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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 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
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* 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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* 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 "vl.h" |
25 |
#include "block_int.h" |
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#include <zlib.h> |
27 |
#include "aes.h" |
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|
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/**************************************************************/
|
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/* QEMU COW block driver with compression and encryption support */
|
31 |
|
32 |
#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
33 |
#define QCOW_VERSION 1 |
34 |
|
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#define QCOW_CRYPT_NONE 0 |
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#define QCOW_CRYPT_AES 1 |
37 |
|
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#define QCOW_OFLAG_COMPRESSED (1LL << 63) |
39 |
|
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typedef struct QCowHeader { |
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uint32_t magic; |
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uint32_t version; |
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uint64_t backing_file_offset; |
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uint32_t backing_file_size; |
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uint32_t mtime; |
46 |
uint64_t size; /* in bytes */
|
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uint8_t cluster_bits; |
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uint8_t l2_bits; |
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uint32_t crypt_method; |
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uint64_t l1_table_offset; |
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} QCowHeader; |
52 |
|
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#define L2_CACHE_SIZE 16 |
54 |
|
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typedef struct BDRVQcowState { |
56 |
int fd;
|
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int cluster_bits;
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int cluster_size;
|
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int cluster_sectors;
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int l2_bits;
|
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int l2_size;
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int l1_size;
|
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uint64_t cluster_offset_mask; |
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uint64_t l1_table_offset; |
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uint64_t *l1_table; |
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uint64_t *l2_cache; |
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uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
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uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
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uint8_t *cluster_cache; |
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uint8_t *cluster_data; |
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uint64_t cluster_cache_offset; |
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uint32_t crypt_method; /* current crypt method, 0 if no key yet */
|
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uint32_t crypt_method_header; |
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AES_KEY aes_encrypt_key; |
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AES_KEY aes_decrypt_key; |
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} BDRVQcowState; |
77 |
|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
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|
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
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|
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if (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; |
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else
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return 0; |
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} |
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|
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static int qcow_open(BlockDriverState *bs, const char *filename) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int fd, len, i, shift;
|
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QCowHeader header; |
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|
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fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE); |
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if (fd < 0) { |
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fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); |
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if (fd < 0) |
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return -1; |
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} |
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s->fd = fd; |
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if (read(fd, &header, sizeof(header)) != sizeof(header)) |
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goto fail;
|
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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); |
