956 lines
29 KiB
C
956 lines
29 KiB
C
/*
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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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/* QEMU COW block driver with compression and encryption support */
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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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#define QCOW_CRYPT_NONE 0
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#define QCOW_CRYPT_AES 1
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#define QCOW_OFLAG_COMPRESSED (1LL << 63)
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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;
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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;
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#define L2_CACHE_SIZE 16
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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;
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static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
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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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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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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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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;
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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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/* 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;
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s->l1_table_offset = header.l1_table_offset;
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s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
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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);
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if (!s->cluster_cache)
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goto fail;
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s->cluster_data = g_malloc(s->cluster_size);
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if (!s->cluster_data)
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goto fail;
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s->cluster_cache_offset = -1;
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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;
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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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qemu_co_mutex_init(&s->lock);
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return 0;
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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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}
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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);
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len = strlen(key);
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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];
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}
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s->crypt_method = s->crypt_method_header;
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
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return -1;
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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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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;
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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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}
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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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{
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BDRVQcowState *s = bs->opaque;
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int min_index, i, j, l1_index, l2_index;
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uint64_t l2_offset, *l2_table, cluster_offset, tmp;
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uint32_t min_count;
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int new_l2_table;
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l1_index = offset >> (s->l2_bits + s->cluster_bits);
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l2_offset = s->l1_table[l1_index];
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new_l2_table = 0;
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if (!l2_offset) {
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if (!allocate)
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return 0;
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/* allocate a new l2 entry */
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l2_offset = bdrv_getlength(bs->file);
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/* round to cluster size */
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l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1);
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/* update the L1 entry */
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s->l1_table[l1_index] = l2_offset;
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tmp = cpu_to_be64(l2_offset);
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if (bdrv_pwrite_sync(bs->file,
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s->l1_table_offset + l1_index * sizeof(tmp),
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&tmp, sizeof(tmp)) < 0)
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return 0;
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new_l2_table = 1;
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}
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for(i = 0; i < L2_CACHE_SIZE; i++) {
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if (l2_offset == s->l2_cache_offsets[i]) {
