Actually, I should rebase it now on Kevin's block branch. So, ignore this, I'll resend.
01.06.2021 19:49, Vladimir Sementsov-Ogievskiy wrote:
> Hi all!
> 
> v3: Keep x-perf.copy-range backup option.
> 
> So, additional function is added to set copy_range in block-copy after creation.
> And if we do so, it's better to set "compress" option same way instead of handling
> x-deprecated-compress option.
> 
> 8: rebased on not yet remove @perf argument, keep r-b
> 11, 21, 23: small related rebase conflicts, keep r-b
> 9, 10, 19: new
> 20: drop x-deprecated-compress option, drop r-b
> 24: fix typo
> 34: fix qmp( , **{}) to qmp( , {})
> 
> also, add a lot of Max's r-bs, thanks!!!
> 
> So, patches without r-b: 9, 10, 19, 20
> 
> v2:
> 01-02: new
> 03: don't bother with supporting empty child: we should never have such
>      at this point
> 05: add comment
> 06: keep checking conflict with global
>      add realized_set_allowed to qdev_prop_drive_iothread
> 07: improve cbw_cbw() name
>      improve commit message
> 10: rebased on unchanged backup_calculate_cluster_size(). keep r-b  CHECK ME
> 12: new
> 13: drop extra bdrv_unref()
> 18: add compress local variable
>      add comment about x-deprecated-compress
> 19: new, replacement for "[PATCH 17/21] block/block-copy: switch to fully set bitmap by default"
> 22: improve qapi documentation
> 23-33: test: a lot of refactoring
> 
> We have image fleecing scheme to export point-in-time state of active
> disk (iotest 222):
> 
> 
>                                        backup(sync=none)
>                       ┌───────────────────────────────────────┐
>                       ▼                                       │
> ┌────────────┐     ┌────────────────┐  backing             ┌─────────────┐
> │ NBD export │ ─── │ temp qcow2 img │ ───────────────────▶ │ active disk │
> └────────────┘     └────────────────┘                      └─────────────┘
>                                                               ▲
> ┌────────────┐                                               │
> │ guest blk  │ ──────────────────────────────────────────────┘
> └────────────┘
> 
> 
> Actually, backup job inserts a backup-top filter, so in detail it looks
> like:
> 
>                                        backup(sync=none)
>                       ┌───────────────────────────────────────┐
>                       ▼                                       │
> ┌────────────┐     ┌────────────────┐  backing             ┌─────────────┐
> │ NBD export │ ─── │ temp qcow2 img │ ───────────────────▶ │ active disk │
> └────────────┘     └────────────────┘                      └─────────────┘
>                       ▲                                       ▲
>                       │ target                                │
>                       │                                       │
> ┌────────────┐     ┌────────────────┐  backing               │
> │ guest blk  │ ──▶ │   backup-top   │ ───────────────────────┘
> └────────────┘     └────────────────┘
> 
> And job does nothing here. In a new blockdev world user is intended to
> operate on node level, and insert/remove filters by hand. Let's get rid
> of job in the scheme:
> 
> ┌────────────┐     ┌────────────────┐  backing             ┌─────────────┐
> │ NBD export │ ─── │ temp qcow2 img │ ───────────────────▶ │ active disk │
> └────────────┘     └────────────────┘                      └─────────────┘
>                       ▲                                       ▲
>                       │ target                                │
>                       │                                       │
> ┌────────────┐     ┌────────────────┐  backing               │
> │ guest blk  │ ──▶ │   backup-top   │ ───────────────────────┘
> └────────────┘     └────────────────┘
> 
> 
> The series prepares qom-set to make possible inserting filters above
> root node (patches 03-06), rename backup-top to copy-before-write, do
> other preparations for publishing the filter, and finally publish it,
> add qapi interface and test new fleecing scheme in 222 (first, some
> good test refactoring).
