v5: Drop immutable_source backup parameter: it's not necessary with new scheme. Other changes:
03,06,07,08,10,13 : add Hanna's r-bs
04: add (Since 7.0)
11: s/filter/block driver/, also add note about snapshot size
12: fix text and s/bs/child->bs/kk
    update iotest 257 output
14: use qemu_io_wrap_args
16: drop 'immutable_source=True' option

===

These series brings several improvements to fleecing scheme:

1. support bitmap in copy-before-write filter

2. introduce snapshot-access API and filter, to make a new fleecing
   scheme. See "block: copy-before-write: realize snapshot-access API"
   commit message for details.

3. support "push backup with fleecing" scheme, when backup job is a
   client of common fleecing scheme. That helps when writes to final
   backup target are slow and we don't want guest writes hang waiting
   for copy-before-write operations to final target.

Vladimir Sementsov-Ogievskiy (16):
  block/block-copy: move copy_bitmap initialization to
    block_copy_state_new()
  block/dirty-bitmap: bdrv_merge_dirty_bitmap(): add return value
  block/block-copy: block_copy_state_new(): add bitmap parameter
  block/copy-before-write: add bitmap open parameter
  block/block-copy: add block_copy_reset()
  block: intoduce reqlist
  block/reqlist: reqlist_find_conflict(): use ranges_overlap()
  block/dirty-bitmap: introduce bdrv_dirty_bitmap_status()
  block/reqlist: add reqlist_wait_all()
  block/io: introduce block driver snapshot-access API
  block: introduce snapshot-access block driver
  block: copy-before-write: realize snapshot-access API
  iotests/image-fleecing: add test-case for fleecing format node
  iotests.py: add qemu_io_pipe_and_status()
  iotests/image-fleecing: add test case with bitmap
  iotests/image-fleecing: test push backup with fleecing

 qapi/block-core.json                        |  14 +-
 include/block/block-copy.h                  |   2 +
 include/block/block_int.h                   |  27 ++
 include/block/dirty-bitmap.h                |   4 +-
 include/block/reqlist.h                     |  75 ++++++
 include/qemu/hbitmap.h                      |  12 +
 block/block-copy.c                          | 150 +++++------
 block/copy-before-write.c                   | 265 +++++++++++++++++++-
 block/dirty-bitmap.c                        |  15 +-
 block/io.c                                  |  69 +++++
 block/monitor/bitmap-qmp-cmds.c             |   5 +-
 block/reqlist.c                             |  85 +++++++
 block/snapshot-access.c                     | 132 ++++++++++
 util/hbitmap.c                              |  33 +++
 MAINTAINERS                                 |   5 +-
 block/meson.build                           |   2 +
 tests/qemu-iotests/257.out                  | 224 +++++++++++++++++
 tests/qemu-iotests/iotests.py               |   3 +
 tests/qemu-iotests/tests/image-fleecing     | 174 ++++++++++---
 tests/qemu-iotests/tests/image-fleecing.out | 223 +++++++++++++++-
 20 files changed, 1378 insertions(+), 141 deletions(-)
 create mode 100644 include/block/reqlist.h
 create mode 100644 block/reqlist.c
 create mode 100644 block/snapshot-access.c

-- 
2.31.1