On 2022/6/14 15:17, Christoph Hellwig wrote:
On Mon, Jun 13, 2022 at 09:39:12PM +0200, David Sterba wrote:
On Fri, Jun 10, 2022 at 12:10:19AM -0700, syzbot wrote:
syzbot has bisected this issue to:
commit 4cd4aed63125ccd4efc35162627827491c2a7be7
Author: Christoph Hellwig <hch@xxxxxx>
Date: Fri May 27 08:43:20 2022 +0000
btrfs: fold repair_io_failure into btrfs_repair_eb_io_failure
Josef also reported a crash and found a bug in the patch, now added as
fixup that'll be in for-next:
The patch looks correct to me. Two things to note here:
- I hadn't realized you had queued up the series. I've actually
started to merge some of my bio work with the bio split at
submission time work from Qu and after a few iterations I think
I would do the repair code a bit differently based on that.
Can you just drop the series for now?
- I find it interesting that syzbot hits btrfs metadata repair.
xfstests seems to have no coverage and I could not come up with
a good idea how to properly test it. Does anyone have a good
idea on how to intentially corrupt metadata in a deterministic
way?
The same way as data?
map-logical to find the location of a mirror, write 4 bytes of zero into
the location, then call it a day.
Although for metadata, you may want to choose a metadata that would
definitely get read.
Thus tree root is a good candidate.
Thanks,
Qu
