Re: [Qemu-devel] [PATCH v2] vmdk: fix cluster size check for flat extents

[Fam Zheng <famz@redhat.com>]

On Mon, 09/23 17:18, Fam Zheng wrote:
> We use the extent size as cluster size for flat extents (where no L1/L2
> table is allocated so it's safe) reuse sector calculating code with
> sparse extents.
> 
> Don't pass in the cluster size for adding flat extent, just set it to
> sectors later, then the cluster size checking will not fail.
> 
> The cluster_sectors is changed to int64_t to allow big flat extent.
> 
> Without this, flat extent opening is broken:
> 
>     # qemu-img create -f vmdk -o subformat=monolithicFlat /tmp/a.vmdk 100G
>     Formatting '/tmp/a.vmdk', fmt=vmdk size=107374182400 compat6=off subformat='monolithicFlat' zeroed_grain=off
>     # qemu-img info /tmp/a.vmdk
>     image: /tmp/a.vmdk
>     file format: raw
>     virtual size: 0 (0 bytes)
>     disk size: 4.0K
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/vmdk.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 96ef1b5..5d56e31 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -105,7 +105,7 @@ typedef struct VmdkExtent {
>      uint32_t l2_cache_offsets[L2_CACHE_SIZE];
>      uint32_t l2_cache_counts[L2_CACHE_SIZE];
>  
> -    unsigned int cluster_sectors;
> +    int64_t cluster_sectors;
>  } VmdkExtent;
>  
>  typedef struct BDRVVmdkState {
> @@ -424,7 +424,7 @@ static int vmdk_add_extent(BlockDriverState *bs,
>      extent->l1_size = l1_size;
>      extent->l1_entry_sectors = l2_size * cluster_sectors;
>      extent->l2_size = l2_size;
> -    extent->cluster_sectors = cluster_sectors;
> +    extent->cluster_sectors = flat ? sectors : cluster_sectors;
>  
>      if (s->num_extents > 1) {
>          extent->end_sector = (*(extent - 1)).end_sector + extent->sectors;
> @@ -741,7 +741,7 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs,
>              VmdkExtent *extent;
>  
>              ret = vmdk_add_extent(bs, extent_file, true, sectors,
> -                            0, 0, 0, 0, sectors, &extent);
> +                            0, 0, 0, 0, 0, &extent);
>              if (ret < 0) {
>                  return ret;
>              }
> -- 
> 1.8.3.1
> 
> 

CC'ing qemu-stable as this applies to 1.6 as well.

Fam