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be64_to_cpus(&header.size); |
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be32_to_cpus(&header.crypt_method); |
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be64_to_cpus(&header.l1_table_offset); |
114 |
|
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if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
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goto fail;
|
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if (header.size <= 1 || header.cluster_bits < 9) |
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goto fail;
|
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if (header.crypt_method > QCOW_CRYPT_AES)
|
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goto fail;
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s->crypt_method_header = header.crypt_method; |
122 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
125 |
s->cluster_size = 1 << s->cluster_bits;
|
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = header.l2_bits; |
128 |
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; |
131 |
|
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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; |
135 |
|
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s->l1_table_offset = header.l1_table_offset; |
137 |
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
|
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if (!s->l1_table)
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goto fail;
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lseek(fd, s->l1_table_offset, SEEK_SET); |
141 |
if (read(fd, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
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s->l1_size * sizeof(uint64_t))
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goto fail;
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for(i = 0;i < s->l1_size; i++) { |
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be64_to_cpus(&s->l1_table[i]); |
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} |
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/* alloc L2 cache */
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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if (!s->l2_cache)
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goto fail;
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s->cluster_cache = qemu_malloc(s->cluster_size); |
152 |
if (!s->cluster_cache)
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goto fail;
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s->cluster_data = qemu_malloc(s->cluster_size); |
155 |
if (!s->cluster_data)
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goto fail;
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s->cluster_cache_offset = -1;
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|
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/* read the backing file name */
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if (header.backing_file_offset != 0) { |
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len = header.backing_file_size; |
162 |
if (len > 1023) |
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len = 1023;
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lseek(fd, header.backing_file_offset, SEEK_SET); |
165 |
if (read(fd, bs->backing_file, len) != len)
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goto fail;
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bs->backing_file[len] = '\0';
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} |
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return 0; |
170 |
|
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fail:
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qemu_free(s->l1_table); |
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qemu_free(s->l2_cache); |
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qemu_free(s->cluster_cache); |
175 |
qemu_free(s->cluster_data); |
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close(fd); |
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return -1; |
178 |
} |
179 |
|
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static int qcow_set_key(BlockDriverState *bs, const char *key) |
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{ |
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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); |
187 |
len = strlen(key); |
188 |
if (len > 16) |
189 |
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++) { |
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keybuf[i] = key[i]; |
194 |
} |
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s->crypt_method = s->crypt_method_header; |
196 |
|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
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return -1; |
199 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
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return -1; |
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#if 0
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/* test */
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{
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uint8_t in[16];
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uint8_t out[16];
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uint8_t tmp[16];
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for(i=0;i<16;i++)
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in[i] = i;
