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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" |
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#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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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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CoMutex lock; |
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} BDRVQcowState; |
78 |
|
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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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|
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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; |
132 |
s->l1_table = g_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 = g_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 = g_malloc(s->cluster_size); |
146 |
if (!s->cluster_cache)
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goto fail;
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s->cluster_data = g_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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} |
162 |
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qemu_co_mutex_init(&s->lock); |
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return 0; |
165 |
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fail:
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g_free(s->l1_table); |
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g_free(s->l2_cache); |
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g_free(s->cluster_cache); |
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g_free(s->cluster_data); |
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return -1; |
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} |
173 |
|
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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); |
181 |
len = strlen(key); |
182 |
if (len > 16) |
183 |
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++) { |
187 |
keybuf[i] = key[i]; |
188 |
} |
189 |
s->crypt_method = s->crypt_method_header; |
190 |
|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
192 |
return -1; |
193 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
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return -1; |
195 |
return 0; |
196 |
} |
197 |
|
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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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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; |
215 |
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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} |
222 |
|
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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) |
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{ |
241 |
BDRVQcowState *s = bs->opaque; |
242 |
int min_index, i, j, l1_index, l2_index;
|
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uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
244 |
uint32_t min_count; |
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int new_l2_table;
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|
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l1_index = offset >> (s->l2_bits + s->cluster_bits); |
248 |
l2_offset = s->l1_table[l1_index]; |
249 |
new_l2_table = 0;
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if (!l2_offset) {
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if (!allocate)
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return 0; |
253 |
/* allocate a new l2 entry */
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l2_offset = bdrv_getlength(bs->file); |
255 |
/* round to cluster size */
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l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
257 |
/* update the L1 entry */
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s->l1_table[l1_index] = l2_offset; |
259 |
tmp = cpu_to_be64(l2_offset); |
260 |
if (bdrv_pwrite_sync(bs->file,
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s->l1_table_offset + l1_index * sizeof(tmp),
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262 |
&tmp, sizeof(tmp)) < 0) |
263 |
return 0; |
264 |
new_l2_table = 1;
|
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} |
266 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
267 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
