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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
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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> |
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#include "aes.h" |
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|
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/**************************************************************/
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/* QEMU COW block driver with compression and encryption support */
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|
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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#define QCOW_VERSION 1 |
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|
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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 { |
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BlockDriverState *hd; |
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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); |
79 |
|
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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 (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; |
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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, int flags) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int len, i, shift, ret;
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QCowHeader header; |
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|
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ret = bdrv_file_open(&s->hd, filename, flags); |
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if (ret < 0) |
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return ret;
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if (bdrv_pread(s->hd, 0, &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); |
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|
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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; |
119 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
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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; |
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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; |
128 |
|
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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; |
132 |
|
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s->l1_table_offset = header.l1_table_offset; |
134 |
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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if (bdrv_pread(s->hd, s->l1_table_offset, 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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} |
143 |
/* 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); |
148 |
if (!s->cluster_cache)
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goto fail;
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s->cluster_data = qemu_malloc(s->cluster_size); |
151 |
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) { |
157 |
len = header.backing_file_size; |
158 |
if (len > 1023) |
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len = 1023;
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if (bdrv_pread(s->hd, header.backing_file_offset, 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; |
165 |
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fail:
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qemu_free(s->l1_table); |
168 |
qemu_free(s->l2_cache); |
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qemu_free(s->cluster_cache); |
170 |
qemu_free(s->cluster_data); |
171 |
bdrv_delete(s->hd); |
172 |
return -1; |
173 |
} |
174 |
|
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static int qcow_set_key(BlockDriverState *bs, const char *key) |
176 |
{ |
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BDRVQcowState *s = bs->opaque; |
178 |
uint8_t keybuf[16];
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int len, i;
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|
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memset(keybuf, 0, 16); |
182 |
len = strlen(key); |
183 |
