diff options
Diffstat (limited to 'block-qcow.c')
| -rw-r--r-- | block-qcow.c | 904 |
1 files changed, 0 insertions, 904 deletions
diff --git a/block-qcow.c b/block-qcow.c deleted file mode 100644 index 1fecf30..0000000 --- a/block-qcow.c +++ /dev/null @@ -1,904 +0,0 @@ -/* - * 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_int.h" -#include <zlib.h> -#include "aes.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 { - BlockDriverState *hd; - 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; -} BDRVQcowState; - -static int decompress_cluster(BDRVQcowState *s, 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, const char *filename, int flags) -{ - BDRVQcowState *s = bs->opaque; - int len, i, shift, ret; - QCowHeader header; - - ret = bdrv_file_open(&s->hd, filename, flags); - if (ret < 0) - return ret; - if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) - 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 || header.version != QCOW_VERSION) - goto fail; - if (header.size <= 1 || header.cluster_bits < 9) - goto fail; - if (header.crypt_method > QCOW_CRYPT_AES) - 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 = qemu_malloc(s->l1_size * sizeof(uint64_t)); - if (!s->l1_table) - goto fail; - if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) != - s->l1_size * sizeof(uint64_t)) - goto fail; - for(i = 0;i < s->l1_size; i++) { - be64_to_cpus(&s->l1_table[i]); - } - /* alloc L2 cache */ - s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); - if (!s->l2_cache) - goto fail; - s->cluster_cache = qemu_malloc(s->cluster_size); - if (!s->cluster_cache) - goto fail; - s->cluster_data = qemu_malloc(s->cluster_size); - if (!s->cluster_data) - goto fail; - 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; - if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len) - goto fail; - bs->backing_file[len] = '\0'; - } - return 0; - - fail: - qemu_free(s->l1_table); - qemu_free(s->l2_cache); - qemu_free(s->cluster_cache); - qemu_free(s->cluster_data); - bdrv_delete(s->hd); - return -1; -} - -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; -#if 0 - /* test */ - { - uint8_t in[16]; - uint8_t out[16]; - uint8_t tmp[16]; - for(i=0;i<16;i++) - in[i] = i; - AES_encrypt(in, tmp, &s->aes_encrypt_key); - AES_decrypt(tmp, out, &s->aes_decrypt_key); - for(i = 0; i < 16; i++) - printf(" %02x", tmp[i]); - printf("\n"); - for(i = 0; i < 16; i++) - printf(" %02x", out[i]); - printf("\n"); - } -#endif - 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(s->hd); - /* 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(s->hd, s->l1_table_offset + l1_index * sizeof(tmp), - &tmp, sizeof(tmp)) != sizeof(tmp)) - 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(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != - s->l2_size * sizeof(uint64_t)) - return 0; - } else { - if (bdrv_pread(s->hd, 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(s, cluster_offset) < 0) - return 0; - cluster_offset = bdrv_getlength(s->hd); - cluster_offset = (cluster_offset + s->cluster_size - 1) & - ~(s->cluster_size - 1); - /* write the cluster content */ - if (bdrv_pwrite(s->hd, cluster_offset, s->cluster_cache, s->cluster_size) != - s->cluster_size) - return -1; - } else { - cluster_offset = bdrv_getlength(s->hd); - /* round to cluster size */ - cluster_offset = (cluster_offset + s->cluster_size - 1) & - ~(s->cluster_size - 1); - bdrv_truncate(s->hd, 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(s->hd, cluster_offset + i * 512, - s->cluster_data, 512) != 512) - return -1; - } - } - } - } - /* update L2 table */ - tmp = cpu_to_be64(cluster_offset); - l2_table[l2_index] = tmp; - if (bdrv_pwrite(s->hd, - l2_offset + l2_index * sizeof(tmp), &tmp, sizeof(tmp)) != sizeof(tmp)) - return 0; - } - return cluster_offset; -} - -static int qcow_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; - - 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; - *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(BDRVQcowState *s, uint64_t cluster_offset) -{ - 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(s->hd, 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; -} - -#if 0 - -static int qcow_read(BlockDriverState *bs, int64_t sector_num, - uint8_t *buf, int nb_sectors) -{ - BDRVQcowState *s = bs->opaque; - int ret, index_in_cluster, n; - uint64_t cluster_offset; - - while (nb_sectors > 0) { - 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 */ - ret = bdrv_read(bs->backing_hd, sector_num, buf, n); - if (ret < 0) - return -1; - } else { - memset(buf, 0, 512 * n); - } - } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { - if (decompress_cluster(s, cluster_offset) < 0) - return -1; - memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); - } else { - ret = bdrv_pread(s->hd, 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 - -static int qcow_write(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) -{ - BDRVQcowState *s = bs->opaque; - int ret, index_in_cluster, n; - uint64_t cluster_offset; - - 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) - return -1; - if (s->crypt_method) { - encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1, - &s->aes_encrypt_key); - ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, - s->cluster_data, n * 512); - } else { - ret = bdrv_pwrite(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512); - } - if (ret != n * 512) - return -1; - nb_sectors -= n; - sector_num += n; - buf += n * 512; - } - s->cluster_cache_offset = -1; /* disable compressed cache */ - return 0; -} - -typedef struct QCowAIOCB { - BlockDriverAIOCB common; - int64_t sector_num; - uint8_t *buf; - int nb_sectors; - int n; - uint64_t cluster_offset; - uint8_t *cluster_data; - BlockDriverAIOCB *hd_aiocb; -} QCowAIOCB; - -static void qcow_aio_read_cb(void *opaque, int ret) -{ - QCowAIOCB *acb = opaque; - BlockDriverState *bs = acb->common.bs; - BDRVQcowState *s = bs->opaque; - int index_in_cluster; - - acb->hd_aiocb = NULL; - if (ret < 0) { - fail: - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); - return; - } - - redo: - /* post process the read buffer */ - if (!acb->cluster_offset) { - /* nothing to do */ - } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { - /* nothing to do */ - } else { - if (s->crypt_method) { - encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf, - acb->n, 0, - &s->aes_decrypt_key); - } - } - - acb->nb_sectors -= acb->n; - acb->sector_num += acb->n; - acb->buf += acb->n * 512; - - if (acb->nb_sectors == 0) { - /* request completed */ - acb->common.cb(acb->common.opaque, 0); - qemu_aio_release(acb); - return; - } - - /* prepare next AIO request */ - acb->cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, - 0, 0, 0, 0); - index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); - acb->n = s->cluster_sectors - index_in_cluster; - if (acb->n > acb->nb_sectors) - acb->n = acb->nb_sectors; - - if (!acb->cluster_offset) { - if (bs->backing_hd) { - /* read from the base image */ - acb->hd_aiocb = bdrv_aio_read(bs->backing_hd, - acb->sector_num, acb->buf, acb->n, qcow_aio_read_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; - } else { - /* Note: in this case, no need to wait */ - memset(acb->buf, 0, 512 * acb->n); - goto redo; - } - } else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) { - /* add AIO support for compressed blocks ? */ - if (decompress_cluster(s, acb->cluster_offset) < 0) - goto fail; - memcpy(acb->buf, - s->cluster_cache + index_in_cluster * 512, 512 * acb->n); - goto redo; - } else { - if ((acb->cluster_offset & 511) != 0) { - ret = -EIO; - goto fail; - } - acb->hd_aiocb = bdrv_aio_read(s->hd, - (acb->cluster_offset >> 9) + index_in_cluster, - acb->buf, acb->n, qcow_aio_read_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; - } -} - -static BlockDriverAIOCB *qcow_aio_read(BlockDriverState *bs, - int64_t sector_num, uint8_t *buf, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - QCowAIOCB *acb; - - acb = qemu_aio_get(bs, cb, opaque); - if (!acb) - return NULL; - acb->hd_aiocb = NULL; - acb->sector_num = sector_num; - acb->buf = buf; - acb->nb_sectors = nb_sectors; - acb->n = 0; - acb->cluster_offset = 0; - - qcow_aio_read_cb(acb, 0); - return &acb->common; -} - -static void qcow_aio_write_cb(void *opaque, int ret) -{ - QCowAIOCB *acb = opaque; - BlockDriverState *bs = acb->common.bs; - BDRVQcowState *s = bs->opaque; - int index_in_cluster; - uint64_t cluster_offset; - const uint8_t *src_buf; - - acb->hd_aiocb = NULL; - - if (ret < 0) { - fail: - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); - return; - } - - acb->nb_sectors -= acb->n; - acb->sector_num += acb->n; - acb->buf += acb->n * 512; - - if (acb->nb_sectors == 0) { - /* request completed */ - acb->common.cb(acb->common.opaque, 0); - qemu_aio_release(acb); - return; - } - - index_in_cluster = acb->sector_num & (s->cluster_sectors - 1); - acb->n = s->cluster_sectors - index_in_cluster; - if (acb->n > acb->nb_sectors) - acb->n = acb->nb_sectors; - cluster_offset = get_cluster_offset(bs, acb->sector_num << 9, 1, 0, - index_in_cluster, - index_in_cluster + acb->n); - if (!cluster_offset || (cluster_offset & 511) != 0) { - ret = -EIO; - goto fail; - } - if (s->crypt_method) { - if (!acb->cluster_data) { - acb->cluster_data = qemu_mallocz(s->cluster_size); - if (!acb->cluster_data) { - ret = -ENOMEM; - goto fail; - } - } - encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf, - acb->n, 1, &s->aes_encrypt_key); - src_buf = acb->cluster_data; - } else { - src_buf = acb->buf; - } - acb->hd_aiocb = bdrv_aio_write(s->hd, - (cluster_offset >> 9) + index_in_cluster, - src_buf, acb->n, - qcow_aio_write_cb, acb); - if (acb->hd_aiocb == NULL) - goto fail; -} - -static BlockDriverAIOCB *qcow_aio_write(BlockDriverState *bs, - int64_t sector_num, const uint8_t *buf, int nb_sectors, - BlockDriverCompletionFunc *cb, void *opaque) -{ - BDRVQcowState *s = bs->opaque; - QCowAIOCB *acb; - - s->cluster_cache_offset = -1; /* disable compressed cache */ - - acb = qemu_aio_get(bs, cb, opaque); - if (!acb) - return NULL; - acb->hd_aiocb = NULL; - acb->sector_num = sector_num; - acb->buf = (uint8_t *)buf; - acb->nb_sectors = nb_sectors; - acb->n = 0; - - qcow_aio_write_cb(acb, 0); - return &acb->common; -} - -static void qcow_aio_cancel(BlockDriverAIOCB *blockacb) -{ - QCowAIOCB *acb = (QCowAIOCB *)blockacb; - if (acb->hd_aiocb) - bdrv_aio_cancel(acb->hd_aiocb); - qemu_aio_release(acb); -} - -static void qcow_close(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - qemu_free(s->l1_table); - qemu_free(s->l2_cache); - qemu_free(s->cluster_cache); - qemu_free(s->cluster_data); - bdrv_delete(s->hd); -} - -static int qcow_create(const char *filename, int64_t total_size, - const char *backing_file, int flags) -{ - int fd, header_size, backing_filename_len, l1_size, i, shift; - QCowHeader header; - uint64_t tmp; - - fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); - if (fd < 0) - return -1; - 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 */ - write(fd, &header, sizeof(header)); - if (backing_file) { - write(fd, backing_file, backing_filename_len); - } - lseek(fd, header_size, SEEK_SET); - tmp = 0; - for(i = 0;i < l1_size; i++) { - write(fd, &tmp, sizeof(tmp)); - } - close(fd); - return 0; -} - -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(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0) - return -1; - ret = bdrv_truncate(s->hd, 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 = qemu_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) { - qemu_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) { - qemu_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 */ - qcow_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(s->hd, cluster_offset, out_buf, out_len) != out_len) { - qemu_free(out_buf); - return -1; - } - } - - qemu_free(out_buf); - return 0; -} - -static void qcow_flush(BlockDriverState *bs) -{ - BDRVQcowState *s = bs->opaque; - bdrv_flush(s->hd); -} - -static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) -{ - BDRVQcowState *s = bs->opaque; - bdi->cluster_size = s->cluster_size; - return 0; -} - -BlockDriver bdrv_qcow = { - "qcow", - sizeof(BDRVQcowState), - qcow_probe, - qcow_open, - NULL, - NULL, - qcow_close, - qcow_create, - qcow_flush, - qcow_is_allocated, - qcow_set_key, - qcow_make_empty, - - .bdrv_aio_read = qcow_aio_read, - .bdrv_aio_write = qcow_aio_write, - .bdrv_aio_cancel = qcow_aio_cancel, - .aiocb_size = sizeof(QCowAIOCB), - .bdrv_write_compressed = qcow_write_compressed, - .bdrv_get_info = qcow_get_info, -}; |