| /* |
| * Block driver for the QCOW format |
| * |
| * Copyright (c) 2004-2006 Fabrice Bellard |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| #include "qemu-common.h" |
| #include "block/block_int.h" |
| #include "qemu/module.h" |
| #include <zlib.h> |
| #include "qemu/aes.h" |
| #include "migration/migration.h" |
| |
| /**************************************************************/ |
| /* QEMU COW block driver with compression and encryption support */ |
| |
| #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
| #define QCOW_VERSION 1 |
| |
| #define QCOW_CRYPT_NONE 0 |
| #define QCOW_CRYPT_AES 1 |
| |
| #define QCOW_OFLAG_COMPRESSED (1LL << 63) |
| |
| typedef struct QCowHeader { |
| uint32_t magic; |
| uint32_t version; |
| uint64_t backing_file_offset; |
| uint32_t backing_file_size; |
| uint32_t mtime; |
| uint64_t size; /* in bytes */ |
| uint8_t cluster_bits; |
| uint8_t l2_bits; |
| uint32_t crypt_method; |
| uint64_t l1_table_offset; |
| } QCowHeader; |
| |
| #define L2_CACHE_SIZE 16 |
| |
| typedef struct BDRVQcowState { |
| int cluster_bits; |
| int cluster_size; |
| int cluster_sectors; |
| int l2_bits; |
| int l2_size; |
| int l1_size; |
| uint64_t cluster_offset_mask; |
| uint64_t l1_table_offset; |
| uint64_t *l1_table; |
| uint64_t *l2_cache; |
| uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
| uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
| uint8_t *cluster_cache; |
| uint8_t *cluster_data; |
| uint64_t cluster_cache_offset; |
| uint32_t crypt_method; /* current crypt method, 0 if no key yet */ |
| uint32_t crypt_method_header; |
| AES_KEY aes_encrypt_key; |
| AES_KEY aes_decrypt_key; |
| CoMutex lock; |
| Error *migration_blocker; |
| } BDRVQcowState; |
| |
| static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); |
| |
| static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
| { |
| const QCowHeader *cow_header = (const void *)buf; |
| |
| if (buf_size >= sizeof(QCowHeader) && |
| be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
| be32_to_cpu(cow_header->version) == QCOW_VERSION) |
| return 100; |
| else |
| return 0; |
| } |
| |
| static int qcow_open(BlockDriverState *bs, QDict *options, int flags) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int len, i, shift, ret; |
| QCowHeader header; |
| |
| ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); |
| if (ret < 0) { |
| goto fail; |
| } |
| be32_to_cpus(&header.magic); |
| be32_to_cpus(&header.version); |
| be64_to_cpus(&header.backing_file_offset); |
| be32_to_cpus(&header.backing_file_size); |
| be32_to_cpus(&header.mtime); |
| be64_to_cpus(&header.size); |
| be32_to_cpus(&header.crypt_method); |
| be64_to_cpus(&header.l1_table_offset); |
| |
| if (header.magic != QCOW_MAGIC) { |
| ret = -EMEDIUMTYPE; |
| goto fail; |
| } |
| if (header.version != QCOW_VERSION) { |
| char version[64]; |
| snprintf(version, sizeof(version), "QCOW version %d", header.version); |
| qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
| bs->device_name, "qcow", version); |
| ret = -ENOTSUP; |
| goto fail; |
| } |
| |
| if (header.size <= 1 || header.cluster_bits < 9) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| if (header.crypt_method > QCOW_CRYPT_AES) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| s->crypt_method_header = header.crypt_method; |
| if (s->crypt_method_header) { |
| bs->encrypted = 1; |
| } |
| s->cluster_bits = header.cluster_bits; |
| s->cluster_size = 1 << s->cluster_bits; |
| s->cluster_sectors = 1 << (s->cluster_bits - 9); |
| s->l2_bits = header.l2_bits; |
| s->l2_size = 1 << s->l2_bits; |
| bs->total_sectors = header.size / 512; |
| s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; |
| |
| /* read the level 1 table */ |
| shift = s->cluster_bits + s->l2_bits; |
| s->l1_size = (header.size + (1LL << shift) - 1) >> shift; |
| |
| s->l1_table_offset = header.l1_table_offset; |
| s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t)); |
| |
| ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, |
| s->l1_size * sizeof(uint64_t)); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| for(i = 0;i < s->l1_size; i++) { |
| be64_to_cpus(&s->l1_table[i]); |
| } |
| /* alloc L2 cache */ |
| s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
| s->cluster_cache = g_malloc(s->cluster_size); |
| s->cluster_data = g_malloc(s->cluster_size); |
| s->cluster_cache_offset = -1; |
| |
| /* read the backing file name */ |
| if (header.backing_file_offset != 0) { |
| len = header.backing_file_size; |
| if (len > 1023) { |
| len = 1023; |
| } |
| ret = bdrv_pread(bs->file, header.backing_file_offset, |
| bs->backing_file, len); |
| if (ret < 0) { |
| goto fail; |
| } |
| bs->backing_file[len] = '\0'; |
| } |
| |
| /* Disable migration when qcow images are used */ |
| error_set(&s->migration_blocker, |
| QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, |
| "qcow", bs->device_name, "live migration"); |
| migrate_add_blocker(s->migration_blocker); |
| |
| qemu_co_mutex_init(&s->lock); |
| return 0; |
| |
| fail: |
| g_free(s->l1_table); |
| g_free(s->l2_cache); |
| g_free(s->cluster_cache); |
| g_free(s->cluster_data); |
| return ret; |
| } |
| |
| |
| /* We have nothing to do for QCOW reopen, stubs just return |
| * success */ |
| static int qcow_reopen_prepare(BDRVReopenState *state, |
| BlockReopenQueue *queue, Error **errp) |
| { |
| return 0; |
| } |
| |
| static int qcow_set_key(BlockDriverState *bs, const char *key) |
| { |
| BDRVQcowState *s = bs->opaque; |
| uint8_t keybuf[16]; |
| int len, i; |
| |
| memset(keybuf, 0, 16); |
| len = strlen(key); |
| if (len > 16) |
| len = 16; |
| /* XXX: we could compress the chars to 7 bits to increase |
| entropy */ |
| for(i = 0;i < len;i++) { |
| keybuf[i] = key[i]; |
| } |
| s->crypt_method = s->crypt_method_header; |
| |
| if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
| return -1; |
| if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
| return -1; |
| return 0; |
| } |
| |
| /* The crypt function is compatible with the linux cryptoloop |
| algorithm for < 4 GB images. NOTE: out_buf == in_buf is |
| supported */ |
| static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
| uint8_t *out_buf, const uint8_t *in_buf, |
| int nb_sectors, int enc, |
| const AES_KEY *key) |
| { |
| union { |
| uint64_t ll[2]; |
| uint8_t b[16]; |
| } ivec; |
| int i; |
| |
| for(i = 0; i < nb_sectors; i++) { |
| ivec.ll[0] = cpu_to_le64(sector_num); |
| ivec.ll[1] = 0; |
| AES_cbc_encrypt(in_buf, out_buf, 512, key, |
| ivec.b, enc); |
| sector_num++; |
| in_buf += 512; |
| out_buf += 512; |
| } |
| } |
| |
| /* 'allocate' is: |
| * |
| * 0 to not allocate. |
| * |
| * 1 to allocate a normal cluster (for sector indexes 'n_start' to |
| * 'n_end') |
| * |
| * 2 to allocate a compressed cluster of size |
| * 'compressed_size'. 'compressed_size' must be > 0 and < |
| * cluster_size |
| * |
| * return 0 if not allocated. |
| */ |
| static uint64_t get_cluster_offset(BlockDriverState *bs, |
| uint64_t offset, int allocate, |
| int compressed_size, |
| int n_start, int n_end) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int min_index, i, j, l1_index, l2_index; |
| uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
| uint32_t min_count; |
| int new_l2_table; |
| |
| l1_index = offset >> (s->l2_bits + s->cluster_bits); |
| l2_offset = s->l1_table[l1_index]; |
| new_l2_table = 0; |
| if (!l2_offset) { |
| if (!allocate) |
| return 0; |
| /* allocate a new l2 entry */ |
| l2_offset = bdrv_getlength(bs->file); |
| /* round to cluster size */ |
| l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
| /* update the L1 entry */ |
| s->l1_table[l1_index] = l2_offset; |
| tmp = cpu_to_be64(l2_offset); |
| if (bdrv_pwrite_sync(bs->file, |
| s->l1_table_offset + l1_index * sizeof(tmp), |
| &tmp, sizeof(tmp)) < 0) |
| return 0; |
| new_l2_table = 1; |
| } |
| for(i = 0; i < L2_CACHE_SIZE; i++) { |
| if (l2_offset == s->l2_cache_offsets[i]) { |
| /* increment the hit count */ |
| if (++s->l2_cache_counts[i] == 0xffffffff) { |
| for(j = 0; j < L2_CACHE_SIZE; j++) { |
| s->l2_cache_counts[j] >>= 1; |
| } |
| } |
| l2_table = s->l2_cache + (i << s->l2_bits); |
| goto found; |
| } |
| } |
| /* not found: load a new entry in the least used one */ |
| min_index = 0; |
| min_count = 0xffffffff; |
| for(i = 0; i < L2_CACHE_SIZE; i++) { |
| if (s->l2_cache_counts[i] < min_count) { |
| min_count = s->l2_cache_counts[i]; |
| min_index = i; |
| } |
| } |
| l2_table = s->l2_cache + (min_index << s->l2_bits); |
| if (new_l2_table) { |
| memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
| if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table, |
| s->l2_size * sizeof(uint64_t)) < 0) |
| return 0; |
| } else { |
| if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != |
| 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 int coroutine_fn qcow_co_is_allocated(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; |
| return (cluster_offset != 0); |
| } |
| |
| 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_blockalign(bs, qiov->size); |
| } 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_blockalign(bs, qiov->size); |
| 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); |
| g_free(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, QEMUOptionParameter *options) |
| { |
| int header_size, backing_filename_len, l1_size, shift, i; |
| QCowHeader header; |
| uint8_t *tmp; |
| int64_t total_size = 0; |
| const char *backing_file = NULL; |
| int flags = 0; |
| int ret; |
| BlockDriverState *qcow_bs; |
| |
| /* 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++; |
| } |
| |
| ret = bdrv_create_file(filename, options); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| ret = bdrv_file_open(&qcow_bs, filename, NULL, BDRV_O_RDWR); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| 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 |
| 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 = 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_delete(qcow_bs); |
| 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); |
| |
| /* 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 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_reopen_prepare = qcow_reopen_prepare, |
| .bdrv_create = qcow_create, |
| |
| .bdrv_co_readv = qcow_co_readv, |
| .bdrv_co_writev = qcow_co_writev, |
| .bdrv_co_is_allocated = qcow_co_is_allocated, |
| |
| .bdrv_set_key = qcow_set_key, |
| .bdrv_make_empty = qcow_make_empty, |
| .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); |
