Re: block: Always check queue limits for cloned requests

[Mike Snitzer <snitzer@redhat.com>]

On Sun, Nov 29 2015 at 11:15am -0500,
Markus Trippelsdorf <markus@trippelsdorf.de> wrote:

> On 2015.11.29 at 16:43 +0100, Hannes Reinecke wrote:
> > On 11/29/2015 12:49 PM, Markus Trippelsdorf wrote:
> > > 
> > > I'm still seeing the issue (BUG at drivers/scsi/scsi_lib.c:1096!) even
> > > with this patch applied.
> > > 
> > > markus@x4 linux % git describe
> > > v4.4-rc2-215-g081f3698e606
> > > 
> > Can you generate a crashdump?
> > I would need to cross-check with the other dumps I'm having to figure
> > out if this really is the same issue.
> > There have been other reports (and fixes) which show we're fighting
> > several distinct issues here.
> 
> Unfortunately no. The crash happens on the disk where I store my log
> files. And after it happened the magic SysRq keys don't work anymore.
> 
> The crash only happens on my spinning rust drive that uses the cfq
> scheduler. The SSDs (deadline) are fine.
> 
> The BUG happens reproducibly when building http://www.sagemath.org/ on
> that drive.

Are you using DM multipath?  If unsure, please let us know which
device(s) map to the "spinning rust drive", and provide output from:
lsblk