Commit cdba7fee authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Simplify calculation for COW area at the end 



copy_sectors() always uses the sum (cluster_offset + n_start) or
(start_sect + n_start), so if some value is added to both cluster_offset
and start_sect, and subtracted from n_start, it's cancelled out anyway.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 6af4e9ea

block/qcow2-cluster.c

+2 −3
Original line number Diff line number Diff line
@@ -642,11 +642,10 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m) 
    }



    if (m->nb_available & (s->cluster_sectors - 1)) {

        uint64_t end = m->nb_available & ~(uint64_t)(s->cluster_sectors - 1);

        cow = true;

        qemu_co_mutex_unlock(&s->lock);

        ret = copy_sectors(bs, start_sect + end, cluster_offset + (end << 9),

                m->nb_available - end, s->cluster_sectors);

        ret = copy_sectors(bs, start_sect, cluster_offset, m->nb_available,

                           align_offset(m->nb_available, s->cluster_sectors));

        qemu_co_mutex_lock(&s->lock);

        if (ret < 0)

            goto err;