if (len > 16) |
184 |
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]; |
189 |
} |
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s->crypt_method = s->crypt_method_header; |
191 |
|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
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return -1; |
194 |
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; |
215 |
} |
216 |
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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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{ |
225 |
union {
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uint64_t ll[2];
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uint8_t b[16];
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} ivec; |
229 |
int i;
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230 |
|
231 |
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; |
234 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
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ivec.b, enc); |
236 |
sector_num++; |
237 |
in_buf += 512;
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out_buf += 512;
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} |
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} |
241 |
|
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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) |
259 |
{ |
260 |
BDRVQcowState *s = bs->opaque; |
261 |
int min_index, i, j, l1_index, l2_index;
|
262 |
uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
263 |
uint32_t min_count; |
264 |
int new_l2_table;
|
265 |
|
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l1_index = offset >> (s->l2_bits + s->cluster_bits); |
267 |
l2_offset = s->l1_table[l1_index]; |
268 |
new_l2_table = 0;
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269 |
if (!l2_offset) {
|
270 |
if (!allocate)
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271 |
return 0; |
272 |
/* allocate a new l2 entry */
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273 |
l2_offset = bdrv_getlength(s->hd); |
274 |
/* round to cluster size */
|
275 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
276 |
/* update the L1 entry */
|
277 |
s->l1_table[l1_index] = l2_offset; |
278 |
tmp = cpu_to_be64(l2_offset); |
279 |
if (bdrv_pwrite(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), |
280 |
&tmp, sizeof(tmp)) != sizeof(tmp)) |
281 |
return 0; |
282 |
new_l2_table = 1;
|
283 |
} |
284 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
285 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
286 |
/* increment the hit count */
|
287 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
288 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
289 |
s->l2_cache_counts[j] >>= 1;
|
290 |
} |
291 |
} |
292 |
l2_table = s->l2_cache + (i << s->l2_bits); |
293 |
goto found;
|
294 |
} |
295 |
} |
296 |
/* not found: load a new entry in the least used one */
|
297 |
min_index = 0;
|
298 |
min_count = 0xffffffff;
|
299 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
300 |
if (s->l2_cache_counts[i] < min_count) {
|
301 |
min_count = s->l2_cache_counts[i]; |
302 |
min_index = i; |
303 |
} |
304 |
} |
305 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
306 |
if (new_l2_table) {
|
307 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
308 |
if (bdrv_pwrite(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
309 |
s->l2_size * sizeof(uint64_t))
|
310 |
return 0; |
311 |
} else {
|
312 |
if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
313 |
s->l2_size * sizeof(uint64_t))
|
314 |
return 0; |
315 |
} |
316 |
s->l2_cache_offsets[min_index] = l2_offset; |
317 |
s->l2_cache_counts[min_index] = 1;
|
318 |
found:
|
319 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
320 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
321 |
if (!cluster_offset ||
|
322 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
323 |
if (!allocate)
|
324 |
return 0; |
325 |
/* allocate a new cluster */
|
326 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
327 |
(n_end - n_start) < s->cluster_sectors) { |
328 |
/* if the cluster is already compressed, we must
|
329 |
decompress it in the case it is not completely
|
330 |
overwritten */
|
331 |
if (decompress_cluster(s, cluster_offset) < 0) |
332 |
return 0; |
333 |
cluster_offset = bdrv_getlength(s->hd); |