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AES_encrypt(in, tmp, &s->aes_encrypt_key);
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AES_decrypt(tmp, out, &s->aes_decrypt_key);
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for(i = 0; i < 16; i++)
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printf(" %02x", tmp[i]);
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printf("\n");
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for(i = 0; i < 16; i++)
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printf(" %02x", out[i]);
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printf("\n");
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}
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#endif
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return 0; |
220 |
} |
221 |
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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, |
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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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{ |
230 |
union {
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uint64_t ll[2];
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uint8_t b[16];
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} ivec; |
234 |
int i;
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|
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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; |
239 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
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ivec.b, enc); |
241 |
sector_num++; |
242 |
in_buf += 512;
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out_buf += 512;
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} |
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} |
246 |
|
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/* 'allocate' is:
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*
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* 0 to not allocate.
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*
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* 1 to allocate a normal cluster (for sector indexes 'n_start' to
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* 'n_end')
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*
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* 2 to allocate a compressed cluster of size
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* 'compressed_size'. 'compressed_size' must be > 0 and <
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* cluster_size
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*
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* return 0 if not allocated.
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*/
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static uint64_t get_cluster_offset(BlockDriverState *bs,
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uint64_t offset, int allocate,
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int compressed_size,
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int n_start, int n_end) |
264 |
{ |
265 |
BDRVQcowState *s = bs->opaque; |
266 |
int min_index, i, j, l1_index, l2_index;
|
267 |
uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
268 |
uint32_t min_count; |
269 |
int new_l2_table;
|
270 |
|
271 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
272 |
l2_offset = s->l1_table[l1_index]; |
273 |
new_l2_table = 0;
|
274 |
if (!l2_offset) {
|
275 |
if (!allocate)
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276 |
return 0; |
277 |
/* allocate a new l2 entry */
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278 |
l2_offset = lseek(s->fd, 0, SEEK_END);
|
279 |
/* round to cluster size */
|
280 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
281 |
/* update the L1 entry */
|
282 |
s->l1_table[l1_index] = l2_offset; |
283 |
tmp = cpu_to_be64(l2_offset); |
284 |
lseek(s->fd, s->l1_table_offset + l1_index * sizeof(tmp), SEEK_SET);
|
285 |
if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) |
286 |
return 0; |
287 |
new_l2_table = 1;
|
288 |
} |
289 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
290 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
291 |
/* increment the hit count */
|
292 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
293 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
294 |
s->l2_cache_counts[j] >>= 1;
|
295 |
} |
296 |
} |
297 |
l2_table = s->l2_cache + (i << s->l2_bits); |
298 |
goto found;
|
299 |
} |
300 |
} |
301 |
/* not found: load a new entry in the least used one */
|
302 |
min_index = 0;
|
303 |
min_count = 0xffffffff;
|
304 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
305 |
if (s->l2_cache_counts[i] < min_count) {
|
306 |
min_count = s->l2_cache_counts[i]; |
307 |
min_index = i; |
308 |
} |
309 |
} |
310 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
311 |
lseek(s->fd, l2_offset, SEEK_SET); |
312 |
if (new_l2_table) {
|
313 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
314 |
if (write(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != |
315 |
s->l2_size * sizeof(uint64_t))
|
316 |
return 0; |
317 |
} else {
|
318 |
if (read(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != |
319 |
s->l2_size * sizeof(uint64_t))
|
320 |
return 0; |
321 |
} |
322 |
s->l2_cache_offsets[min_index] = l2_offset; |
323 |
s->l2_cache_counts[min_index] = 1;
|
324 |
found:
|
325 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
326 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
327 |
