Re: [PATCH 1/5] pNFS: recoalesce when ld write pagelist fails

From: Boaz Harrosh <bharrosh@panasas.com>
To: <tao.peng@emc.com>
Cc: <bergwolf@gmail.com>, <Trond.Myklebust@netapp.com>,
	<benny@tonian.com>, <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH 1/5] pNFS: recoalesce when ld write pagelist fails
Date: Tue, 16 Aug 2011 13:19:26 -0700	[thread overview]
Message-ID: <4E4AD0CE.3000506@panasas.com> (raw)
In-Reply-To: <F19688880B763E40B28B2B462677FBF805BF0EB0A3@MX09A.corp.emc.com>

On 08/16/2011 12:20 AM, tao.peng@emc.com wrote:
> 
> I tried to rewrite the write patch to handle failures inside
> mds_ops->rpc_release. However, I get a problem w.r.t. "redirty and
> rely on next flush". If the failed write is the *last flush*, we end
> up with relying no one and the dirty pages are simply dropped. Do you
> have any suggestions how to handle it?
> 
> Thanks, Tao
> 

Tao Hi.

OK, I see what you mean. That would be a problem

I had a totally different idea You know how today we just do:
	nfs_initiate_write()

Which is bad because it can actually dead lock because
we are taking up the only thread that needs to service
that call. Well I thought, with you thread-for-pnfs patch,
can it not now work? I think it is worth a try?

See if you can advance your thread-for-blocks-objects
patch to current code and inject some errors. I think
it will work this time. What do you think?

Thanks
Boaz