334 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
335 |
~(s->cluster_size - 1);
|
336 |
/* write the cluster content */
|
337 |
if (bdrv_pwrite(s->hd, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
338 |
s->cluster_size) |
339 |
return -1; |
340 |
} else {
|
341 |
cluster_offset = bdrv_getlength(s->hd); |
342 |
if (allocate == 1) { |
343 |
/* round to cluster size */
|
344 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
345 |
~(s->cluster_size - 1);
|
346 |
bdrv_truncate(s->hd, cluster_offset + s->cluster_size); |
347 |
/* if encrypted, we must initialize the cluster
|
348 |
content which won't be written */
|
349 |
if (s->crypt_method &&
|
350 |
(n_end - n_start) < s->cluster_sectors) { |
351 |
uint64_t start_sect; |
352 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
353 |
memset(s->cluster_data + 512, 0x00, 512); |
354 |
for(i = 0; i < s->cluster_sectors; i++) { |
355 |
if (i < n_start || i >= n_end) {
|
356 |
encrypt_sectors(s, start_sect + i, |
357 |
s->cluster_data, |
358 |
s->cluster_data + 512, 1, 1, |
359 |
&s->aes_encrypt_key); |
360 |
if (bdrv_pwrite(s->hd, cluster_offset + i * 512, |
361 |
s->cluster_data, 512) != 512) |
362 |
return -1; |
363 |
} |
364 |
} |
365 |
} |
366 |
} else {
|
367 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
368 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
369 |
} |
370 |
} |
371 |
/* update L2 table */
|
372 |
tmp = cpu_to_be64(cluster_offset); |
373 |
l2_table[l2_index] = tmp; |
374 |
if (bdrv_pwrite(s->hd,
|
375 |
l2_offset + l2_index * sizeof(tmp), &tmp, sizeof(tmp)) != sizeof(tmp)) |
376 |
return 0; |
377 |
} |
378 |
return cluster_offset;
|
379 |
} |
380 |
|
381 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
382 |
int nb_sectors, int *pnum) |
383 |
{ |
384 |
BDRVQcowState *s = bs->opaque; |
385 |
int index_in_cluster, n;
|
386 |
uint64_t cluster_offset; |
387 |
|
388 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
389 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
390 |
n = s->cluster_sectors - index_in_cluster; |
391 |
if (n > nb_sectors)
|
392 |
n = nb_sectors; |
393 |
*pnum = n; |
394 |
return (cluster_offset != 0); |
395 |
} |
396 |
|
397 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
398 |
const uint8_t *buf, int buf_size) |
399 |
{ |
400 |
z_stream strm1, *strm = &strm1; |
401 |
int ret, out_len;
|
402 |
|
403 |
memset(strm, 0, sizeof(*strm)); |
404 |
|
405 |
strm->next_in = (uint8_t *)buf; |
406 |
strm->avail_in = buf_size; |
407 |
strm->next_out = out_buf; |
408 |
strm->avail_out = out_buf_size; |
409 |
|
410 |
ret = inflateInit2(strm, -12);
|
411 |
if (ret != Z_OK)
|
412 |
return -1; |
413 |
ret = inflate(strm, Z_FINISH); |
414 |
out_len = strm->next_out - out_buf; |
415 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
416 |
out_len != out_buf_size) { |
417 |
inflateEnd(strm); |
418 |
return -1; |
419 |
} |
420 |
inflateEnd(strm); |
421 |
return 0; |
422 |
} |
423 |
|
424 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
425 |
{ |
426 |
int ret, csize;
|
427 |
uint64_t coffset; |
428 |
|
429 |
coffset = cluster_offset & s->cluster_offset_mask; |
430 |
if (s->cluster_cache_offset != coffset) {
|
431 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
432 |
csize &= (s->cluster_size - 1);
|
433 |
ret = bdrv_pread(s->hd, coffset, s->cluster_data, csize); |
434 |
if (ret != csize)
|
435 |
return -1; |
436 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
437 |
s->cluster_data, csize) < 0) {
|
438 |
return -1; |
439 |
} |
440 |
s->cluster_cache_offset = coffset; |
441 |
} |
442 |
return 0; |
443 |
} |
444 |
|
445 |
#if 0
|
446 |
|
447 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num,
|
448 |
uint8_t *buf, int nb_sectors)
|
449 |
{
|
450 |
BDRVQcowState *s = bs->opaque;
|
451 |
int ret, index_in_cluster, n;
|
452 |
uint64_t cluster_offset;
|
453 |
|
454 |
while (nb_sectors > 0) {
|
455 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
|
456 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
457 |
n = s->cluster_sectors - index_in_cluster;
|
458 |
if (n > nb_sectors)
|
459 |
n = nb_sectors;
|
460 |
if (!cluster_offset) {
|
461 |
if (bs->backing_hd) {
|
462 |
/* read from the base image */
|
463 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
|
464 |
if (ret < 0)
|
465 |
return -1;
|
466 |
} else {
|
467 |
memset(buf, 0, 512 * n);
|
468 |
}
|