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/* increment the hit count */
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if (++s->l2_cache_counts[i] == 0xffffffff) {
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for(j = 0; j < L2_CACHE_SIZE; j++) {
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s->l2_cache_counts[j] >>= 1;
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}
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}
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l2_table = s->l2_cache + (i << s->l2_bits);
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goto found;
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}
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}
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/* not found: load a new entry in the least used one */
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min_index = 0;
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min_count = 0xffffffff;
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for(i = 0; i < L2_CACHE_SIZE; i++) {
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if (s->l2_cache_counts[i] < min_count) {
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min_count = s->l2_cache_counts[i];
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min_index = i;
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}
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}
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l2_table = s->l2_cache + (min_index << s->l2_bits);
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if (new_l2_table) {
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memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
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if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
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s->l2_size * sizeof(uint64_t)) < 0)
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return 0;
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} else {
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if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
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s->l2_size * sizeof(uint64_t))
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return 0;
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}
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s->l2_cache_offsets[min_index] = l2_offset;
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s->l2_cache_counts[min_index] = 1;
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found:
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l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
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cluster_offset = be64_to_cpu(l2_table[l2_index]);
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if (!cluster_offset ||
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((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
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if (!allocate)
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return 0;
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/* allocate a new cluster */
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if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
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(n_end - n_start) < s->cluster_sectors) {
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/* if the cluster is already compressed, we must
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decompress it in the case it is not completely
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overwritten */
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if (decompress_cluster(bs, cluster_offset) < 0)
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return 0;
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cluster_offset = bdrv_getlength(bs->file);
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cluster_offset = (cluster_offset + s->cluster_size - 1) &
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~(s->cluster_size - 1);
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/* write the cluster content */
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if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
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s->cluster_size)
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return -1;
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} else {
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cluster_offset = bdrv_getlength(bs->file);
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if (allocate == 1) {
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/* round to cluster size */
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cluster_offset = (cluster_offset + s->cluster_size - 1) &
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~(s->cluster_size - 1);
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bdrv_truncate(bs->file, cluster_offset + s->cluster_size);
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/* if encrypted, we must initialize the cluster
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content which won't be written */
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if (s->crypt_method &&
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(n_end - n_start) < s->cluster_sectors) {
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uint64_t start_sect;
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start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
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memset(s->cluster_data + 512, 0x00, 512);
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for(i = 0; i < s->cluster_sectors; i++) {
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if (i < n_start || i >= n_end) {
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encrypt_sectors(s, start_sect + i,
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s->cluster_data,
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s->cluster_data + 512, 1, 1,
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&s->aes_encrypt_key);
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if (bdrv_pwrite(bs->file, cluster_offset + i * 512,
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s->cluster_data, 512) != 512)
