Re: [Qemu-devel] [PATCH v3 1/4] qemu-img: Convert by cluster size if target is compressed

Re: [Qemu-devel] [PATCH v3 1/4] qemu-img: Convert by cluster size if target is compressed

[Stefan Hajnoczi]

On Fri, Apr 25, 2014 at 04:00:49PM +0800, Fam Zheng wrote:
> diff --git a/include/block/block.h b/include/block/block.h
> index b3230a2..8a1cb83 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -34,6 +34,10 @@ typedef struct BlockDriverInfo {
>       * opened with BDRV_O_UNMAP flag for this to work.
>       */
>      bool can_write_zeroes_with_unmap;
> +    /*
> +     * True if the driver is writing data clusters compressed
> +     */
> +    bool is_compressed;

"is_compressed" is more general than what this flag actually
communicates:

/*
 * True if this block driver only supports compressed writes
 */
bool needs_compressed_writes;

Re: [Qemu-devel] [PATCH v3 0/4] Fix conversion from ISO to VMDK streamOptimized

[Stefan Hajnoczi]

On Fri, Apr 25, 2014 at 04:00:48PM +0800, Fam Zheng wrote:
> Previouly, convert from ISO to VMDK with subformat=streamOptimized fails:
> 
>     $ ./qemu-img convert -O vmdk -o subformat=streamOptimized foo.iso bar.vmdk
>     VMDK: can't write to allocated cluster for streamOptimized
>     qemu-img: error while writing sector 64: Input/output error
> 
> Because current code in qemu-img.c uses the normal convert loop, rather than
> the compressed == true loop. In VMDK streamOptimized, writes must be in cluster
> granularity, because overlapped write to an allocated cluster is -EIO.
> 
> This series adds is_compressed into BlockDriverInfo, and uses compressed
> convertion loop if the target block driver sets this field to true.
> 
> It also implements .bdrv_get_info and .bdrv_write_compressed in VMDK driver to
> fit into this framework.
> 
> Adds a test case to cover the code path in question: source image cluster size
> is smaller.
> 
> v3: Finally revisit and address Stefan's review comments on v2 from 2 months
>     ago. Sorry for being so slow on this one.
>     The general approach is the same, changes include:
> 
>     - Split originial "[PATCH v2 5/5] mirror: Check for bdrv_get_info result" and
>       send to list separately, because it's irrelevant with this series.
>     - Don't report cluster_size in bdrv_get_info if it's a flat extent, no need
>       to change type of BlockDriverInfo.cluster_size to 64 bits. So drop
>       "[PATCH v2 3/5] block: Change BlockDriverInfo.cluster_size to 64 bits".
>     - Add qemu-iotests case as [PATCH 4/4].
> 
> 
> Fam Zheng (4):
>   qemu-img: Convert by cluster size if target is compressed
>   vmdk: Implement .bdrv_write_compressed
>   vmdk: Implement .bdrv_get_info()
>   qemu-iotests: Test converting to streamOptimized from small cluster
>     size
> 
>  block/vmdk.c               | 35 +++++++++++++++++++++++++++++++++++
>  include/block/block.h      |  4 ++++
>  qemu-img.c                 |  1 +
>  tests/qemu-iotests/059     |  7 +++++++
>  tests/qemu-iotests/059.out |  8 ++++++++
>  5 files changed, 55 insertions(+)

Looks good.  I left a comment on Patch 1 asking you to rename the flag.

Re: [Qemu-devel] [PATCH v3 0/4] Fix conversion from ISO to VMDK streamOptimized

[Fam Zheng]

On Tue, 05/06 14:52, Stefan Hajnoczi wrote:
> On Fri, Apr 25, 2014 at 04:00:48PM +0800, Fam Zheng wrote:
> > Previouly, convert from ISO to VMDK with subformat=streamOptimized fails:
> > 
> >     $ ./qemu-img convert -O vmdk -o subformat=streamOptimized foo.iso bar.vmdk
> >     VMDK: can't write to allocated cluster for streamOptimized
> >     qemu-img: error while writing sector 64: Input/output error
> > 
> > Because current code in qemu-img.c uses the normal convert loop, rather than
> > the compressed == true loop. In VMDK streamOptimized, writes must be in cluster
> > granularity, because overlapped write to an allocated cluster is -EIO.
> > 
> > This series adds is_compressed into BlockDriverInfo, and uses compressed
> > convertion loop if the target block driver sets this field to true.
> > 
> > It also implements .bdrv_get_info and .bdrv_write_compressed in VMDK driver to
> > fit into this framework.
> > 
> > Adds a test case to cover the code path in question: source image cluster size
> > is smaller.
> > 
> > v3: Finally revisit and address Stefan's review comments on v2 from 2 months
> >     ago. Sorry for being so slow on this one.
> >     The general approach is the same, changes include:
> > 
> >     - Split originial "[PATCH v2 5/5] mirror: Check for bdrv_get_info result" and
> >       send to list separately, because it's irrelevant with this series.
> >     - Don't report cluster_size in bdrv_get_info if it's a flat extent, no need
> >       to change type of BlockDriverInfo.cluster_size to 64 bits. So drop
> >       "[PATCH v2 3/5] block: Change BlockDriverInfo.cluster_size to 64 bits".
> >     - Add qemu-iotests case as [PATCH 4/4].
> > 
> > 
> > Fam Zheng (4):
> >   qemu-img: Convert by cluster size if target is compressed
> >   vmdk: Implement .bdrv_write_compressed
> >   vmdk: Implement .bdrv_get_info()
> >   qemu-iotests: Test converting to streamOptimized from small cluster
> >     size
> > 
> >  block/vmdk.c               | 35 +++++++++++++++++++++++++++++++++++
> >  include/block/block.h      |  4 ++++
> >  qemu-img.c                 |  1 +
> >  tests/qemu-iotests/059     |  7 +++++++
> >  tests/qemu-iotests/059.out |  8 ++++++++
> >  5 files changed, 55 insertions(+)
> 
> Looks good.  I left a comment on Patch 1 asking you to rename the flag.
> 

Thanks, will respin and send another revision soon.

Fam