469 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
470 |
if (decompress_cluster(s, cluster_offset) < 0)
|
471 |
return -1;
|
472 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
|
473 |
} else {
|
474 |
ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, 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 |
#endif
|
489 |
|
490 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
491 |
const uint8_t *buf, int nb_sectors) |
492 |
{ |
493 |
BDRVQcowState *s = bs->opaque; |
494 |
int ret, index_in_cluster, n;
|
495 |
uint64_t cluster_offset; |
496 |
|
497 |
while (nb_sectors > 0) { |
498 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
499 |
n = s->cluster_sectors - index_in_cluster; |
500 |
if (n > nb_sectors)
|
501 |
n = nb_sectors; |
502 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
503 |
index_in_cluster, |
504 |
index_in_cluster + n); |
505 |
if (!cluster_offset)
|
506 |
return -1; |
507 |
if (s->crypt_method) {
|
508 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
509 |
&s->aes_encrypt_key); |
510 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512,
|
511 |
s->cluster_data, n * 512);
|
512 |
} else {
|
513 |
ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); |
514 |
} |
515 |
if (ret != n * 512) |
516 |
return -1; |
517 |
nb_sectors -= n; |
518 |
sector_num += n; |
519 |
buf += n * 512;
|
520 |
} |
521 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
522 |
return 0; |
523 |
} |
524 |
|
525 |
typedef struct QCowAIOCB { |
526 |
BlockDriverAIOCB common; |
527 |
int64_t sector_num; |
528 |
uint8_t *buf; |
529 |
int nb_sectors;
|
530 |
int n;
|
531 |
uint64_t cluster_offset; |
532 |
uint8_t *cluster_data; |
533 |
BlockDriverAIOCB *hd_aiocb; |
534 |
} QCowAIOCB; |
535 |
|
536 |
static void qcow_aio_read_cb(void *opaque, int ret) |
537 |
{ |
538 |
QCowAIOCB *acb = opaque; |
539 |
BlockDriverState *bs = acb->common.bs; |
540 |
BDRVQcowState *s = bs->opaque; |
541 |
int index_in_cluster;
|
542 |
|
543 |
acb->hd_aiocb = NULL;
|
544 |
if (ret < 0) { |
545 |
fail:
|
546 |
acb->common.cb(acb->common.opaque, ret); |
547 |
qemu_aio_release(acb); |
548 |
return;
|
549 |
} |
550 |
|
551 |
redo:
|
552 |
/* post process the read buffer */
|
553 |
if (!acb->cluster_offset) {
|
554 |
/* nothing to do */
|
555 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
556 |
/* nothing to do */
|
557 |
} else {
|
558 |
if (s->crypt_method) {
|
559 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
560 |
acb->n, 0,
|
561 |
&s->aes_decrypt_key); |
562 |
} |
563 |
} |
564 |
|
565 |
acb->nb_sectors -= acb->n; |
566 |
acb->sector_num += acb->n; |
567 |
acb->buf += acb->n * 512;
|
568 |
|
569 |
if (acb->nb_sectors == 0) { |
570 |
/* request completed */
|
571 |
acb->common.cb(acb->common.opaque, 0);
|
572 |
qemu_aio_release(acb); |
573 |
return;
|
574 |
} |
575 |
|
576 |
/* prepare next AIO request */
|
577 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
|
578 |
0, 0, 0, 0); |
579 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
580 |
acb->n = s->cluster_sectors - index_in_cluster; |
581 |
if (acb->n > acb->nb_sectors)
|
582 |
acb->n = acb->nb_sectors; |
583 |
|
584 |
if (!acb->cluster_offset) {
|
585 |
if (bs->backing_hd) {
|
586 |
/* read from the base image */
|
587 |
acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, |
588 |
acb->sector_num, acb->buf, acb->n, qcow_aio_read_cb, acb); |
589 |
if (acb->hd_aiocb == NULL) |
590 |
goto fail;
|
591 |
} else {
|
592 |
/* Note: in this case, no need to wait */
|
593 |
memset(acb->buf, 0, 512 * acb->n); |
594 |
goto redo;
|
595 |
} |
596 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
597 |
/* add AIO support for compressed blocks ? */
|
598 |
if (decompress_cluster(s, acb->cluster_offset) < 0) |
599 |
goto fail;
|
600 |
memcpy(acb->buf, |
601 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
602 |
goto redo;
|
603 |
} else {
|
604 |
if ((acb->cluster_offset & 511) != 0) { |
605 |
ret = -EIO; |
606 |
goto fail;
|
607 |
} |
608 |
acb->hd_aiocb = bdrv_aio_read(s->hd, |
609 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
610 |
acb->buf, acb->n, qcow_aio_read_cb, acb); |
611 |
if (acb->hd_aiocb == NULL) |
612 |
goto fail;
|
613 |
} |
614 |
} |
615 |
|
616 |
static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs,
|
617 |
int64_t sector_num, uint8_t *buf, int nb_sectors,
|
618 |
BlockDriverCompletionFunc *cb, void *opaque)
