@@ -655,7 +655,7 @@ static int write_l2_entries(BlockDriverState *bs, uint64_t *l2_table,
int ret;
BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
- ret = bdrv_pwrite_sync(bs->file, l2_offset + start_offset,
+ ret = bdrv_pwrite(bs->file, l2_offset + start_offset,
&l2_table[l2_start_index], len);
if (ret < 0) {
return ret;
@@ -718,9 +718,17 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
goto err;
}
- for (i = 0; i < j; i++)
- qcow2_free_any_clusters(bs,
- be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
+ /*
+ * If this was a COW, we need to decrease the refcount of the old cluster.
+ * Also flush bs->file to get the right order for L2 and refcount update.
+ */
+ if (j != 0) {
+ bdrv_flush(bs->file);
+ for (i = 0; i < j; i++) {
+ qcow2_free_any_clusters(bs,
+ be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
+ }
+ }
ret = 0;
err:
When a new cluster was allocated, we only need a flush after the write to the L2 table if it was a COW and we need to decrease the refcounts of the old clusters. Signed-off-by: Kevin Wolf <kwolf@redhat.com> (cherry picked from commit 7ec5e6a4ca43494949465f9f9f3d9e4c7c620503) --- block/qcow2-cluster.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-)