update_header_sync itself does not need to flush the caches to disk. The only paths that allocate clusters are:
- bitmap_list_store with in_place=false, called by update_ext_header_and_dir - store_bitmap_data, called by store_bitmap - store_bitmap, called by qcow2_store_persistent_dirty_bitmaps and followed by update_ext_header_and_dir So in the end the central place where we need to flush the caches is update_ext_header_and_dir. Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- block/qcow2-bitmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index efa10c6663..a2dbd9fab4 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -110,7 +110,7 @@ static int update_header_sync(BlockDriverState *bs) return ret; } - return bdrv_flush(bs); + return bdrv_flush(bs->file->bs); } static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t size) @@ -882,7 +882,7 @@ static int update_ext_header_and_dir(BlockDriverState *bs, return ret; } - ret = bdrv_flush(bs->file->bs); + ret = qcow2_flush_caches(bs); if (ret < 0) { goto fail; } -- 2.14.3