Re: [Qemu-devel] [Qemu-block] [PATCH] vmdk: Set vmdk parent backing_format to vmdk

[Sam Eiderman]

Thanks,

Also please notice that the mentioned commit in the commit message has it’s 
commit id changed to b69864e.

Sam

> On 27 Mar 2019, at 2:35, Eric Blake <address@hidden> wrote:
> 
> On 3/26/19 2:58 PM, Sam Eiderman wrote:
>> Commit fb2105b ("vmdk: Support version=3 in VMDK descriptor files") fixed
>> the probe function to correctly guess vmdk descriptors with version=3.
> 
> All patches need to cc qemu-devel in addition to their maintainers (I've
> added that now).
> 
>> 
>> This solves the issue where vmdk snapshot with parent vmdk descriptor
>> containing "version=3" would be treated as raw instead vmdk.
>> 
>> In the future case where a new vmdk version is introduced, we will again
>> experience this issue, even if the user will provide "-f vmdk" it will
>> only apply to the tip image and not to the underlying "misprobed" parent
>> image.
>> 
>> The code in vmdk.c already assumes that the backing file of vmdk must be
>> vmdk (see vmdk_is_cid_valid which returns 0 if backing file is not
>> vmdk).
>> 
>> So let's make it official by supplying the backing_format as vmdk.
>> 
>> Reviewed-by: Mark Kanda <address@hidden>
>> Reviewed-By: Liran Alon <address@hidden>
>> Reviewed-by: Arbel Moshe <address@hidden>
>> Signed-off-by: Shmuel Eiderman <address@hidden>
>> ---
>> block/vmdk.c | 2 ++
>> 1 file changed, 2 insertions(+)
>> 
>> diff --git a/block/vmdk.c b/block/vmdk.c
>> index 8dec6ef767..de8cb859f8 100644
>> --- a/block/vmdk.c
>> +++ b/block/vmdk.c
>> @@ -397,6 +397,8 @@ static int vmdk_parent_open(BlockDriverState *bs)
>>         pstrcpy(bs->auto_backing_file, end_name - p_name + 1, p_name);
>>         pstrcpy(bs->backing_file, sizeof(bs->backing_file),
>>                 bs->auto_backing_file);
>> +        pstrcpy(bs->backing_format, sizeof(bs->backing_format),
>> +                "vmdk");
>>     }
> 
> Reviewed-by: Eric Blake <address@hidden <mailto:address@hidden>>
> 
> Makes sense for 4.0-rc2.
> 
> -- 
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3226
> Virtualization:  qemu.org <http://qemu.org/> | libvirt.org 
> <http://libvirt.org/>