How to turn on SMB3 POSIX extensions in Samba server?

[Rowland penny]

On 05/10/2019 22:28, Jeremy Allison via samba-technical wrote:
> On Sat, Oct 05, 2019 at 11:02:21PM +0800, Chris Han via samba-technical wrote:
>> Hi, I want to use the SMB3 POSIX extensions in the latest Samba (with
>> SMB3.1.1, vers=3.1.1). By following the user manual, I have added the
>> "posix" mount option when mounting, but it shows the following error
>> messages.
>>
>> Error messages:
>> [xxxxx] CIFS VFS: Server does not support mounting with posix SMB3.11
>> extensions.
>> [xxxxx] CIFS VFS: cifs_mount failed w/return code = -95
>>
>> Mount option:
>> https://www.mankier.com/8/mount.cifs#posix%7Cunix%7Clinux
>> https://wiki.samba.org/index.php/SMB3-Linux
>>
>> Mount commands:
>> mount –t cifs -o username=<user>,vers=3.1.1,posix //<address>/share
>> /mnt/share
>> mount –t cifs -o username=<user>,vers=3.1.1,posix,mfsymlinks
>> //<address>/share /mnt/share
>>
>> Software and kernel version:
>> 1. Ubuntu 19.04, Kernel 5.0, Samba 4.10
>> 2. Ubuntu 18.04.3, Kernel 5.0, Samba 4.7
>>
>> Example of using the "vers=3.1.1,posix" mount option: (Page 46)
>> https://www.snia.org/sites/default/files/SDC/2018/presentations/SMB/Steve_French_SMB311.pdf
>>
>> How to turn on SMB3 POSIX extensions in Samba server?
> There is no officially released version of Samba that
> implements the SMB3 POSIX extensions yet. The code still
> lives in an experimental branch that hasn't yet been
> merged with mainline.
>
> The plan is to finish the VFS refactoring, which will
> bring the internals of Samba closer to the modern OpenGroup
> handle-based VFS interface, then merge the extensions code
> into mainline after that. The released code will be in
> the next supported Samba version after the VFS refactoring
> is done. Realistically, this will be sometime in 2020 unless
> someone else wants to help me with the code :-).
>
> Jeremy.
>
Hi Jeremy, I advised the OP over on the samba mailing that unix 
extensions for SMBv3 do not exist yet, but he seems to think that 
something similar should work with mount.cifs and the kernel.

Rowland