--- /dev/null
+/*
+ * 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 "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, 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) {
+ char version[64];
+ snprintf(version, sizeof(version), "QCOW version %" PRIu32,
+ header.version);
+ error_setg(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+ bdrv_get_device_or_node_name(bs), "qcow", 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) {
+ 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, 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,
+ 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, 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);
+ /* 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 (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, 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->cipher) {
+ 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;
+ 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_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 (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,
+ (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;
+ BlockDriverState *qcow_bs;
+
+ /* 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_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);
+ 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 = 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,
+
+ .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);
Code Review / kvmfornfv.git / blobdiff