Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 10 Oct 2017 17:01:29 +0200
Greg KH <gregkh@linuxfoundation.org> wrote:

> On Thu, Sep 07, 2017 at 08:41:13AM -0700, Stephen Hemminger wrote:
> > On Thu, 7 Sep 2017 06:27:25 +0200
> > Greg KH <gregkh@linuxfoundation.org> wrote:
> >   
> > > On Thu, Sep 07, 2017 at 12:54:09AM +0000, Dexuan Cui wrote:  
> > > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > > > > Sent: Wednesday, August 16, 2017 9:16 AM
> > > > > To: Greg KH <gregkh@linuxfoundation.org>
> > > > > Cc: KY Srinivasan <kys@microsoft.com>; Dexuan Cui <decui@microsoft.com>;
> > > > > devel@linuxdriverproject.org; linux-kernel@vger.kernel.org;
> > > > > stable@vger.kernel.org; Stephen Hemminger <sthemmin@microsoft.com>;
> > > > > John Starks <jon.Starks@microsoft.com>
> > > > > Subject: Re: [PATCH] vmbus: fix missing signaling in hv_signal_on_read()
> > > > > 
> > > > > On Wed, 16 Aug 2017 09:10:40 -0700
> > > > > Greg KH <gregkh@linuxfoundation.org> wrote:
> > > > >     
> > > > > > On Wed, Aug 16, 2017 at 08:49:46AM -0700, Stephen Hemminger wrote:    
> > > > > > > When the space available before start of reading (cached_write_sz)
> > > > > > > is the same as the host required space (pending_sz), we need to
> > > > > > > still signal host.
> > > > > > >
> > > > > > > Fixes: 433e19cf33d3 ("Drivers: hv: vmbus: finally fix    
> > > > > hv_need_to_signal_on_read()")    
> > > > > > >
> > > > > > > Signed-off-by: John Starks <jon.Starks@microsoft.com>
> > > > > > > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > > > > > > Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> > > > > > > ---
> > > > > > > This patch is for 4.13 (and stable).
> > > > > > > A different fix is needed for linux-next.    
> > > > > >
> > > > > > Is there a fix for this in Linus's tree?  If so, what's the git commit
> > > > > > id?  We need to wait for that until I can take it in -stable.    
> > > > > 
> > > > > There is no commit yet in Linus's tree. Was submitting for both Linus
> > > > > and stable. Wasn't sure about the timing since 4.13 might close before he gets
> > > > > to it.    
> > > > 
> > > > Hi Greg and stable@vger.kernel.org,
> > > > We need the patch for the stable kernels:  v4.13, v4.12.10 and v4.9.47.
> > > > 
> > > > The patch is not in Linus's tree, because the bug is resolved there by a series
> > > >  of 4 patches (see the below).
> > > > 
> > > > IMO it's better to apply this small patch to the stable kernels rather than 
> > > > backporting the 4 big commits?    
> > > 
> > > It is always better to backport the original commits.  Will they work
> > > as-is, or do they need porting?
> > > 
> > > thanks,
> > > 
> > > greg k-h  
> > 
> > The four patches apply (and kernel builds and runs) for 4.12.10 and 4.13.
> > They do not apply to 4.9 unless several other patches are  dragged in.  
> 
> Ok, any suggestion of what I should do here?  Drag in the series for
> 4.13?  Something else for 4.9?  As long as you all are willing to
> "support" whatever we do here, I'll go along with it...
> 
> thanks,
> 
> greg k-h

I would prefer the single patch for 4.9 rather than creating increased
risk by dragging in the full patch set.