1 files changed, 1 insertions, 1 deletions
diff --git a/block.c b/block.c
index af6366bcef..361005cba9 100644
--- a/block.c
+++ b/block.c
@@ -3424,7 +3424,7 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Error **errp)
         ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
         bdrv_dirty_bitmap_truncate(bs);
         bdrv_parent_cb_resize(bs);
-        ++bs->write_gen;
+        atomic_inc(&bs->write_gen);
     }
     return ret;
 }