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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 "qemu-common.h" |
25 |
#include "block_int.h" |
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#include "module.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 |
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|
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#define QCOW_OFLAG_COMPRESSED (1LL << 63) |
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|
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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; |
46 |
uint32_t mtime; |
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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; |
53 |
|
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#define L2_CACHE_SIZE 16 |
55 |
|
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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; |
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|
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static int decompress_cluster(BlockDriverState *bs, 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 (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, int flags) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int len, i, shift;
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QCowHeader header; |
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if (bdrv_pread(bs->file, 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; |
117 |
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; |
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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; |
130 |
|
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s->l1_table_offset = header.l1_table_offset; |
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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(bs->file, 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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} |
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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); |
146 |
if (!s->cluster_cache)
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goto fail;
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s->cluster_data = qemu_malloc(s->cluster_size); |
149 |
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; |
156 |
if (len > 1023) |
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len = 1023;
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if (bdrv_pread(bs->file, 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; |
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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); |
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qemu_free(s->cluster_data); |
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return -1; |
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} |
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|
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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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memset(keybuf, 0, 16); |
179 |
len = strlen(key); |
180 |
if (len > 16) |
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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]; |
186 |
} |
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s->crypt_method = s->crypt_method_header; |
188 |
|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
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return -1; |
191 |
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; |
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} |
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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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{ |
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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; |
