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authorMax Reitz <mreitz@redhat.com>2013-09-27 10:21:48 +0200
committerKevin Wolf <kwolf@redhat.com>2013-09-27 17:22:43 +0200
commit320c70666687db4dd4df8165f9fe6960de782ca9 (patch)
tree2e992ef44883af06a0c9ad5da19864cc3a09c9bc
parentbe0b742ee320d1139d57062fa18490e7aa485f2a (diff)
qcow2: Free only newly allocated clusters on error
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 <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/qcow2-cluster.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c743db1c01..91d07f2203 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1554,6 +1554,7 @@ 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;
@@ -1579,8 +1580,7 @@ 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 */
@@ -1599,16 +1599,20 @@ 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;
}