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

[Max Reitz <mreitz@redhat.com>]

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


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

-- 
2.1.0