root / block / qcow.c @ 4bc74be9
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/*
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|---|---|
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* Block driver for the QCOW format
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*
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* Copyright (c) 2004-2006 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
|
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* of this software and associated documentation files (the "Software"), to deal
|
| 8 |
* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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| 11 |
* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
|
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*/
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#include "qemu-common.h" |
| 25 |
#include "block/block_int.h" |
| 26 |
#include "qemu/module.h" |
| 27 |
#include <zlib.h> |
| 28 |
#include "qemu/aes.h" |
| 29 |
#include "migration/migration.h" |
| 30 |
|
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/**************************************************************/
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| 32 |
/* QEMU COW block driver with compression and encryption support */
|
| 33 |
|
| 34 |
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
| 35 |
#define QCOW_VERSION 1 |
| 36 |
|
| 37 |
#define QCOW_CRYPT_NONE 0 |
| 38 |
#define QCOW_CRYPT_AES 1 |
| 39 |
|
| 40 |
#define QCOW_OFLAG_COMPRESSED (1LL << 63) |
| 41 |
|
| 42 |
typedef struct QCowHeader { |
| 43 |
uint32_t magic; |
| 44 |
uint32_t version; |
| 45 |
uint64_t backing_file_offset; |
| 46 |
uint32_t backing_file_size; |
| 47 |
uint32_t mtime; |
| 48 |
uint64_t size; /* in bytes */
|
| 49 |
uint8_t cluster_bits; |
| 50 |
uint8_t l2_bits; |
| 51 |
uint32_t crypt_method; |
| 52 |
uint64_t l1_table_offset; |
| 53 |
} QCowHeader; |
| 54 |
|
| 55 |
#define L2_CACHE_SIZE 16 |
| 56 |
|
| 57 |
typedef struct BDRVQcowState { |
| 58 |
int cluster_bits;
|
| 59 |
int cluster_size;
|
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int cluster_sectors;
|
| 61 |
int l2_bits;
|
| 62 |
int l2_size;
|
| 63 |
int l1_size;
|
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uint64_t cluster_offset_mask; |
| 65 |
uint64_t l1_table_offset; |
| 66 |
uint64_t *l1_table; |
| 67 |
uint64_t *l2_cache; |
| 68 |
uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
| 69 |
uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
| 70 |
uint8_t *cluster_cache; |
| 71 |
uint8_t *cluster_data; |
| 72 |
uint64_t cluster_cache_offset; |
| 73 |
uint32_t crypt_method; /* current crypt method, 0 if no key yet */
|
| 74 |
uint32_t crypt_method_header; |
| 75 |
AES_KEY aes_encrypt_key; |
| 76 |
AES_KEY aes_decrypt_key; |
| 77 |
CoMutex lock; |
| 78 |
Error *migration_blocker; |
| 79 |
} BDRVQcowState; |
| 80 |
|
| 81 |
static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); |
| 82 |
|
| 83 |
static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
| 84 |
{
|
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const QCowHeader *cow_header = (const void *)buf; |
| 86 |
|
| 87 |
if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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return 100; |
| 91 |
else
|
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return 0; |
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} |
| 94 |
|
| 95 |
static int qcow_open(BlockDriverState *bs, QDict *options, int flags) |
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{
|
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BDRVQcowState *s = bs->opaque; |
| 98 |
int len, i, shift, ret;
|
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QCowHeader header; |
| 100 |
|
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ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
| 102 |
if (ret < 0) { |
| 103 |
goto fail;
|
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} |
| 105 |
be32_to_cpus(&header.magic); |
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be32_to_cpus(&header.version); |
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be64_to_cpus(&header.backing_file_offset); |
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be32_to_cpus(&header.backing_file_size); |
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be32_to_cpus(&header.mtime); |
| 110 |
be64_to_cpus(&header.size); |
| 111 |
be32_to_cpus(&header.crypt_method); |
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be64_to_cpus(&header.l1_table_offset); |
| 113 |
|
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if (header.magic != QCOW_MAGIC) {
|
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ret = -EMEDIUMTYPE; |
| 116 |
goto fail;
|
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} |
| 118 |
if (header.version != QCOW_VERSION) {
|
| 119 |
char version[64]; |
| 120 |
snprintf(version, sizeof(version), "QCOW version %d", header.version); |
| 121 |
qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
| 122 |
bs->device_name, "qcow", version);
|
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ret = -ENOTSUP; |
| 124 |
goto fail;
|
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} |
| 126 |
|
| 127 |
if (header.size <= 1 || header.cluster_bits < 9) { |
| 128 |
ret = -EINVAL; |
| 129 |
goto fail;
|
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} |
| 131 |
if (header.crypt_method > QCOW_CRYPT_AES) {
|
| 132 |
ret = -EINVAL; |
| 133 |
goto fail;
|
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} |
| 135 |
s->crypt_method_header = header.crypt_method; |
| 136 |
if (s->crypt_method_header) {
|
| 137 |
bs->encrypted = 1;
|
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} |
| 139 |
s->cluster_bits = header.cluster_bits; |
| 140 |
s->cluster_size = 1 << s->cluster_bits;
|
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
| 142 |
s->l2_bits = header.l2_bits; |
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s->l2_size = 1 << s->l2_bits;
|
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bs->total_sectors = header.size / 512;
|
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s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; |
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|