268 |
/* increment the hit count */
|
269 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
270 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
271 |
s->l2_cache_counts[j] >>= 1;
|
272 |
} |
273 |
} |
274 |
l2_table = s->l2_cache + (i << s->l2_bits); |
275 |
goto found;
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276 |
} |
277 |
} |
278 |
/* not found: load a new entry in the least used one */
|
279 |
min_index = 0;
|
280 |
min_count = 0xffffffff;
|
281 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
282 |
if (s->l2_cache_counts[i] < min_count) {
|
283 |
min_count = s->l2_cache_counts[i]; |
284 |
min_index = i; |
285 |
} |
286 |
} |
287 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
288 |
if (new_l2_table) {
|
289 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
290 |
if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
|
291 |
s->l2_size * sizeof(uint64_t)) < 0) |
292 |
return 0; |
293 |
} else {
|
294 |
if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
295 |
s->l2_size * sizeof(uint64_t))
|
296 |
return 0; |
297 |
} |
298 |
s->l2_cache_offsets[min_index] = l2_offset; |
299 |
s->l2_cache_counts[min_index] = 1;
|
300 |
found:
|
301 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
302 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
303 |
if (!cluster_offset ||
|
304 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
305 |
if (!allocate)
|
306 |
return 0; |
307 |
/* allocate a new cluster */
|
308 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
309 |
(n_end - n_start) < s->cluster_sectors) { |
310 |
/* if the cluster is already compressed, we must
|
311 |
decompress it in the case it is not completely
|
312 |
overwritten */
|
313 |
if (decompress_cluster(bs, cluster_offset) < 0) |
314 |
return 0; |
315 |
cluster_offset = bdrv_getlength(bs->file); |
316 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
317 |
~(s->cluster_size - 1);
|
318 |
/* write the cluster content */
|
319 |
if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
320 |
s->cluster_size) |
321 |
return -1; |
322 |
} else {
|
323 |
cluster_offset = bdrv_getlength(bs->file); |
324 |
if (allocate == 1) { |
325 |
/* round to cluster size */
|
326 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
327 |
~(s->cluster_size - 1);
|
328 |
bdrv_truncate(bs->file, cluster_offset + s->cluster_size); |
329 |
/* if encrypted, we must initialize the cluster
|
330 |
content which won't be written */
|
331 |
if (s->crypt_method &&
|
332 |
(n_end - n_start) < s->cluster_sectors) { |
333 |
uint64_t start_sect; |
334 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
335 |
memset(s->cluster_data + 512, 0x00, 512); |
336 |
for(i = 0; i < s->cluster_sectors; i++) { |
337 |
if (i < n_start || i >= n_end) {
|
338 |
encrypt_sectors(s, start_sect + i, |
339 |
s->cluster_data, |
340 |
s->cluster_data + 512, 1, 1, |
341 |
&s->aes_encrypt_key); |
342 |
if (bdrv_pwrite(bs->file, cluster_offset + i * 512, |
343 |
s->cluster_data, 512) != 512) |
344 |
return -1; |
345 |
} |
346 |
} |
347 |
} |
348 |
} else if (allocate == 2) { |
349 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
350 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
351 |
} |
352 |
} |
353 |
/* update L2 table */
|
354 |
tmp = cpu_to_be64(cluster_offset); |
355 |
l2_table[l2_index] = tmp; |
356 |
if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), |
357 |
&tmp, sizeof(tmp)) < 0) |
358 |
return 0; |
359 |
} |
360 |
return cluster_offset;
|
361 |
} |
362 |
|
363 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
364 |
int nb_sectors, int *pnum) |
365 |
{ |
366 |
BDRVQcowState *s = bs->opaque; |
367 |
int index_in_cluster, n;
|
368 |
uint64_t cluster_offset; |
369 |
|
370 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
371 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
372 |
n = s->cluster_sectors - index_in_cluster; |
373 |
if (n > nb_sectors)
|
374 |
n = nb_sectors; |
375 |
*pnum = n; |
376 |
return (cluster_offset != 0); |
377 |
} |
378 |
|
379 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
380 |
const uint8_t *buf, int buf_size) |
381 |
{ |
382 |
z_stream strm1, *strm = &strm1; |
383 |
int ret, out_len;
|
384 |
|
385 |
memset(strm, 0, sizeof(*strm)); |
386 |
|
387 |
strm->next_in = (uint8_t *)buf; |
388 |
strm->avail_in = buf_size; |
389 |
strm->next_out = out_buf; |
390 |
strm->avail_out = out_buf_size; |
391 |
|
392 |
ret = inflateInit2(strm, -12);
|
393 |
