[PATCH 0/6] qemu-img: rebase: add compression support

[Andrey Drobyshev]

This series is adding [-c | --compress] option to "qemu-img rebase"
command, which might prove useful for saving some disk space when, for
instance, manipulating chains of backup images.  Along the way I had to
make a couple of minor improvements.

The first 2 patches are a bug fix + corresponding test case.
Patch 3 merely fixes wrong args used in allocation.
Patch 4 makes write requests during rebase operation cluster_size-aligned,
which seems to be beneficial for both non-compressed and compressed mode.
The last 2 patches are the actual feature implementation + tests.

Andrey Drobyshev (6):
  qemu-img: rebase: stop when reaching EOF of old backing file
  qemu-iotests: 024: add rebasing test case for overlay_size >
    backing_size
  qemu-img: rebase: use backing files' BlockBackend for buffer alignment
  qemu-img: rebase: avoid unnecessary COW operations
  qemu-img: add compression option to rebase subcommand
  iotests: add test 314 for "qemu-img rebase" with compression

 docs/tools/qemu-img.rst    |   6 +-
 qemu-img-cmds.hx           |   4 +-
 qemu-img.c                 | 106 ++++++++++++++++++------
 tests/qemu-iotests/024     |  57 +++++++++++++
 tests/qemu-iotests/024.out |  30 +++++++
 tests/qemu-iotests/314     | 165 +++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/314.out |  75 +++++++++++++++++
 7 files changed, 415 insertions(+), 28 deletions(-)
 create mode 100755 tests/qemu-iotests/314
 create mode 100644 tests/qemu-iotests/314.out

-- 
2.31.1