> 
> Vladimir Sementsov-Ogievskiy (35):
>    block: rename bdrv_replace_child to bdrv_replace_child_tran
>    block: comment graph-modifying function not updating permissions
>    block: introduce bdrv_replace_child_bs()
>    block: introduce blk_replace_bs
>    qdev-properties: PropertyInfo: add realized_set_allowed field
>    qdev: allow setting drive property for realized device
>    block: rename backup-top to copy-before-write
>    block-copy: always set BDRV_REQ_SERIALISING flag
>    block/block-copy: introduce block_copy_set_copy_opts()
>    block/backup: set copy_range and compress after filter insertion
>    block/backup: move cluster size calculation to block-copy
>    block/copy-before-write: relax permission requirements when no parents
>    block/copy-before-write: drop extra bdrv_unref on failure path
>    block/copy-before-write: use file child instead of backing
>    block/copy-before-write: bdrv_cbw_append(): replace child at last
>    block/copy-before-write: introduce cbw_init()
>    block/copy-before-write: cbw_init(): rename variables
>    block/copy-before-write: cbw_init(): use file child after attaching
>    block/copy-before-write: bdrv_cbw_append(): drop unused compress arg
>    block/copy-before-write: cbw_init(): use options
>    block/copy-before-write: initialize block-copy bitmap
>    block/block-copy: make setting progress optional
>    block/copy-before-write: make public block driver
>    qapi: publish copy-before-write filter
>    python/qemu/machine.py: refactor _qemu_args()
>    python/qemu/machine: QEMUMachine: improve qmp() method
>    iotests.py: VM: add own __enter__ method
>    iotests/222: fix pylint and mypy complains
>    iotests/222: constantly use single quotes for strings
>    iotests: move 222 to tests/image-fleecing
>    iotests.py: hmp_qemu_io: support qdev
>    iotests/image-fleecing: proper source device
>    iotests/image-fleecing: rename tgt_node
>    iotests/image-fleecing: prepare for adding new test-case
>    iotests/image-fleecing: add test-case for copy-before-write filter
> 
>   qapi/block-core.json                        |  30 ++-
>   block/{backup-top.h => copy-before-write.h} |  25 +-
>   include/block/block-copy.h                  |   6 +-
>   include/block/block.h                       |   2 +
>   include/hw/qdev-properties.h                |   1 +
>   include/sysemu/block-backend.h              |   1 +
>   block.c                                     |  52 +++-
>   block/backup-top.c                          | 253 -------------------
>   block/backup.c                              | 116 ++-------
>   block/block-backend.c                       |   8 +
>   block/block-copy.c                          | 148 ++++++++---
>   block/copy-before-write.c                   | 256 ++++++++++++++++++++
>   hw/core/qdev-properties-system.c            |  43 +++-
>   hw/core/qdev-properties.c                   |   6 +-
>   MAINTAINERS                                 |   4 +-
>   block/meson.build                           |   2 +-
>   python/qemu/machine.py                      |  30 ++-
>   tests/qemu-iotests/222                      | 159 ------------
>   tests/qemu-iotests/222.out                  |  67 -----
>   tests/qemu-iotests/283                      |  35 ++-
>   tests/qemu-iotests/283.out                  |   4 +-
>   tests/qemu-iotests/297                      |   2 +-
>   tests/qemu-iotests/iotests.py               |   9 +-
>   tests/qemu-iotests/tests/image-fleecing     | 192 +++++++++++++++
>   tests/qemu-iotests/tests/image-fleecing.out | 139 +++++++++++
>   25 files changed, 910 insertions(+), 680 deletions(-)
>   rename block/{backup-top.h => copy-before-write.h} (56%)
>   delete mode 100644 block/backup-top.c
>   create mode 100644 block/copy-before-write.c
>   delete mode 100755 tests/qemu-iotests/222
>   delete mode 100644 tests/qemu-iotests/222.out
>   create mode 100755 tests/qemu-iotests/tests/image-fleecing
>   create mode 100644 tests/qemu-iotests/tests/image-fleecing.out
> 
-- 
Best regards,
Vladimir