if (ret != Z_OK)
|
394 |
return -1; |
395 |
ret = inflate(strm, Z_FINISH); |
396 |
out_len = strm->next_out - out_buf; |
397 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
398 |
out_len != out_buf_size) { |
399 |
inflateEnd(strm); |
400 |
return -1; |
401 |
} |
402 |
inflateEnd(strm); |
403 |
return 0; |
404 |
} |
405 |
|
406 |
static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) |
407 |
{ |
408 |
BDRVQcowState *s = bs->opaque; |
409 |
int ret, csize;
|
410 |
uint64_t coffset; |
411 |
|
412 |
coffset = cluster_offset & s->cluster_offset_mask; |
413 |
if (s->cluster_cache_offset != coffset) {
|
414 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
415 |
csize &= (s->cluster_size - 1);
|
416 |
ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize); |
417 |
if (ret != csize)
|
418 |
return -1; |
419 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
420 |
s->cluster_data, csize) < 0) {
|
421 |
return -1; |
422 |
} |
423 |
s->cluster_cache_offset = coffset; |
424 |
} |
425 |
return 0; |
426 |
} |
427 |
|
428 |
static int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, |
429 |
int nb_sectors, QEMUIOVector *qiov)
|
430 |
{ |
431 |
BDRVQcowState *s = bs->opaque; |
432 |
int index_in_cluster;
|
433 |
int ret = 0, n; |
434 |
uint64_t cluster_offset; |
435 |
struct iovec hd_iov;
|
436 |
QEMUIOVector hd_qiov; |
437 |
uint8_t *buf; |
438 |
void *orig_buf;
|
439 |
|
440 |
if (qiov->niov > 1) { |
441 |
buf = orig_buf = qemu_blockalign(bs, qiov->size); |
442 |
} else {
|
443 |
orig_buf = NULL;
|
444 |
buf = (uint8_t *)qiov->iov->iov_base; |
445 |
} |
446 |
|
447 |
qemu_co_mutex_lock(&s->lock); |
448 |
|
449 |
while (nb_sectors != 0) { |
450 |
/* prepare next request */
|
451 |
cluster_offset = get_cluster_offset(bs, sector_num << 9,
|
452 |
0, 0, 0, 0); |
453 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
454 |
n = s->cluster_sectors - index_in_cluster; |
455 |
if (n > nb_sectors) {
|
456 |
n = nb_sectors; |
457 |
} |
458 |
|
459 |
if (!cluster_offset) {
|
460 |
if (bs->backing_hd) {
|
461 |
/* read from the base image */
|
462 |
hd_iov.iov_base = (void *)buf;
|
463 |
hd_iov.iov_len = n * 512;
|
464 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
465 |
qemu_co_mutex_unlock(&s->lock); |
466 |
ret = bdrv_co_readv(bs->backing_hd, sector_num, |
467 |
n, &hd_qiov); |
468 |
qemu_co_mutex_lock(&s->lock); |
469 |
if (ret < 0) { |
470 |
goto fail;
|
471 |
} |
472 |
} else {
|
473 |
/* Note: in this case, no need to wait */
|
474 |
memset(buf, 0, 512 * n); |
475 |
} |
476 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
477 |
/* add AIO support for compressed blocks ? */
|
478 |
if (decompress_cluster(bs, cluster_offset) < 0) { |
479 |
goto fail;
|
480 |
} |
481 |
memcpy(buf, |
482 |
s->cluster_cache + index_in_cluster * 512, 512 * n); |
483 |
} else {
|
484 |
if ((cluster_offset & 511) != 0) { |
485 |
goto fail;
|
486 |
} |
487 |
hd_iov.iov_base = (void *)buf;
|
488 |
hd_iov.iov_len = n * 512;
|
489 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
490 |
qemu_co_mutex_unlock(&s->lock); |
491 |
ret = bdrv_co_readv(bs->file, |
492 |
(cluster_offset >> 9) + index_in_cluster,
|
493 |
n, &hd_qiov); |
494 |
qemu_co_mutex_lock(&s->lock); |
495 |
if (ret < 0) { |
496 |
break;
|
497 |
} |
498 |
if (s->crypt_method) {
|
499 |
encrypt_sectors(s, sector_num, buf, buf, |
500 |
n, 0,
|
501 |
&s->aes_decrypt_key); |
502 |
} |
503 |
} |
504 |
ret = 0;
|
505 |
|
506 |
nb_sectors -= n; |
507 |
sector_num += n; |
508 |
buf += n * 512;
|
509 |
} |
510 |
|
511 |
done:
|
512 |
qemu_co_mutex_unlock(&s->lock); |
513 |
|
514 |
if (qiov->niov > 1) { |
515 |
qemu_iovec_from_buffer(qiov, orig_buf, qiov->size); |
516 |
qemu_vfree(orig_buf); |
517 |
} |
518 |
|
519 |
return ret;
|
520 |
|
521 |
fail:
|
522 |
ret = -EIO; |
523 |
goto done;
|
524 |
} |
525 |
|
526 |
static int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, |
527 |
int nb_sectors, QEMUIOVector *qiov)
|
528 |
{ |
529 |
BDRVQcowState *s = bs->opaque; |
530 |
int index_in_cluster;
|
531 |
uint64_t cluster_offset; |
532 |
const uint8_t *src_buf;
|
533 |
int ret = 0, n; |
534 |
uint8_t *cluster_data = NULL;
|
535 |
struct iovec hd_iov;
|
536 |
QEMUIOVector hd_qiov; |
537 |
uint8_t *buf; |
538 |
void *orig_buf;
|
539 |
|
540 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
541 |
|
542 |
if (qiov->niov > 1) { |
543 |
buf = orig_buf = qemu_blockalign(bs, qiov->size); |
544 |
qemu_iovec_to_buffer(qiov, buf); |
545 |
} else {
|
546 |
