Re: [devel branch]Btrfs-convert assert at volumes.c:1846

[David Sterba <dsterba@suse.cz>]

On Mon, Oct 19, 2015 at 05:30:16PM +0800, Qu Wenruo wrote:
> Recently I'm reworking the btrfs-convert chunk allocater to make it able 
> to separate data and meta chunk.
> 
> But when I was testing, I found that, your devel branch, with the 
> following commit just fails to convert an empty ext4 filesystem:
> 
> commit 0002085c53a5ac9ad1c538bfc3e39c80891c4a1a
> Author: Zhao Lei <zhaolei@cn.fujitsu.com>
> Date:   Mon Oct 12 21:23:04 2015 +0800
> 
>      btrfs-progs: fragments: use btrfs_open_dir for btrfs-fragments command

That's the top commit, but it's not causing the breakage. I've bisected
the breakage to the patch

commit 893b7a6815a735449613afbb4040f486a4a4e1d0
Author: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date:   Wed May 13 17:15:34 2015 +0800

    btrfs-progs: Read the whole superblock instead of struct btrfs_super_block.

Looks familiar? :)

The patch caused some trouble in the past (on ppc64 machines) and I've
been holding it back due to that. The plan is to add it to 4.3 devel
branch and get it fixed before the final release, so the convert could
fail in the meantime. I'm trying to put together all pending branches
for the next release so I can't say when the convert will be fixed.