[Qemu-devel] [PATCH v4 00/11] backup compression

["Denis V. Lunev" <den@openvz.org>]

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.

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 (10, 11)

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 (8, 9)

Pavel Butsykin (11):
  block: switch blk_write_compressed() to byte-based interface
  block/io: add bdrv_co_write_compressed
  qcow2: add qcow2_co_write_compressed
  vmdk: add vmdk_co_write_compressed
  qcow: add qcow_co_write_compressed
  block: remove BlockDriver.bdrv_write_compressed
  block: optimization blk_pwrite_compressed()
  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                 |  13 +++++
 block/block-backend.c          |  23 +++++---
 block/io.c                     |  14 +++--
 block/qcow.c                   |  78 +++++++++++++++------------
 block/qcow2.c                  |  89 ++++++++++++++++++-------------
 block/vmdk.c                   |  56 +++----------------
 blockdev.c                     |  20 ++++++-
 hmp-commands.hx                |   8 +--
 hmp.c                          |   3 +-
 include/block/block.h          |   3 +-
 include/block/block_int.h      |   7 ++-
 include/sysemu/block-backend.h |   7 ++-
 qapi/block-core.json           |   9 +++-
 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, 322 insertions(+), 159 deletions(-)

-- 
2.1.4