[PATCH v2 00/11] Make blockdev-mirror dest sparse in more cases

[Eric Blake <eblake@redhat.com>]

V1 was here: https://lists.gnu.org/archive/html/qemu-devel/2025-04/msg01654.html

In v2:
 - Rearrange and split several patches
 - Fewer changes to file-posix.c; instead,
 - New bdrv_co_is_all_zeroes() in io.c, which works on both file-posix and NBD
 - Clean up several corner cases spotted during review
 - Better iotest coverage, required pulling in Andrey's patch for disk_usage

Andrey Drobyshev (1):
  iotests/common.rc: add disk_usage function

Eric Blake (10):
  block: Expand block status mode from bool to enum
  file-posix: Handle zero block status hint better
  block: Let bdrv_co_is_zero_fast consolidate adjacent extents
  block: Add new bdrv_co_is_all_zeroes() function
  iotests: Improve iotest 194 to mirror data
  mirror: Minor refactoring
  mirror: Skip pre-zeroing destination if it is already zero
  mirror: Skip writing zeroes when target is already zero
  tests: Add iotest mirror-sparse for recent patches
  mirror: Allow QMP override to declare target already zero

 qapi/block-core.json                       |   8 +-
 block/coroutines.h                         |   4 +-
 include/block/block-common.h               |  26 ++++
 include/block/block-io.h                   |   2 +
 include/block/block_int-common.h           |  25 ++--
 include/block/block_int-global-state.h     |   3 +-
 include/block/block_int-io.h               |   4 +-
 block/io.c                                 | 120 ++++++++++++----
 block/blkdebug.c                           |   6 +-
 block/copy-before-write.c                  |   4 +-
 block/file-posix.c                         |   5 +-
 block/gluster.c                            |   4 +-
 block/iscsi.c                              |   6 +-
 block/mirror.c                             | 121 +++++++++++++---
 block/nbd.c                                |   4 +-
 block/null.c                               |   6 +-
 block/parallels.c                          |   6 +-
 block/qcow.c                               |   2 +-
 block/qcow2.c                              |   6 +-
 block/qed.c                                |   6 +-
 block/quorum.c                             |   4 +-
 block/raw-format.c                         |   4 +-
 block/rbd.c                                |   6 +-
 block/snapshot-access.c                    |   4 +-
 block/vdi.c                                |   4 +-
 block/vmdk.c                               |   2 +-
 block/vpc.c                                |   2 +-
 block/vvfat.c                              |   6 +-
 blockdev.c                                 |  18 ++-
 tests/unit/test-block-iothread.c           |   4 +-
 tests/qemu-iotests/common.rc               |   6 +
 tests/qemu-iotests/194                     |   1 +
 tests/qemu-iotests/250                     |   5 -
 tests/qemu-iotests/tests/mirror-sparse     | 109 +++++++++++++++
 tests/qemu-iotests/tests/mirror-sparse.out | 153 +++++++++++++++++++++
 35 files changed, 571 insertions(+), 125 deletions(-)
 create mode 100755 tests/qemu-iotests/tests/mirror-sparse
 create mode 100644 tests/qemu-iotests/tests/mirror-sparse.out

-- 
2.49.0