Kevin Wolf | qemu_free(l2_table); |
966 | f7d0fe02 | Kevin Wolf | return -EIO;
|
967 | f7d0fe02 | Kevin Wolf | } |
968 | f7d0fe02 | Kevin Wolf | |
969 | f7d0fe02 | Kevin Wolf | /*
|
970 | f7d0fe02 | Kevin Wolf | * Increases the refcount for the L1 table, its L2 tables and all referenced
|
971 | f7d0fe02 | Kevin Wolf | * clusters in the given refcount table. While doing so, performs some checks
|
972 | f7d0fe02 | Kevin Wolf | * on L1 and L2 entries.
|
973 | f7d0fe02 | Kevin Wolf | *
|
974 | f7d0fe02 | Kevin Wolf | * Returns the number of errors found by the checks or -errno if an internal
|
975 | f7d0fe02 | Kevin Wolf | * error occurred.
|
976 | f7d0fe02 | Kevin Wolf | */
|
977 | f7d0fe02 | Kevin Wolf | static int check_refcounts_l1(BlockDriverState *bs, |
978 | f7d0fe02 | Kevin Wolf | uint16_t *refcount_table, |
979 | f7d0fe02 | Kevin Wolf | int refcount_table_size,
|
980 | f7d0fe02 | Kevin Wolf | int64_t l1_table_offset, int l1_size,
|
981 | f7d0fe02 | Kevin Wolf | int check_copied)
|
982 | f7d0fe02 | Kevin Wolf | { |
983 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
984 | f7d0fe02 | Kevin Wolf | uint64_t *l1_table, l2_offset, l1_size2; |
985 | f7d0fe02 | Kevin Wolf | int i, refcount, ret;
|
986 | f7d0fe02 | Kevin Wolf | int errors = 0; |
987 | f7d0fe02 | Kevin Wolf | |
988 | f7d0fe02 | Kevin Wolf | l1_size2 = l1_size * sizeof(uint64_t);
|
989 | f7d0fe02 | Kevin Wolf | |
990 | f7d0fe02 | Kevin Wolf | /* Mark L1 table as used */
|
991 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, refcount_table_size, |
992 | f7d0fe02 | Kevin Wolf | l1_table_offset, l1_size2); |
993 | f7d0fe02 | Kevin Wolf | |
994 | f7d0fe02 | Kevin Wolf | /* Read L1 table entries from disk */
|
995 | 702ef63f | Kevin Wolf | if (l1_size2 == 0) { |
996 | 702ef63f | Kevin Wolf | l1_table = NULL;
|
997 | 702ef63f | Kevin Wolf | } else {
|
998 | 702ef63f | Kevin Wolf | l1_table = qemu_malloc(l1_size2); |
999 | 66f82cee | Kevin Wolf | if (bdrv_pread(bs->file, l1_table_offset,
|
1000 | 702ef63f | Kevin Wolf | l1_table, l1_size2) != l1_size2) |
1001 | 702ef63f | Kevin Wolf | goto fail;
|
1002 | 702ef63f | Kevin Wolf | for(i = 0;i < l1_size; i++) |
1003 | 702ef63f | Kevin Wolf | be64_to_cpus(&l1_table[i]); |
1004 | 702ef63f | Kevin Wolf | } |
1005 | f7d0fe02 | Kevin Wolf | |
1006 | f7d0fe02 | Kevin Wolf | /* Do the actual checks */
|
1007 | f7d0fe02 | Kevin Wolf | for(i = 0; i < l1_size; i++) { |
1008 | f7d0fe02 | Kevin Wolf | l2_offset = l1_table[i]; |
1009 | f7d0fe02 | Kevin Wolf | if (l2_offset) {
|
1010 | f7d0fe02 | Kevin Wolf | /* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
|
1011 | f7d0fe02 | Kevin Wolf | if (check_copied) {
|
1012 | f7d0fe02 | Kevin Wolf | refcount = get_refcount(bs, (l2_offset & ~QCOW_OFLAG_COPIED) |
1013 | f7d0fe02 | Kevin Wolf | >> s->cluster_bits); |
1014 | f7d0fe02 | Kevin Wolf | if ((refcount == 1) != ((l2_offset & QCOW_OFLAG_COPIED) != 0)) { |
1015 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR OFLAG_COPIED: l2_offset=%" PRIx64
|
1016 | f7d0fe02 | Kevin Wolf | " refcount=%d\n", l2_offset, refcount);
|
1017 | f7d0fe02 | Kevin Wolf | errors++; |
1018 | f7d0fe02 | Kevin Wolf | } |