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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; |
231 |
AES_cbc_encrypt(in_buf, out_buf, 512, key,
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ivec.b, enc); |
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sector_num++; |
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in_buf += 512;
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out_buf += 512;
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} |
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} |
238 |
|
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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) |
256 |
{ |
257 |
BDRVQcowState *s = bs->opaque; |
258 |
int min_index, i, j, l1_index, l2_index;
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uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
260 |
uint32_t min_count; |
261 |
int new_l2_table;
|
262 |
|
263 |
l1_index = offset >> (s->l2_bits + s->cluster_bits); |
264 |
l2_offset = s->l1_table[l1_index]; |
265 |
new_l2_table = 0;
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266 |
if (!l2_offset) {
|
267 |
if (!allocate)
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return 0; |
269 |
/* allocate a new l2 entry */
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270 |
l2_offset = bdrv_getlength(bs->file); |
271 |
/* round to cluster size */
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272 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
273 |
/* update the L1 entry */
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274 |
s->l1_table[l1_index] = l2_offset; |
275 |
tmp = cpu_to_be64(l2_offset); |
276 |
if (bdrv_pwrite_sync(bs->file,
|
277 |
s->l1_table_offset + l1_index * sizeof(tmp),
|
278 |
&tmp, sizeof(tmp)) < 0) |
279 |
return 0; |
280 |
new_l2_table = 1;
|
281 |
} |
282 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
283 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
284 |
/* increment the hit count */
|
285 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
286 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
287 |
s->l2_cache_counts[j] >>= 1;
|
288 |
} |
289 |
} |
290 |
l2_table = s->l2_cache + (i << s->l2_bits); |
291 |
goto found;
|
292 |
} |
293 |
} |
294 |
/* not found: load a new entry in the least used one */
|
295 |
min_index = 0;
|
296 |
min_count = 0xffffffff;
|
297 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
298 |
if (s->l2_cache_counts[i] < min_count) {
|
299 |
min_count = s->l2_cache_counts[i]; |
300 |
min_index = i; |
301 |
} |
302 |
} |
303 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
304 |
if (new_l2_table) {
|
305 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
306 |
if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
|
307 |
s->l2_size * sizeof(uint64_t)) < 0) |
308 |
return 0; |
309 |
} else {
|
310 |
if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
311 |
s->l2_size * sizeof(uint64_t))
|
312 |
return 0; |
313 |
} |
314 |
s->l2_cache_offsets[min_index] = l2_offset; |
315 |
s->l2_cache_counts[min_index] = 1;
|
316 |
found:
|
317 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
318 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
319 |
if (!cluster_offset ||
|
320 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
321 |
if (!allocate)
|
322 |
return 0; |
323 |
/* allocate a new cluster */
|
324 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
325 |
(n_end - n_start) < s->cluster_sectors) { |
326 |
/* if the cluster is already compressed, we must
|
327 |
decompress it in the case it is not completely
|
328 |
overwritten */
|
329 |
if (decompress_cluster(bs, cluster_offset) < 0) |
330 |
return 0; |
331 |
cluster_offset = bdrv_getlength(bs->file); |
332 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
333 |
~(s->cluster_size - 1);
|
334 |
/* write the cluster content */
|
335 |
if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
336 |
s->cluster_size) |
337 |
return -1; |
