block: Turn on "unmap" in active commit
We already specified BDRV_O_UNMAP when opening images in 'qemu-img commit', but didn't turn on the "unmap" in the active commit job. This patch fixes that so that zeroed clusters in top image can be discarded which is desired in the virt-sparsify use case, where a temporary overlay is created and fstrim'ed before commiting back, to free space in the original image. This also enables it for block-commit. Signed-off-by: NFam Zheng <famz@redhat.com> Reviewed-by: NEric Blake <eblake@redhat.com> Message-id: 1474974892-5031-1-git-send-email-famz@redhat.com Signed-off-by: NJeff Cody <jcody@redhat.com>
Showing
想要评论请 注册 或 登录