Date: Mon, 28 Sep 2015 17:04:59 -0400
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Steve Wise <swise@opengridcomputing.com>
Cc: trond.myklebust@primarydata.com, linux-nfs@vger.kernel.org,
        linux-rdma@vger.kernel.org
Subject: Re: [PATCH 2/3] svcrdma: handle rdma read with a non-zero initial
 page offset
Message-ID: <20150928210459.GC3190@fieldses.org>
References: <20150921172423.9761.92399.stgit@build2.ogc.int>
 <20150921172428.9761.27838.stgit@build2.ogc.int>
 <56094F3D.2030002@opengridcomputing.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <56094F3D.2030002@opengridcomputing.com>
Sender: linux-nfs-owner@vger.kernel.org

On Mon, Sep 28, 2015 at 09:31:25AM -0500, Steve Wise wrote:
> On 9/21/2015 12:24 PM, Steve Wise wrote:
> >The server rdma_read_chunk_lcl() and rdma_read_chunk_frmr() functions
> >were not taking into account the initial page_offset when determining
> >the rdma read length.  This resulted in a read who's starting address
> >and length exceeded the base/bounds of the frmr.
> >
> >Most work loads don't tickle this bug apparently, but one test hit it
> >every time: building the linux kernel on a 16 core node with 'make -j
> >16 O=/mnt/0' where /mnt/0 is a ramdisk mounted via NFSRDMA.
> >
> >This bug seems to only be tripped with devices having small fastreg page
> >list depths.  I didn't see it with mlx4, for instance.
> >
> >Fixes: 0bf4828983df ('svcrdma: refactor marshalling logic')
> >Signed-off-by: Steve Wise <swise@opengridcomputing.com>
> >Tested-by: Chuck Lever <chuck.lever@oracle.com>
> >---
> >
> >
> 
> Hey Bruce, can this make 4.3-rc?  Also, what do you think about
> pushing it to stable?

It looks like a reasonable candidate for stable.  Apologies, somehow I
missed it when you posted it--would you mind resending?

--b.