338 |
} else {
|
339 |
cluster_offset = bdrv_getlength(bs->file); |
340 |
if (allocate == 1) { |
341 |
/* round to cluster size */
|
342 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
343 |
~(s->cluster_size - 1);
|
344 |
bdrv_truncate(bs->file, cluster_offset + s->cluster_size); |
345 |
/* if encrypted, we must initialize the cluster
|
346 |
content which won't be written */
|
347 |
if (s->crypt_method &&
|
348 |
(n_end - n_start) < s->cluster_sectors) { |
349 |
uint64_t start_sect; |
350 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
351 |
memset(s->cluster_data + 512, 0x00, 512); |
352 |
for(i = 0; i < s->cluster_sectors; i++) { |
353 |
if (i < n_start || i >= n_end) {
|
354 |
encrypt_sectors(s, start_sect + i, |
355 |
s->cluster_data, |
356 |
s->cluster_data + 512, 1, 1, |
357 |
&s->aes_encrypt_key); |
358 |
if (bdrv_pwrite(bs->file, cluster_offset + i * 512, |
359 |
s->cluster_data, 512) != 512) |
360 |
return -1; |
361 |
} |
362 |
} |
363 |
} |
364 |
} else if (allocate == 2) { |
365 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
366 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
367 |
} |
368 |
} |
369 |
/* update L2 table */
|
370 |
tmp = cpu_to_be64(cluster_offset); |
371 |
l2_table[l2_index] = tmp; |
372 |
if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), |
373 |
&tmp, sizeof(tmp)) < 0) |
374 |
return 0; |
375 |
} |
376 |
return cluster_offset;
|
377 |
} |
378 |
|
379 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
380 |
int nb_sectors, int *pnum) |
381 |
{ |
382 |
BDRVQcowState *s = bs->opaque; |
383 |
int index_in_cluster, n;
|
384 |
uint64_t cluster_offset; |
385 |
|
386 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
387 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
388 |
n = s->cluster_sectors - index_in_cluster; |
389 |
if (n > nb_sectors)
|
390 |
n = nb_sectors; |
391 |
*pnum = n; |
392 |
return (cluster_offset != 0); |
393 |
} |
394 |
|
395 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
396 |
const uint8_t *buf, int buf_size) |
397 |
{ |
398 |
z_stream strm1, *strm = &strm1; |
399 |
int ret, out_len;
|
400 |
|
401 |
memset(strm, 0, sizeof(*strm)); |
402 |
|
403 |
strm->next_in = (uint8_t *)buf; |
404 |
strm->avail_in = buf_size; |
405 |
strm->next_out = out_buf; |
406 |
strm->avail_out = out_buf_size; |
407 |
|
408 |
ret = inflateInit2(strm, -12);
|
409 |
if (ret != Z_OK)
|
410 |
return -1; |
411 |
ret = inflate(strm, Z_FINISH); |
412 |
out_len = strm->next_out - out_buf; |
413 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
414 |
out_len != out_buf_size) { |
415 |
inflateEnd(strm); |
416 |
return -1; |
417 |
} |
418 |
inflateEnd(strm); |
419 |
return 0; |
420 |
} |
421 |
|
422 |
static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) |
423 |
{ |
424 |
BDRVQcowState *s = bs->opaque; |
425 |
int ret, csize;
|
426 |
uint64_t coffset; |
427 |
|
428 |
coffset = cluster_offset & s->cluster_offset_mask; |
429 |
if (s->cluster_cache_offset != coffset) {
|
430 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
431 |
csize &= (s->cluster_size - 1);
|
432 |
ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize); |
433 |
if (ret != csize)
|
434 |
return -1; |
435 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
436 |
s->cluster_data, csize) < 0) {
|
437 |
return -1; |
438 |
} |
439 |
s->cluster_cache_offset = coffset; |
440 |
} |
441 |
return 0; |
442 |
} |
443 |
|
444 |
#if 0
|
445 |
|
446 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num,
|
447 |
uint8_t *buf, int nb_sectors)
|
448 |
{
|
449 |
BDRVQcowState *s = bs->opaque;
|
450 |
int ret, index_in_cluster, n;
|
451 |
uint64_t cluster_offset;
|
452 |
|
453 |
while (nb_sectors > 0) {
|
454 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
|
455 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
456 |
n = s->cluster_sectors - index_in_cluster;
|
457 |
if (n > nb_sectors)
|
458 |
n = nb_sectors;
|
459 |
if (!cluster_offset) {
|
460 |