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/* read the level 1 table */
|
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shift = s->cluster_bits + s->l2_bits; |
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s->l1_size = (header.size + (1LL << shift) - 1) >> shift; |
| 150 |
|
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s->l1_table_offset = header.l1_table_offset; |
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s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
|
| 153 |
|
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ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, |
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s->l1_size * sizeof(uint64_t));
|
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if (ret < 0) { |
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goto fail;
|
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} |
| 159 |
|
| 160 |
for(i = 0;i < s->l1_size; i++) { |
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be64_to_cpus(&s->l1_table[i]); |
| 162 |
} |
| 163 |
/* alloc L2 cache */
|
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s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
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s->cluster_cache = g_malloc(s->cluster_size); |
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s->cluster_data = g_malloc(s->cluster_size); |
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s->cluster_cache_offset = -1;
|
| 168 |
|
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/* read the backing file name */
|
| 170 |
if (header.backing_file_offset != 0) { |
| 171 |
len = header.backing_file_size; |
| 172 |
if (len > 1023) { |
| 173 |
len = 1023;
|
| 174 |
} |
| 175 |
ret = bdrv_pread(bs->file, header.backing_file_offset, |
| 176 |
bs->backing_file, len); |
| 177 |
if (ret < 0) { |
| 178 |
goto fail;
|
| 179 |
} |
| 180 |
bs->backing_file[len] = '\0';
|
| 181 |
} |
| 182 |
|
| 183 |
/* Disable migration when qcow images are used */
|
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error_set(&s->migration_blocker, |
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QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, |
| 186 |
"qcow", bs->device_name, "live migration"); |
| 187 |
migrate_add_blocker(s->migration_blocker); |
| 188 |
|
| 189 |
qemu_co_mutex_init(&s->lock); |
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return 0; |
| 191 |
|
| 192 |
fail:
|
| 193 |
g_free(s->l1_table); |
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g_free(s->l2_cache); |
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g_free(s->cluster_cache); |
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g_free(s->cluster_data); |
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return ret;
|
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} |
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|
| 200 |
|
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/* We have nothing to do for QCOW reopen, stubs just return
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* success */
|
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static int qcow_reopen_prepare(BDRVReopenState *state, |
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BlockReopenQueue *queue, Error **errp) |
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{
|
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return 0; |
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} |
| 208 |
|
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static int qcow_set_key(BlockDriverState *bs, const char *key) |
| 210 |
{
|
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BDRVQcowState *s = bs->opaque; |
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uint8_t keybuf[16];
|
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int len, i;
|
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|
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memset(keybuf, 0, 16); |
| 216 |
len = strlen(key); |
| 217 |
if (len > 16) |
| 218 |
len = 16;
|
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/* XXX: we could compress the chars to 7 bits to increase
|
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entropy */
|
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for(i = 0;i < len;i++) { |
| 222 |
keybuf[i] = key[i]; |
| 223 |
} |
| 224 |
s->crypt_method = s->crypt_method_header; |
| 225 |
|
| 226 |
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
| 227 |
return -1; |
| 228 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
| 229 |
return -1; |
| 230 |
return 0; |
| 231 |
} |
| 232 |
|
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/* The crypt function is compatible with the linux cryptoloop
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algorithm for < 4 GB images. NOTE: out_buf == in_buf is
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supported */
|
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static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
| 237 |
uint8_t *out_buf, const uint8_t *in_buf,
|
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int nb_sectors, int enc, |
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const AES_KEY *key)
|
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{
|
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union {
|
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uint64_t ll[2];
|
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uint8_t b[16];
|
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} ivec; |
| 245 |
int i;
|
| 246 |
|
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for(i = 0; i < nb_sectors; i++) { |
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ivec.ll[0] = cpu_to_le64(sector_num);
|
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ivec.ll[1] = 0; |
| 250 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
|
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ivec.b, enc); |
| 252 |
sector_num++; |
| 253 |
in_buf += 512;
|
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out_buf += 512;
|
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} |
| 256 |
} |
| 257 |
|
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/* 'allocate' is:
|
| 259 |
*
|
| 260 |
* 0 to not allocate.
