block: Mark bdrv_filter_bs() and callers GRAPH_RDLOCK

[mirror_qemu.git] / block / qcow2-cluster.c

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 904f00d1b370fde01e5eedea2dfb0c0174b6343d..5af439bd1148723ce0c3502ccb5e8149f1705c9d 100644 (file)
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1983,7 +1983,7 @@ discard_in_l2_slice(BlockDriverState *bs, uint64_t offset, uint64_t nb_clusters,
             /* If we keep the reference, pass on the discard still */
             bdrv_pdiscard(s->data_file, old_l2_entry & L2E_OFFSET_MASK,
                           s->cluster_size);
-       }
+        }
     }
 
     qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
@@ -2061,9 +2061,15 @@ zero_in_l2_slice(BlockDriverState *bs, uint64_t offset,
         QCow2ClusterType type = qcow2_get_cluster_type(bs, old_l2_entry);
         bool unmap = (type == QCOW2_CLUSTER_COMPRESSED) ||
             ((flags & BDRV_REQ_MAY_UNMAP) && qcow2_cluster_is_allocated(type));
-        uint64_t new_l2_entry = unmap ? 0 : old_l2_entry;
+        bool keep_reference =
+            (s->discard_no_unref && type != QCOW2_CLUSTER_COMPRESSED);
+        uint64_t new_l2_entry = old_l2_entry;
         uint64_t new_l2_bitmap = old_l2_bitmap;
 
+        if (unmap && !keep_reference) {
+            new_l2_entry = 0;
+        }
+
         if (has_subclusters(s)) {
             new_l2_bitmap = QCOW_L2_BITMAP_ALL_ZEROES;
         } else {
@@ -2081,9 +2087,17 @@ zero_in_l2_slice(BlockDriverState *bs, uint64_t offset,
             set_l2_bitmap(s, l2_slice, l2_index + i, new_l2_bitmap);
         }
 
-        /* Then decrease the refcount */
         if (unmap) {
-            qcow2_free_any_cluster(bs, old_l2_entry, QCOW2_DISCARD_REQUEST);
+            if (!keep_reference) {
+                /* Then decrease the refcount */
+                qcow2_free_any_cluster(bs, old_l2_entry, QCOW2_DISCARD_REQUEST);
+            } else if (s->discard_passthrough[QCOW2_DISCARD_REQUEST] &&
+                       (type == QCOW2_CLUSTER_NORMAL ||
+                        type == QCOW2_CLUSTER_ZERO_ALLOC)) {
+                /* If we keep the reference, pass on the discard still */
+                bdrv_pdiscard(s->data_file, old_l2_entry & L2E_OFFSET_MASK,
+                            s->cluster_size);
+            }
         }
     }