1 files changed, 8 insertions, 1 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 52dc6bf..b7c5994 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3058,12 +3058,19 @@ static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
     return ret;
 }
 
-static int qcow2_truncate(BlockDriverState *bs, int64_t offset, Error **errp)
+static int qcow2_truncate(BlockDriverState *bs, int64_t offset,
+                          PreallocMode prealloc, Error **errp)
 {
     BDRVQcow2State *s = bs->opaque;
     int64_t new_l1_size;
     int ret;
 
+    if (prealloc != PREALLOC_MODE_OFF) {
+        error_setg(errp, "Unsupported preallocation mode '%s'",
+                   PreallocMode_lookup[prealloc]);
+        return -ENOTSUP;
+    }
+
     if (offset & 511) {
         error_setg(errp, "The new size must be a multiple of 512");
         return -EINVAL;