In expand_zero_clusters_in_l1, a new cluster is only allocated if it was
not already preallocated. On error, such preallocated clusters should
not be freed, but only the newly allocated ones.
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/qcow2-cluster.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index cab5f2e..077b42b 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1551,6 +1551,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState
*bs, uint64_t *l1_table,
uint64_t l2_entry = be64_to_cpu(l2_table[j]);
int64_t offset = l2_entry & L2E_OFFSET_MASK, cluster_index;
int cluster_type = qcow2_get_cluster_type(l2_entry);
+ bool preallocated = offset != 0;
if (cluster_type == QCOW2_CLUSTER_NORMAL) {
cluster_index = offset >> s->cluster_bits;
@@ -1576,8 +1577,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState
*bs, uint64_t *l1_table,
continue;
}
- if (!offset) {
- /* not preallocated */
+ if (!preallocated) {
if (!bs->backing_hd) {
/* not backed; therefore we can simply deallocate the
* cluster */
@@ -1596,16 +1596,20 @@ static int expand_zero_clusters_in_l1(BlockDriverState
*bs, uint64_t *l1_table,
ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT,
offset, s->cluster_size);
if (ret < 0) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_ALWAYS);
+ if (!preallocated) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
goto fail;
}
ret = bdrv_write_zeroes(bs->file, offset / BDRV_SECTOR_SIZE,
s->cluster_sectors);
if (ret < 0) {
- qcow2_free_clusters(bs, offset, s->cluster_size,
- QCOW2_DISCARD_ALWAYS);
+ if (!preallocated) {
+ qcow2_free_clusters(bs, offset, s->cluster_size,
+ QCOW2_DISCARD_ALWAYS);
+ }
goto fail;
}
--
1.8.3.1
