Re: [Qemu-devel] [PATCH v2 00/21] qcow2: Rework cluster allocation even more

[Stefan Hajnoczi]

On Tue, Mar 26, 2013 at 05:49:52PM +0100, Kevin Wolf wrote:
> This is the start of the latest Delayed COW series. As there seem to be 
> serious
> problems with the actual Delayed COW (which in fact exist today, but would
> become a bit easier to hit) and I don't have the time to complete this at the
> moment, here is another series with preparatory patches, for which there's no
> reason to not get them applied now.
> 
> The result is a somewhat cleaner cluster allocation code in qcow2, and in
> theory some cases should show improved performance - in practice I think these
> cases are unlikely to occur, but as the optimisation falls out naturally, 
> let's
> just take it.
> 
> Kevin Wolf (21):
>   qemu-iotests: More concurrent allocation scenarios
>   qcow2: Fix "total clusters" number in bdrv_check
>   qcow2: Remove bogus unlock of s->lock
>   qcow2: Handle dependencies earlier
>   qcow2: Improve check for overlapping allocations
>   qcow2: Change handle_dependency to byte granularity
>   qcow2: Decouple cluster allocation from cluster reuse code
>   qcow2: Factor out handle_alloc()
>   qcow2: handle_alloc(): Get rid of nb_clusters parameter
>   qcow2: handle_alloc(): Get rid of keep_clusters parameter
>   qcow2: Finalise interface of handle_alloc()
>   qcow2: Clean up handle_alloc()
>   qcow2: Factor out handle_copied()
>   qcow2: handle_copied(): Get rid of nb_clusters parameter
>   qcow2: handle_copied(): Get rid of keep_clusters parameter
>   qcow2: handle_copied(): Implement non-zero host_offset
>   qcow2: Prepare handle_alloc/copied() for byte granularity
>   qcow2: Use byte granularity in qcow2_alloc_cluster_offset()
>   qcow2: Allow requests with multiple l2metas
>   qcow2: Move cluster gathering to a non-looping loop
>   qcow2: Gather clusters in a looping loop
> 
>  block/qcow2-cluster.c      | 507 
> ++++++++++++++++++++++++++++++++-------------
>  block/qcow2-refcount.c     |   4 +-
>  block/qcow2.c              |  16 +-
>  block/qcow2.h              |  29 +++
>  tests/qemu-iotests/038.out |  10 +-
>  tests/qemu-iotests/044.out |   4 +-
>  tests/qemu-iotests/046     |  49 ++++-
>  tests/qemu-iotests/046.out |  76 +++++++
>  trace-events               |   2 +
>  9 files changed, 534 insertions(+), 163 deletions(-)
> 
> -- 
> 1.8.1.4
> 

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan