Re: [PATCH 1/2] nfs: Only update callback sequnce id when CB_SEQUENCE success

From: Kinglong Mee <kinglongmee@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>,
	"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
	Weston Andros Adamson <dros@primarydata.com>,
	"J. Bruce Fields" <bfields@fieldses.org>,
	kinglongmee@gmail.com
Subject: Re: [PATCH 1/2] nfs: Only update callback sequnce id when CB_SEQUENCE success
Date: Thu, 11 Jun 2015 17:13:15 +0800	[thread overview]
Message-ID: <5579512B.60009@gmail.com> (raw)
In-Reply-To: <20150611082028.GA11330@infradead.org>

On 6/11/2015 4:20 PM, Christoph Hellwig wrote:
> Hi Kinglong,
> 
> when we last brought up this issue the recommendation was to follow
> the model in the clients nfs41_sequence_done() which handles even
> more corner cases.  Given that my previous fixes in that area were
> just a bandaid I probably shouldn't complain about piece mail handling,
> but if you have a little spare time available implementing the full
> set of checks might be worthwhile.

Thank you for your comments.

I have see your patches sits "nfsd: callback fixes". You said process as
nfs41_sequence_done() for handling error cases is server's logical.

Those two patches for NFS client are fix two bugs.

The first one is fix that between validate_seqid() nfs can return error
to nfs server. NFS server cannot make sure whether NFS client has update
the sequence ID.

Also, according to RFC, "If CB_SEQUENCE returns an error, then the state
of the slot (sequence ID, cached reply) MUST NOT change.",
so that this this patch is out.

The second for nfs is fix the initialize problem of cb_sequenceres
when meeting NFS4ERR_RETRY_UNCACHED_REP.

And, other two patches for nfsd, 
The first is fix a infinite loop caused by your last patch I meet.
The second is as you said following to nfs41_sequence_done() maybe better.

thanks
Kinglong Mee