--- /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_int.h"
+#include "module.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);
+ if (allocate == 1) {
+ /* 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;
+ }
+ }
+ }
+ } 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(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
+
+typedef struct QCowAIOCB {
+ BlockDriverAIOCB common;
+ int64_t sector_num;
+ QEMUIOVector *qiov;
+ uint8_t *buf;
+ void *orig_buf;
+ int nb_sectors;
+ int n;
+ uint64_t cluster_offset;
+ uint8_t *cluster_data;
+ struct iovec hd_iov;
+ QEMUIOVector hd_qiov;
+ BlockDriverAIOCB *hd_aiocb;
+} QCowAIOCB;
+
+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 AIOPool qcow_aio_pool = {
+ .aiocb_size = sizeof(QCowAIOCB),
+ .cancel = qcow_aio_cancel,
+};
+
+static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque, int is_write)
+{
+ QCowAIOCB *acb;
+
+ acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
+ if (!acb)
+ return NULL;
+ acb->hd_aiocb = NULL;
+ acb->sector_num = sector_num;
+ acb->qiov = qiov;
+ if (qiov->niov > 1) {
+ acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
+ if (is_write)
+ qemu_iovec_to_buffer(qiov, acb->buf);
+ } else {
+ acb->buf = (uint8_t *)qiov->iov->iov_base;
+ }
+ acb->nb_sectors = nb_sectors;
+ acb->n = 0;
+ acb->cluster_offset = 0;
+ return acb;
+}
+
+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)
+ goto done;
+
+ 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 */
+ ret = 0;
+ goto done;
+ }
+
+ /* 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_iov.iov_base = (void *)acb->buf;
+ acb->hd_iov.iov_len = acb->n * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
+ &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
+ if (acb->hd_aiocb == NULL)
+ goto done;
+ } 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 done;
+ 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 done;
+ }
+ acb->hd_iov.iov_base = (void *)acb->buf;
+ acb->hd_iov.iov_len = acb->n * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ acb->hd_aiocb = bdrv_aio_readv(s->hd,
+ (acb->cluster_offset >> 9) + index_in_cluster,
+ &acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
+ if (acb->hd_aiocb == NULL)
+ goto done;
+ }
+
+ return;
+
+done:
+ if (acb->qiov->niov > 1) {
+ qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
+ qemu_vfree(acb->orig_buf);
+ }
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
+}
+
+static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ QCowAIOCB *acb;
+
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ if (!acb)
+ return NULL;
+
+ 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)
+ goto done;
+
+ acb->nb_sectors -= acb->n;
+ acb->sector_num += acb->n;
+ acb->buf += acb->n * 512;
+
+ if (acb->nb_sectors == 0) {
+ /* request completed */
+ ret = 0;
+ goto done;
+ }
+
+ 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 done;
+ }
+ if (s->crypt_method) {
+ if (!acb->cluster_data) {
+ acb->cluster_data = qemu_mallocz(s->cluster_size);
+ if (!acb->cluster_data) {
+ ret = -ENOMEM;
+ goto done;
+ }
+ }
+ 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_iov.iov_base = (void *)src_buf;
+ acb->hd_iov.iov_len = acb->n * 512;
+ qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+ acb->hd_aiocb = bdrv_aio_writev(s->hd,
+ (cluster_offset >> 9) + index_in_cluster,
+ &acb->hd_qiov, acb->n,
+ qcow_aio_write_cb, acb);
+ if (acb->hd_aiocb == NULL)
+ goto done;
+ return;
+
+done:
+ if (acb->qiov->niov > 1)
+ qemu_vfree(acb->orig_buf);
+ acb->common.cb(acb->common.opaque, ret);
+ qemu_aio_release(acb);
+}
+
+static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
+ int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
+ BlockDriverCompletionFunc *cb, void *opaque)
+{
+ BDRVQcowState *s = bs->opaque;
+ QCowAIOCB *acb;
+
+ s->cluster_cache_offset = -1; /* disable compressed cache */
+
+ acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
+ if (!acb)
+ return NULL;
+
+
+ qcow_aio_write_cb(acb, 0);
+ return &acb->common;
+}
+
+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, QEMUOptionParameter *options)
+{
+ int fd, header_size, backing_filename_len, l1_size, i, shift;
+ QCowHeader header;
+ uint64_t tmp;
+ int64_t total_size = 0;
+ const char *backing_file = NULL;
+ int flags = 0;
+
+ /* 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++;
+ }
+
+ 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 */
+ bdrv_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;
+}
+
+
+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_create = qcow_create,
+ .bdrv_flush = qcow_flush,
+ .bdrv_is_allocated = qcow_is_allocated,
+ .bdrv_set_key = qcow_set_key,
+ .bdrv_make_empty = qcow_make_empty,
+ .bdrv_aio_readv = qcow_aio_readv,
+ .bdrv_aio_writev = qcow_aio_writev,
+ .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);
projects / qemu / blobdiff