if (bs->backing_hd) {
|
461 |
/* read from the base image */
|
462 |
ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
|
463 |
if (ret < 0)
|
464 |
return -1;
|
465 |
} else {
|
466 |
memset(buf, 0, 512 * n);
|
467 |
}
|
468 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
469 |
if (decompress_cluster(bs, cluster_offset) < 0)
|
470 |
return -1;
|
471 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
|
472 |
} else {
|
473 |
ret = bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512);
|
474 |
if (ret != n * 512)
|
475 |
return -1;
|
476 |
if (s->crypt_method) {
|
477 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
478 |
&s->aes_decrypt_key);
|
479 |
}
|
480 |
}
|
481 |
nb_sectors -= n;
|
482 |
sector_num += n;
|
483 |
buf += n * 512;
|
484 |
}
|
485 |
return 0;
|
486 |
}
|
487 |
#endif
|
488 |
|
489 |
typedef struct QCowAIOCB { |
490 |
BlockDriverAIOCB common; |
491 |
int64_t sector_num; |
492 |
QEMUIOVector *qiov; |
493 |
uint8_t *buf; |
494 |
void *orig_buf;
|
495 |
int nb_sectors;
|
496 |
int n;
|
497 |
uint64_t cluster_offset; |
498 |
uint8_t *cluster_data; |
499 |
struct iovec hd_iov;
|
500 |
QEMUIOVector hd_qiov; |
501 |
BlockDriverAIOCB *hd_aiocb; |
502 |
} QCowAIOCB; |
503 |
|
504 |
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) |
505 |
{ |
506 |
QCowAIOCB *acb = container_of(blockacb, QCowAIOCB, common); |
507 |
if (acb->hd_aiocb)
|
508 |
bdrv_aio_cancel(acb->hd_aiocb); |
509 |
qemu_aio_release(acb); |
510 |
} |
511 |
|
512 |
static AIOPool qcow_aio_pool = {
|
513 |
.aiocb_size = sizeof(QCowAIOCB),
|
514 |
.cancel = qcow_aio_cancel, |
515 |
}; |
516 |
|
517 |
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
518 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
519 |
BlockDriverCompletionFunc *cb, void *opaque, int is_write) |
520 |
{ |
521 |
QCowAIOCB *acb; |
522 |
|
523 |
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque); |
524 |
if (!acb)
|
525 |
return NULL; |
526 |
acb->hd_aiocb = NULL;
|
527 |
acb->sector_num = sector_num; |
528 |
acb->qiov = qiov; |
529 |
if (qiov->niov > 1) { |
530 |
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size); |
531 |
if (is_write)
|
532 |
qemu_iovec_to_buffer(qiov, acb->buf); |
533 |
} else {
|
534 |
acb->buf = (uint8_t *)qiov->iov->iov_base; |
535 |
} |
536 |
acb->nb_sectors = nb_sectors; |
537 |
acb->n = 0;
|
538 |
acb->cluster_offset = 0;
|
539 |
return acb;
|
540 |
} |
541 |
|
542 |
static void qcow_aio_read_cb(void *opaque, int ret) |
543 |
{ |
544 |
QCowAIOCB *acb = opaque; |
545 |
BlockDriverState *bs = acb->common.bs; |
546 |
BDRVQcowState *s = bs->opaque; |
547 |
int index_in_cluster;
|
548 |
|
549 |
acb->hd_aiocb = NULL;
|
550 |
if (ret < 0) |
551 |
goto done;
|
552 |
|
553 |
redo:
|
554 |
/* post process the read buffer */
|
555 |
if (!acb->cluster_offset) {
|
556 |
/* nothing to do */
|
557 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
558 |
/* nothing to do */
|
559 |
} else {
|
560 |
if (s->crypt_method) {
|
561 |
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, |
562 |
acb->n, 0,
|
563 |
&s->aes_decrypt_key); |
564 |
} |
565 |
} |
566 |
|
567 |
acb->nb_sectors -= acb->n; |
568 |
acb->sector_num += acb->n; |
569 |
acb->buf += acb->n * 512;
|
570 |
|
571 |
if (acb->nb_sectors == 0) { |
572 |
/* request completed */
|
573 |
ret = 0;
|
574 |
goto done;
|
575 |
} |
576 |
|
577 |
/* prepare next AIO request */
|
578 |
acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
|
579 |
0, 0, 0, 0); |
580 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
581 |
acb->n = s->cluster_sectors - index_in_cluster; |
582 |
if (acb->n > acb->nb_sectors)
|
583 |
acb->n = acb->nb_sectors; |
584 |
|
585 |
if (!acb->cluster_offset) {
|
586 |
if (bs->backing_hd) {
|
587 |
/* read from the base image */
|
588 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
589 |
acb->hd_iov.iov_len = acb->n * 512;
|
590 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
591 |
