diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 9036bd8fae..d640328b5c 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -831,24 +831,35 @@ static int handle_dependencies(BlockDriverState *bs, uint64_t guest_offset, * * -errno: in error cases * - * TODO Get rid of keep_clusters, nb_clusters parameters + * TODO Get rid of keep_clusters parameter * TODO Make bytes behave like described above * TODO Make non-zero host_offset behave like describe above */ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m, - unsigned int *keep_clusters, unsigned int *nb_clusters) + unsigned int *keep_clusters) { BDRVQcowState *s = bs->opaque; int l2_index; uint64_t cluster_offset; uint64_t *l2_table; + unsigned int nb_clusters; int ret, pret; trace_qcow2_handle_copied(qemu_coroutine_self(), guest_offset, *host_offset, *bytes); assert(*host_offset == 0); + /* + * Calculate the number of clusters to look for. We stop at L2 table + * boundaries to keep things simple. + */ + nb_clusters = + size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes); + + l2_index = offset_to_l2_index(s, guest_offset); + nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); + /* Find L2 entry for the first involved cluster */ ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index); if (ret < 0) { @@ -863,11 +874,10 @@ static int handle_copied(BlockDriverState *bs, uint64_t guest_offset, { /* We keep all QCOW_OFLAG_COPIED clusters */ *keep_clusters = - count_contiguous_clusters(*nb_clusters, s->cluster_size, + count_contiguous_clusters(nb_clusters, s->cluster_size, &l2_table[l2_index], 0, QCOW_OFLAG_COPIED | QCOW_OFLAG_ZERO); - assert(*keep_clusters <= *nb_clusters); - *nb_clusters -= *keep_clusters; + assert(*keep_clusters <= nb_clusters); ret = 1; } else { @@ -1159,10 +1169,12 @@ again: */ uint64_t tmp_bytes = cur_bytes; ret = handle_copied(bs, offset, &cluster_offset, &tmp_bytes, m, - &keep_clusters, &nb_clusters); + &keep_clusters); if (ret < 0) { return ret; } else if (ret) { + nb_clusters -= keep_clusters; + if (!*host_offset) { *host_offset = cluster_offset; }