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return -1;
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}
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}
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}
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} else if (allocate == 2) {
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cluster_offset |= QCOW_OFLAG_COMPRESSED |
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(uint64_t)compressed_size << (63 - s->cluster_bits);
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}
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}
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/* update L2 table */
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tmp = cpu_to_be64(cluster_offset);
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l2_table[l2_index] = tmp;
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if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
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&tmp, sizeof(tmp)) < 0)
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return 0;
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}
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return cluster_offset;
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}
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static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
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int nb_sectors, int *pnum)
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{
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BDRVQcowState *s = bs->opaque;
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int index_in_cluster, n;
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uint64_t cluster_offset;
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
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index_in_cluster = sector_num & (s->cluster_sectors - 1);
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n = s->cluster_sectors - index_in_cluster;
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if (n > nb_sectors)
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n = nb_sectors;
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*pnum = n;
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return (cluster_offset != 0);
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}
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static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
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const uint8_t *buf, int buf_size)
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{
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z_stream strm1, *strm = &strm1;
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int ret, out_len;
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memset(strm, 0, sizeof(*strm));
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strm->next_in = (uint8_t *)buf;
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strm->avail_in = buf_size;
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strm->next_out = out_buf;
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strm->avail_out = out_buf_size;
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ret = inflateInit2(strm, -12);
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if (ret != Z_OK)
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return -1;
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ret = inflate(strm, Z_FINISH);
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out_len = strm->next_out - out_buf;
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if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
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out_len != out_buf_size) {
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inflateEnd(strm);
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return -1;
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}
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inflateEnd(strm);
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return 0;
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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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BDRVQcowState *s = bs->opaque;
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int ret, csize;
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uint64_t coffset;
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coffset = cluster_offset & s->cluster_offset_mask;
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if (s->cluster_cache_offset != coffset) {
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csize = cluster_offset >> (63 - s->cluster_bits);
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csize &= (s->cluster_size - 1);
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ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
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if (ret != csize)
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return -1;
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if (decompress_buffer(s->cluster_cache, s->cluster_size,
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s->cluster_data, csize) < 0) {
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return -1;
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}
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s->cluster_cache_offset = coffset;
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}
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return 0;
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}
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#if 0
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static int qcow_read(BlockDriverState *bs, int64_t sector_num,
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uint8_t *buf, int nb_sectors)
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{
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BDRVQcowState *s = bs->opaque;
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int ret, index_in_cluster, n;
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uint64_t cluster_offset;
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while (nb_sectors > 0) {
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cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
