Re: Patch for mapping EILSEQ into NFSERR_INVAL

["Antti Tönkyrä" <daedalus@pingtimeout.net>]

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.
Ewh...

I did some further testing and managed to get stale NFS file handles 
instead of I/O errors on one run. (Haven't been able to repeat this 
behaviour)

After that I did another run (which errored with I/O errors) and found 
out that I am able to touch existing files but not create any new files. 
Touching an existing file changes the mtime as expected on both the NFS 
share and backing FS so something is still being exchanged by the NFS 
client and server. I also tested to write into a touchable file but that 
returned an I/O error again.

Example below:
# ls -l p
-rwxrwxrwx 1 root root 0 Dec  4 14:26 p
# touch p
# ls -l p
-rwxrwxrwx 1 root root 0 Dec  4 14:31 p
# touch newfile
touch: cannot touch `newfile': Input/output error
# echo test > p
-su: p: Input/output error

- Antti