983 lines
30 KiB
C
983 lines
30 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/block_int.h"
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#include "qemu/module.h"
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#include <zlib.h>
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#include "qemu/aes.h"
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#include "migration/migration.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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uint16_t padding;
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uint32_t crypt_method;
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uint64_t l1_table_offset;
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} QEMU_PACKED 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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unsigned 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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Error *migration_blocker;
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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, QDict *options, int flags,
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Error **errp)
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{
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BDRVQcowState *s = bs->opaque;
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unsigned int len, i, shift;
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int ret;
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QCowHeader header;
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ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
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if (ret < 0) {
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goto fail;
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}
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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) {
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error_setg(errp, "Image not in qcow format");
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ret = -EINVAL;
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goto fail;
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}
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if (header.version != QCOW_VERSION) {
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char version[64];
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snprintf(version, sizeof(version), "QCOW version %" PRIu32,
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header.version);
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error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
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bs->device_name, "qcow", version);
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ret = -ENOTSUP;
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goto fail;
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}
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if (header.size <= 1) {
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error_setg(errp, "Image size is too small (must be at least 2 bytes)");
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ret = -EINVAL;
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goto fail;
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}
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if (header.cluster_bits < 9 || header.cluster_bits > 16) {
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error_setg(errp, "Cluster size must be between 512 and 64k");
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ret = -EINVAL;
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goto fail;
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}
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/* l2_bits specifies number of entries; storing a uint64_t in each entry,
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* so bytes = num_entries << 3. */
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if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
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error_setg(errp, "L2 table size must be between 512 and 64k");
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ret = -EINVAL;
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goto fail;
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}
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if (header.crypt_method > QCOW_CRYPT_AES) {
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error_setg(errp, "invalid encryption method in qcow header");
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ret = -EINVAL;
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goto fail;
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}
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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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}
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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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if (header.size > UINT64_MAX - (1LL << shift)) {
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error_setg(errp, "Image too large");
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ret = -EINVAL;
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goto fail;
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} else {
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uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
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if (l1_size > INT_MAX / sizeof(uint64_t)) {
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error_setg(errp, "Image too large");
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ret = -EINVAL;
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goto fail;
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}
