Date: Thu, 21 May 2009 15:53:56 +0100 From: Doug Rabson <dfr@rabson.org> To: Sam Leffler <sam@freebsd.org> Cc: Andre Oppermann <andre@freebsd.org>, rmacklem@uoguelph.ca, Robert Watson <rwatson@freebsd.org>, freebsd-current@freebsd.org Subject: Re: Socket related code duplication in NFS Message-ID: <dee26af6064ba8b3e608df7841a282e4@mail.rabson.org> In-Reply-To: <4A156630.5080507@freebsd.org> References: <4A1460A3.2010202@freebsd.org> <alpine.BSF.2.00.0905202102100.25537@fledge.watson.org> <alpine.BSF.2.00.0905211135300.25537@fledge.watson.org> <a31e4950277c2c6049da0e29cdf71992@mail.rabson.org> <4A156630.5080507@freebsd.org>
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On Thu, 21 May 2009 07:33:20 -0700, Sam Leffler <sam@freebsd.org> wrote:
> Doug Rabson wrote:
>> On Thu, 21 May 2009 11:36:49 +0100 (BST), Robert Watson
>> <rwatson@FreeBSD.org> wrote:
>>
>>> On Wed, 20 May 2009, Robert Watson wrote:
>>>
>>>
>>>> On Wed, 20 May 2009, Andre Oppermann wrote:
>>>>
>>>>
>>>>> While working on an optimized soreceive_stream() function [1] and
>>>>> checking
>>>>> the code how it is used I've come across quite a bit of code
>>>>>
>> duplication
>>
>>>>> in
>>>>> the various NFS directories.
>>>>>
>>>>> Socket (read) operations are handled multiple times in a very similar
>>>>> manner in these places:
>>>>>
>>>> My recommendation would be to do this analysis against the new NFS
>>>>
>> client
>>
>>>> and server found in sys/{kgssapi,nlm,fs/{nfs,nfsclient,nfsserver}},
>>>>
>> which
>>
>>>> is
>>>> the NFSv234 implementation. Note in particular that in the new world
>>>> order
>>>> there's a centralize RPC implementation.
>>>>
>>>> The code you're looking at is a blend of the old NFSv23 client/server
>>>> (nfsclient/nfsserver) and the old NFSv4 client (rpc/nfs4client), all
if
>>>>
>>>> which are on a gradual de-orbit burn.
>>>>
>>> After re-reading this e-mail, I realize that I'd mislabeled src/sys/rpc
>>>
>> as
>>
>>> being only used by the old code -- this is in fact not the case, it's
>>>
>> also
>>
>>> used by the new code.
>>>
>>
>> Everything in src/sys/rpc except rpcclient.[ch] is part of the new RPC
>> transport. The files rpcclient.c and rpcclient.h are part of the old
>> broken
>> NFSv4 client which is scheduled for removal.
>>
>> There is older RPC transport code in src/sys/nfsclient and
>> src/sys/nfsserver which is currently used if the user uses the
>> NFS_LEGACYRPC option. This too should be removed before 8.0 ships.
>>
>
> NFS_LEGACYRPC is the only code that works reliably for me on xscale (BE
> arm). The new code randomly causes alignment faults. I've not had time
> to track down this problem but gonzo@ also reported this problem on mips
> and I believe sent you a line# and stack trace of a fault. Until this
> problem is fixed removing legacy support cannot happen.
I'm aware of this one but I'm not exactly certain where the problem is. I
did spend some time dredging through email archives trying to find out
without success. I have a good idea where the bug is but I'd like to see at
least one stacktrace or similar which confirms my suspicion before I commit
a fix. When I get home, I'll take another look and see if I can find your
original report. I'm certainly not going to be removing the NFS_LEGACYRPC
option until this is fixed.
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