|
| 261 |
*
|
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* 1 to allocate a normal cluster (for sector indexes 'n_start' to
|
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* 'n_end')
|
| 264 |
*
|
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* 2 to allocate a compressed cluster of size
|
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* 'compressed_size'. 'compressed_size' must be > 0 and <
|
| 267 |
* cluster_size
|
| 268 |
*
|
| 269 |
* return 0 if not allocated.
|
| 270 |
*/
|
| 271 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
| 272 |
uint64_t offset, int allocate,
|
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int compressed_size,
|
| 274 |
int n_start, int n_end) |
| 275 |
{
|
| 276 |
BDRVQcowState *s = bs->opaque; |
| 277 |
int min_index, i, j, l1_index, l2_index;
|
| 278 |
uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
| 279 |
uint32_t min_count; |
| 280 |
int new_l2_table;
|
| 281 |
|
| 282 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
| 283 |
l2_offset = s->l1_table[l1_index]; |
| 284 |
new_l2_table = 0;
|
| 285 |
if (!l2_offset) {
|
| 286 |
if (!allocate)
|
| 287 |
return 0; |
| 288 |
/* allocate a new l2 entry */
|
| 289 |
l2_offset = bdrv_getlength(bs->file); |
| 290 |
/* round to cluster size */
|
| 291 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
| 292 |
/* update the L1 entry */
|
| 293 |
s->l1_table[l1_index] = l2_offset; |
| 294 |
tmp = cpu_to_be64(l2_offset); |
| 295 |
if (bdrv_pwrite_sync(bs->file,
|
| 296 |
s->l1_table_offset + l1_index * sizeof(tmp),
|
| 297 |
&tmp, sizeof(tmp)) < 0) |
| 298 |
return 0; |
| 299 |
new_l2_table = 1;
|
| 300 |
} |
| 301 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
| 302 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
| 303 |
/* increment the hit count */
|
| 304 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
| 305 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
| 306 |
s->l2_cache_counts[j] >>= 1;
|
| 307 |
} |
| 308 |
} |
| 309 |
l2_table = s->l2_cache + (i << s->l2_bits); |
| 310 |
goto found;
|
| 311 |
} |
| 312 |
} |
| 313 |
/* not found: load a new entry in the least used one */
|
| 314 |
min_index = 0;
|
| 315 |
min_count = 0xffffffff;
|
| 316 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
| 317 |
if (s->l2_cache_counts[i] < min_count) {
|
| 318 |
min_count = s->l2_cache_counts[i]; |
| 319 |
min_index = i; |
| 320 |
} |
| 321 |
} |
| 322 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
| 323 |
if (new_l2_table) {
|
| 324 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
| 325 |
if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
|
| 326 |
s->l2_size * sizeof(uint64_t)) < 0) |
| 327 |
return 0; |
| 328 |
} else {
|
| 329 |
if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
| 330 |
s->l2_size * sizeof(uint64_t))
|
| 331 |
return 0; |
| 332 |
} |
| 333 |
s->l2_cache_offsets[min_index] = l2_offset; |
| 334 |
s->l2_cache_counts[min_index] = 1;
|
| 335 |
found:
|
| 336 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
| 337 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
| 338 |
if (!cluster_offset ||
|
| 339 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
| 340 |
if (!allocate)
|
| 341 |
return 0; |
| 342 |
/* allocate a new cluster */
|
| 343 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
| 344 |
(n_end - n_start) < s->cluster_sectors) {
|
| 345 |
/* if the cluster is already compressed, we must
|
| 346 |
decompress it in the case it is not completely
|
| 347 |
overwritten */
|
| 348 |
if (decompress_cluster(bs, cluster_offset) < 0) |
| 349 |
return 0; |
| 350 |
cluster_offset = bdrv_getlength(bs->file); |
| 351 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