1019 | f7d0fe02 | Kevin Wolf | } |
1020 | f7d0fe02 | Kevin Wolf | |
1021 | f7d0fe02 | Kevin Wolf | /* Mark L2 table as used */
|
1022 | f7d0fe02 | Kevin Wolf | l2_offset &= ~QCOW_OFLAG_COPIED; |
1023 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, |
1024 | f7d0fe02 | Kevin Wolf | refcount_table_size, |
1025 | f7d0fe02 | Kevin Wolf | l2_offset, |
1026 | f7d0fe02 | Kevin Wolf | s->cluster_size); |
1027 | f7d0fe02 | Kevin Wolf | |
1028 | f7d0fe02 | Kevin Wolf | /* L2 tables are cluster aligned */
|
1029 | f7d0fe02 | Kevin Wolf | if (l2_offset & (s->cluster_size - 1)) { |
1030 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not " |
1031 | f7d0fe02 | Kevin Wolf | "cluster aligned; L1 entry corrupted\n", l2_offset);
|
1032 | f7d0fe02 | Kevin Wolf | errors++; |
1033 | f7d0fe02 | Kevin Wolf | } |
1034 | f7d0fe02 | Kevin Wolf | |
1035 | f7d0fe02 | Kevin Wolf | /* Process and check L2 entries */
|
1036 | f7d0fe02 | Kevin Wolf | ret = check_refcounts_l2(bs, refcount_table, refcount_table_size, |
1037 | f7d0fe02 | Kevin Wolf | l2_offset, check_copied); |
1038 | f7d0fe02 | Kevin Wolf | if (ret < 0) { |
1039 | f7d0fe02 | Kevin Wolf | goto fail;
|
1040 | f7d0fe02 | Kevin Wolf | } |
1041 | f7d0fe02 | Kevin Wolf | errors += ret; |
1042 | f7d0fe02 | Kevin Wolf | } |
1043 | f7d0fe02 | Kevin Wolf | } |
1044 | f7d0fe02 | Kevin Wolf | qemu_free(l1_table); |
1045 | f7d0fe02 | Kevin Wolf | return errors;
|
1046 | f7d0fe02 | Kevin Wolf | |
1047 | f7d0fe02 | Kevin Wolf | fail:
|
1048 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR: I/O error in check_refcounts_l1\n");
|
1049 | f7d0fe02 | Kevin Wolf | qemu_free(l1_table); |
1050 | f7d0fe02 | Kevin Wolf | return -EIO;
|
1051 | f7d0fe02 | Kevin Wolf | } |
1052 | f7d0fe02 | Kevin Wolf | |
1053 | f7d0fe02 | Kevin Wolf | /*
|
1054 | f7d0fe02 | Kevin Wolf | * Checks an image for refcount consistency.
|
1055 | f7d0fe02 | Kevin Wolf | *
|
1056 | f7d0fe02 | Kevin Wolf | * Returns 0 if no errors are found, the number of errors in case the image is
|
1057 | f7d0fe02 | Kevin Wolf | * detected as corrupted, and -errno when an internal error occured.
|
1058 | f7d0fe02 | Kevin Wolf | */
|
1059 | ed6ccf0f | Kevin Wolf | int qcow2_check_refcounts(BlockDriverState *bs)
|
1060 | f7d0fe02 | Kevin Wolf | { |
1061 | f7d0fe02 | Kevin Wolf | BDRVQcowState *s = bs->opaque; |
1062 | f7d0fe02 | Kevin Wolf | int64_t size; |
1063 | f7d0fe02 | Kevin Wolf | int nb_clusters, refcount1, refcount2, i;
|
1064 | f7d0fe02 | Kevin Wolf | QCowSnapshot *sn; |
1065 | f7d0fe02 | Kevin Wolf | uint16_t *refcount_table; |
1066 | f7d0fe02 | Kevin Wolf | int ret, errors = 0; |
1067 | f7d0fe02 | Kevin Wolf | |
1068 | 66f82cee | Kevin Wolf | size = bdrv_getlength(bs->file); |
1069 | f7d0fe02 | Kevin Wolf | nb_clusters = size_to_clusters(s, size); |
1070 | f7d0fe02 | Kevin Wolf | refcount_table = qemu_mallocz(nb_clusters * sizeof(uint16_t));
|
1071 | f7d0fe02 | Kevin Wolf | |
1072 | f7d0fe02 | Kevin Wolf | /* header */
|
1073 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1074 | f7d0fe02 | Kevin Wolf | 0, s->cluster_size);
|
1075 | f7d0fe02 | Kevin Wolf | |
1076 | f7d0fe02 | Kevin Wolf | /* current L1 table */
|
