RE: [PATCH 1/1] [SCSI] Fix a bug in deriving the FLUSH_TIMEOUT from the basic I/O timeout

KY Srinivasan
2014-07-18T17:05:50Z

> -----Original Message-----
> From: James Bottomley [mailto:jbottomley@parallels.com]
> Sent: Friday, July 18, 2014 9:57 AM
> To: KY Srinivasan
> Cc: linux-kernel@vger.kernel.org; hch@infradead.org; apw@canonical.com;
> devel@linuxdriverproject.org; michaelc@cs.wisc.edu; axboe@kernel.dk;
> linux-scsi@vger.kernel.org; ohering@suse.com;
> gregkh@linuxfoundation.org; jasowang@redhat.com
> Subject: Re: [PATCH 1/1] [SCSI] Fix a bug in deriving the FLUSH_TIMEOUT
> from the basic I/O timeout
>
> On Fri, 2014-07-18 at 16:44 +0000, KY Srinivasan wrote:
> >
> > > -----Original Message-----
> > > From: Christoph Hellwig (hch@infradead.org)
> > > [mailto:hch@infradead.org]
> > > Sent: Friday, July 18, 2014 8:11 AM
> > > To: KY Srinivasan
> > > Cc: Jens Axboe; James Bottomley; michaelc@cs.wisc.edu; Christoph
> > > Hellwig (hch@infradead.org); linux-scsi@vger.kernel.org;
> > > gregkh@linuxfoundation.org; jasowang@redhat.com; linux-
> > > kernel@vger.kernel.org; ohering@suse.com; apw@canonical.com;
> > > devel@linuxdriverproject.org
> > > Subject: Re: [PATCH 1/1] [SCSI] Fix a bug in deriving the
> > > FLUSH_TIMEOUT from the basic I/O timeout
> > >
> > > On Thu, Jul 17, 2014 at 11:53:33PM +0000, KY Srinivasan wrote:
> > > > I still see this problem. There was talk of fixing it elsewhere.
> > >
> > > Well, what we have right not is entirely broken, given that the
> > > block layer doesn't initialize ->timeout on TYPE_FS requeuests.
> > >
> > > We either need to revert that initial commit or apply something like
> > > the attached patch as a quick fix.
> > I had sent this exact patch sometime back:
> >
> > http://www.spinics.net/lists/linux-scsi/msg75385.html
>
> Actually, no you didn't. The difference is in the derivation of the timeout.
> Christoph's patch is absolute in terms of SD_TIMEOUT; yours is relative to the
> queue timeout setting ... I thought there was a reason for preferring the
> relative version.

You are right; sorry about that. I think my version is better since we do want to base the
flush timeout relative to the basic timeout.

K. Y
>
> James