| 352 |
~(s->cluster_size - 1);
|
| 353 |
/* write the cluster content */
|
| 354 |
if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
| 355 |
s->cluster_size) |
| 356 |
return -1; |
| 357 |
} else {
|
| 358 |
cluster_offset = bdrv_getlength(bs->file); |
| 359 |
if (allocate == 1) { |
| 360 |
/* round to cluster size */
|
| 361 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
| 362 |
~(s->cluster_size - 1);
|
| 363 |
bdrv_truncate(bs->file, cluster_offset + s->cluster_size); |
| 364 |
/* if encrypted, we must initialize the cluster
|
| 365 |
content which won't be written */
|
| 366 |
if (s->crypt_method &&
|
| 367 |
(n_end - n_start) < s->cluster_sectors) {
|
| 368 |
uint64_t start_sect; |
| 369 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
| 370 |
memset(s->cluster_data + 512, 0x00, 512); |
| 371 |
for(i = 0; i < s->cluster_sectors; i++) { |
| 372 |
if (i < n_start || i >= n_end) {
|
| 373 |
encrypt_sectors(s, start_sect + i, |
| 374 |
s->cluster_data, |
| 375 |
s->cluster_data + 512, 1, 1, |
| 376 |
&s->aes_encrypt_key); |
| 377 |
if (bdrv_pwrite(bs->file, cluster_offset + i * 512, |
| 378 |
s->cluster_data, 512) != 512) |
| 379 |
return -1; |
| 380 |
} |
| 381 |
} |
| 382 |
} |
| 383 |
} else if (allocate == 2) { |
| 384 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
| 385 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
| 386 |
} |
| 387 |
} |
| 388 |
/* update L2 table */
|
| 389 |
tmp = cpu_to_be64(cluster_offset); |
| 390 |
l2_table[l2_index] = tmp; |
| 391 |
if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), |
| 392 |
&tmp, sizeof(tmp)) < 0) |
| 393 |
return 0; |
| 394 |
} |
| 395 |
return cluster_offset;
|
| 396 |
} |
| 397 |
|
| 398 |
static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
|
| 399 |
int64_t sector_num, int nb_sectors, int *pnum) |
| 400 |
{
|
| 401 |
BDRVQcowState *s = bs->opaque; |
| 402 |
int index_in_cluster, n;
|
| 403 |
uint64_t cluster_offset; |
| 404 |
|
| 405 |
qemu_co_mutex_lock(&s->lock); |
| 406 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
| 407 |
qemu_co_mutex_unlock(&s->lock); |
| 408 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
| 409 |
n = s->cluster_sectors - index_in_cluster; |
| 410 |
if (n > nb_sectors)
|
| 411 |
n = nb_sectors; |
| 412 |
*pnum = n; |
| 413 |
if (!cluster_offset) {
|
| 414 |
return 0; |
| 415 |
} |
| 416 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypt_method) {
|
| 417 |
return BDRV_BLOCK_DATA;
|
| 418 |
} |
| 419 |
cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); |
| 420 |
return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset;
|
| 421 |
} |
| 422 |
|
| 423 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
| 424 |
const uint8_t *buf, int buf_size) |
| 425 |
{
|
| 426 |
z_stream strm1, *strm = &strm1; |
| 427 |
int ret, out_len;
|
| 428 |
|
| 429 |
memset(strm, 0, sizeof(*strm)); |
| 430 |
|
| 431 |
strm->next_in = (uint8_t *)buf; |
| 432 |
strm->avail_in = buf_size; |
| 433 |
strm->next_out = out_buf; |
| 434 |
strm->avail_out = out_buf_size; |
| 435 |
|
| 436 |
ret = inflateInit2(strm, -12);
|
| 437 |
if (ret != Z_OK)
|
| 438 |
return -1; |
| 439 |
ret = inflate(strm, Z_FINISH); |
| 440 |
out_len = strm->next_out - out_buf; |
| 441 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
| 442 |
out_len != out_buf_size) {
|
| 443 |
inflateEnd(strm); |
| 444 |
return -1; |
| 445 |
} |
| 446 |
inflateEnd(strm); |
| 447 |
return 0; |
| 448 |
} |
| 449 |
|
| 450 |
static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) |
| 451 |
{
|
| 452 |
BDRVQcowState *s = bs->opaque; |
| 453 |
int ret, csize;
|
| 454 |
uint64_t coffset; |
| 455 |
|
| 456 |
coffset = cluster_offset & s->cluster_offset_mask; |