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index_in_cluster = sector_num & (s->cluster_sectors - 1);
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n = s->cluster_sectors - index_in_cluster;
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if (n > nb_sectors)
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n = nb_sectors;
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if (!cluster_offset) {
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if (bs->backing_hd) {
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/* read from the base image */
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ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
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if (ret < 0)
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return -1;
|
|
} else {
|
|
memset(buf, 0, 512 * n);
|
|
}
|
|
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
if (decompress_cluster(bs, cluster_offset) < 0)
|
|
return -1;
|
|
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
|
|
} else {
|
|
ret = bdrv_pread(bs->file, cluster_offset + index_in_cluster * 512, buf, n * 512);
|
|
if (ret != n * 512)
|
|
return -1;
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
nb_sectors -= n;
|
|
sector_num += n;
|
|
buf += n * 512;
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
typedef struct QCowAIOCB {
|
|
BlockDriverState *bs;
|
|
int64_t sector_num;
|
|
QEMUIOVector *qiov;
|
|
uint8_t *buf;
|
|
void *orig_buf;
|
|
int nb_sectors;
|
|
} QCowAIOCB;
|
|
|
|
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
int is_write, QCowAIOCB *acb)
|
|
{
|
|
acb->bs = bs;
|
|
acb->sector_num = sector_num;
|
|
acb->qiov = qiov;
|
|
|
|
if (qiov->niov > 1) {
|
|
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
|
|
if (is_write)
|
|
qemu_iovec_to_buffer(qiov, acb->buf);
|
|
} else {
|
|
acb->orig_buf = NULL;
|
|
acb->buf = (uint8_t *)qiov->iov->iov_base;
|
|
}
|
|
acb->nb_sectors = nb_sectors;
|
|
return acb;
|
|
}
|
|
|
|
static int qcow_aio_read_cb(QCowAIOCB *acb)
|
|
{
|
|
BlockDriverState *bs = acb->bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
int ret, n;
|
|
uint64_t cluster_offset;
|
|
struct iovec hd_iov;
|
|
QEMUIOVector hd_qiov;
|
|
|
|
redo:
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
return 0;
|
|
}
|
|
|
|
/* prepare next request */
|
|
cluster_offset = get_cluster_offset(bs, acb->sector_num << 9,
|
|
0, 0, 0, 0);
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
n = s->cluster_sectors - index_in_cluster;
|
|
if (n > acb->nb_sectors) {
|
|
n = acb->nb_sectors;
|
|
}
|
|
|
|
if (!cluster_offset) {
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
hd_iov.iov_base = (void *)acb->buf;
|
|
hd_iov.iov_len = n * 512;
|
|
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
ret = bdrv_co_readv(bs->backing_hd, acb->sector_num,
|
|
n, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
return -EIO;
|
|
}
|
|
} else {
|
|
/* Note: in this case, no need to wait */
|
|
memset(acb->buf, 0, 512 * n);
|
|
}
|
|
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* add AIO support for compressed blocks ? */
|
|
if (decompress_cluster(bs, cluster_offset) < 0) {
|
|
return -EIO;
|
|
}
|
|
memcpy(acb->buf,
|
|
s->cluster_cache + index_in_cluster * 512, 512 * n);
|
|
} else {
|
|
if ((cluster_offset & 511) != 0) {
|
|
return -EIO;
|
|
}
|
|
hd_iov.iov_base = (void *)acb->buf;
|
|
hd_iov.iov_len = n * 512;
|
|
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
ret = bdrv_co_readv(bs->file,
|
|
(cluster_offset >> 9) + index_in_cluster,
|
|
n, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
/* post process the read buffer */
|
|
if (!cluster_offset) {
|
|
/* nothing to do */
|
|
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* nothing to do */
|
|
} else {
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
|
|
n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
|
|
acb->nb_sectors -= n;
|
|
acb->sector_num += n;
|
|
acb->buf += n * 512;
|
|
|
|
goto redo;
|
|
}
|
|
|
|
static int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowAIOCB acb;
|
|
int ret;
|
|
|
|
qcow_aio_setup(bs, sector_num, qiov, nb_sectors, 0, &acb);
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow_aio_read_cb(&acb);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
if (acb.qiov->niov > 1) {
|
|
qemu_iovec_from_buffer(acb.qiov, acb.orig_buf, acb.qiov->size);
|
|
qemu_vfree(acb.orig_buf);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int qcow_aio_write_cb(QCowAIOCB *acb)
|
|
{
|
|
BlockDriverState *bs = acb->bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
uint64_t cluster_offset;
|
|
const uint8_t *src_buf;
|
|
int ret, n;
|
|
uint8_t *cluster_data = NULL;
|
|
struct iovec hd_iov;
|
|
QEMUIOVector hd_qiov;
|
|
|
|
redo:
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
return 0;
|
|
}
|
|
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
n = s->cluster_sectors - index_in_cluster;
|
|
if (n > acb->nb_sectors) {
|
|
n = acb->nb_sectors;
|
|
}
|
|
cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0,
|
|
index_in_cluster,
|
|
index_in_cluster + n);
|
|
if (!cluster_offset || (cluster_offset & 511) != 0) {
|
|
return -EIO;
|
|
}
|
|
if (s->crypt_method) {
|
|
if (!cluster_data) {
|
|
cluster_data = g_malloc0(s->cluster_size);
|
|
}
|
|
encrypt_sectors(s, acb->sector_num, cluster_data, acb->buf,
|
|
n, 1, &s->aes_encrypt_key);
|
|
src_buf = cluster_data;
|
|
} else {
|
|
src_buf = acb->buf;
|
|
}
|
|
|
|
hd_iov.iov_base = (void *)src_buf;
|
|
hd_iov.iov_len = n * 512;
|
|
qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
ret = bdrv_co_writev(bs->file,
|
|
(cluster_offset >> 9) + index_in_cluster,
|
|
n, &hd_qiov);
|
|
if (cluster_data) {
|
|
free(cluster_data);
|
|
cluster_data = NULL;
|
|
}
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
acb->nb_sectors -= n;
|
|
acb->sector_num += n;
|
|
acb->buf += n * 512;
|
|
|
|
goto redo;
|
|
}
|
|
|
|
static int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowAIOCB acb;
|
|
int ret;
|
|
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
|
|
qcow_aio_setup(bs, sector_num, qiov, nb_sectors, 1, &acb);
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
ret = qcow_aio_write_cb(&acb);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
