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Date: Wed, 04 Dec 2013 08:55:04 +0200
From: =?ISO-8859-1?Q?Antti_T=F6nkyr=E4?= <daedalus@pingtimeout.net>
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To: Dr Fields James Bruce <bfields@fieldses.org>
CC: Trond Myklebust <trond.myklebust@primarydata.com>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: Patch for mapping EILSEQ into NFSERR_INVAL
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On 2013-12-03 23:22, Dr Fields James Bruce wrote:
> On Tue, Dec 03, 2013 at 03:48:06PM -0500, Dr Fields James Bruce wrote:
>> OK, it makes sense that touching a file with a bad name would get an
>> error, but you're seeing that cause later creates of files on the same
>> filesystem fail.  I can't figure out why that would happen.
> ...
>
> So maybe there's some other problem here, but...
>
>>>>> Given that widely used ntfs-3g FUSE module also returns EILSEQ on the same case (I tested this) I would argue that a fix should be done for upstream especially since RFC5661 clearly defines that invalid UTF-8 sequence should map into NFSERR_INVAL, exact quote: "Where the client sends an invalid UTF-8 string, the server should return NFS4ERR_INVAL (see Table 5)".
>>>> The NFS client will then happily map that straight into EINVAL for you...
> This seems like a spec bug?
>
> NFS4ERR_INVAL only makes sense if you could really mandate UTF-8 on the
> wire all the time.  But I don't know what other error would work.
>
> I guess a client could map INVAL to EILSEQ on open or lookup (is there
> any other reason a correct client should ever see INVAL on those ops?).
> Or do that only if fs_charset is supported and has
> FSCHARSET_CAP4_ALLOWS_ONLY_UTF8 set.  Yuch.
>
> --b.
Hello,

I don't really think it's an issue if we don't do any mapping here 
either, I/O error is perfectly acceptable to me but the whole share 
dying is of course not very desirable...

I have been conducting my tests with ntfs-3g for now and after applying 
my patch to map EILSEQ into INVAL I didn't witness the share dying 
anymore. I captured network traffic from both cases (urls below). The 
tests were conducted so that after mounting the NFS share a file was 
opened (with w-mode) after which pcap was started. After that the 
following commands were executed:

touch `echo -e $'\some_bad_sequence'` (I tested these with \377 and \375)
<wait a bit>
touch something

http://daedalus.pingtimeout.net/dbg/eilseq_ioerr.pcap
http://daedalus.pingtimeout.net/dbg/eilseq_mapped.pcap

With mapping patch applied, the bad sequence touch returns invalid 
argument but doesn't kill the share as somewhat visible from the pcap.

BR, Antti