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s->l1_size = l1_size;
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}
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s->l1_table_offset = header.l1_table_offset;
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s->l1_table = g_try_malloc(s->l1_size * sizeof(uint64_t));
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if (s->l1_table == NULL) {
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error_setg(errp, "Could not allocate memory for L1 table");
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ret = -ENOMEM;
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goto fail;
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}
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ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
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s->l1_size * sizeof(uint64_t));
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if (ret < 0) {
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goto fail;
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}
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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 (max. 64k * 16 * 8 = 8 MB) */
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s->l2_cache =
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qemu_try_blockalign(bs->file,
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s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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if (s->l2_cache == NULL) {
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error_setg(errp, "Could not allocate L2 table cache");
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ret = -ENOMEM;
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goto fail;
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}
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s->cluster_cache = g_malloc(s->cluster_size);
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s->cluster_data = g_malloc(s->cluster_size);
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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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error_setg(errp, "Backing file name too long");
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ret = -EINVAL;
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goto fail;
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}
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ret = bdrv_pread(bs->file, header.backing_file_offset,
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bs->backing_file, len);
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if (ret < 0) {
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goto fail;
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}
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bs->backing_file[len] = '\0';
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}
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/* Disable migration when qcow images are used */
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error_set(&s->migration_blocker,
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QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
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"qcow", bs->device_name, "live migration");
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migrate_add_blocker(s->migration_blocker);
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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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qemu_vfree(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 ret;
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}
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/* We have nothing to do for QCOW reopen, stubs just return
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* success */
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static int qcow_reopen_prepare(BDRVReopenState *state,
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BlockReopenQueue *queue, Error **errp)
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{
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return 0;
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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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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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|
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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 {
|
|
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))
|
|
return 0;
|
|
}
|
|
s->l2_cache_offsets[min_index] = l2_offset;
|
|
s->l2_cache_counts[min_index] = 1;
|
|
found:
|
|
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
|
cluster_offset = be64_to_cpu(l2_table[l2_index]);
|
|
if (!cluster_offset ||
|
|
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
|
if (!allocate)
|
|
return 0;
|
|
/* allocate a new cluster */
|
|
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
|
(n_end - n_start) < s->cluster_sectors) {
|
|
/* if the cluster is already compressed, we must
|
|
decompress it in the case it is not completely
|
|
overwritten */
|
|
if (decompress_cluster(bs, cluster_offset) < 0)
|
|
return 0;
|
|
cluster_offset = bdrv_getlength(bs->file);
|
|
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
|
~(s->cluster_size - 1);
|
|
/* write the cluster content */
|
|
if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
|
|
s->cluster_size)
|
|
return -1;
|
|
} else {
|
|
cluster_offset = bdrv_getlength(bs->file);
|
|
if (allocate == 1) {
|
|
/* round to cluster size */
|
|
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
|
~(s->cluster_size - 1);
|
|
bdrv_truncate(bs->file, cluster_offset + s->cluster_size);
|
|
/* if encrypted, we must initialize the cluster
|
|
content which won't be written */
|
|
if (s->crypt_method &&
|
|