|
619 |
{ |
620 |
QCowAIOCB *acb; |
621 |
|
622 |
acb = qemu_aio_get(bs, cb, opaque); |
623 |
if (!acb)
|
624 |
return NULL; |
625 |
acb->hd_aiocb = NULL;
|
626 |
acb->sector_num = sector_num; |
627 |
acb->buf = buf; |
628 |
acb->nb_sectors = nb_sectors; |
629 |
acb->n = 0;
|
630 |
acb->cluster_offset = 0;
|
631 |
|
632 |
qcow_aio_read_cb(acb, 0);
|
633 |
return &acb->common;
|
634 |
} |
635 |
|
636 |
static void qcow_aio_write_cb(void *opaque, int ret) |
637 |
{ |
638 |
QCowAIOCB *acb = opaque; |
639 |
BlockDriverState *bs = acb->common.bs; |
640 |
BDRVQcowState *s = bs->opaque; |
641 |
int index_in_cluster;
|
642 |
uint64_t cluster_offset; |
643 |
const uint8_t *src_buf;
|
644 |
|
645 |
acb->hd_aiocb = NULL;
|
646 |
|
647 |
if (ret < 0) { |
648 |
fail:
|
649 |
acb->common.cb(acb->common.opaque, ret); |
650 |
qemu_aio_release(acb); |
651 |
return;
|
652 |
} |
653 |
|
654 |
acb->nb_sectors -= acb->n; |
655 |
acb->sector_num += acb->n; |
656 |
acb->buf += acb->n * 512;
|
657 |
|
658 |
if (acb->nb_sectors == 0) { |
659 |
/* request completed */
|
660 |
acb->common.cb(acb->common.opaque, 0);
|
661 |
qemu_aio_release(acb); |
662 |
return;
|
663 |
} |
664 |
|
665 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
666 |
acb->n = s->cluster_sectors - index_in_cluster; |
667 |
if (acb->n > acb->nb_sectors)
|
668 |
acb->n = acb->nb_sectors; |
669 |
cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0, |
670 |
index_in_cluster, |
671 |
index_in_cluster + acb->n); |
672 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
673 |
ret = -EIO; |
674 |
goto fail;
|
675 |
} |
676 |
if (s->crypt_method) {
|
677 |
if (!acb->cluster_data) {
|
678 |
acb->cluster_data = qemu_mallocz(s->cluster_size); |
679 |
if (!acb->cluster_data) {
|
680 |
ret = -ENOMEM; |
681 |
goto fail;
|
682 |
} |
683 |
} |
684 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
685 |
acb->n, 1, &s->aes_encrypt_key);
|
686 |
src_buf = acb->cluster_data; |
687 |
} else {
|
688 |
src_buf = acb->buf; |
689 |
} |
690 |
acb->hd_aiocb = bdrv_aio_write(s->hd, |
691 |
(cluster_offset >> 9) + index_in_cluster,
|
692 |
src_buf, acb->n, |
693 |
qcow_aio_write_cb, acb); |
694 |
if (acb->hd_aiocb == NULL) |
695 |
goto fail;
|
696 |
} |
697 |
|
698 |
static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs,
|
699 |
int64_t sector_num, const uint8_t *buf, int nb_sectors, |
700 |
BlockDriverCompletionFunc *cb, void *opaque)
|
701 |
{ |
702 |
BDRVQcowState *s = bs->opaque; |
703 |
QCowAIOCB *acb; |
704 |
|
705 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
706 |
|
707 |
acb = qemu_aio_get(bs, cb, opaque); |
708 |
if (!acb)
|
709 |
return NULL; |
710 |
acb->hd_aiocb = NULL;
|
711 |
acb->sector_num = sector_num; |
712 |
acb->buf = (uint8_t *)buf; |
713 |
acb->nb_sectors = nb_sectors; |
714 |
acb->n = 0;
|
715 |
|
716 |
qcow_aio_write_cb(acb, 0);
|
717 |
return &acb->common;
|
718 |
} |
719 |
|
720 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
721 |
{ |
722 |
QCowAIOCB *acb = (QCowAIOCB *)blockacb; |
723 |
if (acb->hd_aiocb)
|
724 |
bdrv_aio_cancel(acb->hd_aiocb); |
725 |
qemu_aio_release(acb); |
726 |
} |
727 |
|
728 |
static void qcow_close(BlockDriverState *bs) |
729 |
{ |
730 |
BDRVQcowState *s = bs->opaque; |
731 |
qemu_free(s->l1_table); |
732 |
qemu_free(s->l2_cache); |
733 |
qemu_free(s->cluster_cache); |
734 |
qemu_free(s->cluster_data); |
735 |
bdrv_delete(s->hd); |
736 |
} |
737 |
|
738 |
static int qcow_create(const char *filename, int64_t total_size, |
739 |
const char *backing_file, int flags) |
740 |
{ |
741 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
742 |
QCowHeader header; |
743 |
uint64_t tmp; |
744 |
|
745 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
746 |
if (fd < 0) |
747 |
return -1; |
748 |
memset(&header, 0, sizeof(header)); |
749 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
750 |
header.version = cpu_to_be32(QCOW_VERSION); |
751 |
header.size = cpu_to_be64(total_size * 512);
|
752 |
header_size = sizeof(header);
|
753 |
backing_filename_len = 0;
|
754 |
if (backing_file) {
|
755 |
header.backing_file_offset = cpu_to_be64(header_size); |
756 |
backing_filename_len = strlen(backing_file); |
757 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
758 |
header_size += backing_filename_len; |
759 |
header.mtime = cpu_to_be32(0);
|
760 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
