From: "Denis V. Lunev" <d...@openvz.org> All .bdrv_co_write_zeroes callbacks nowadays work perfectly even with backing store attached. If future new callbacks would be unable to do that - they have a chance to block this in bdrv_get_info().
Signed-off-by: Denis V. Lunev <d...@openvz.org> Reviewed-by: Eric Blake <ebl...@redhat.com> Reviewed-by: John Snow <js...@redhat.com> Reviewed-by: Fam Zheng <f...@redhat.com> Message-id: 1468503209-19498-6-git-send-email-...@openvz.org CC: Stefan Hajnoczi <stefa...@redhat.com> CC: Kevin Wolf <kw...@redhat.com> CC: Max Reitz <mre...@redhat.com> CC: Jeff Cody <jc...@redhat.com> Signed-off-by: Jeff Cody <jc...@redhat.com> --- block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block.c b/block.c index d2dac3d..30d64e6 100644 --- a/block.c +++ b/block.c @@ -2837,7 +2837,7 @@ bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) { BlockDriverInfo bdi; - if (bs->backing || !(bs->open_flags & BDRV_O_UNMAP)) { + if (!(bs->open_flags & BDRV_O_UNMAP)) { return false; } -- 1.9.3