On Mon, 07/07 10:54, Milos Vyletel wrote:
> VMDK's streamOptimized format is different that regular sparse format.
s/that/from/
> L1(GD) and L2(GT) tables are not predefined but rather generated and
> written during image creation mainly because there is no way to tell
> how much space data will occupy once they are compressed. Also the
> location of header, L1 and L2 tables differs.
s/differs/differ/
>
> - L2 tables (grain tables) are written after all grains they point to
> - L1 tables are written after all grains and L2 tables
> - footer at the end is used instead of header in first sector
>
> This patch improves streamOptimized support and adds possibility to
> create true streamOptimized images using qemu-img. Some of the changes
> are from VMDK specs, some of them from hexdump-ing images from VMWare
> and VirtualBox.
>
> I have compared these images to the ones generated by VMWare and vbox
> and they are identical with the exception of DescriptorFile that has
> some differences but none that would change behavior(CID and some
> additional DDB entries differ) and streamOptimized image generated from
> raw image was succesfully imported (as OVA) into VMWare ESXi and Oracle
> OVM.
>
> Signed-off-by: Milos Vyletel <milos.vyle...@gmail.com>
> ---
> block/vmdk.c | 363
> +++++++++++++++++++++++++++++++++++++++++++++-------------
> 1 files changed, 281 insertions(+), 82 deletions(-)
>
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 27a78da..f482225 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -81,6 +81,21 @@ typedef struct {
> uint16_t compressAlgorithm;
> } QEMU_PACKED VMDK4Header;
>
> +typedef struct {
> + uint64_t val;
> + uint32_t size;
> + uint32_t type;
> + uint8_t pad[BDRV_SECTOR_SIZE - sizeof(uint64_t) - 2*sizeof(uint32_t)];
> +} QEMU_PACKED VMDK4MetaMarker;
> +
> +typedef struct {
> + VMDK4MetaMarker footer_marker;
> + uint32_t magic;
> + VMDK4Header header;
> + uint8_t pad[BDRV_SECTOR_SIZE - sizeof(uint32_t) - sizeof(VMDK4Header)];
> + VMDK4MetaMarker eos_marker;
> +} QEMU_PACKED VMDK4Footer;
> +
> #define L2_CACHE_SIZE 16
>
> typedef struct VmdkExtent {
> @@ -89,24 +104,29 @@ typedef struct VmdkExtent {
> bool compressed;
> bool has_marker;
> bool has_zero_grain;
> + bool has_footer;
> int version;
> int64_t sectors;
> int64_t end_sector;
> int64_t flat_start_offset;
> int64_t l1_table_offset;
> int64_t l1_backup_table_offset;
> + uint32_t l1_index;
Could you track the allocation staus of grain table with l1_table entry value?
For those with value 0, we allocate grain table in file, and update its l1
entry. That way the fields l1_index and l2_table are not necessary here.
> uint32_t *l1_table;
> uint32_t *l1_backup_table;
> unsigned int l1_size;
> uint32_t l1_entry_sectors;
>
> unsigned int l2_size;
> + uint32_t *l2_table;
> uint32_t *l2_cache;
> uint32_t l2_cache_offsets[L2_CACHE_SIZE];
> uint32_t l2_cache_counts[L2_CACHE_SIZE];
>
> int64_t cluster_sectors;
> char *type;
> +
> + VMDK4Footer footer;
> } VmdkExtent;
<snip>
>
> typedef struct BDRVVmdkState {
> @@ -1026,6 +1066,97 @@ static int vmdk_L2update(VmdkExtent *extent,
> VmdkMetaData *m_data)
> return VMDK_OK;
> }
>
> +static int vmdk_write_footer(BlockDriverState *bs,
> + VMDK4Footer *footer,
> + VmdkExtent *extent)
Bad alignment.