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num, |
592 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
593 |
if (acb->hd_aiocb == NULL) |
594 |
goto done;
|
595 |
} else {
|
596 |
/* Note: in this case, no need to wait */
|
597 |
memset(acb->buf, 0, 512 * acb->n); |
598 |
goto redo;
|
599 |
} |
600 |
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { |
601 |
/* add AIO support for compressed blocks ? */
|
602 |
if (decompress_cluster(bs, acb->cluster_offset) < 0) |
603 |
goto done;
|
604 |
memcpy(acb->buf, |
605 |
s->cluster_cache + index_in_cluster * 512, 512 * acb->n); |
606 |
goto redo;
|
607 |
} else {
|
608 |
if ((acb->cluster_offset & 511) != 0) { |
609 |
ret = -EIO; |
610 |
goto done;
|
611 |
} |
612 |
acb->hd_iov.iov_base = (void *)acb->buf;
|
613 |
acb->hd_iov.iov_len = acb->n * 512;
|
614 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
615 |
acb->hd_aiocb = bdrv_aio_readv(bs->file, |
616 |
(acb->cluster_offset >> 9) + index_in_cluster,
|
617 |
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb); |
618 |
if (acb->hd_aiocb == NULL) |
619 |
goto done;
|
620 |
} |
621 |
|
622 |
return;
|
623 |
|
624 |
done:
|
625 |
if (acb->qiov->niov > 1) { |
626 |
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); |
627 |
qemu_vfree(acb->orig_buf); |
628 |
} |
629 |
acb->common.cb(acb->common.opaque, ret); |
630 |
qemu_aio_release(acb); |
631 |
} |
632 |
|
633 |
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
634 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
635 |
BlockDriverCompletionFunc *cb, void *opaque)
|
636 |
{ |
637 |
QCowAIOCB *acb; |
638 |
|
639 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
640 |
if (!acb)
|
641 |
return NULL; |
642 |
|
643 |
qcow_aio_read_cb(acb, 0);
|
644 |
return &acb->common;
|
645 |
} |
646 |
|
647 |
static void qcow_aio_write_cb(void *opaque, int ret) |
648 |
{ |
649 |
QCowAIOCB *acb = opaque; |
650 |
BlockDriverState *bs = acb->common.bs; |
651 |
BDRVQcowState *s = bs->opaque; |
652 |
int index_in_cluster;
|
653 |
uint64_t cluster_offset; |
654 |
const uint8_t *src_buf;
|
655 |
|
656 |
acb->hd_aiocb = NULL;
|
657 |
|
658 |
if (ret < 0) |
659 |
goto done;
|
660 |
|
661 |
acb->nb_sectors -= acb->n; |
662 |
acb->sector_num += acb->n; |
663 |
acb->buf += acb->n * 512;
|
664 |
|
665 |
if (acb->nb_sectors == 0) { |
666 |
/* request completed */
|
667 |
ret = 0;
|
668 |
goto done;
|
669 |
} |
670 |
|
671 |
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
672 |
acb->n = s->cluster_sectors - index_in_cluster; |
673 |
if (acb->n > acb->nb_sectors)
|
674 |
acb->n = acb->nb_sectors; |
675 |
cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0, |
676 |
index_in_cluster, |
677 |
index_in_cluster + acb->n); |
678 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
679 |
ret = -EIO; |
680 |
goto done;
|
681 |
} |
682 |
if (s->crypt_method) {
|
683 |
if (!acb->cluster_data) {
|
684 |
acb->cluster_data = qemu_mallocz(s->cluster_size); |
685 |
if (!acb->cluster_data) {
|
686 |
ret = -ENOMEM; |
687 |
goto done;
|
688 |
} |
689 |
} |
690 |
encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, |
691 |
acb->n, 1, &s->aes_encrypt_key);
|
692 |
src_buf = acb->cluster_data; |
693 |
} else {
|
694 |
src_buf = acb->buf; |
695 |
} |
696 |
|
697 |
acb->hd_iov.iov_base = (void *)src_buf;
|
698 |
acb->hd_iov.iov_len = acb->n * 512;
|
699 |
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
700 |
acb->hd_aiocb = bdrv_aio_writev(bs->file, |
701 |
(cluster_offset >> 9) + index_in_cluster,
|
702 |
&acb->hd_qiov, acb->n, |
703 |
qcow_aio_write_cb, acb); |
704 |
if (acb->hd_aiocb == NULL) |
705 |
goto done;
|
706 |
return;
|
707 |
|
708 |
done:
|
709 |
if (acb->qiov->niov > 1) |
710 |
qemu_vfree(acb->orig_buf); |
711 |
acb->common.cb(acb->common.opaque, ret); |
712 |
qemu_aio_release(acb); |
713 |
} |
714 |
|
715 |
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
716 |
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
717 |