| 457 |
if (s->cluster_cache_offset != coffset) {
|
| 458 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
| 459 |
csize &= (s->cluster_size - 1);
|
| 460 |
ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize); |
| 461 |
if (ret != csize)
|
| 462 |
return -1; |
| 463 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
| 464 |
s->cluster_data, csize) < 0) {
|
| 465 |
return -1; |
| 466 |
} |
| 467 |
s->cluster_cache_offset = coffset; |
| 468 |
} |
| 469 |
return 0; |
| 470 |
} |
| 471 |
|
| 472 |
static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, |
| 473 |
int nb_sectors, QEMUIOVector *qiov)
|
| 474 |
{
|
| 475 |
BDRVQcowState *s = bs->opaque; |
| 476 |
int index_in_cluster;
|
| 477 |
int ret = 0, n; |
| 478 |
uint64_t cluster_offset; |
| 479 |
struct iovec hd_iov;
|
| 480 |
QEMUIOVector hd_qiov; |
| 481 |
uint8_t *buf; |
| 482 |
void *orig_buf;
|
| 483 |
|
| 484 |
if (qiov->niov > 1) { |
| 485 |
buf = orig_buf = qemu_blockalign(bs, qiov->size); |
| 486 |
} else {
|
| 487 |
orig_buf = NULL;
|
| 488 |
buf = (uint8_t *)qiov->iov->iov_base; |
| 489 |
} |
| 490 |
|
| 491 |
qemu_co_mutex_lock(&s->lock); |
| 492 |
|
| 493 |
while (nb_sectors != 0) { |
| 494 |
/* prepare next request */
|
| 495 |
cluster_offset = get_cluster_offset(bs, sector_num << 9,
|
| 496 |
0, 0, 0, 0); |
| 497 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
| 498 |
n = s->cluster_sectors - index_in_cluster; |
| 499 |
if (n > nb_sectors) {
|
| 500 |
n = nb_sectors; |
| 501 |
} |
| 502 |
|
| 503 |
if (!cluster_offset) {
|
| 504 |
if (bs->backing_hd) {
|
| 505 |
/* read from the base image */
|
| 506 |
hd_iov.iov_base = (void *)buf;
|
| 507 |
hd_iov.iov_len = n * 512;
|
| 508 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
| 509 |
qemu_co_mutex_unlock(&s->lock); |
| 510 |
ret = bdrv_co_readv(bs->backing_hd, sector_num, |
| 511 |
n, &hd_qiov); |
| 512 |
qemu_co_mutex_lock(&s->lock); |
| 513 |
if (ret < 0) { |
| 514 |
goto fail;
|
| 515 |
} |
| 516 |
} else {
|
| 517 |
/* Note: in this case, no need to wait */
|
| 518 |
memset(buf, 0, 512 * n); |
| 519 |
} |
| 520 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
| 521 |
/* add AIO support for compressed blocks ? */
|
| 522 |
if (decompress_cluster(bs, cluster_offset) < 0) { |
| 523 |
goto fail;
|
| 524 |
} |
| 525 |
memcpy(buf, |
| 526 |
s->cluster_cache + index_in_cluster * 512, 512 * n); |
| 527 |
} else {
|
| 528 |
if ((cluster_offset & 511) != 0) { |
| 529 |
goto fail;
|
| 530 |
} |
| 531 |
hd_iov.iov_base = (void *)buf;
|
| 532 |
hd_iov.iov_len = n * 512;
|
| 533 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
| 534 |
qemu_co_mutex_unlock(&s->lock); |
| 535 |
ret = bdrv_co_readv(bs->file, |
| 536 |
(cluster_offset >> 9) + index_in_cluster,
|
| 537 |
n, &hd_qiov); |
| 538 |
qemu_co_mutex_lock(&s->lock); |
| 539 |
if (ret < 0) { |
| 540 |
break;
|
| 541 |
} |
| 542 |
if (s->crypt_method) {
|
| 543 |
encrypt_sectors(s, sector_num, buf, buf, |
| 544 |
n, 0,
|
| 545 |
&s->aes_decrypt_key); |
| 546 |
} |
| 547 |
} |
| 548 |
ret = 0;
|
| 549 |
|
| 550 |
nb_sectors -= n; |
| 551 |
sector_num += n; |
| 552 |
buf += n * 512;
|
| 553 |
} |
| 554 |
|
| 555 |
done:
|
| 556 |
qemu_co_mutex_unlock(&s->lock); |
| 557 |
|
| 558 |
if (qiov->niov > 1) { |
| 559 |
qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
|
| 560 |
qemu_vfree(orig_buf); |
| 561 |
} |
| 562 |
|
| 563 |
return ret;
|
| 564 |
|
| 565 |
fail:
|
| 566 |
ret = -EIO; |
| 567 |
goto done;
|
| 568 |
} |
| 569 |
|
| 570 |
static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, |
| 571 |
int nb_sectors, QEMUIOVector *qiov)
|
| 572 |
{
|
| 573 |
BDRVQcowState *s = bs->opaque; |
| 574 |
int index_in_cluster;
|
| 575 |