orig_buf = NULL;
|
547 |
buf = (uint8_t *)qiov->iov->iov_base; |
548 |
} |
549 |
|
550 |
qemu_co_mutex_lock(&s->lock); |
551 |
|
552 |
while (nb_sectors != 0) { |
553 |
|
554 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
555 |
n = s->cluster_sectors - index_in_cluster; |
556 |
if (n > nb_sectors) {
|
557 |
n = nb_sectors; |
558 |
} |
559 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
560 |
index_in_cluster, |
561 |
index_in_cluster + n); |
562 |
if (!cluster_offset || (cluster_offset & 511) != 0) { |
563 |
ret = -EIO; |
564 |
break;
|
565 |
} |
566 |
if (s->crypt_method) {
|
567 |
if (!cluster_data) {
|
568 |
cluster_data = g_malloc0(s->cluster_size); |
569 |
} |
570 |
encrypt_sectors(s, sector_num, cluster_data, buf, |
571 |
n, 1, &s->aes_encrypt_key);
|
572 |
src_buf = cluster_data; |
573 |
} else {
|
574 |
src_buf = buf; |
575 |
} |
576 |
|
577 |
hd_iov.iov_base = (void *)src_buf;
|
578 |
hd_iov.iov_len = n * 512;
|
579 |
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
580 |
qemu_co_mutex_unlock(&s->lock); |
581 |
ret = bdrv_co_writev(bs->file, |
582 |
(cluster_offset >> 9) + index_in_cluster,
|
583 |
n, &hd_qiov); |
584 |
qemu_co_mutex_lock(&s->lock); |
585 |
if (ret < 0) { |
586 |
break;
|
587 |
} |
588 |
ret = 0;
|
589 |
|
590 |
nb_sectors -= n; |
591 |
sector_num += n; |
592 |
buf += n * 512;
|
593 |
} |
594 |
qemu_co_mutex_unlock(&s->lock); |
595 |
|
596 |
if (qiov->niov > 1) { |
597 |
qemu_vfree(orig_buf); |
598 |
} |
599 |
g_free(cluster_data); |
600 |
|
601 |
return ret;
|
602 |
} |
603 |
|
604 |
static void qcow_close(BlockDriverState *bs) |
605 |
{ |
606 |
BDRVQcowState *s = bs->opaque; |
607 |
g_free(s->l1_table); |
608 |
g_free(s->l2_cache); |
609 |
g_free(s->cluster_cache); |
610 |
g_free(s->cluster_data); |
611 |
} |
612 |
|
613 |
static int qcow_create(const char *filename, QEMUOptionParameter *options) |
614 |
{ |
615 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
616 |
QCowHeader header; |
617 |
uint64_t tmp; |
618 |
int64_t total_size = 0;
|
619 |
const char *backing_file = NULL; |
620 |
int flags = 0; |
621 |
int ret;
|
622 |
|
623 |
/* Read out options */
|
624 |
while (options && options->name) {
|
625 |
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
626 |
total_size = options->value.n / 512;
|
627 |
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { |
628 |
backing_file = options->value.s; |
629 |
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) { |
630 |
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
631 |
} |
632 |
options++; |
633 |
} |
634 |
|
635 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
636 |
if (fd < 0) |
637 |
return -errno;
|
638 |
memset(&header, 0, sizeof(header)); |
639 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
640 |
header.version = cpu_to_be32(QCOW_VERSION); |
641 |
header.size = cpu_to_be64(total_size * 512);
|
642 |
header_size = sizeof(header);
|
643 |
backing_filename_len = 0;
|
644 |
if (backing_file) {
|
645 |
if (strcmp(backing_file, "fat:")) { |
646 |
header.backing_file_offset = cpu_to_be64(header_size); |
647 |
backing_filename_len = strlen(backing_file); |
648 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
649 |
header_size += backing_filename_len; |
650 |
} else {
|
651 |
/* special backing file for vvfat */
|
652 |
backing_file = NULL;
|
653 |
} |
654 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
655 |
unmodifyed sectors */
|
656 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
657 |
} else {
|
658 |
header.cluster_bits = 12; /* 4 KB clusters */ |
659 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
660 |
} |
661 |
header_size = (header_size + 7) & ~7; |
662 |
shift = header.cluster_bits + header.l2_bits; |
663 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
664 |
|
665 |
header.l1_table_offset = cpu_to_be64(header_size); |
666 |
if (flags & BLOCK_FLAG_ENCRYPT) {
|
667 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
668 |
} else {
|
669 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
670 |
} |
671 |
|
672 |
/* write all the data */
|
673 |
ret = qemu_write_full(fd, &header, sizeof(header));
|
674 |
if (ret != sizeof(header)) { |
675 |
ret = -errno; |
676 |
goto exit;
|
677 |
} |
678 |
|
679 |
if (backing_file) {
|
680 |
ret = qemu_write_full(fd, backing_file, backing_filename_len); |
681 |
if (ret != backing_filename_len) {
|
682 |
ret = -errno; |
683 |
goto exit;
|
684 |
} |
685 |
|
686 |
} |
687 |
lseek(fd, header_size, SEEK_SET); |
