Based-on: https://lore.kernel.org/qemu-devel/20240228141501.455989-1-vsement...@yandex-team.ru/
Useful to make discard-source work in the context of backup fleecing when the fleecing image has a larger granularity than the backup target. Backup/block-copy will use at least this granularity for copy operations and in particular, discard requests to the backup source will too. If the granularity is too small, they will just be aligned down in cbw_co_pdiscard_snapshot() and thus effectively ignored. Fiona Ebner (2): copy-before-write: allow specifying minimum cluster size backup: add minimum cluster size to performance options block/backup.c | 2 +- block/block-copy.c | 17 +++++++++++++---- block/copy-before-write.c | 5 ++++- block/copy-before-write.h | 1 + blockdev.c | 3 +++ include/block/block-copy.h | 1 + qapi/block-core.json | 17 ++++++++++++++--- 7 files changed, 37 insertions(+), 9 deletions(-) -- 2.39.2