(n_end - n_start) < s->cluster_sectors) {
|
|
uint64_t start_sect;
|
|
start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
|
|
memset(s->cluster_data + 512, 0x00, 512);
|
|
for(i = 0; i < s->cluster_sectors; i++) {
|
|
if (i < n_start || i >= n_end) {
|
|
encrypt_sectors(s, start_sect + i,
|
|
s->cluster_data,
|
|
s->cluster_data + 512, 1, 1,
|
|
&s->aes_encrypt_key);
|
|
if (bdrv_pwrite(bs->file, cluster_offset + i * 512,
|
|
s->cluster_data, 512) != 512)
|
|
return -1;
|
|
}
|
|
}
|
|
}
|
|
} else if (allocate == 2) {
|
|
cluster_offset |= QCOW_OFLAG_COMPRESSED |
|
|
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
|
}
|
|
}
|
|
/* update L2 table */
|
|
tmp = cpu_to_be64(cluster_offset);
|
|
l2_table[l2_index] = tmp;
|
|
if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
|
|
&tmp, sizeof(tmp)) < 0)
|
|
return 0;
|
|
}
|
|
return cluster_offset;
|
|
}
|
|
|
|
static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
|
|
int64_t sector_num, int nb_sectors, int *pnum)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster, n;
|
|
uint64_t cluster_offset;
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
n = s->cluster_sectors - index_in_cluster;
|
|
if (n > nb_sectors)
|
|
n = nb_sectors;
|
|
*pnum = n;
|
|
if (!cluster_offset) {
|
|
return 0;
|
|
}
|
|
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypt_method) {
|
|
return BDRV_BLOCK_DATA;
|
|
}
|
|
cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
|
|
return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset;
|
|
}
|
|
|
|
static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
z_stream strm1, *strm = &strm1;
|
|
int ret, out_len;
|
|
|
|
memset(strm, 0, sizeof(*strm));
|
|
|
|
strm->next_in = (uint8_t *)buf;
|
|
strm->avail_in = buf_size;
|
|
strm->next_out = out_buf;
|
|
strm->avail_out = out_buf_size;
|
|
|
|
ret = inflateInit2(strm, -12);
|
|
if (ret != Z_OK)
|
|
return -1;
|
|
ret = inflate(strm, Z_FINISH);
|
|
out_len = strm->next_out - out_buf;
|
|
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
|
out_len != out_buf_size) {
|
|
inflateEnd(strm);
|
|
return -1;
|
|
}
|
|
inflateEnd(strm);
|
|
return 0;
|
|
}
|
|
|
|
static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int ret, csize;
|
|
uint64_t coffset;
|
|
|
|
coffset = cluster_offset & s->cluster_offset_mask;
|
|
if (s->cluster_cache_offset != coffset) {
|
|
csize = cluster_offset >> (63 - s->cluster_bits);
|
|
csize &= (s->cluster_size - 1);
|
|
ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
|
|
if (ret != csize)
|
|
return -1;
|
|
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
|
s->cluster_data, csize) < 0) {
|
|
return -1;
|
|
}
|
|
s->cluster_cache_offset = coffset;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
int ret = 0, n;
|
|
uint64_t cluster_offset;
|
|
struct iovec hd_iov;
|
|
QEMUIOVector hd_qiov;
|
|
uint8_t *buf;
|
|
void *orig_buf;
|
|
|
|
if (qiov->niov > 1) {
|
|
buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
|
|
if (buf == NULL) {
|
|
return -ENOMEM;
|
|
}
|
|
} else {
|
|
orig_buf = NULL;
|
|
buf = (uint8_t *)qiov->iov->iov_base;
|
|
}
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
|
|
while (nb_sectors != 0) {
|
|
/* prepare next request */
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9,
|
|
0, 0, 0, 0);
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
n = s->cluster_sectors - index_in_cluster;
|
|
if (n > nb_sectors) {
|
|
n = nb_sectors;
|
|
}
|
|
|
|
if (!cluster_offset) {
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
hd_iov.iov_base = (void *)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, sector_num,
|
|
n, &hd_qiov);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
} else {
|
|
/* Note: in this case, no need to wait */
|
|
memset(buf, 0, 512 * n);
|
|
}
|
|
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* add AIO support for compressed blocks ? */
|
|
if (decompress_cluster(bs, cluster_offset) < 0) {
|
|
goto fail;
|
|
}
|
|
memcpy(buf,
|
|
s->cluster_cache + index_in_cluster * 512, 512 * n);
|
|
} else {
|
|
if ((cluster_offset & 511) != 0) {
|
|
goto fail;
|
|
}
|
|
hd_iov.iov_base = (void *)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) {
|
|
break;
|
|
}
|
|
if (s->crypt_method) {
|
|
encrypt_sectors(s, sector_num, buf, buf,
|
|
n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
ret = 0;
|
|
|
|
nb_sectors -= n;
|
|
sector_num += n;
|
|
buf += n * 512;
|
|
}
|
|
|
|
done:
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
if (qiov->niov > 1) {
|
|
qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
|
|
qemu_vfree(orig_buf);
|
|
}
|
|
|
|
return ret;
|
|
|
|
fail:
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
|
|
static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, QEMUIOVector *qiov)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
uint64_t cluster_offset;
|
|
const uint8_t *src_buf;
|
|
int ret = 0, n;
|
|
uint8_t *cluster_data = NULL;
|
|
struct iovec hd_iov;
|
|
QEMUIOVector hd_qiov;
|
|
uint8_t *buf;
|
|
void *orig_buf;
|
|
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
|
|
if (qiov->niov > 1) {
|
|
buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
|
|
if (buf == NULL) {
|
|
return -ENOMEM;
|
|
}
|
|
qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
|
|
} else {
|
|
orig_buf = NULL;
|
|
buf = (uint8_t *)qiov->iov->iov_base;
|
|
}
|
|
|
|
qemu_co_mutex_lock(&s->lock);
|
|
|
|
while (nb_sectors != 0) {
|
|
|
|
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
|
n = s->cluster_sectors - index_in_cluster;
|
|
if (n > nb_sectors) {
|
|
n = nb_sectors;
|
|
}
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0,
|
|
index_in_cluster,
|
|
index_in_cluster + n);
|
|
if (!cluster_offset || (cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
if (s->crypt_method) {
|
|
if (!cluster_data) {
|
|
cluster_data = g_malloc0(s->cluster_size);
|
|
}
|
|
encrypt_sectors(s, sector_num, cluster_data, buf,
|
|
n, 1, &s->aes_encrypt_key);
|
|
