Re: [Qemu-devel] [PATCH v5 00/15] backup compression

[Pavel Butsykin <pbutsykin@virtuozzo.com>]

On 20.07.2016 00:58, Jeff Cody wrote:
> On Mon, Jul 04, 2016 at 03:28:11PM +0300, Denis V. Lunev wrote:
>> The idea is simple - backup is "written-once" data. It is written block
>> by block and it is large enough. It would be nice to save storage
>> space and compress it.
>>
>> These patches add the ability to compress data during backup. This
>> functionality is implemented by means of adding options to the qmp/hmp
>> commands(drive-backup, blockdev-backup). The implementation is quite
>> simple, because the responsibility for data compression imposed on the
>> format driver.
>>
>> This patchset is based on the Eric's QAPI changes
>>    http://repo.or.cz/qemu/ericb.git/shortlog/refs/heads/qapi
>>
>> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
>> Signed-off-by: Denis V. Lunev <den@openvz.org>
>> CC: Jeff Cody <jcody@redhat.com>
>> CC: Markus Armbruster <armbru@redhat.com>
>> CC: Eric Blake <eblake@redhat.com>
>> CC: John Snow <jsnow@redhat.com>
>> CC: Stefan Hajnoczi <stefanha@redhat.com>
>> CC: Kevin Wolf <kwolf@redhat.com>
>>
>> Changes from v1:
>> - added unittest for backup compression (12, 13)
>>
>> Changes from v2:
>> - implemented a new .bdrv_co_write_compressed interface to replace the
>>    old .bdrv_write_compressed (2,3,4,5,6)
>>
>> Changes from v3:
>> - added the byte-based interfaces:
>>    blk_pwrite_compressed()/blk_co_pwritev_compressed() (1, 7)
>> - fix drive/blockdev-backup documentation (10, 11)
>>
>> Changes form v4:
>> - added assert that offset and count are aligned (1)
>> - reuse RwCo and bdrv_co_pwritev() for write compressed (2)
>> - converted interfaces to byte-based for format drivers (2, 3, 5, 6)
>> - move an unrelated cleanup in a separate patches (4, 7)
>> - turn on dirty_bitmaps for the compressed writes (9)
>> - added simplify drive/blockdev-backup by using the boxed commands (10, 11)
>> - reworded drive/blockdev-backup documentation about compression (12, 13)
>> - fix s/bakup/backup/ (14)
>>
>> Pavel Butsykin (15):
>>    block: switch blk_write_compressed() to byte-based interface
>>    block/io: reuse bdrv_co_pwritev() for write compressed
>>    qcow2: add qcow2_co_pwritev_compressed
>>    qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursion
>>    vmdk: add vmdk_co_pwritev_compressed
>>    qcow: add qcow_co_pwritev_compressed
>>    qcow: cleanup qcow_co_pwritev_compressed to avoid the recursion
>>    block: remove BlockDriver.bdrv_write_compressed
>>    block/io: turn on dirty_bitmaps for the compressed writes
>>    block: simplify drive-backup
>>    block: simplify blockdev-backup
>>    drive-backup: added support for data compression
>>    blockdev-backup: added support for data compression
>>    qemu-iotests: test backup compression in 055
>>    qemu-iotests: add vmdk for test backup compression in 055
>>
>>   block/backup.c                 |  12 ++-
>>   block/block-backend.c          |  12 +--
>>   block/io.c                     |  37 ++++-----
>>   block/qcow.c                   |  71 +++++++++-------
>>   block/qcow2.c                  |  83 +++++++++++--------
>>   block/vmdk.c                   |  55 ++-----------
>>   blockdev.c                     | 182 ++++++++++++++---------------------------
>>   hmp-commands.hx                |   8 +-
>>   hmp.c                          |  32 +++++---
>>   include/block/block.h          |   5 +-
>>   include/block/block_int.h      |   5 +-
>>   include/sysemu/block-backend.h |   4 +-
>>   qapi/block-core.json           |  18 +++-
>>   qemu-img.c                     |   8 +-
>>   qemu-io-cmds.c                 |   2 +-
>>   qmp-commands.hx                |   9 +-
>>   tests/qemu-iotests/055         | 118 ++++++++++++++++++++++++++
>>   tests/qemu-iotests/055.out     |   4 +-
>>   tests/qemu-iotests/iotests.py  |  10 +--
>>   19 files changed, 369 insertions(+), 306 deletions(-)
>>
>> --
>> 2.1.4
>>
>
> This series needs a rebase, I cannot apply it to my branch (or qemu/master)
> without a lot of conflicts.  Can you rebase?
>
Ok, probably will have to add a separate patch for convert
bdrv_pwrite_compressed() to BdrvChild.

> Thanks,
> Jeff
>