Re: btrfs check --init-csum-tree removes csums again

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

-------- Original Message --------
Subject: Re: btrfs check --init-csum-tree removes csums again
From: Chris Murphy <lists@colorremedies.com>
To: Karl-Philipp Richter <richter@richtercloud.de>
Date: 2015年02月16日 13:59
> On Sun, Feb 15, 2015 at 1:50 AM, Karl-Philipp Richter
> <richter@richtercloud.de> wrote:
>> Hi,
>> After running `btrfs check --init-csum-tree` 3.18.2 and 3.19-rc2 on a
>> btrfs all checksums are gone (thousands of line in the form of `no csum
>> found for inode X start Y` in `/var/log/kern.log`). I know that this
>> behavior (to delete all csums) was a stub in a dev version and remember
>> that it was fixed and that I even fixed a csum tree at one point. Could
>> someone please confirm and maybe even point me to a working version?
> I just tried this on CentOS 7 with kernel-3.19-0 and
> btrfs-progs-3.18.2 (from Fedora 21) and it rebuilt the csums, and took
> a little while to do it, unlike 3.12 which was very fast by just
> removing the csums. So... worksforme. However I used it with --repair,
> not by itself.
>
>
The behavior that deletes all csum tree but not to rebuilt them maybe a 
bug happens when extent tree is also
corrupted or with '--init-extent-tree' in 3.18.2.

And --init-csum-tree should imply --repair, so Chris' result should also 
be OK.

To Karl:
Would you please provide the full output of "btrfs check 
--init-csum-tree" and the kernel log?
IMHO this should help to find the bug in btrfsck.

Thanks,
Qu