if (!cluster_offset ||
|
328 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
329 |
if (!allocate)
|
330 |
return 0; |
331 |
/* allocate a new cluster */
|
332 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
333 |
(n_end - n_start) < s->cluster_sectors) { |
334 |
/* if the cluster is already compressed, we must
|
335 |
decompress it in the case it is not completely
|
336 |
overwritten */
|
337 |
if (decompress_cluster(s, cluster_offset) < 0) |
338 |
return 0; |
339 |
cluster_offset = lseek(s->fd, 0, SEEK_END);
|
340 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
341 |
~(s->cluster_size - 1);
|
342 |
/* write the cluster content */
|
343 |
lseek(s->fd, cluster_offset, SEEK_SET); |
344 |
if (write(s->fd, s->cluster_cache, s->cluster_size) !=
|
345 |
s->cluster_size) |
346 |
return -1; |
347 |
} else {
|
348 |
cluster_offset = lseek(s->fd, 0, SEEK_END);
|
349 |
if (allocate == 1) { |
350 |
/* round to cluster size */
|
351 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
352 |
~(s->cluster_size - 1);
|
353 |
ftruncate(s->fd, cluster_offset + s->cluster_size); |
354 |
/* if encrypted, we must initialize the cluster
|
355 |
content which won't be written */
|
356 |
if (s->crypt_method &&
|
357 |
(n_end - n_start) < s->cluster_sectors) { |
358 |
uint64_t start_sect; |
359 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
360 |
memset(s->cluster_data + 512, 0xaa, 512); |
361 |
for(i = 0; i < s->cluster_sectors; i++) { |
362 |
if (i < n_start || i >= n_end) {
|
363 |
encrypt_sectors(s, start_sect + i, |
364 |
s->cluster_data, |
365 |
s->cluster_data + 512, 1, 1, |
366 |
&s->aes_encrypt_key); |
367 |
lseek(s->fd, cluster_offset + i * 512, SEEK_SET);
|
368 |
if (write(s->fd, s->cluster_data, 512) != 512) |
369 |
return -1; |
370 |
} |
371 |
} |
372 |
} |
373 |
} else {
|
374 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
375 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
376 |
} |
377 |
} |
378 |
/* update L2 table */
|
379 |
tmp = cpu_to_be64(cluster_offset); |
380 |
l2_table[l2_index] = tmp; |
381 |
lseek(s->fd, l2_offset + l2_index * sizeof(tmp), SEEK_SET);
|
382 |
if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) |
383 |
return 0; |
384 |
} |
385 |
return cluster_offset;
|
386 |
} |
387 |
|
388 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
389 |
int nb_sectors, int *pnum) |
390 |
{ |
391 |
BDRVQcowState *s = bs->opaque; |
392 |
int index_in_cluster, n;
|
393 |
uint64_t cluster_offset; |
394 |
|
395 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
396 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
397 |
n = s->cluster_sectors - index_in_cluster; |
398 |
if (n > nb_sectors)
|
399 |
n = nb_sectors; |
400 |
*pnum = n; |
401 |
return (cluster_offset != 0); |
402 |
} |
403 |
|
404 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
405 |
const uint8_t *buf, int buf_size) |
406 |
{ |
407 |
z_stream strm1, *strm = &strm1; |
408 |
int ret, out_len;
|
409 |
|
410 |
memset(strm, 0, sizeof(*strm)); |
411 |
|
412 |
strm->next_in = (uint8_t *)buf; |
413 |
strm->avail_in = buf_size; |
414 |
strm->next_out = out_buf; |
415 |
strm->avail_out = out_buf_size; |
416 |
|
417 |
ret = inflateInit2(strm, -12);
|
418 |
if (ret != Z_OK)
|
419 |
return -1; |
420 |
ret = inflate(strm, Z_FINISH); |
421 |
out_len = strm->next_out - out_buf; |
422 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
423 |
out_len != out_buf_size) { |
424 |
inflateEnd(strm); |
425 |
return -1; |
426 |
} |
427 |
inflateEnd(strm); |
428 |
return 0; |
429 |
} |
430 |
|
431 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
432 |
{ |
433 |
int ret, csize;
|
434 |
uint64_t coffset; |
435 |
|
436 |
coffset = cluster_offset & s->cluster_offset_mask; |
437 |
if (s->cluster_cache_offset != coffset) {
|
438 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
439 |
csize &= (s->cluster_size - 1);
|
440 |
lseek(s->fd, coffset, SEEK_SET); |
441 |
ret = read(s->fd, s->cluster_data, csize); |
442 |
if (ret != csize)
|
443 |
return -1; |
444 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
445 |
s->cluster_data, csize) < 0) {
|
446 |
return -1; |
447 |
} |
448 |
s->cluster_cache_offset = coffset; |
449 |
} |
450 |
return 0; |
451 |
} |
452 |
|
453 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
454 |
uint8_t *buf, int nb_sectors)
|
455 |
{ |
456 |
BDRVQcowState *s = bs->opaque; |
457 |
int ret, index_in_cluster, n;
|
458 |
uint64_t cluster_offset; |
459 |
|
460 |
while (nb_sectors > 0) { |
461 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
462 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
463 |
n = s->cluster_sectors - index_in_cluster; |
464 |
if (n > nb_sectors)
|
465 |
n = nb_sectors; |
466 |
if (!cluster_offset) {
|
467 |
memset(buf, 0, 512 * n); |
468 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
469 |
if (decompress_cluster(s, cluster_offset) < 0) |
470 |
return -1; |
471 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
472 |
} else {
|
473 |
lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
|
474 |
ret = read(s->fd, buf, n * 512);
|
475 |
if (ret != n * 512) |
476 |
return -1; |
477 |
if (s->crypt_method) {
|
478 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
479 |
&s->aes_decrypt_key); |
480 |
} |
481 |
} |
482 |
nb_sectors -= n; |
483 |
sector_num += n; |
484 |
buf += n * 512;
|
485 |
} |
486 |
return 0; |
487 |
} |
488 |
|
489 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
490 |
const uint8_t *buf, int nb_sectors) |
491 |
{ |
492 |
BDRVQcowState *s = bs->opaque; |
493 |
int ret, index_in_cluster, n;
|
494 |