src_buf = cluster_data;
|
|
} else {
|
|
src_buf = 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);
|
|
qemu_co_mutex_lock(&s->lock);
|
|
if (ret < 0) {
|
|
break;
|
|
}
|
|
ret = 0;
|
|
|
|
nb_sectors -= n;
|
|
sector_num += n;
|
|
buf += n * 512;
|
|
}
|
|
qemu_co_mutex_unlock(&s->lock);
|
|
|
|
if (qiov->niov > 1) {
|
|
qemu_vfree(orig_buf);
|
|
}
|
|
g_free(cluster_data);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void qcow_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
|
|
g_free(s->l1_table);
|
|
qemu_vfree(s->l2_cache);
|
|
g_free(s->cluster_cache);
|
|
g_free(s->cluster_data);
|
|
|
|
migrate_del_blocker(s->migration_blocker);
|
|
error_free(s->migration_blocker);
|
|
}
|
|
|
|
static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
|
|
{
|
|
int header_size, backing_filename_len, l1_size, shift, i;
|
|
QCowHeader header;
|
|
uint8_t *tmp;
|
|
int64_t total_size = 0;
|
|
char *backing_file = NULL;
|
|
int flags = 0;
|
|
Error *local_err = NULL;
|
|
int ret;
|
|
BlockDriverState *qcow_bs;
|
|
|
|
/* Read out options */
|
|
total_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0) / 512;
|
|
backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
|
|
if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
|
|
flags |= BLOCK_FLAG_ENCRYPT;
|
|
}
|
|
|
|
ret = bdrv_create_file(filename, opts, &local_err);
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
goto cleanup;
|
|
}
|
|
|
|
qcow_bs = NULL;
|
|
ret = bdrv_open(&qcow_bs, filename, NULL, NULL,
|
|
BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err);
|
|
if (ret < 0) {
|
|
error_propagate(errp, local_err);
|
|
goto cleanup;
|
|
}
|
|
|
|
ret = bdrv_truncate(qcow_bs, 0);
|
|
if (ret < 0) {
|
|
goto exit;
|
|
}
|
|
|
|
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
|
|
unmodified 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 = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header));
|
|
if (ret != sizeof(header)) {
|
|
goto exit;
|
|
}
|
|
|
|
if (backing_file) {
|
|
ret = bdrv_pwrite(qcow_bs, sizeof(header),
|
|
backing_file, backing_filename_len);
|
|
if (ret != backing_filename_len) {
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
tmp = g_malloc0(BDRV_SECTOR_SIZE);
|
|
for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/
|
|
BDRV_SECTOR_SIZE); i++) {
|
|
ret = bdrv_pwrite(qcow_bs, header_size +
|
|
BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE);
|
|
if (ret != BDRV_SECTOR_SIZE) {
|
|
g_free(tmp);
|
|
goto exit;
|
|
}
|
|
}
|
|
|
|
g_free(tmp);
|
|
ret = 0;
|
|
exit:
|
|
bdrv_unref(qcow_bs);
|
|
cleanup:
|
|
g_free(backing_file);
|
|
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) {
|
|
ret = -EINVAL;
|
|
|
|
/* Zero-pad last write if image size is not cluster aligned */
|
|
if (sector_num + nb_sectors == bs->total_sectors &&
|
|
nb_sectors < s->cluster_sectors) {
|
|
uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
|
|
memset(pad_buf, 0, s->cluster_size);
|
|
memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE);
|
|
ret = qcow_write_compressed(bs, sector_num,
|
|
pad_buf, s->cluster_sectors);
|
|
qemu_vfree(pad_buf);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
|
|
|
|
/* 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) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
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) {
|
|
deflateEnd(&strm);
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
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 */
|
|
ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
} else {
|
|
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
|
|
out_len, 0, 0);
|
|
if (cluster_offset == 0) {
|
|
ret = -EIO;
|
|
goto fail;
|
|
}
|
|
|
|
cluster_offset &= s->cluster_offset_mask;
|
|
ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
fail:
|
|
g_free(out_buf);
|
|
return ret;
|
|
}
|
|
|
|
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdi->cluster_size = s->cluster_size;
|
|
return 0;
|
|
}
|
|
|
|
static QemuOptsList qcow_create_opts = {
|
|
.name = "qcow-create-opts",
|
|
.head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
|
|
.desc = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = QEMU_OPT_SIZE,
|
|
.help = "Virtual disk size"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FILE,
|
|
.type = QEMU_OPT_STRING,
|
|
.help = "File name of a base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_ENCRYPT,
|
|
.type = QEMU_OPT_BOOL,
|
|
.help = "Encrypt the image",
|
|
.def_value_str = "off"
|
|
},
|
|
{ /* end of list */ }
|
|
}
|
|
};
|
|
|
|
static BlockDriver bdrv_qcow = {
|
|
.format_name = "qcow",
|
|
.instance_size = sizeof(BDRVQcowState),
|
|
.bdrv_probe = qcow_probe,
|
|
.bdrv_open = qcow_open,
|
|
.bdrv_close = qcow_close,
|
|
.bdrv_reopen_prepare = qcow_reopen_prepare,
|
|
.bdrv_create = qcow_create,
|
|
.bdrv_has_zero_init = bdrv_has_zero_init_1,
|
|
.supports_backing = true,
|
|
|
|
.bdrv_co_readv = qcow_co_readv,
|
|
.bdrv_co_writev = qcow_co_writev,
|
|
.bdrv_co_get_block_status = qcow_co_get_block_status,
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.bdrv_set_key = qcow_set_key,
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.bdrv_make_empty = qcow_make_empty,
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.bdrv_write_compressed = qcow_write_compressed,
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|
.bdrv_get_info = qcow_get_info,
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|
|
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.create_opts = &qcow_create_opts,
|
|
};
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static void bdrv_qcow_init(void)
|
|
{
|
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bdrv_register(&bdrv_qcow);
|
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}
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|
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block_init(bdrv_qcow_init);
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