Re: [Qemu-devel] [PATCH v12 00/14] qemu-img: Implement commit like QMP

[Max Reitz <mreitz@redhat.com>]

On 26.08.2014 23:36, Max Reitz wrote:
> qemu-img should use QMP commands whenever possible in order to ensure
> feature completeness of both online and offline image operations. For
> the "commit" command, this is relatively easy, so implement it first
> (in the hope that indeed others will follow).
>
> As qemu-img does not have access to QMP (due to QMP being intertwined
> with basically everything in qemu), we cannot directly use QMP, but at
> least use the functions the corresponding QMP commands are using (which
> would be "block-commit", in this case).
>
>
> As of this version, this series depends on my series
> '[PATCH v3 00/10] qcow2: Fix image repairing' (or on any later version).
>
>
> Patches without a Reviewed-by: 3 and 14

Ping. I kind of want to make Kevin responsible for the state in which 
patch 3 is now, so I'm hoping he'll review it despite of the now 
official reviewer policy. ;-)

Although everyone is welcome; patch 3 is now much more simple than in 
previous versions, so don't be afraid.

Max

> v12:
> - Rewrote patch 3 according to Kevin's proposal (in reply to v8):
>    Instead of keeping the image constantly clean and recreating a new
>    refcount structure in unallocated clusters, just mark the image dirty,
>    overwrite the beginning of the image with zeroes, place the reftable
>    and the L1 table there and go from there.
>    This is much easier than the previous version but was not possible
>    like this before, because qcow2's repair function could not repair
>    images with completely lost refcount information. This is now
>    possible which makes this variant feasible.
> - Pulled patch 14 before patch 6; therefore, patch 14 is now patch 6 and
>    patches 6 to 13 are now patches 7 to 14, respectively. I did this
>    because patches 7 and 8 break several tests which are fixed by patch
>    14, so it makes sense to apply the fix before breaking the tests.
> - Adjusted patch 14 (previously 13) according to the changes to patch 3.
>    In particular, images do not leak clusters when the emptying process
>    fails, but are dirty (their refcount structure is broken) and need to
>    be repaired (which is done automatically when they are opened).
>
>
> git-backport-diff output against v11:
>
> Key:
> [----] : patches are identical
> [####] : number of functional differences between upstream/downstream patch
> [down] : patch is downstream-only
> The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively
>
> 001/14:[----] [--] 'qcow2: Allow "full" discard'
> 002/14:[----] [--] 'qcow2: Implement bdrv_make_empty()'
> 003/14:[0430] [FC] 'qcow2: Optimize bdrv_make_empty()'
> 004/14:[----] [--] 'blockjob: Introduce block_job_complete_sync()'
> 005/14:[----] [--] 'blockjob: Add "ready" field'
> 006/14:[----] [--] 'iotests: Omit length/offset test in 040 and 041'
> 007/14:[----] [--] 'block/mirror: Improve progress report'
> 008/14:[----] [--] 'qemu-img: Implement commit like QMP'
> 009/14:[----] [-C] 'qemu-img: Empty image after commit'
> 010/14:[----] [--] 'qemu-img: Enable progress output for commit'
> 011/14:[----] [-C] 'qemu-img: Specify backing file for commit'
> 012/14:[----] [--] 'iotests: Add _filter_qemu_img_map'
> 013/14:[----] [-C] 'iotests: Add test for backing-chain commits'
> 014/14:[0046] [FC] 'iotests: Add test for qcow2's bdrv_make_empty'
>
>
> Max Reitz (14):
>    qcow2: Allow "full" discard
>    qcow2: Implement bdrv_make_empty()
>    qcow2: Optimize bdrv_make_empty()
>    blockjob: Introduce block_job_complete_sync()
>    blockjob: Add "ready" field
>    iotests: Omit length/offset test in 040 and 041
>    block/mirror: Improve progress report
>    qemu-img: Implement commit like QMP
>    qemu-img: Empty image after commit
>    qemu-img: Enable progress output for commit
>    qemu-img: Specify backing file for commit
>    iotests: Add _filter_qemu_img_map
>    iotests: Add test for backing-chain commits
>    iotests: Add test for qcow2's bdrv_make_empty
>
>   block/Makefile.objs              |   2 +-
>   block/blkdebug.c                 |   2 +
>   block/mirror.c                   |  34 +++++----
>   block/qcow2-cluster.c            |  27 ++++---
>   block/qcow2-snapshot.c           |   2 +-
>   block/qcow2.c                    | 136 ++++++++++++++++++++++++++++++++++-
>   block/qcow2.h                    |   2 +-
>   blockjob.c                       |  42 +++++++++--
>   include/block/block.h            |   2 +
>   include/block/blockjob.h         |  20 ++++++
>   qapi/block-core.json             |   4 +-
>   qemu-img-cmds.hx                 |   4 +-
>   qemu-img.c                       | 149 +++++++++++++++++++++++++++++++++------
>   qemu-img.texi                    |  13 +++-
>   tests/qemu-iotests/040           |   4 +-
>   tests/qemu-iotests/041           |   3 +-
>   tests/qemu-iotests/097           | 122 ++++++++++++++++++++++++++++++++
>   tests/qemu-iotests/097.out       | 119 +++++++++++++++++++++++++++++++
>   tests/qemu-iotests/098           |  78 ++++++++++++++++++++
>   tests/qemu-iotests/098.out       |  45 ++++++++++++
>   tests/qemu-iotests/common.filter |   7 ++
>   tests/qemu-iotests/group         |   2 +
>   tests/qemu-iotests/iotests.py    |   3 +-
>   23 files changed, 755 insertions(+), 67 deletions(-)
>   create mode 100755 tests/qemu-iotests/097
>   create mode 100644 tests/qemu-iotests/097.out
>   create mode 100755 tests/qemu-iotests/098
>   create mode 100644 tests/qemu-iotests/098.out
>