[PATCH v3 0/6] block: add block-dirty-bitmap-populate job

[Eric Blake]

[From John's original cover letter:]
This is a new (very small) block job that writes a pattern into a
bitmap. The only pattern implemented is the top allocation information.

This can be used to "recover" an incremental bitmap chain if an external
snapshot was taken without creating a new bitmap first: any writes made
to the image will be reflected by the allocation status and can be
written back into a bitmap.

This is useful for e.g. libvirt managing backup chains if a user creates
an external snapshot outside of libvirt.

v3:
 - Addressed a bit more feedback
 - Make it easier to decide if we want an x- prefix if we think there
 are more tweaks to be made to the interface
 - Drop dependency on John's JobRunner iotest series
 - Renumber the new iotest

I know there was a lot of discussion about whether there are
optimizations to be made with populating directly into the target
bitmap rather than into a temporary that then gets merged in at the
completion of the job, but the QMP aspect seems fairly stable.  Even
so, we may still want to consider using an x- prefix until we know for
sure whether libvirt can make decent use of the interface.

Eric Blake (1):
  bitmaps: Use x- prefix for block-dirty-bitmap-popluate

John Snow (5):
  block: add bitmap-populate job
  blockdev: combine DriveBackupState and BlockdevBackupState
  qmp: expose block-dirty-bitmap-populate
  iotests: move bitmap helpers into their own file
  iotests: add 298 for block-dirty-bitmap-populate

 qapi/block-core.json          |   66 +
 qapi/job.json                 |    6 +-
 qapi/transaction.json         |    2 +
 include/block/block_int.h     |   21 +
 block/bitmap-populate.c       |  207 ++
 blockdev.c                    |  104 +-
 blockjob.c                    |    3 +-
 MAINTAINERS                   |    1 +
 block/Makefile.objs           |    1 +
 tests/qemu-iotests/257        |  110 +-
 tests/qemu-iotests/298        |  232 ++
 tests/qemu-iotests/298.out    | 4544 +++++++++++++++++++++++++++++++++
 tests/qemu-iotests/bitmaps.py |  131 +
 tests/qemu-iotests/group      |    1 +
 14 files changed, 5300 insertions(+), 129 deletions(-)
 create mode 100644 block/bitmap-populate.c
 create mode 100755 tests/qemu-iotests/298
 create mode 100644 tests/qemu-iotests/298.out
 create mode 100644 tests/qemu-iotests/bitmaps.py

-- 
2.27.0