BlockDriverCompletionFunc *cb, void *opaque)
|
718 |
{ |
719 |
BDRVQcowState *s = bs->opaque; |
720 |
QCowAIOCB *acb; |
721 |
|
722 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
723 |
|
724 |
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
725 |
if (!acb)
|
726 |
return NULL; |
727 |
|
728 |
|
729 |
qcow_aio_write_cb(acb, 0);
|
730 |
return &acb->common;
|
731 |
} |
732 |
|
733 |
static void qcow_close(BlockDriverState *bs) |
734 |
{ |
735 |
BDRVQcowState *s = bs->opaque; |
736 |
qemu_free(s->l1_table); |
737 |
qemu_free(s->l2_cache); |
738 |
qemu_free(s->cluster_cache); |
739 |
qemu_free(s->cluster_data); |
740 |
} |
741 |
|
742 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
743 |
{ |
744 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
745 |
QCowHeader header; |
746 |
uint64_t tmp; |
747 |
int64_t total_size = 0;
|
748 |
const char *backing_file = NULL; |
749 |
int flags = 0; |
750 |
int ret;
|
751 |
|
752 |
/* Read out options */
|
753 |
while (options && options->name) {
|
754 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
755 |
total_size = options->value.n / 512;
|
756 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
757 |
backing_file = options->value.s; |
758 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
759 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
760 |
} |
761 |
options++; |
762 |
} |
763 |
|
764 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
765 |
if (fd < 0) |
766 |
return -errno;
|
767 |
memset(&header, 0, sizeof(header)); |
768 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
769 |
header.version = cpu_to_be32(QCOW_VERSION); |
770 |
header.size = cpu_to_be64(total_size * 512);
|
771 |
header_size = sizeof(header);
|
772 |
backing_filename_len = 0;
|
773 |
if (backing_file) {
|
774 |
if (strcmp(backing_file, "fat:")) { |
775 |
header.backing_file_offset = cpu_to_be64(header_size); |
776 |
backing_filename_len = strlen(backing_file); |
777 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
778 |
header_size += backing_filename_len; |
779 |
} else {
|
780 |
/* special backing file for vvfat */
|
781 |
backing_file = NULL;
|
782 |
} |
783 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
784 |
unmodifyed sectors */
|
785 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
786 |
} else {
|
787 |
header.cluster_bits = 12; /* 4 KB clusters */ |
788 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
789 |
} |
790 |
header_size = (header_size + 7) & ~7; |
791 |
shift = header.cluster_bits + header.l2_bits; |
792 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
793 |
|
794 |
header.l1_table_offset = cpu_to_be64(header_size); |
795 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
796 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
797 |
} else {
|
798 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
799 |
} |
800 |
|
801 |
/* write all the data */
|
802 |
ret = qemu_write_full(fd, &header, sizeof(header));
|
803 |
if (ret != sizeof(header)) { |
804 |
ret = -errno; |
805 |
goto exit;
|
806 |
} |
807 |
|
808 |
if (backing_file) {
|
809 |
ret = qemu_write_full(fd, backing_file, backing_filename_len); |
810 |
if (ret != backing_filename_len) {
|
811 |
ret = -errno; |
812 |
goto exit;
|
813 |
} |
814 |
|
815 |
} |
816 |
lseek(fd, header_size, SEEK_SET); |
817 |
tmp = 0;
|
818 |
for(i = 0;i < l1_size; i++) { |
819 |
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
|
820 |
if (ret != sizeof(tmp)) { |
821 |
ret = -errno; |
822 |
goto exit;
|
823 |
} |
824 |
} |
825 |
|
826 |
ret = 0;
|
827 |
exit:
|
828 |
close(fd); |
829 |
return ret;
|
830 |
} |
831 |
|
832 |
static int qcow_make_empty(BlockDriverState *bs) |
833 |
{ |
834 |
BDRVQcowState *s = bs->opaque; |
835 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
836 |
int ret;
|
837 |
|
838 |
memset(s->l1_table, 0, l1_length);
|
839 |
if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
|
840 |
l1_length) < 0)
|
841 |
return -1; |