uint64_t cluster_offset; |
| 576 |
const uint8_t *src_buf;
|
| 577 |
int ret = 0, n; |
| 578 |
uint8_t *cluster_data = NULL;
|
| 579 |
struct iovec hd_iov;
|
| 580 |
QEMUIOVector hd_qiov; |
| 581 |
uint8_t *buf; |
| 582 |
void *orig_buf;
|
| 583 |
|
| 584 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
| 585 |
|
| 586 |
if (qiov->niov > 1) { |
| 587 |
buf = orig_buf = qemu_blockalign(bs, qiov->size); |
| 588 |
qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
|
| 589 |
} else {
|
| 590 |
orig_buf = NULL;
|
| 591 |
buf = (uint8_t *)qiov->iov->iov_base; |
| 592 |
} |
| 593 |
|
| 594 |
qemu_co_mutex_lock(&s->lock); |
| 595 |
|
| 596 |
while (nb_sectors != 0) { |
| 597 |
|
| 598 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
| 599 |
n = s->cluster_sectors - index_in_cluster; |
| 600 |
if (n > nb_sectors) {
|
| 601 |
n = nb_sectors; |
| 602 |
} |
| 603 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
| 604 |
index_in_cluster, |
| 605 |
index_in_cluster + n); |
| 606 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
| 607 |
ret = -EIO; |
| 608 |
break;
|
| 609 |
} |
| 610 |
if (s->crypt_method) {
|
| 611 |
if (!cluster_data) {
|
| 612 |
cluster_data = g_malloc0(s->cluster_size); |
| 613 |
} |
| 614 |
encrypt_sectors(s, sector_num, cluster_data, buf, |
| 615 |
n, 1, &s->aes_encrypt_key);
|
| 616 |
src_buf = cluster_data; |
| 617 |
} else {
|
| 618 |
src_buf = buf; |
| 619 |
} |
| 620 |
|
| 621 |
hd_iov.iov_base = (void *)src_buf;
|
| 622 |
hd_iov.iov_len = n * 512;
|
| 623 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
| 624 |
qemu_co_mutex_unlock(&s->lock); |
| 625 |
ret = bdrv_co_writev(bs->file, |
| 626 |
(cluster_offset >> 9) + index_in_cluster,
|
| 627 |
n, &hd_qiov); |
| 628 |
qemu_co_mutex_lock(&s->lock); |
| 629 |
if (ret < 0) { |
| 630 |
break;
|
| 631 |
} |
| 632 |
ret = 0;
|
| 633 |
|
| 634 |
nb_sectors -= n; |
| 635 |
sector_num += n; |
| 636 |
buf += n * 512;
|
| 637 |
} |
| 638 |
qemu_co_mutex_unlock(&s->lock); |
| 639 |
|
| 640 |
if (qiov->niov > 1) { |
| 641 |
qemu_vfree(orig_buf); |
| 642 |
} |
| 643 |
g_free(cluster_data); |
| 644 |
|
| 645 |
return ret;
|
| 646 |
} |
| 647 |
|
| 648 |
static void qcow_close(BlockDriverState *bs) |
| 649 |
{
|
| 650 |
BDRVQcowState *s = bs->opaque; |
| 651 |
|
| 652 |
g_free(s->l1_table); |
| 653 |
g_free(s->l2_cache); |
| 654 |
g_free(s->cluster_cache); |
| 655 |
g_free(s->cluster_data); |
| 656 |
|
| 657 |
migrate_del_blocker(s->migration_blocker); |
| 658 |
error_free(s->migration_blocker); |
| 659 |
} |
| 660 |
|
| 661 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
| 662 |
{
|
| 663 |
int header_size, backing_filename_len, l1_size, shift, i;
|
| 664 |
QCowHeader header; |
| 665 |
uint8_t *tmp; |
| 666 |
int64_t total_size = 0;
|
| 667 |
const char *backing_file = NULL; |
| 668 |
int flags = 0; |
| 669 |
int ret;
|
| 670 |
BlockDriverState *qcow_bs; |
| 671 |
|
| 672 |
/* Read out options */
|
| 673 |
while (options && options->name) {
|
| 674 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
| 675 |
total_size = options->value.n / 512;
|
| 676 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
| 677 |
backing_file = options->value.s; |
| 678 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
| 679 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
| 680 |
} |
| 681 |
options++; |
| 682 |
} |
| 683 |
|
| 684 |
ret = bdrv_create_file(filename, options); |
| 685 |
if (ret < 0) { |
| 686 |
return ret;
|
| 687 |
} |
| 688 |
|
| 689 |
ret = bdrv_file_open(&qcow_bs, filename, NULL, BDRV_O_RDWR);
|
| 690 |
if (ret < 0) { |
| 691 |
return ret;
|
| 692 |
} |
| 693 |
|
| 694 |
ret = bdrv_truncate(qcow_bs, 0);
|
| 695 |
if (ret < 0) { |
| 696 |
goto exit;
|
| 697 |
} |