761 |
unmodifyed sectors */
|
762 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
763 |
} else {
|
764 |
header.cluster_bits = 12; /* 4 KB clusters */ |
765 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
766 |
} |
767 |
header_size = (header_size + 7) & ~7; |
768 |
shift = header.cluster_bits + header.l2_bits; |
769 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
770 |
|
771 |
header.l1_table_offset = cpu_to_be64(header_size); |
772 |
if (flags) {
|
773 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
774 |
} else {
|
775 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
776 |
} |
777 |
|
778 |
/* write all the data */
|
779 |
write(fd, &header, sizeof(header));
|
780 |
if (backing_file) {
|
781 |
write(fd, backing_file, backing_filename_len); |
782 |
} |
783 |
lseek(fd, header_size, SEEK_SET); |
784 |
tmp = 0;
|
785 |
for(i = 0;i < l1_size; i++) { |
786 |
write(fd, &tmp, sizeof(tmp));
|
787 |
} |
788 |
close(fd); |
789 |
return 0; |
790 |
} |
791 |
|
792 |
static int qcow_make_empty(BlockDriverState *bs) |
793 |
{ |
794 |
BDRVQcowState *s = bs->opaque; |
795 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
796 |
int ret;
|
797 |
|
798 |
memset(s->l1_table, 0, l1_length);
|
799 |
if (bdrv_pwrite(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) |
800 |
return -1; |
801 |
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length); |
802 |
if (ret < 0) |
803 |
return ret;
|
804 |
|
805 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
806 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
807 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
808 |
|
809 |
return 0; |
810 |
} |
811 |
|
812 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
813 |
tables to avoid losing bytes in alignment */
|
814 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
815 |
const uint8_t *buf, int nb_sectors) |
816 |
{ |
817 |
BDRVQcowState *s = bs->opaque; |
818 |
z_stream strm; |
819 |
int ret, out_len;
|
820 |
uint8_t *out_buf; |
821 |
uint64_t cluster_offset; |
822 |
|
823 |
if (nb_sectors != s->cluster_sectors)
|
824 |
return -EINVAL;
|
825 |
|
826 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
827 |
if (!out_buf)
|
828 |
return -1; |
829 |
|
830 |
/* best compression, small window, no zlib header */
|
831 |
memset(&strm, 0, sizeof(strm)); |
832 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
833 |
Z_DEFLATED, -12,
|
834 |
9, Z_DEFAULT_STRATEGY);
|
835 |
if (ret != 0) { |
836 |
qemu_free(out_buf); |
837 |
return -1; |
838 |
} |
839 |
|
840 |
strm.avail_in = s->cluster_size; |
841 |
strm.next_in = (uint8_t *)buf; |
842 |
strm.avail_out = s->cluster_size; |
843 |
strm.next_out = out_buf; |
844 |
|
845 |
ret = deflate(&strm, Z_FINISH); |
846 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
847 |
qemu_free(out_buf); |
848 |
deflateEnd(&strm); |
849 |
return -1; |
850 |
} |
851 |
out_len = strm.next_out - out_buf; |
852 |
|
853 |
deflateEnd(&strm); |
854 |
|
855 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
856 |
/* could not compress: write normal cluster */
|
857 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
858 |
} else {
|
859 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
860 |
out_len, 0, 0); |
861 |
cluster_offset &= s->cluster_offset_mask; |
862 |
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
863 |
qemu_free(out_buf); |
864 |
return -1; |
865 |
} |
866 |
} |
867 |
|
868 |
qemu_free(out_buf); |
869 |
return 0; |
870 |
} |
871 |
|
872 |
static void qcow_flush(BlockDriverState *bs) |
873 |
{ |
874 |
BDRVQcowState *s = bs->opaque; |
875 |
bdrv_flush(s->hd); |
876 |
} |
877 |
|
878 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
879 |
{ |
880 |
BDRVQcowState *s = bs->opaque; |
881 |
bdi->cluster_size = s->cluster_size; |
882 |
return 0; |
883 |
} |
884 |
|
885 |
BlockDriver bdrv_qcow = { |
886 |
"qcow",
|
887 |
sizeof(BDRVQcowState),
|
888 |
qcow_probe, |
889 |
qcow_open, |
890 |
NULL,
|
891 |
NULL,
|
892 |
qcow_close, |
893 |
qcow_create, |
894 |
qcow_flush, |
895 |
qcow_is_allocated, |
896 |
qcow_set_key, |
897 |
qcow_make_empty, |
898 |
|
899 |
.bdrv_aio_read = qcow_aio_read, |
900 |
.bdrv_aio_write = qcow_aio_write, |
901 |
.bdrv_aio_cancel = qcow_aio_cancel, |
902 |
.aiocb_size = sizeof(QCowAIOCB),
|
903 |
.bdrv_write_compressed = qcow_write_compressed, |
904 |
.bdrv_get_info = qcow_get_info, |
905 |
}; |