842 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length); |
843 |
if (ret < 0) |
844 |
return ret;
|
845 |
|
846 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
847 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
848 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
849 |
|
850 |
return 0; |
851 |
} |
852 |
|
853 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
854 |
tables to avoid losing bytes in alignment */
|
855 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
856 |
const uint8_t *buf, int nb_sectors) |
857 |
{ |
858 |
BDRVQcowState *s = bs->opaque; |
859 |
z_stream strm; |
860 |
int ret, out_len;
|
861 |
uint8_t *out_buf; |
862 |
uint64_t cluster_offset; |
863 |
|
864 |
if (nb_sectors != s->cluster_sectors)
|
865 |
return -EINVAL;
|
866 |
|
867 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
868 |
if (!out_buf)
|
869 |
return -1; |
870 |
|
871 |
/* best compression, small window, no zlib header */
|
872 |
memset(&strm, 0, sizeof(strm)); |
873 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
874 |
Z_DEFLATED, -12,
|
875 |
9, Z_DEFAULT_STRATEGY);
|
876 |
if (ret != 0) { |
877 |
qemu_free(out_buf); |
878 |
return -1; |
879 |
} |
880 |
|
881 |
strm.avail_in = s->cluster_size; |
882 |
strm.next_in = (uint8_t *)buf; |
883 |
strm.avail_out = s->cluster_size; |
884 |
strm.next_out = out_buf; |
885 |
|
886 |
ret = deflate(&strm, Z_FINISH); |
887 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
888 |
qemu_free(out_buf); |
889 |
deflateEnd(&strm); |
890 |
return -1; |
891 |
} |
892 |
out_len = strm.next_out - out_buf; |
893 |
|
894 |
deflateEnd(&strm); |
895 |
|
896 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
897 |
/* could not compress: write normal cluster */
|
898 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
899 |
} else {
|
900 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
901 |
out_len, 0, 0); |
902 |
cluster_offset &= s->cluster_offset_mask; |
903 |
if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
|
904 |
qemu_free(out_buf); |
905 |
return -1; |
906 |
} |
907 |
} |
908 |
|
909 |
qemu_free(out_buf); |
910 |
return 0; |
911 |
} |
912 |
|
913 |
static void qcow_flush(BlockDriverState *bs) |
914 |
{ |
915 |
bdrv_flush(bs->file); |
916 |
} |
917 |
|
918 |
static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
|
919 |
BlockDriverCompletionFunc *cb, void *opaque)
|
920 |
{ |
921 |
return bdrv_aio_flush(bs->file, cb, opaque);
|
922 |
} |
923 |
|
924 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
925 |
{ |
926 |
BDRVQcowState *s = bs->opaque; |
927 |
bdi->cluster_size = s->cluster_size; |
928 |
return 0; |
929 |
} |
930 |
|
931 |
|
932 |
static QEMUOptionParameter qcow_create_options[] = {
|
933 |
{ |
934 |
.name = BLOCK_OPT_SIZE, |
935 |
.type = OPT_SIZE, |
936 |
.help = "Virtual disk size"
|
937 |
}, |
938 |
{ |
939 |
.name = BLOCK_OPT_BACKING_FILE, |
940 |
.type = OPT_STRING, |
941 |
.help = "File name of a base image"
|
942 |
}, |
943 |
{ |
944 |
.name = BLOCK_OPT_ENCRYPT, |
945 |
.type = OPT_FLAG, |
946 |
.help = "Encrypt the image"
|
947 |
}, |
948 |
{ NULL }
|
949 |
}; |
950 |
|
951 |
static BlockDriver bdrv_qcow = {
|
952 |
.format_name = "qcow",
|
953 |
.instance_size = sizeof(BDRVQcowState),
|
954 |
.bdrv_probe = qcow_probe, |
955 |
.bdrv_open = qcow_open, |
956 |
.bdrv_close = qcow_close, |
957 |
.bdrv_create = qcow_create, |
958 |
.bdrv_flush = qcow_flush, |
959 |
.bdrv_is_allocated = qcow_is_allocated, |
960 |
.bdrv_set_key = qcow_set_key, |
961 |
.bdrv_make_empty = qcow_make_empty, |
962 |
.bdrv_aio_readv = qcow_aio_readv, |
963 |
.bdrv_aio_writev = qcow_aio_writev, |
964 |
.bdrv_aio_flush = qcow_aio_flush, |
965 |
.bdrv_write_compressed = qcow_write_compressed, |
966 |
.bdrv_get_info = qcow_get_info, |
967 |
|
968 |
.create_options = qcow_create_options, |
969 |
}; |
970 |
|
971 |
static void bdrv_qcow_init(void) |
972 |
{ |
973 |
bdrv_register(&bdrv_qcow); |
974 |
} |
975 |
|
976 |
block_init(bdrv_qcow_init); |