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From: "Steve Wise" <swise@opengridcomputing.com>
To: "'Chuck Lever'" <chucklever@gmail.com>
Cc: "'J. Bruce Fields'" <bfields@fieldses.org>,
	"'Linux NFS Mailing List'" <linux-nfs@vger.kernel.org>,
	"'linux-rdma'" <linux-rdma@vger.kernel.org>,
	"'Tom Tucker'" <tom@opengridcomputing.com>
Subject: RE: [PATCH V2 RFC 2/3] svcrdma: Recvfrom changes
Date: Wed, 14 May 2014 13:24:00 -0500	[thread overview]
Message-ID: <009a01cf6fa1$ad1906b0$074b1410$@opengridcomputing.com> (raw)
In-Reply-To: <639CE8CC-46CE-4EC9-A97B-2F146BA045C4@gmail.com>


> >>
> >
> > So the code as it stands violates the RFC by sending 2 chunks?
> 
> The Linux client is non-compliant because it sends two chunks. A compliant server
ignores the
> second chunk, so this is functionally harmless (but a waste of resources).
> 
> The Linux server is non-compliant because it _requires_ the XDR pad chunk. A compliant
client
> (eg. Linux with pad optimization enabled) does not interoperate with it.
> 
> > And if I change the server
> > to only consume 1, then everything unaligned will break?
> 
> If you change the server to consume only the first chunk, but do not also make it deal
with XDR
> padding as recommended in chapter 3 of RFC 5666, then WRITEs with a length that is not a
> multiple of four will fail. SYMLINKs with a large payload will also have this problem.
> 

Thanks Chuck for clarifying this!  So I'm going to defer this issue and fix it with a
subsequent patch to only process 1 chunk and handle pad correctly.

Steve.



WARNING: multiple messages have this Message-ID (diff)
From: "Steve Wise" <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
To: 'Chuck Lever' <chucklever-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: "'J. Bruce Fields'"
	<bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>,
	'Linux NFS Mailing List'
	<linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	'linux-rdma' <linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	'Tom Tucker'
	<tom-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
Subject: RE: [PATCH V2 RFC 2/3] svcrdma: Recvfrom changes
Date: Wed, 14 May 2014 13:24:00 -0500	[thread overview]
Message-ID: <009a01cf6fa1$ad1906b0$074b1410$@opengridcomputing.com> (raw)
In-Reply-To: <639CE8CC-46CE-4EC9-A97B-2F146BA045C4-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>


> >>
> >
> > So the code as it stands violates the RFC by sending 2 chunks?
> 
> The Linux client is non-compliant because it sends two chunks. A compliant server
ignores the
> second chunk, so this is functionally harmless (but a waste of resources).
> 
> The Linux server is non-compliant because it _requires_ the XDR pad chunk. A compliant
client
> (eg. Linux with pad optimization enabled) does not interoperate with it.
> 
> > And if I change the server
> > to only consume 1, then everything unaligned will break?
> 
> If you change the server to consume only the first chunk, but do not also make it deal
with XDR
> padding as recommended in chapter 3 of RFC 5666, then WRITEs with a length that is not a
> multiple of four will fail. SYMLINKs with a large payload will also have this problem.
> 

Thanks Chuck for clarifying this!  So I'm going to defer this issue and fix it with a
subsequent patch to only process 1 chunk and handle pad correctly.

Steve.


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  reply	other threads:[~2014-05-14 18:23 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-06 17:46 [PATCH V2 RFC 0/3] svcrdma: refactor marshalling logic Steve Wise
2014-05-06 17:46 ` Steve Wise
2014-05-06 17:46 ` [PATCH V2 RFC 1/3] svcrdma: Transport and header file changes Steve Wise
2014-05-06 17:46   ` Steve Wise
2014-05-06 19:21   ` J. Bruce Fields
2014-05-06 19:21     ` J. Bruce Fields
2014-05-06 21:02     ` Steve Wise
2014-05-06 21:02       ` Steve Wise
2014-05-06 21:13       ` J. Bruce Fields
2014-05-06 21:13         ` J. Bruce Fields
2014-05-06 17:46 ` [PATCH V2 RFC 2/3] svcrdma: Recvfrom changes Steve Wise
2014-05-06 17:46   ` Steve Wise
2014-05-13 18:22   ` Chuck Lever
2014-05-13 18:22     ` Chuck Lever
2014-05-13 20:37     ` Steve Wise
2014-05-13 20:37       ` Steve Wise
2014-05-13 21:44       ` Chuck Lever
2014-05-13 21:44         ` Chuck Lever
2014-05-14 14:26         ` Steve Wise
2014-05-14 14:26           ` Steve Wise
2014-05-14 14:39           ` Chuck Lever
2014-05-14 14:39             ` Chuck Lever
2014-05-14 18:11             ` Steve Wise
2014-05-14 18:11               ` Steve Wise
2014-05-14 18:21               ` Chuck Lever
2014-05-14 18:21                 ` Chuck Lever
2014-05-14 18:24                 ` Steve Wise [this message]
2014-05-14 18:24                   ` Steve Wise
2014-05-06 17:46 ` [PATCH V2 RFC 3/3] svcrdma: Sendto changes Steve Wise
2014-05-06 17:46   ` Steve Wise
2014-05-06 19:27 ` [PATCH V2 RFC 0/3] svcrdma: refactor marshalling logic J. Bruce Fields
2014-05-06 19:27   ` J. Bruce Fields
2014-05-06 21:09   ` Steve Wise
2014-05-06 21:09     ` Steve Wise
2014-05-19 19:07     ` Devesh Sharma
2014-05-19 19:07       ` Devesh Sharma
2014-05-19 19:14       ` Steve Wise
2014-05-19 19:14         ` Steve Wise
2014-05-20  5:42         ` Devesh Sharma
2014-05-20  5:42           ` Devesh Sharma

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