On Fri, Dec 01, 2017 at 06:04:29PM +0100, Alban Browaeys wrote:
> I initially reported as https://bugzilla.kernel.org/show_bug.cgi?id=198
> 023 .
>
> I have now bisected this issue to commit a6a252e6491443c1c1 "blk-mq-
> sched: decide how to handle flush rq via RQF_FLUSH_SEQ".
>
> This is with an USB stick Sandisk Cruzer (USB Version: 2.10) I
> regressed with.
> systemctl restart systemd-udevd restores sanity.
>From my investigation, looks the issue is in BFQ:
https://marc.info/?l=linux-block&m=151214241518562&w=2
Could you apply the attached debug patch, run your test and provide us the log?
Thanks,
Ming