> +{
> + int i, ret, gd_buf_size;
> + uint32_t *gd_buf = NULL;
> + uint32_t grains, gd_sectors, gt_size, gt_count;
> + uint64_t offset;
> + VMDK4Header header;
> + VMDK4MetaMarker gd_marker;
> +
> + header = footer->header;
> + offset = le64_to_cpu(header.gd_offset);
> +
> + grains = DIV_ROUND_UP(header.capacity, header.granularity);
> + gt_size = DIV_ROUND_UP(header.num_gtes_per_gt * sizeof(uint32_t),
> + BDRV_SECTOR_SIZE);
> + gt_count = DIV_ROUND_UP(grains, header.num_gtes_per_gt);
> + gd_sectors = DIV_ROUND_UP(gt_count * sizeof(uint32_t), BDRV_SECTOR_SIZE);
> +
> + /* write grain directory marker */
> + memset(&gd_marker, 0, sizeof(gd_marker));
> + gd_marker.val = cpu_to_le64(gd_sectors);
> + gd_marker.type = cpu_to_le32(MARKER_GRAIN_DIRECTORY);
> +
> + ret = bdrv_pwrite(bs, offset * BDRV_SECTOR_SIZE, &gd_marker,
> sizeof(gd_marker));
> + if (ret < 0)
> + goto exit;
Always add braces around if body. Again, scripts/checkpatch.pl can help
check style issue.
> + offset += sizeof(gd_marker) / BDRV_SECTOR_SIZE;
> +
> + /* write grain directory */
> + gd_buf_size = gd_sectors * BDRV_SECTOR_SIZE;
> + gd_buf = g_malloc0(gd_buf_size);
gd_buf is never freed.
> + if (extent) {
> + /* copy over L1 table if we have it */
> + for (i = 0; i < gt_count; i++) {
> + gd_buf[i] = cpu_to_le32(extent->l1_table[i]);
> + }
> + }
> + ret = bdrv_pwrite(bs, offset * BDRV_SECTOR_SIZE, gd_buf, gd_buf_size);
> + if (ret < 0)
> + goto exit;
> +
> + /* save real gd_offset */
> + footer->header.gd_offset = cpu_to_le64(offset);
> + offset += gd_sectors;
> +
> + /* write footer */
> + ret = bdrv_pwrite(bs, offset * BDRV_SECTOR_SIZE, footer,
> sizeof(*footer));
> + if (ret < 0)
> + goto exit;
> +
> + ret = 0;
> + exit:
> + return ret;
> +}
<snip>
> static int get_cluster_offset(BlockDriverState *bs,
> VmdkExtent *extent,
> VmdkMetaData *m_data,
> @@ -1034,8 +1165,8 @@ static int get_cluster_offset(BlockDriverState *bs,
> uint64_t *cluster_offset)
> {
> unsigned int l1_index, l2_offset, l2_index;
> - int min_index, i, j;
> - uint32_t min_count, *l2_table;
> + int min_index, i, j, ret;
> + uint32_t min_count;
> bool zeroed = false;
>
> if (m_data) {
> @@ -1048,11 +1179,25 @@ static int get_cluster_offset(BlockDriverState *bs,
>
> offset -= (extent->end_sector - extent->sectors) * SECTOR_SIZE;
> l1_index = (offset >> 9) / extent->l1_entry_sectors;
> - if (l1_index >= extent->l1_size) {
> + if (extent->compressed && l1_index &&
> + extent->l1_index != l1_index) {
> + ret = vmdk_write_grain_table(extent);
> + if (ret < 0)
> + return ret;
> + }
> +
> + extent->l1_index = l1_index;
> + if (extent->l1_index >= extent->l1_size) {
> return VMDK_ERROR;
> }
> - l2_offset = extent->l1_table[l1_index];
> + retry:
> + l2_offset = extent->l1_table[extent->l1_index];
> +
> if (!l2_offset) {
> + if (extent->compressed) {
> + extent->l1_table[extent->l1_index] =
> bdrv_getlength(extent->file);
This control flow desn't make sense. We just write a new grain table at the end
of file and update the l1_table entry.
> + goto retry;
> + }
> return VMDK_UNALLOC;
> }
> for (i = 0; i < L2_CACHE_SIZE; i++) {
