samba - Feb 2019 - Issues with using Samba share from Mac OS

I am an old UNIX and Mac hand but new to samba.  My ultimate aim is to use a
samba share with Time Machine.
I have built an up to date version of samba (4.9.2) which has the necessary
support for Time Machine and installed it on my linux system (ubuntu 18.04), and
I have it sharing a volume which I can mount from my Mac. A good start ;)

The problem is that I get permission errors whenever I try and create any files
or directories on the share from the Mac:

henry-crunn:timemachine rful011$ id
uid=501(rful011) gid=20(staff) …

henry-crunn:timemachine rful011$ ls -l /Volumes/
total 64
lrwxr-xr-x  1 root     wheel      1  3 Feb 10:43 Macintosh HD -> /
drwx------  1 rful011  staff  16384  3 Feb 12:04 timemachine

henry-crunn:timemachine rful011$ touch  /Volumes/timemachine/test
touch: /Volumes/timemachine/test: Permission denied

The permissions as shown by ls -l look fine but I still get permission denied on
any operation that creates files on the volume.

/etc/samba/smb.conf:

[global]
………..
# Mac OS support
  vfs objects = catia fruit streams_xattr
  fruit:aapl = yes


[timemachine]
  comment = Time Machine
  path = /mnt/macmini-bb/timemachine
  browseable = yes
  writeable = yes
  create mask = 0600
  directory mask = 0700
  spotlight = no
  fruit:time machine = yes

Should the vfs object be in global or share section?   

I posted a detailed query to AskDifferent but it did not elicit any useful
responses — link below.  It has more detail including screenshot showing a popup
stating that a file on the share was *locked* when I tried to edit it.

It isn’t clear to me it the issue is a bug in the fruit support or simply
something that I have screwed up
https://apple.stackexchange.com/questions/350422/can-not-create-files-on-samba-share-for-time-machine

On Mon, 11 Feb 2019 09:14:03 +1300
Russell Fulton via samba <samba at lists.samba.org> wrote:
> I am an old UNIX and Mac hand but new to samba.  My ultimate aim is
> to use a samba share with Time Machine. I have built an up to date
> version of samba (4.9.2) 
Samba is now at 4.9.4 and you can get packages for 18.04 here:

http://apt.van-belle.nl/
>which has the necessary support for Time
> Machine and installed it on my linux system (ubuntu 18.04), and I
> have it sharing a volume which I can mount from my Mac. A good
> start ;)
> 
> The problem is that I get permission errors whenever I try and create
> any files or directories on the share from the Mac:
> 
> henry-crunn:timemachine rful011$ id
> uid=501(rful011) gid=20(staff) …
'501' is a low number for a user id on Linux, these usually start at
'1000'
> 
> henry-crunn:timemachine rful011$ ls -l /Volumes/
> total 64
> lrwxr-xr-x  1 root     wheel      1  3 Feb 10:43 Macintosh HD -> /
> drwx------  1 rful011  staff  16384  3 Feb 12:04 timemachine
> 
> henry-crunn:timemachine rful011$ touch  /Volumes/timemachine/test
> touch: /Volumes/timemachine/test: Permission denied
> 
> The permissions as shown by ls -l look fine but I still get
> permission denied on any operation that creates files on the volume.
> 
> /etc/samba/smb.conf:
> 
> [global]
> ………..
Any chance you can post just what '..... .' really is, that, from the
Linux and Samba point of view is the interesting part ;-)
> # Mac OS support
>   vfs objects = catia fruit streams_xattr
>   fruit:aapl = yes
> 
> 
> [timemachine]
>   comment = Time Machine
>   path = /mnt/macmini-bb/timemachine
>   browseable = yes
>   writeable = yes
>   create mask = 0600
>   directory mask = 0700
>   spotlight = no
>   fruit:time machine = yes
> 
> Should the vfs object be in global or share section?   
Either, if it is in [global], it affects everything, if it is in a
share, it just affects that share.

Rowland