diff options
Diffstat (limited to 'qemu/block/qcow.c')
| -rw-r--r-- | qemu/block/qcow.c | 1050 |
1 files changed, 0 insertions, 1050 deletions
diff --git a/qemu/block/qcow.c b/qemu/block/qcow.c deleted file mode 100644 index 60ddb12ec..000000000 --- a/qemu/block/qcow.c +++ /dev/null @@ -1,1050 +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/osdep.h" -#include "qapi/error.h" -#include "qemu-common.h" -#include "qemu/error-report.h" -#include "block/block_int.h" -#include "sysemu/block-backend.h" -#include "qemu/module.h" -#include <zlib.h> -#include "qapi/qmp/qerror.h" -#include "crypto/cipher.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; - uint16_t padding; - uint32_t crypt_method; - uint64_t l1_table_offset; -} QEMU_PACKED QCowHeader; - -#define L2_CACHE_SIZE 16 - -typedef struct BDRVQcowState { - int cluster_bits; - int cluster_size; - int cluster_sectors; - int l2_bits; - int l2_size; - unsigned 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; - QCryptoCipher *cipher; /* NULL if no key yet */ - uint32_t crypt_method_header; - 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, - Error **errp) -{ - BDRVQcowState *s = bs->opaque; - unsigned int len, i, shift; - int ret; - QCowHeader header; - - ret = bdrv_pread(bs->file->bs, 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) { - error_setg(errp, "Image not in qcow format"); - ret = -EINVAL; - goto fail; - } - if (header.version != QCOW_VERSION) { - error_setg(errp, "Unsupported qcow version %" PRIu32, header.version); - ret = -ENOTSUP; - goto fail; - } - - if (header.size <= 1) { - error_setg(errp, "Image size is too small (must be at least 2 bytes)"); - ret = -EINVAL; - goto fail; - } - if (header.cluster_bits < 9 || header.cluster_bits > 16) { - error_setg(errp, "Cluster size must be between 512 and 64k"); - ret = -EINVAL; - goto fail; - } - - /* l2_bits specifies number of entries; storing a uint64_t in each entry, - * so bytes = num_entries << 3. */ - if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) { - error_setg(errp, "L2 table size must be between 512 and 64k"); - ret = -EINVAL; - goto fail; - } - - if (header.crypt_method > QCOW_CRYPT_AES) { - error_setg(errp, "invalid encryption method in qcow header"); - ret = -EINVAL; - goto fail; - } - if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) { - error_setg(errp, "AES cipher not available"); - ret = -EINVAL; - goto fail; - } - s->crypt_method_header = header.crypt_method; - if (s->crypt_method_header) { - if (bdrv_uses_whitelist() && - s->crypt_method_header == QCOW_CRYPT_AES) { - error_report("qcow built-in AES encryption is deprecated"); - error_printf("Support for it will be removed in a future release.\n" - "You can use 'qemu-img convert' to switch to an\n" - "unencrypted qcow image, or a LUKS raw image.\n"); - } - - 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; - if (header.size > UINT64_MAX - (1LL << shift)) { - error_setg(errp, "Image too large"); - ret = -EINVAL; - goto fail; - } else { - uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift; - if (l1_size > INT_MAX / sizeof(uint64_t)) { - error_setg(errp, "Image too large"); - ret = -EINVAL; - goto fail; - } - s->l1_size = l1_size; - } - - s->l1_table_offset = header.l1_table_offset; - s->l1_table = g_try_new(uint64_t, s->l1_size); - if (s->l1_table == NULL) { - error_setg(errp, "Could not allocate memory for L1 table"); - ret = -ENOMEM; - goto fail; - } - - ret = bdrv_pread(bs->file->bs, 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 (max. 64k * 16 * 8 = 8 MB) */ - s->l2_cache = - qemu_try_blockalign(bs->file->bs, - s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); - if (s->l2_cache == NULL) { - error_setg(errp, "Could not allocate L2 table cache"); - ret = -ENOMEM; - goto fail; - } - 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 >= sizeof(bs->backing_file)) { - error_setg(errp, "Backing file name too long"); - ret = -EINVAL; - goto fail; - } - ret = bdrv_pread(bs->file->bs, 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_setg(&s->migration_blocker, "The qcow format used by node '%s' " - "does not support live migration", - bdrv_get_device_or_node_name(bs)); - migrate_add_blocker(s->migration_blocker); - - qemu_co_mutex_init(&s->lock); - return 0; - - fail: - g_free(s->l1_table); - qemu_vfree(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; - Error *err; - - 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]; - } - assert(bs->encrypted); - - qcrypto_cipher_free(s->cipher); - s->cipher = qcrypto_cipher_new( - QCRYPTO_CIPHER_ALG_AES_128, - QCRYPTO_CIPHER_MODE_CBC, - keybuf, G_N_ELEMENTS(keybuf), - &err); - - if (!s->cipher) { - /* XXX would be nice if errors in this method could - * be properly propagate to the caller. Would need - * the bdrv_set_key() API signature to be fixed. */ - error_free(err); - 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 int encrypt_sectors(BDRVQcowState *s, int64_t