VMDK: read/write compressed extent
Add support for reading/writing compressed extent. Signed-off-by: Fam Zheng <famcool@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
parent
432bb170af
commit
2b2c8c5dec
113
block/vmdk.c
113
block/vmdk.c
@ -775,10 +775,12 @@ static int get_cluster_offset(BlockDriverState *bs,
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/* Avoid the L2 tables update for the images that have snapshots. */
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*cluster_offset = bdrv_getlength(extent->file);
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bdrv_truncate(
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extent->file,
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*cluster_offset + (extent->cluster_sectors << 9)
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);
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if (!extent->compressed) {
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bdrv_truncate(
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extent->file,
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*cluster_offset + (extent->cluster_sectors << 9)
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);
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}
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*cluster_offset >>= 9;
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tmp = cpu_to_le32(*cluster_offset);
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@ -854,9 +856,28 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
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int nb_sectors, int64_t sector_num)
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{
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int ret;
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VmdkGrainMarker *data = NULL;
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uLongf buf_len;
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const uint8_t *write_buf = buf;
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int write_len = nb_sectors * 512;
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if (extent->compressed) {
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if (!extent->has_marker) {
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ret = -EINVAL;
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goto out;
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}
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buf_len = (extent->cluster_sectors << 9) * 2;
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data = g_malloc(buf_len + sizeof(VmdkGrainMarker));
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if (compress(data->data, &buf_len, buf, nb_sectors << 9) != Z_OK ||
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buf_len == 0) {
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ret = -EINVAL;
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goto out;
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}
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data->lba = sector_num;
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data->size = buf_len;
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write_buf = (uint8_t *)data;
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write_len = buf_len + sizeof(VmdkGrainMarker);
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}
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ret = bdrv_pwrite(extent->file,
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cluster_offset + offset_in_cluster,
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write_buf,
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@ -867,6 +888,7 @@ static int vmdk_write_extent(VmdkExtent *extent, int64_t cluster_offset,
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}
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ret = 0;
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out:
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g_free(data);
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return ret;
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}
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@ -875,15 +897,65 @@ static int vmdk_read_extent(VmdkExtent *extent, int64_t cluster_offset,
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int nb_sectors)
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{
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int ret;
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int cluster_bytes, buf_bytes;
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uint8_t *cluster_buf, *compressed_data;
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uint8_t *uncomp_buf;
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uint32_t data_len;
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VmdkGrainMarker *marker;
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uLongf buf_len;
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ret = bdrv_pread(extent->file,
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cluster_offset + offset_in_cluster,
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buf, nb_sectors * 512);
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if (ret == nb_sectors * 512) {
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return 0;
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} else {
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return -EIO;
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if (!extent->compressed) {
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ret = bdrv_pread(extent->file,
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cluster_offset + offset_in_cluster,
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buf, nb_sectors * 512);
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if (ret == nb_sectors * 512) {
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return 0;
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} else {
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return -EIO;
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}
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}
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cluster_bytes = extent->cluster_sectors * 512;
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/* Read two clusters in case GrainMarker + compressed data > one cluster */
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buf_bytes = cluster_bytes * 2;
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cluster_buf = g_malloc(buf_bytes);
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uncomp_buf = g_malloc(cluster_bytes);
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ret = bdrv_pread(extent->file,
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cluster_offset,
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cluster_buf, buf_bytes);
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if (ret < 0) {
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goto out;
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}
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compressed_data = cluster_buf;
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buf_len = cluster_bytes;
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data_len = cluster_bytes;
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if (extent->has_marker) {
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marker = (VmdkGrainMarker *)cluster_buf;
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compressed_data = marker->data;
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data_len = le32_to_cpu(marker->size);
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}
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if (!data_len || data_len > buf_bytes) {
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ret = -EINVAL;
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goto out;
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}
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ret = uncompress(uncomp_buf, &buf_len, compressed_data, data_len);
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if (ret != Z_OK) {
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ret = -EINVAL;
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goto out;
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}
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if (offset_in_cluster < 0 ||
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offset_in_cluster + nb_sectors * 512 > buf_len) {
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ret = -EINVAL;
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goto out;
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}
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memcpy(buf, uncomp_buf + offset_in_cluster, nb_sectors * 512);
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ret = 0;
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out:
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g_free(uncomp_buf);
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g_free(cluster_buf);
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return ret;
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}
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static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
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@ -963,8 +1035,25 @@ static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
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bs,
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extent,
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&m_data,
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sector_num << 9, 1,
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sector_num << 9, !extent->compressed,
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&cluster_offset);
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if (extent->compressed) {
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if (ret == 0) {
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/* Refuse write to allocated cluster for streamOptimized */
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fprintf(stderr,
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"VMDK: can't write to allocated cluster"
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" for streamOptimized\n");
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return -EIO;
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} else {
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/* allocate */
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ret = get_cluster_offset(
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bs,
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extent,
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&m_data,
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sector_num << 9, 1,
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&cluster_offset);
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}
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}
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if (ret) {
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return -EINVAL;
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}
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