On Thu, Sep 17, 2020 at 10:20:51AM +0800, Ming Lei wrote:
> 
> Obviously there is other more serious issue, since 568f27006577 is
> completely reverted in your test, and you still see list corruption
> issue.
> 
> So I'd suggest to find the big issue first. Once it is fixed, maybe
> everything becomes fine.
> ...
> Looks it is more like a memory corruption issue, is there any helpful log
> dumped when running kernel with kasan?

Last night, I ran six VM's using -rc4 with and without KASAN; without
Kasan, half of them hung.  With KASAN enabled, all of the test VM's
ran to completion.

This strongly suggests whatever the problem is, it's timing related.
I'll run a larger set of test runs to see if this pattern is confirmed
today.

> BTW, I have kvm/qumu auto test which runs blktest/xfstest over virtio-blk/virito-scsi/loop/nvme
> with xfs/ext4 every two days, and not see such failure recently, but the kernel config is based
> rhel8's config.

Here is the configs I'm using, with and without KASAN.  (With KASAN is
enabled is sent as a diff to avoid running into LKML's e-mail size
restrictrions.)

     	     	     	 	     	 	 - Ted