linux-kernel - Re: [NFS] blocks of zeros (NULLs) in NFS files in kernels >= 2.6.20

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Date:	Thu, 11 Sep 2008 10:19:08 -0700
From:	Aaron Straus <aaron@...finllc.com>
To:	Chuck Lever <chuck.lever@...cle.com>
Cc:	Neil Brown <neilb@...e.de>,
	Linux NFS Mailing List <linux-nfs@...r.kernel.org>,
	Trond Myklebust <trond.myklebust@....uio.no>,
	LKML Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [NFS] blocks of zeros (NULLs) in NFS files in kernels >= 2.6.20

Hi,

On Sep 11 12:55 PM, Chuck Lever wrote:
> A more thorough review of the NFS write and flush logic that exists in
> 2.6.27 is needed if we choose to recognize this issue as a real
> problem.

Yep.  

Sorry.  I didn't mean we should revert the hunk.  I was just trying to
help identify the cause of the new behavior.

I think this is a real problem albeit not a "serious" one.  Network
file-systems usually try to avoid readers seeing blocks of zeros in
files, especially in this simple writer/reader case.

It wouldn't be bad if the file is written out of order occasionally, but
we see this constantly now.

We cannot write/read log files to NFS mounts reliably any more.  That
seems like a valid use case which no longer works?

Anyway, thanks for your time!

				=a=

-- 
===================
Aaron Straus
aaron@...finllc.com
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