| 698 |
|
| 699 |
memset(&header, 0, sizeof(header)); |
| 700 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
| 701 |
header.version = cpu_to_be32(QCOW_VERSION); |
| 702 |
header.size = cpu_to_be64(total_size * 512);
|
| 703 |
header_size = sizeof(header);
|
| 704 |
backing_filename_len = 0;
|
| 705 |
if (backing_file) {
|
| 706 |
if (strcmp(backing_file, "fat:")) { |
| 707 |
header.backing_file_offset = cpu_to_be64(header_size); |
| 708 |
backing_filename_len = strlen(backing_file); |
| 709 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
| 710 |
header_size += backing_filename_len; |
| 711 |
} else {
|
| 712 |
/* special backing file for vvfat */
|
| 713 |
backing_file = NULL;
|
| 714 |
} |
| 715 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
| 716 |
unmodifyed sectors */
|
| 717 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
| 718 |
} else {
|
| 719 |
header.cluster_bits = 12; /* 4 KB clusters */ |
| 720 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
| 721 |
} |
| 722 |
header_size = (header_size + 7) & ~7; |
| 723 |
shift = header.cluster_bits + header.l2_bits; |
| 724 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
| 725 |
|
| 726 |
header.l1_table_offset = cpu_to_be64(header_size); |
| 727 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
| 728 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
| 729 |
} else {
|
| 730 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
| 731 |
} |
| 732 |
|
| 733 |
/* write all the data */
|
| 734 |
ret = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header)); |
| 735 |
if (ret != sizeof(header)) { |
| 736 |
goto exit;
|
| 737 |
} |
| 738 |
|
| 739 |
if (backing_file) {
|
| 740 |
ret = bdrv_pwrite(qcow_bs, sizeof(header),
|
| 741 |
backing_file, backing_filename_len); |
| 742 |
if (ret != backing_filename_len) {
|
| 743 |
goto exit;
|
| 744 |
} |
| 745 |
} |
| 746 |
|
| 747 |
tmp = g_malloc0(BDRV_SECTOR_SIZE); |
| 748 |
for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/ |
| 749 |
BDRV_SECTOR_SIZE); i++) {
|
| 750 |
ret = bdrv_pwrite(qcow_bs, header_size + |
| 751 |
BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE); |
| 752 |
if (ret != BDRV_SECTOR_SIZE) {
|
| 753 |
g_free(tmp); |
| 754 |
goto exit;
|
| 755 |
} |
| 756 |
} |
| 757 |
|
| 758 |
g_free(tmp); |
| 759 |
ret = 0;
|
| 760 |
exit:
|
| 761 |
bdrv_unref(qcow_bs); |
| 762 |
return ret;
|
| 763 |
} |
| 764 |
|
| 765 |
static int qcow_make_empty(BlockDriverState *bs) |
| 766 |
{
|
| 767 |
BDRVQcowState *s = bs->opaque; |
| 768 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
| 769 |
int ret;
|
| 770 |
|
| 771 |
memset(s->l1_table, 0, l1_length);
|
| 772 |
if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
|
| 773 |
l1_length) < 0)
|
| 774 |
return -1; |
| 775 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length); |
| 776 |
if (ret < 0) |
| 777 |
return ret;
|
| 778 |
|
| 779 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
| 780 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
| 781 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
| 782 |
|
| 783 |
return 0; |
| 784 |
} |
| 785 |
|
| 786 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
| 787 |
tables to avoid losing bytes in alignment */
|
| 788 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
| 789 |
const uint8_t *buf, int nb_sectors) |
| 790 |
{
|
| 791 |
BDRVQcowState *s = bs->opaque; |
| 792 |
z_stream strm; |
| 793 |
int ret, out_len;
|
| 794 |
uint8_t *out_buf; |
| 795 |
uint64_t cluster_offset; |
| 796 |
|
| 797 |
if (nb_sectors != s->cluster_sectors) {
|
| 798 |
ret = -EINVAL; |
| 799 |
|
| 800 |
/* Zero-pad last write if image size is not cluster aligned */
|
| 801 |
