From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp2130.oracle.com ([141.146.126.79]:49586 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751838AbeAHFb1 (ORCPT ); Mon, 8 Jan 2018 00:31:27 -0500 Subject: Re: [PATCH 2/2] btrfs: add support for SUPER_FLAG_CHANGING_FSID in btrfs.ko To: Qu Wenruo , linux-btrfs@vger.kernel.org Cc: wqu@suse.com References: <20180108030512.22344-1-anand.jain@oracle.com> <20180108030512.22344-2-anand.jain@oracle.com> <83756e06-446f-2807-8c9a-b918f609b741@gmx.com> From: Anand Jain Message-ID: Date: Mon, 8 Jan 2018 13:10:34 +0800 MIME-Version: 1.0 In-Reply-To: <83756e06-446f-2807-8c9a-b918f609b741@gmx.com> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >> index a69e5944dc08..8b76faa77235 100644 >> --- a/fs/btrfs/disk-io.c >> +++ b/fs/btrfs/disk-io.c >> @@ -61,7 +61,8 @@ >> BTRFS_HEADER_FLAG_RELOC |\ >> BTRFS_SUPER_FLAG_ERROR |\ >> BTRFS_SUPER_FLAG_SEEDING |\ >> - BTRFS_SUPER_FLAG_METADUMP) >> + BTRFS_SUPER_FLAG_METADUMP |\ >> + BTRFS_SUPER_FLAG_CHANGING_FSID) > > If we don't want the half changed fs to be mounted, it's better not to > include FLAG_CHANGING_FSID into BTRFS_SUPER_FLAG_SUPP. Anyway BTRFS_SUPER_FLAG_SUPP as such does not stop to mount, it just warns. So when there is a new flag which is not supported we get this warning. As in the case with BTRFS_SUPER_FLAG_METADUMP_V2. As in 1/2 BTRFS_SUPER_FLAG_METADUMP_V2 in kernel is defined but not supported. However since we are supporting BTRFS_SUPER_FLAG_CHANGING_FSID, so adding to BTRFS_SUPER_FLAG_SUPP make sense to me. ? Thanks, Anand