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From: Christoph Hellwig <hch@infradead.org>
To: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Christoph Hellwig <hch@infradead.org>,
	Chuck Lever <chuck.lever@oracle.com>,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH, RFC] backchannel overflows
Date: Fri, 1 May 2015 10:37:59 -0700	[thread overview]
Message-ID: <20150501173759.GA23778@infradead.org> (raw)
In-Reply-To: <CAHQdGtTAiwQ4rRpLCtS+V04n6hSg3R4Q3V_QFn+V2OR7bK+41w@mail.gmail.com>

On Fri, May 01, 2015 at 01:28:12PM -0400, Trond Myklebust wrote:
> The concern is not so much static vs dynamic. The concern is limiting
> incoming RPC calls to the number allowed by the NFSv4.1 session. Right
> now, the static allocation enforces the limit of 1 slot that the
> client offers to the server (albeit with the race) and so I want any
> replacement to meet the same requirement.

Either variant will allow accepting more than one backchannel
request at the RPC layer, that's the whole point.  With the simple
patch I posted it will accept a 2nd one, with dynamic allocation
the number would be potentially unbound.

But given that the NFS client already enforces the slot limit
properly in validate_seqid, and even returns the proper nfs error
for this case I don't really see what enforcing it at a lower level
we we can't even report proper errors buys us.

  reply	other threads:[~2015-05-01 17:38 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-28 20:21 [PATCH, RFC] backchannel overflows Christoph Hellwig
2015-04-29 12:08 ` Kinglong Mee
2015-04-29 13:46   ` Christoph Hellwig
2015-04-29 14:55 ` Chuck Lever
2015-04-29 14:58   ` Trond Myklebust
2015-04-29 15:14   ` Christoph Hellwig
2015-04-29 15:24     ` Trond Myklebust
2015-04-29 17:34       ` J. Bruce Fields
2015-04-30  6:25         ` Christoph Hellwig
2015-04-30 14:34           ` Chuck Lever
2015-04-30 14:37             ` Christoph Hellwig
     [not found]               ` <CAHQdGtRgEVXidNNYtYf4c3uS0vc6fbm-SZ5AxrY=awXYynmACw@mail.gmail.com>
2015-04-30 15:02                 ` Trond Myklebust
2015-04-30 15:11                 ` Chuck Lever
2015-04-30 17:41                   ` Chuck Lever
2015-05-01 17:23                     ` Christoph Hellwig
2015-05-01 17:28                       ` Trond Myklebust
2015-05-01 17:37                         ` Christoph Hellwig [this message]
2015-05-01 17:47                           ` Trond Myklebust
2015-05-01 17:31                       ` Chuck Lever

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