[Samba] Share mounts in SMBv1 mode, but fails weirdly in SMBv2 mode

Fri Oct 20 07:42:55 UTC 2017

Thank you for the feed back, very appriciated.  

> -----Oorspronkelijk bericht-----
> Van: samba [mailto:samba-bounces at lists.samba.org] Namens 
> Hadrien Grasland via samba
> Verzonden: donderdag 19 oktober 2017 10:49
> Aan: samba at lists.samba.org
> Onderwerp: Re: [Samba] Share mounts in SMBv1 mode, but fails 
> weirdly in SMBv2 mode
> 
> So, as a follow-up on this, I also took this matter to the linux-cifs 
> mailing list. After a bit of analysis, it turns out that...
> 
>  1. The Linux CIFS client was sending ill-formed QUERY_INFO packets to
>     the server. There is a patch for this in the pipeline.
>  2. There is also a bug in the server, which refuses to send all info
>     about the root filesystem inode, in spite of knowing this info in
>     principle. Considering that the bug is known and fixed 
> upstream, and
>     the problem is on our side (we cannot apply the server update for
>     some unclear reason), it was decided not to work around it.
> 
> Thanks for your help in this investigation!
> Hadrien Grasland
> 
> 
> Le 13/10/2017 à 17:01, L.P.H. van Belle via samba a écrit :
> >   
> >
> >> -----Oorspronkelijk bericht-----
> >> Van: samba [mailto:samba-bounces at lists.samba.org] Namens
> >> Hadrien Grasland via samba
> >> Verzonden: vrijdag 13 oktober 2017 15:34
> >> Aan: samba at lists.samba.org
> >> Onderwerp: Re: [Samba] Share mounts in SMBv1 mode, but fails
> >> weirdly in SMBv2 mode
> >>
> >> Hi Louis,
> >>
> >> Thanks for your reply!
> >>
> >>> This might be a kernel thing. 4.13.5-1 .. ? Archlinux?
> >> OpenSUSE Tumbleweed, actually.
> >>
> >> At some point, I got tired of rebuilding the entire world all
> >> the time
> >> because of the millenary tension between the wishes of 
> stable distro
> >> maintainers (who would rather not fix what isn't broken, and keep
> >> packages as stable as possible) and those of my developer 
> colleagues
> >> (who would rather put hard requirements on GCC 7 or CMake 3.9
> >> whenever
> >> they can get away with it), and decided that I could live with the
> >> occasional breakages of a rolling distro at work, as long 
> as rolling
> >> back a broken system was easy.
> >>
> >>
> >>> There where recently e-mail about this on technical.
> >>> So maybe its not implemented parts in samba or mount 
> commands (yet)
> >> I would welcome any clarification on this.
> >>
> >>> And i point to this : smb2_get_dfs_refer
> >>>>>>> [13424.783242] CIFS VFS: ioctl error in 
> smb2_get_dfs_refer rc=-2
> >>>>>>> [13424.789504] CIFS VFS: cifs_read_super: get root 
> inode failed
> >>>    
> >>> To give an idea..
> >>>
> >> https://kernel.opensuse.org/cgit/kernel-source/diff/patches.fi
> >> xes/0001-CIFS-implement-get_dfs_refer-for-SMB2.patch?id=98a4a0
> >> 402b8b564b24414c3f2d6b0268f6843341
> >>
> >> I ended up on this kernel patch as well while googling the error,
> >> however from a look at the code and the dmesg output, the
> >> error seemed
> >> to originate from an underlying call to the SMB2_ioctl() function.
> >> Juding from the short name and the long list of parameters, this
> >> function seemed like a big piece of machinery on its own, so
> >> I decided
> >> not to investigate it further without extra help. Which is
> >> why I came here.
> >>
> >>
> >>> This italian site shows exact the same problem.
> >>> http://forum.html.it/forum/showthread/t-2959605.html
> >>>
> >>> I suggest, lower you kernel to 4.9 somewhere around there.
> >>> See if that works, and then try vers=2.1
> >> Rolling back the kernel this far may be a bit difficult on
> >> Tumbleweed. I
> >> never tried it, but the maintainers tend to be quite agressive at
> >> removing old package versions from the repos. I guess that 
> going for
> >> older kernels is not true to their vision of the rolling
> >> release spirit :)
> >>
> >> As for version 2.1, I have tried it already, but unfortunately the
> >> server does not seem to support it (dmesg gives a "Dialect
> >> not supported
> >> by server." error).
> > Ah, wel at least that a better result, not what you want, 
> but better.
> >
> >> Note that I am not in an immediate hurry to get SMBv2 
> working. SMBv1
> >> works for me today, and from discussion with the sysadmins,
> >> it will be a
> >> long while before they disable it entirely. So I have time to
> >> investigate this issue, file any needed bug report to the relevant
> >> software projects, and would even help working on the fix 
> myself if I
> >> had even a remote idea of what's going on here. Sadly, my technical
> >> background is more in scientific computing than distributed
> >> filesystems.
> >>
> >> By the way, if you could tell me a bit more about the relationship
> >> between the kernel CIFS support and Samba, it might help. I
> >> naively went
> >> for the samba mailing list first as I got the impression 
> that this is
> >> the project where all Linux SMB protocol support is
> >> implemented first,
> >> but perhaps I should take this to the kernel mailing 
> list(s) instead ?
> > Phoe.. Good question. It never hurst to ask them also.
> > I suggest, ask it on samba-technical, or wait a bit, often 
> they look in the samba threah also.
> >
> >> Thanks for the help,
> >> Hadrien
> >>
> >>
> >>
> >>>
> >>> Greetz,
> >>>
> >>> Louis
> >>>
> >>>
> >
> 
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