688 |
tmp = 0;
|
689 |
for(i = 0;i < l1_size; i++) { |
690 |
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
|
691 |
if (ret != sizeof(tmp)) { |
692 |
ret = -errno; |
693 |
goto exit;
|
694 |
} |
695 |
} |
696 |
|
697 |
ret = 0;
|
698 |
exit:
|
699 |
close(fd); |
700 |
return ret;
|
701 |
} |
702 |
|
703 |
static int qcow_make_empty(BlockDriverState *bs) |
704 |
{ |
705 |
BDRVQcowState *s = bs->opaque; |
706 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
707 |
int ret;
|
708 |
|
709 |
memset(s->l1_table, 0, l1_length);
|
710 |
if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
|
711 |
l1_length) < 0)
|
712 |
return -1; |
713 |
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length); |
714 |
if (ret < 0) |
715 |
return ret;
|
716 |
|
717 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
718 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
719 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
720 |
|
721 |
return 0; |
722 |
} |
723 |
|
724 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
725 |
tables to avoid losing bytes in alignment */
|
726 |
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, |
727 |
const uint8_t *buf, int nb_sectors) |
728 |
{ |
729 |
BDRVQcowState *s = bs->opaque; |
730 |
z_stream strm; |
731 |
int ret, out_len;
|
732 |
uint8_t *out_buf; |
733 |
uint64_t cluster_offset; |
734 |
|
735 |
if (nb_sectors != s->cluster_sectors)
|
736 |
return -EINVAL;
|
737 |
|
738 |
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
739 |
if (!out_buf)
|
740 |
return -1; |
741 |
|
742 |
/* best compression, small window, no zlib header */
|
743 |
memset(&strm, 0, sizeof(strm)); |
744 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
745 |
Z_DEFLATED, -12,
|
746 |
9, Z_DEFAULT_STRATEGY);
|
747 |
if (ret != 0) { |
748 |
g_free(out_buf); |
749 |
return -1; |
750 |
} |
751 |
|
752 |
strm.avail_in = s->cluster_size; |
753 |
strm.next_in = (uint8_t *)buf; |
754 |
strm.avail_out = s->cluster_size; |
755 |
strm.next_out = out_buf; |
756 |
|
757 |
ret = deflate(&strm, Z_FINISH); |
758 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
759 |
g_free(out_buf); |
760 |
deflateEnd(&strm); |
761 |
return -1; |
762 |
} |
763 |
out_len = strm.next_out - out_buf; |
764 |
|
765 |
deflateEnd(&strm); |
766 |
|
767 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
768 |
/* could not compress: write normal cluster */
|
769 |
bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
770 |
} else {
|
771 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
772 |
out_len, 0, 0); |
773 |
cluster_offset &= s->cluster_offset_mask; |
774 |
if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
|
775 |
g_free(out_buf); |
776 |
return -1; |
777 |
} |
778 |
} |
779 |
|
780 |
g_free(out_buf); |
781 |
return 0; |
782 |
} |
783 |
|
784 |
static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
|
785 |
BlockDriverCompletionFunc *cb, void *opaque)
|
786 |
{ |
787 |
return bdrv_aio_flush(bs->file, cb, opaque);
|
788 |
} |
789 |
|
790 |
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
791 |
{ |
792 |
BDRVQcowState *s = bs->opaque; |
793 |
bdi->cluster_size = s->cluster_size; |
794 |
return 0; |
795 |
} |
796 |
|
797 |
|
798 |
static QEMUOptionParameter qcow_create_options[] = {
|
799 |
{ |
800 |
.name = BLOCK_OPT_SIZE, |
801 |
.type = OPT_SIZE, |
802 |
.help = "Virtual disk size"
|
803 |
}, |
804 |
{ |
805 |
.name = BLOCK_OPT_BACKING_FILE, |
806 |
.type = OPT_STRING, |
807 |
.help = "File name of a base image"
|
808 |
}, |
809 |
{ |
810 |
.name = BLOCK_OPT_ENCRYPT, |
811 |
.type = OPT_FLAG, |
812 |
.help = "Encrypt the image"
|
813 |
}, |
814 |
{ NULL }
|
815 |
}; |
816 |
|
817 |
static BlockDriver bdrv_qcow = {
|
818 |
.format_name = "qcow",
|
819 |
.instance_size = sizeof(BDRVQcowState),
|
820 |
.bdrv_probe = qcow_probe, |
821 |
.bdrv_open = qcow_open, |
822 |
.bdrv_close = qcow_close, |
823 |
.bdrv_create = qcow_create, |
824 |
.bdrv_is_allocated = qcow_is_allocated, |
825 |
.bdrv_set_key = qcow_set_key, |
826 |
.bdrv_make_empty = qcow_make_empty, |
827 |
.bdrv_co_readv = qcow_co_readv, |
828 |
.bdrv_co_writev = qcow_co_writev, |
829 |
.bdrv_aio_flush = qcow_aio_flush, |
830 |
.bdrv_write_compressed = qcow_write_compressed, |
831 |
.bdrv_get_info = qcow_get_info, |
832 |
|
833 |
.create_options = qcow_create_options, |
834 |
}; |
835 |
|
836 |
static void bdrv_qcow_init(void) |
837 |
{ |
838 |
bdrv_register(&bdrv_qcow); |
839 |
} |
840 |
|
841 |
block_init(bdrv_qcow_init); |