if (acb.qiov->niov > 1) {
|
|
qemu_vfree(acb.orig_buf);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void qcow_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
g_free(s->l1_table);
|
|
g_free(s->l2_cache);
|
|
g_free(s->cluster_cache);
|
|
g_free(s->cluster_data);
|
|
}
|
|
|
|
static int qcow_create(const char *filename, QEMUOptionParameter *options)
|
|
{
|
|
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
|
QCowHeader header;
|
|
uint64_t tmp;
|
|
int64_t total_size = 0;
|
|
const char *backing_file = NULL;
|
|
int flags = 0;
|
|
int ret;
|
|
|
|
/* Read out options */
|
|
while (options && options->name) {
|
|
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
|
total_size = options->value.n / 512;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
|
|
backing_file = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
|
|
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
|
}
|
|
options++;
|
|
}
|
|
|
|
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
|
if (fd < 0)
|
|
return -errno;
|
|
memset(&header, 0, sizeof(header));
|
|
header.magic = cpu_to_be32(QCOW_MAGIC);
|
|
header.version = cpu_to_be32(QCOW_VERSION);
|
|
header.size = cpu_to_be64(total_size * 512);
|
|
header_size = sizeof(header);
|
|
backing_filename_len = 0;
|
|
if (backing_file) {
|
|
if (strcmp(backing_file, "fat:")) {
|
|
header.backing_file_offset = cpu_to_be64(header_size);
|
|
backing_filename_len = strlen(backing_file);
|
|
header.backing_file_size = cpu_to_be32(backing_filename_len);
|
|
header_size += backing_filename_len;
|
|
} else {
|
|
/* special backing file for vvfat */
|
|
backing_file = NULL;
|
|
}
|
|
header.cluster_bits = 9; /* 512 byte cluster to avoid copying
|
|
unmodifyed sectors */
|
|
header.l2_bits = 12; /* 32 KB L2 tables */
|
|
} else {
|
|
header.cluster_bits = 12; /* 4 KB clusters */
|
|
header.l2_bits = 9; /* 4 KB L2 tables */
|
|
}
|
|
header_size = (header_size + 7) & ~7;
|
|
shift = header.cluster_bits + header.l2_bits;
|
|
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift;
|
|
|
|
header.l1_table_offset = cpu_to_be64(header_size);
|
|
if (flags & BLOCK_FLAG_ENCRYPT) {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
|
|
} else {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
|
|
}
|
|
|
|
/* write all the data */
|
|
ret = qemu_write_full(fd, &header, sizeof(header));
|
|
if (ret != sizeof(header)) {
|
|
ret = -errno;
|
|
goto exit;
|
|
}
|
|
|
|
if (backing_file) {
|
|
ret = qemu_write_full(fd, backing_file, backing_filename_len);
|
|
if (ret != backing_filename_len) {
|
|
ret = -errno;
|
|
goto exit;
|
|
}
|
|
|
|
}
|
|
lseek(fd, header_size, SEEK_SET);
|
|
tmp = 0;
|
|
for(i = 0;i < l1_size; i++) {
|
|
ret = qemu_write_full(fd, &tmp, sizeof(tmp));
|
|
if (ret != sizeof(tmp)) {
|
|
ret = -errno;
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
exit:
|
|
close(fd);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow_make_empty(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
|
int ret;
|
|
|
|
memset(s->l1_table, 0, l1_length);
|
|
if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
|
|
l1_length) < 0)
|
|
return -1;
|
|
ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
|
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
|
|
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* XXX: put compressed sectors first, then all the cluster aligned
|
|
tables to avoid losing bytes in alignment */
|
|
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
z_stream strm;
|
|
int ret, out_len;
|
|
uint8_t *out_buf;
|
|
uint64_t cluster_offset;
|
|
|
|
if (nb_sectors != s->cluster_sectors)
|
|
return -EINVAL;
|
|
|
|
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
|
|
if (!out_buf)
|
|
return -1;
|
|
|
|
/* best compression, small window, no zlib header */
|
|
memset(&strm, 0, sizeof(strm));
|
|
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
|
|
Z_DEFLATED, -12,
|
|
9, Z_DEFAULT_STRATEGY);
|
|
if (ret != 0) {
|
|
g_free(out_buf);
|
|
return -1;
|
|
}
|
|
|
|
strm.avail_in = s->cluster_size;
|
|
strm.next_in = (uint8_t *)buf;
|
|
strm.avail_out = s->cluster_size;
|
|
strm.next_out = out_buf;
|
|
|
|
ret = deflate(&strm, Z_FINISH);
|
|
if (ret != Z_STREAM_END && ret != Z_OK) {
|
|
g_free(out_buf);
|
|
deflateEnd(&strm);
|
|
return -1;
|
|
}
|
|
out_len = strm.next_out - out_buf;
|
|
|
|
deflateEnd(&strm);
|
|
|
|
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
|
/* could not compress: write normal cluster */
|
|
bdrv_write(bs, sector_num, buf, s->cluster_sectors);
|
|
} else {
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
|
|
out_len, 0, 0);
|
|
cluster_offset &= s->cluster_offset_mask;
|
|
if (bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len) != out_len) {
|
|
g_free(out_buf);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
g_free(out_buf);
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_flush(BlockDriverState *bs)
|
|
{
|
|
return bdrv_flush(bs->file);
|
|
}
|
|
|
|
static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
return bdrv_aio_flush(bs->file, cb, opaque);
|
|
}
|
|
|
|
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdi->cluster_size = s->cluster_size;
|
|
return 0;
|
|
}
|
|
|
|
|
|
static QEMUOptionParameter qcow_create_options[] = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "Virtual disk size"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FILE,
|
|
.type = OPT_STRING,
|
|
.help = "File name of a base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_ENCRYPT,
|
|
.type = OPT_FLAG,
|
|
.help = "Encrypt the image"
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static BlockDriver bdrv_qcow = {
|
|
.format_name = "qcow",
|
|
.instance_size = sizeof(BDRVQcowState),
|
|
.bdrv_probe = qcow_probe,
|
|
.bdrv_open = qcow_open,
|
|
.bdrv_close = qcow_close,
|
|
.bdrv_create = qcow_create,
|
|
.bdrv_flush = qcow_flush,
|
|
.bdrv_is_allocated = qcow_is_allocated,
|
|
.bdrv_set_key = qcow_set_key,
|
|
.bdrv_make_empty = qcow_make_empty,
|
|
.bdrv_co_readv = qcow_co_readv,
|
|
.bdrv_co_writev = qcow_co_writev,
|
|
.bdrv_aio_flush = qcow_aio_flush,
|
|
.bdrv_write_compressed = qcow_write_compressed,
|
|
.bdrv_get_info = qcow_get_info,
|
|
|
|
.create_options = qcow_create_options,
|
|
};
|
|
|
|
static void bdrv_qcow_init(void)
|
|
{
|
|
bdrv_register(&bdrv_qcow);
|
|
}
|
|
|
|
block_init(bdrv_qcow_init);
|