if (sector_num + nb_sectors == bs->total_sectors &&
|
| 802 |
nb_sectors < s->cluster_sectors) {
|
| 803 |
uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); |
| 804 |
memset(pad_buf, 0, s->cluster_size);
|
| 805 |
memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); |
| 806 |
ret = qcow_write_compressed(bs, sector_num, |
| 807 |
pad_buf, s->cluster_sectors); |
| 808 |
qemu_vfree(pad_buf); |
| 809 |
} |
| 810 |
return ret;
|
| 811 |
} |
| 812 |
|
| 813 |
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
| 814 |
|
| 815 |
/* best compression, small window, no zlib header */
|
| 816 |
memset(&strm, 0, sizeof(strm)); |
| 817 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
| 818 |
Z_DEFLATED, -12,
|
| 819 |
9, Z_DEFAULT_STRATEGY);
|
| 820 |
if (ret != 0) { |
| 821 |
ret = -EINVAL; |
| 822 |
goto fail;
|
| 823 |
} |
| 824 |
|
| 825 |
strm.avail_in = s->cluster_size; |
| 826 |
strm.next_in = (uint8_t *)buf; |
| 827 |
strm.avail_out = s->cluster_size; |
| 828 |
strm.next_out = out_buf; |
| 829 |
|
| 830 |
ret = deflate(&strm, Z_FINISH); |
| 831 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
| 832 |
deflateEnd(&strm); |
| 833 |
ret = -EINVAL; |
| 834 |
goto fail;
|
| 835 |
} |
| 836 |
out_len = strm.next_out - out_buf; |
| 837 |
|
| 838 |
deflateEnd(&strm); |
| 839 |
|
| 840 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
| 841 |
/* could not compress: write normal cluster */
|
| 842 |
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
| 843 |
if (ret < 0) { |
| 844 |
goto fail;
|
| 845 |
} |
| 846 |
} else {
|
| 847 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
| 848 |
out_len, 0, 0); |
| 849 |
if (cluster_offset == 0) { |
| 850 |
ret = -EIO; |
| 851 |
goto fail;
|
| 852 |
} |
| 853 |
|
| 854 |
cluster_offset &= s->cluster_offset_mask; |
| 855 |
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); |
| 856 |
if (ret < 0) { |
| 857 |
goto fail;
|
| 858 |
} |
| 859 |
} |
| 860 |
|
| 861 |
ret = 0;
|
| 862 |
fail:
|
| 863 |
g_free(out_buf); |
| 864 |
return ret;
|
| 865 |
} |
| 866 |
|
| 867 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| 868 |
{
|
| 869 |
BDRVQcowState *s = bs->opaque; |
| 870 |
bdi->cluster_size = s->cluster_size; |
| 871 |
return 0; |
| 872 |
} |
| 873 |
|
| 874 |
|
| 875 |
static QEMUOptionParameter qcow_create_options[] = {
|
| 876 |
{
|
| 877 |
.name = BLOCK_OPT_SIZE, |
| 878 |
.type = OPT_SIZE, |
| 879 |
.help = "Virtual disk size"
|
| 880 |
}, |
| 881 |
{
|
| 882 |
.name = BLOCK_OPT_BACKING_FILE, |
| 883 |
.type = OPT_STRING, |
| 884 |
.help = "File name of a base image"
|
| 885 |
}, |
| 886 |
{
|
| 887 |
.name = BLOCK_OPT_ENCRYPT, |
| 888 |
.type = OPT_FLAG, |
| 889 |
.help = "Encrypt the image"
|
| 890 |
}, |
| 891 |
{ NULL }
|
| 892 |
}; |
| 893 |
|
| 894 |
static BlockDriver bdrv_qcow = {
|
| 895 |
.format_name = "qcow",
|
| 896 |
.instance_size = sizeof(BDRVQcowState),
|
| 897 |
.bdrv_probe = qcow_probe, |
| 898 |
.bdrv_open = qcow_open, |
| 899 |
.bdrv_close = qcow_close, |
| 900 |
.bdrv_reopen_prepare = qcow_reopen_prepare, |
| 901 |
.bdrv_create = qcow_create, |
| 902 |
.bdrv_has_zero_init = bdrv_has_zero_init_1, |
| 903 |
|
| 904 |
.bdrv_co_readv = qcow_co_readv, |
| 905 |
.bdrv_co_writev = qcow_co_writev, |
| 906 |
.bdrv_co_get_block_status = qcow_co_get_block_status, |
| 907 |
|
| 908 |
.bdrv_set_key = qcow_set_key, |
| 909 |
.bdrv_make_empty = qcow_make_empty, |
| 910 |
.bdrv_write_compressed = qcow_write_compressed, |
| 911 |
.bdrv_get_info = qcow_get_info, |
| 912 |
|
| 913 |
.create_options = qcow_create_options, |
| 914 |
}; |
| 915 |
|
| 916 |
static void bdrv_qcow_init(void) |
| 917 |
{
|
| 918 |
bdrv_register(&bdrv_qcow); |
| 919 |
} |
| 920 |
|
| 921 |
block_init(bdrv_qcow_init); |