@@ -2774,6 +2774,20 @@ int open_ctree(struct super_block *sb,
err = -EINVAL;
goto fail_alloc;
}
+ /*
+ * We have unsupported RO compat features, although RO mounted, we
+ * should not cause any metadata write, including log replay.
+ * Or we could screw up whatever the new feature requires.
+ */
+ if (unlikely(features && btrfs_super_log_root(disk_super) &&
+ !btrfs_test_opt(fs_info, NOLOGREPLAY))) {
+ btrfs_err(fs_info,
+"cannot replay dirty log with unsupported compat_ro features (0x%llx), try rescue=nologreplay",
+ features);
+ err = -EINVAL;
+ goto fail_alloc;
+ }
+
max_active = fs_info->thread_pool_size;