diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c4752ee812..c2b59e7d6a 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -652,9 +652,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
     uint64_t cluster_offset = m->alloc_offset;
 
     trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters);
-
-    if (m->nb_clusters == 0)
-        return 0;
+    assert(m->nb_clusters > 0);
 
     old_cluster = g_malloc(m->nb_clusters * sizeof(uint64_t));
 
@@ -856,7 +854,7 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
  * Return 0 on success and -errno in error cases
  */
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta *m)
+    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m)
 {
     BDRVQcowState *s = bs->opaque;
     int l2_index, ret, sectors;
@@ -928,11 +926,6 @@ again:
     }
 
     /* If there is something left to allocate, do that now */
-    *m = (QCowL2Meta) {
-        .nb_clusters        = 0,
-    };
-    qemu_co_queue_init(&m->dependent_requests);
-
     if (nb_clusters > 0) {
         uint64_t alloc_offset;
         uint64_t alloc_cluster_offset;
@@ -980,7 +973,9 @@ again:
                 cluster_offset = alloc_cluster_offset;
             }
 
-            *m = (QCowL2Meta) {
+            *m = g_malloc0(sizeof(**m));
+
+            **m = (QCowL2Meta) {
                 .alloc_offset   = alloc_cluster_offset,
                 .offset         = alloc_offset & ~(s->cluster_size - 1),
                 .nb_clusters    = nb_clusters,
@@ -995,8 +990,8 @@ again:
                     .nb_sectors = avail_sectors - nb_sectors,
                 },
             };
-            qemu_co_queue_init(&m->dependent_requests);
-            QLIST_INSERT_HEAD(&s->cluster_allocs, m, next_in_flight);
+            qemu_co_queue_init(&(*m)->dependent_requests);
+            QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight);
         }
     }
 
@@ -1013,8 +1008,8 @@ again:
     return 0;
 
 fail:
-    if (m->nb_clusters > 0) {
-        QLIST_REMOVE(m, next_in_flight);
+    if (*m && (*m)->nb_clusters > 0) {
+        QLIST_REMOVE(*m, next_in_flight);
     }
     return ret;
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index 66ca12f94e..08d92cc6e3 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -787,8 +787,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
 
     while (remaining_sectors != 0) {
 
-        l2meta = g_malloc0(sizeof(*l2meta));
-        qemu_co_queue_init(&l2meta->dependent_requests);
+        l2meta = NULL;
 
         trace_qcow2_writev_start_part(qemu_coroutine_self());
         index_in_cluster = sector_num & (s->cluster_sectors - 1);
@@ -799,7 +798,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
         }
 
         ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
-            index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, l2meta);
+            index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, &l2meta);
         if (ret < 0) {
             goto fail;
         }
@@ -845,14 +844,16 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
             goto fail;
         }
 
-        ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
-        if (ret < 0) {
-            goto fail;
-        }
+        if (l2meta != NULL) {
+            ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
+            if (ret < 0) {
+                goto fail;
+            }
 
-        run_dependent_requests(s, l2meta);
-        g_free(l2meta);
-        l2meta = NULL;
+            run_dependent_requests(s, l2meta);
+            g_free(l2meta);
+            l2meta = NULL;
+        }
 
         remaining_sectors -= cur_nr_sectors;
         sector_num += cur_nr_sectors;
@@ -1134,11 +1135,10 @@ static int preallocate(BlockDriverState *bs)
     uint64_t host_offset = 0;
     int num;
     int ret;
-    QCowL2Meta meta;
+    QCowL2Meta *meta;
 
     nb_sectors = bdrv_getlength(bs) >> 9;
     offset = 0;
-    qemu_co_queue_init(&meta.dependent_requests);
 
     while (nb_sectors) {
         num = MIN(nb_sectors, INT_MAX >> 9);
@@ -1148,15 +1148,17 @@ static int preallocate(BlockDriverState *bs)
             return ret;
         }
 
-        ret = qcow2_alloc_cluster_link_l2(bs, &meta);
+        ret = qcow2_alloc_cluster_link_l2(bs, meta);
         if (ret < 0) {
-            qcow2_free_any_clusters(bs, meta.alloc_offset, meta.nb_clusters);
+            qcow2_free_any_clusters(bs, meta->alloc_offset, meta->nb_clusters);
             return ret;
         }
 
         /* There are no dependent requests, but we need to remove our request
          * from the list of in-flight requests */
-        run_dependent_requests(bs->opaque, &meta);
+        if (meta != NULL) {
+            run_dependent_requests(bs->opaque, meta);
+        }
 
         /* TODO Preallocate data if requested */
 
diff --git a/block/qcow2.h b/block/qcow2.h
index 24f100125c..6dc79b5af4 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -207,7 +207,10 @@ typedef struct Qcow2COWRegion {
     int         nb_sectors;
 } Qcow2COWRegion;
 
-/* XXX This could be private for qcow2-cluster.c */
+/**
+ * Describes an in-flight (part of a) write request that writes to clusters
+ * that are not referenced in their L2 table yet.
+ */
 typedef struct QCowL2Meta
 {
     /** Guest offset of the first newly allocated cluster */
@@ -333,7 +336,7 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     int *num, uint64_t *cluster_offset);
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta *m);
+    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m);
 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
                                          uint64_t offset,
                                          int compressed_size);