From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: linux-nfs@vger.kernel.org, mchan-dY08KVG/lbpWk0Htik3J/w@public.gmane.org
Subject: Re: RPC retransmission of write requests containing bogus data
Date: Fri, 17 Oct 2008 09:22:52 -0400 [thread overview]
Message-ID: <1224249772.7722.9.camel@localhost> (raw)
In-Reply-To: <1224248469.9053.119.camel-o4Be2W7LfRlXesXXhkcM7miJhflN2719@public.gmane.org>
On Fri, 2008-10-17 at 14:01 +0100, Ian Campbell wrote:
> On Fri, 2008-10-17 at 08:48 -0400, Trond Myklebust wrote:
> > I don't see how this could be an RPC bug. The networking layer is
> > supposed to either copy the data sent to the socket, or take a reference
> > to any pages that are pushed via the ->sendpage() abi.
> >
> > IOW: the pages are supposed to be still referenced by the networking
> > layer even if the NFS layer and page cache have dropped their
> > references.
>
> The pages are still referenced by the networking layer. The problem is
> that the userspace app has been told that the write has completed so it
> is free to write new data to those pages.
>
> Ian.
OK, I see your point.
Does this happen at all with NFSv4? I ask because the NFSv4 client will
always ensure that the TCP connection gets broken before a
retransmission. I wouldn't therefore expect any races between a reply to
the previous transmission and the new one...
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@netapp.com
www.netapp.com
next prev parent reply other threads:[~2008-10-17 13:23 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-17 11:01 RPC retransmission of write requests containing bogus data Ian Campbell
[not found] ` <1224241273.9053.109.camel-o4Be2W7LfRlXesXXhkcM7miJhflN2719@public.gmane.org>
2008-10-17 12:48 ` Trond Myklebust
2008-10-17 13:01 ` Ian Campbell
[not found] ` <1224248469.9053.119.camel-o4Be2W7LfRlXesXXhkcM7miJhflN2719@public.gmane.org>
2008-10-17 13:22 ` Trond Myklebust [this message]
2008-10-17 13:33 ` Ian Campbell
2008-10-20 14:25 ` Ian Campbell
[not found] ` <1224512708.15736.12.camel-o4Be2W7LfRlXesXXhkcM7miJhflN2719@public.gmane.org>
2008-10-20 16:38 ` Ian Campbell
[not found] ` <1224520738.15736.22.camel-o4Be2W7LfRlXesXXhkcM7miJhflN2719@public.gmane.org>
2008-10-23 14:42 ` Ian Campbell
2008-11-11 13:08 ` Ian Campbell
2008-10-17 13:32 ` Talpey, Thomas
[not found] ` <RTPCLUEXC1-PRDVjCRG000001ab-rtwIt2gI0FxT+ZUat5FNkAK/GNPrWCqfQQ4Iyu8u01E@public.gmane.org>
2008-10-17 13:36 ` Trond Myklebust
2008-10-17 13:51 ` Talpey, Thomas
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