1077 | f7d0fe02 | Kevin Wolf | ret = check_refcounts_l1(bs, refcount_table, nb_clusters, |
1078 | f7d0fe02 | Kevin Wolf | s->l1_table_offset, s->l1_size, 1);
|
1079 | f7d0fe02 | Kevin Wolf | if (ret < 0) { |
1080 | f7d0fe02 | Kevin Wolf | return ret;
|
1081 | f7d0fe02 | Kevin Wolf | } |
1082 | f7d0fe02 | Kevin Wolf | errors += ret; |
1083 | f7d0fe02 | Kevin Wolf | |
1084 | f7d0fe02 | Kevin Wolf | /* snapshots */
|
1085 | f7d0fe02 | Kevin Wolf | for(i = 0; i < s->nb_snapshots; i++) { |
1086 | f7d0fe02 | Kevin Wolf | sn = s->snapshots + i; |
1087 | f7d0fe02 | Kevin Wolf | check_refcounts_l1(bs, refcount_table, nb_clusters, |
1088 | f7d0fe02 | Kevin Wolf | sn->l1_table_offset, sn->l1_size, 0);
|
1089 | f7d0fe02 | Kevin Wolf | } |
1090 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1091 | f7d0fe02 | Kevin Wolf | s->snapshots_offset, s->snapshots_size); |
1092 | f7d0fe02 | Kevin Wolf | |
1093 | f7d0fe02 | Kevin Wolf | /* refcount data */
|
1094 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1095 | f7d0fe02 | Kevin Wolf | s->refcount_table_offset, |
1096 | f7d0fe02 | Kevin Wolf | s->refcount_table_size * sizeof(uint64_t));
|
1097 | f7d0fe02 | Kevin Wolf | for(i = 0; i < s->refcount_table_size; i++) { |
1098 | f7d0fe02 | Kevin Wolf | int64_t offset; |
1099 | f7d0fe02 | Kevin Wolf | offset = s->refcount_table[i]; |
1100 | 746c3cb5 | Kevin Wolf | |
1101 | 746c3cb5 | Kevin Wolf | /* Refcount blocks are cluster aligned */
|
1102 | 746c3cb5 | Kevin Wolf | if (offset & (s->cluster_size - 1)) { |
1103 | 746c3cb5 | Kevin Wolf | fprintf(stderr, "ERROR refcount block %d is not "
|
1104 | 746c3cb5 | Kevin Wolf | "cluster aligned; refcount table entry corrupted\n", i);
|
1105 | 746c3cb5 | Kevin Wolf | errors++; |
1106 | 746c3cb5 | Kevin Wolf | } |
1107 | 746c3cb5 | Kevin Wolf | |
1108 | f7d0fe02 | Kevin Wolf | if (offset != 0) { |
1109 | f7d0fe02 | Kevin Wolf | errors += inc_refcounts(bs, refcount_table, nb_clusters, |
1110 | f7d0fe02 | Kevin Wolf | offset, s->cluster_size); |
1111 | 746c3cb5 | Kevin Wolf | if (refcount_table[offset / s->cluster_size] != 1) { |
1112 | 746c3cb5 | Kevin Wolf | fprintf(stderr, "ERROR refcount block %d refcount=%d\n",
|
1113 | 746c3cb5 | Kevin Wolf | i, refcount_table[offset / s->cluster_size]); |
1114 | 746c3cb5 | Kevin Wolf | } |
1115 | f7d0fe02 | Kevin Wolf | } |
1116 | f7d0fe02 | Kevin Wolf | } |
1117 | f7d0fe02 | Kevin Wolf | |
1118 | f7d0fe02 | Kevin Wolf | /* compare ref counts */
|
1119 | f7d0fe02 | Kevin Wolf | for(i = 0; i < nb_clusters; i++) { |
1120 | f7d0fe02 | Kevin Wolf | refcount1 = get_refcount(bs, i); |
1121 | f7d0fe02 | Kevin Wolf | refcount2 = refcount_table[i]; |
1122 | f7d0fe02 | Kevin Wolf | if (refcount1 != refcount2) {
|
1123 | f7d0fe02 | Kevin Wolf | fprintf(stderr, "ERROR cluster %d refcount=%d reference=%d\n",
|
1124 | f7d0fe02 | Kevin Wolf | i, refcount1, refcount2); |
1125 | f7d0fe02 | Kevin Wolf | errors++; |
1126 | f7d0fe02 | Kevin Wolf | } |
1127 | f7d0fe02 | Kevin Wolf | } |
1128 | f7d0fe02 | Kevin Wolf | |
1129 | f7d0fe02 | Kevin Wolf | qemu_free(refcount_table); |
1130 | f7d0fe02 | Kevin Wolf | |
1131 | f7d0fe02 | Kevin Wolf | return errors;
|
1132 | f7d0fe02 | Kevin Wolf | } |