From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:33768 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbcJJN4J (ORCPT ); Mon, 10 Oct 2016 09:56:09 -0400 Subject: Re: [PATCH] btrfs-progs: btrfstune: Register new UUIDs after uuid change To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: <20161010092101.469-1-quwenruo@cn.fujitsu.com> <20161010110855.GI11398@twin.jikos.cz> From: Anand Jain Message-ID: <9551e873-23f6-0e17-f895-cf15513e27f8@oracle.com> Date: Mon, 10 Oct 2016 21:58:08 +0800 MIME-Version: 1.0 In-Reply-To: <20161010110855.GI11398@twin.jikos.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 10/10/16 19:08, David Sterba wrote: > On Mon, Oct 10, 2016 at 06:54:08PM +0800, Anand Jain wrote: >> >> >> On 10/10/16 17:21, Qu Wenruo wrote: >>> For multi-device btrfs, after UUID change we should info kernel, or new >>> fs can't be mounted due to false alert on missing devices. >>> >>> Signed-off-by: Qu Wenruo >>> --- >>> btrfstune.c | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/btrfstune.c b/btrfstune.c >>> index 15dde90..23d06ce 100644 >>> --- a/btrfstune.c >>> +++ b/btrfstune.c >>> @@ -369,6 +369,15 @@ static int change_uuid(struct btrfs_fs_info *fs_info, const char *new_fsid_str) >>> fs_info->new_fsid = NULL; >>> fs_info->new_chunk_tree_uuid = NULL; >>> printf("Fsid change finished\n"); >>> + >>> + /* >>> + * Register new devices, or multi-volume btrfs can't be mounted until >>> + * device scan happens. >>> + * Ignore any error, as such register is optional. >>> + */ >>> + printf("Register new UUIDs(error can be ignored)\n"); >> >> Whats the error in particular in this context. ? > > If /dev/btrfs-control cannot be opened by the user, in > btrfs_register_one_device() . I was wondering if there is any error specific to change in FSID ? looks like there isn't. >>> + btrfs_register_all_devices(); >> >> That means after a reboot -> change uuid it will register the devices >> though the devices weren't registered to the kernel before. >> >> Its fair enough just remind user to run dev scan so that kernel can >> see them. > > This is similar to mkfs that is not able to register the devices for > the same reason. right. inline with mkfs.btrfs -f makes sense. Thanks, Anand > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >