diff options
| -rw-r--r-- | block-qcow2.c | 54 |
1 files changed, 36 insertions, 18 deletions
diff --git a/block-qcow2.c b/block-qcow2.c index fa664a74c9..b9f1688663 100644 --- a/block-qcow2.c +++ b/block-qcow2.c @@ -870,7 +870,7 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, BDRVQcowState *s = bs->opaque; int l2_index, ret; uint64_t l2_offset, *l2_table, cluster_offset; - int nb_available, nb_clusters, i; + int nb_available, nb_clusters, i, j; uint64_t start_sect, current; ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index); @@ -909,32 +909,50 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs, if (cluster_offset & QCOW_OFLAG_COMPRESSED) nb_clusters = 1; - /* how many empty or how many to free ? */ + /* how many available clusters ? */ - if (!cluster_offset) { + i = 0; + while (i < nb_clusters) { - /* how many free clusters ? */ + i++; - i = 1; - while (i < nb_clusters && - l2_table[l2_index + i] == 0) { - i++; - } - nb_clusters = i; + if (!cluster_offset) { - } else { + /* how many free clusters ? */ - /* how many contiguous clusters ? */ + while (i < nb_clusters) { + cluster_offset = l2_table[l2_index + i]; + if (cluster_offset != 0) + break; + i++; + } - for (i = 1; i < nb_clusters; i++) { - current = be64_to_cpu(l2_table[l2_index + i]); - if (cluster_offset + (i << s->cluster_bits) != current) + if ((cluster_offset & QCOW_OFLAG_COPIED) || + (cluster_offset & QCOW_OFLAG_COMPRESSED)) break; - } - nb_clusters = i; - free_any_clusters(bs, cluster_offset, i); + } else { + + /* how many contiguous clusters ? */ + + j = 1; + current = 0; + while (i < nb_clusters) { + current = be64_to_cpu(l2_table[l2_index + i]); + if (cluster_offset + (j << s->cluster_bits) != current) + break; + + i++; + j++; + } + + free_any_clusters(bs, cluster_offset, j); + if (current) + break; + cluster_offset = current; + } } + nb_clusters = i; /* allocate a new cluster */ |