Re: kernel BUG at drivers/scsi/scsi_lib.c:1096!
From: Ming Lei
Date: Sat Nov 21 2015 - 11:58:17 EST
On Sat, 21 Nov 2015 12:30:14 +0100
Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> wrote:
> On 20/11/2015 13:10, Michael Ellerman wrote:
> > On Thu, 2015-11-19 at 00:23 -0800, Christoph Hellwig wrote:
> >> It's pretty much guaranteed a block layer bug, most likely in the
> >> merge bios to request infrastucture where we don't obey the merging
> >> limits properly.
> >> Does either of you have a known good and first known bad kernel?
> > Not me, I've only hit it one or two times. All I can say is I have hit it in
> > 4.4-rc1.
> > Laurent, can you narrow it down at all?
> It seems that the panic is triggered by the commit bdced438acd8 ("block:
> setup bi_phys_segments after splitting") which has been pulled by the
> merge d9734e0d1ccf ("Merge branch 'for-4.4/core' of
> My system is panicing promptly when running a kernel built at
> d9734e0d1ccf, while reverting the commit bdced438acd8, it can run hours
> without panicing.
> This being said, I can't explain what's going wrong.
> May Ming shed some light here ?
Laurent, looks there is one bug in blk_bio_segment_split(), would you
mind testing the following patch to see if it fixes your issue?