diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 29a6111a68d2..2e6f69908303 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4438,29 +4438,25 @@ try_submit_last:
 }
 
 /*
- * Sanity check for fiemap cache
+ * Emit last fiemap cache
  *
- * All fiemap cache should be submitted by emit_fiemap_extent()
- * Iteration should be terminated either by last fiemap extent or
- * fieinfo->fi_extents_max.
- * So no cached fiemap should exist.
+ * The last fiemap cache may still be cached in the following case:
+ * 0		      4k		    8k
+ * |<- Fiemap range ->|
+ * |<------------  First extent ----------->|
+ *
+ * In this case, the first extent range will be cached but not emitted.
+ * So we must emit it before ending extent_fiemap().
  */
-static int check_fiemap_cache(struct btrfs_fs_info *fs_info,
-			       struct fiemap_extent_info *fieinfo,
-			       struct fiemap_cache *cache)
+static int emit_last_fiemap_cache(struct btrfs_fs_info *fs_info,
+				  struct fiemap_extent_info *fieinfo,
+				  struct fiemap_cache *cache)
 {
 	int ret;
 
 	if (!cache->cached)
 		return 0;
 
-	/* Small and recoverbale problem, only to info developer */
-#ifdef CONFIG_BTRFS_DEBUG
-	WARN_ON(1);
-#endif
-	btrfs_warn(fs_info,
-		   "unhandled fiemap cache detected: offset=%llu phys=%llu len=%llu flags=0x%x",
-		   cache->offset, cache->phys, cache->len, cache->flags);
 	ret = fiemap_fill_next_extent(fieinfo, cache->offset, cache->phys,
 				      cache->len, cache->flags);
 	cache->cached = false;
@@ -4676,7 +4672,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 	}
 out_free:
 	if (!ret)
-		ret = check_fiemap_cache(root->fs_info, fieinfo, &cache);
+		ret = emit_last_fiemap_cache(root->fs_info, fieinfo, &cache);
 	free_extent_map(em);
 out:
 	btrfs_free_path(path);