uint64_t cluster_offset; |
495 |
|
496 |
while (nb_sectors > 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 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
502 |
index_in_cluster, |
503 |
index_in_cluster + n); |
504 |
if (!cluster_offset)
|
505 |
return -1; |
506 |
lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
|
507 |
if (s->crypt_method) {
|
508 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
509 |
&s->aes_encrypt_key); |
510 |
ret = write(s->fd, s->cluster_data, n * 512);
|
511 |
} else {
|
512 |
ret = write(s->fd, buf, n * 512);
|
513 |
} |
514 |
if (ret != n * 512) |
515 |
return -1; |
516 |
nb_sectors -= n; |
517 |
sector_num += n; |
518 |
buf += n * 512;
|
519 |
} |
520 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
521 |
return 0; |
522 |
} |
523 |
|
524 |
static void qcow_close(BlockDriverState *bs) |
525 |
{ |
526 |
BDRVQcowState *s = bs->opaque; |
527 |
qemu_free(s->l1_table); |
528 |
qemu_free(s->l2_cache); |
529 |
qemu_free(s->cluster_cache); |
530 |
qemu_free(s->cluster_data); |
531 |
close(s->fd); |
532 |
} |
533 |
|
534 |
static int qcow_create(const char *filename, int64_t total_size, |
535 |
const char *backing_file, int flags) |
536 |
{ |
537 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
538 |
QCowHeader header; |
539 |
char backing_filename[1024]; |
540 |
uint64_t tmp; |
541 |
struct stat st;
|
542 |
|
543 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, |
544 |
0644);
|
545 |
if (fd < 0) |
546 |
return -1; |
547 |
memset(&header, 0, sizeof(header)); |
548 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
549 |
header.version = cpu_to_be32(QCOW_VERSION); |
550 |
header.size = cpu_to_be64(total_size * 512);
|
551 |
header_size = sizeof(header);
|
552 |
backing_filename_len = 0;
|
553 |
if (backing_file) {
|
554 |
realpath(backing_file, backing_filename); |
555 |
if (stat(backing_filename, &st) != 0) { |
556 |
return -1; |
557 |
} |
558 |
header.mtime = cpu_to_be32(st.st_mtime); |
559 |
header.backing_file_offset = cpu_to_be64(header_size); |
560 |
backing_filename_len = strlen(backing_filename); |
561 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
562 |
header_size += backing_filename_len; |
563 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
564 |
unmodifyed sectors */
|
565 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
566 |
} else {
|
567 |
header.cluster_bits = 12; /* 4 KB clusters */ |
568 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
569 |
} |
570 |
header_size = (header_size + 7) & ~7; |
571 |
shift = header.cluster_bits + header.l2_bits; |
572 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
573 |
|
574 |
header.l1_table_offset = cpu_to_be64(header_size); |
575 |
if (flags) {
|
576 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
577 |
} else {
|
578 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
579 |
} |
580 |
|
581 |
/* write all the data */
|
582 |
write(fd, &header, sizeof(header));
|
583 |
if (backing_file) {
|
584 |
write(fd, backing_filename, backing_filename_len); |
585 |
} |
586 |
lseek(fd, header_size, SEEK_SET); |
587 |
tmp = 0;
|
588 |
for(i = 0;i < l1_size; i++) { |
589 |
write(fd, &tmp, sizeof(tmp));
|
590 |
} |
591 |
close(fd); |
592 |
return 0; |
593 |
} |
594 |
|
595 |
int qcow_get_cluster_size(BlockDriverState *bs)
|
596 |
{ |
597 |
BDRVQcowState *s = bs->opaque; |
598 |
if (bs->drv != &bdrv_qcow)
|
599 |
return -1; |
600 |
return s->cluster_size;
|
601 |
} |
602 |
|
603 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
604 |
tables to avoid losing bytes in alignment */
|
605 |
int qcow_compress_cluster(BlockDriverState *bs, int64_t sector_num,
|
606 |
const uint8_t *buf)
|
607 |
{ |
608 |
BDRVQcowState *s = bs->opaque; |
609 |
z_stream strm; |
610 |
int ret, out_len;
|
611 |
uint8_t *out_buf; |
612 |
uint64_t cluster_offset; |
613 |
|
614 |
if (bs->drv != &bdrv_qcow)
|
615 |
return -1; |
616 |
|
617 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
618 |
if (!out_buf)
|
619 |
return -1; |
620 |
|
621 |
/* best compression, small window, no zlib header */
|
622 |
memset(&strm, 0, sizeof(strm)); |
623 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
624 |
Z_DEFLATED, -12,
|
625 |
9, Z_DEFAULT_STRATEGY);
|
626 |
if (ret != 0) { |
627 |
qemu_free(out_buf); |
628 |
return -1; |
629 |
} |
630 |
|
631 |
strm.avail_in = s->cluster_size; |
632 |
strm.next_in = (uint8_t *)buf; |
633 |
strm.avail_out = s->cluster_size; |
634 |
strm.next_out = out_buf; |
635 |
|
636 |
ret = deflate(&strm, Z_FINISH); |
637 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
638 |
qemu_free(out_buf); |
639 |
deflateEnd(&strm); |
640 |
return -1; |
641 |
} |
642 |
out_len = strm.next_out - out_buf; |
643 |
|
644 |
deflateEnd(&strm); |
645 |
|
646 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
647 |
/* could not compress: write normal cluster */
|
648 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
649 |
} else {
|
650 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
651 |
out_len, 0, 0); |
652 |
cluster_offset &= s->cluster_offset_mask; |
653 |
lseek(s->fd, cluster_offset, SEEK_SET); |
654 |
if (write(s->fd, out_buf, out_len) != out_len) {
|
655 |
qemu_free(out_buf); |
656 |
return -1; |
657 |
} |
658 |
} |
659 |
|
660 |
qemu_free(out_buf); |
661 |
return 0; |
662 |
} |
663 |
|
664 |
BlockDriver bdrv_qcow = { |
665 |
"qcow",
|
666 |
sizeof(BDRVQcowState),
|
667 |
qcow_probe, |
668 |
qcow_open, |
669 |
qcow_read, |
670 |
qcow_write, |
671 |
qcow_close, |
672 |
qcow_create, |
673 |
qcow_is_allocated, |
674 |
qcow_set_key, |
675 |
}; |
676 |
|
677 |
|