sector_num, - uint8_t *out_buf, const uint8_t *in_buf, - int nb_sectors, bool enc, Error **errp) -{ - union { - uint64_t ll[2]; - uint8_t b[16]; - } ivec; - int i; - int ret; - - for(i = 0; i < nb_sectors; i++) { - ivec.ll[0] = cpu_to_le64(sector_num); - ivec.ll[1] = 0; - if (qcrypto_cipher_setiv(s->cipher, - ivec.b, G_N_ELEMENTS(ivec.b), - errp) < 0) { - return -1; - } - if (enc) { - ret = qcrypto_cipher_encrypt(s->cipher, - in_buf, - out_buf, - 512, - errp); - } else { - ret = qcrypto_cipher_decrypt(s->cipher, - in_buf, - out_buf, - 512, - errp); - } - if (ret < 0) { - return -1; - } - sector_num++; - in_buf += 512; - out_buf += 512; - } - return 0; -} - -/* '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->bs); - /* 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->bs, - 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->bs, l2_offset, l2_table, - s->l2_size * sizeof(uint64_t)) < 0) - return 0; - } else { - if (bdrv_pread(bs->file->bs, 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->bs); - cluster_offset = (cluster_offset + s->cluster_size - 1) & - ~(s->cluster_size - 1); - /* write the cluster content */ - if (bdrv_pwrite(bs->file->bs, cluster_offset, s->cluster_cache, - s->cluster_size) != - s->cluster_size) - return -1; - } else { - cluster_offset = bdrv_getlength(bs->file->bs); - if (allocate == 1) { - /* round to cluster size */ - cluster_offset = (cluster_offset + s->cluster_size - 1) & - ~(s->cluster_size - 1); - bdrv_truncate(bs->file->bs, cluster_offset + s->cluster_size); - /* if encrypted, we must initialize the cluster - content which won't be written */ - if (bs->encrypted && - (n_end - n_start) < s->cluster_sectors) { - uint64_t start_sect; - assert(s->cipher); - 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) { - Error *err = NULL; - if (encrypt_sectors(s, start_sect + i, - s->cluster_data, - s->cluster_data + 512, 1, - true, &err) < 0) { - error_free(err); - errno = EIO; - return -1; - } - if (bdrv_pwrite(bs->file->bs, - 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->bs, 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, BlockDriverState **file) -{ - 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->cipher) { - return BDRV_BLOCK_DATA; - } - cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); - *file = bs->file->bs; - 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->bs, 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; - Error *err = NULL; - - 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) { - /* 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->bs, 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->bs, - (cluster_offset >> 9) + index_in_cluster, - n, &hd_qiov); - qemu_co_mutex_lock(&s->lock); - if (ret < 0) { - break; - } - if (bs->encrypted) { - assert(s->cipher); - if (encrypt_sectors(s, sector_num, buf, buf, - n, false, &err) < 0) { - goto fail; - } - } - } - 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: - error_free(err); - 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 (bs->encrypted) { - Error *err = NULL; - assert(s->cipher); - if (!cluster_data) { - cluster_data = g_malloc0(s->cluster_size); - } - if (encrypt_sectors(s, sector_num, cluster_data, buf, - n, true, &err) < 0) { - error_free(err); - ret = -EIO; - break; - } - 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->bs, - (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; - - qcrypto_cipher_free(s->cipher); - s->cipher = NULL; - 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; - BlockBackend *qcow_blk; - - /* Read out options */ - total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), - BDRV_SECTOR_SIZE); - 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_blk = blk_new_open(filename, NULL, NULL, - BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err); - if (qcow_blk == NULL) { - error_propagate(errp, local_err); - ret = -EIO; - goto cleanup; - } - - blk_set_allow_write_beyond_eof(qcow_blk, true); - - ret = blk_truncate(qcow_blk, 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); - 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 + (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 = blk_pwrite(qcow_blk, 0, &header, sizeof(header)); - if (ret != sizeof(header)) { - goto exit; - } - - if (backing_file) { - ret = blk_pwrite(qcow_blk, 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 = blk_pwrite(qcow_blk, 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: - blk_unref(qcow_blk); -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->bs, s->l1_table_offset, s->l1_table, - l1_length) < 0) - return -1; - ret = bdrv_truncate(bs->file->bs, 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->bs, 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, - - .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_opts = &qcow_create_opts, -}; - -static void bdrv_qcow_init(void) -{ - bdrv_register(&bdrv_qcow); -} - -block_init(bdrv_qcow_init); |