samba - Sep 2017 - Questions around deleting a file accessed by others

Yesterday I received a call from a customer ... in panic.

Some users couldn't access an important binary on the samba file server
while it was visible in Windows explorer and on the linux server.

It's a debian domain member server with Samba version 4.5.12-Debian.

The users get connected to a share via GPO, additionally I put an icon
on their desktops, linking to \\server\something\wfibn.exe

I can't reconstruct what happened in detail, they always pretend to not
having done *anything* ;-)

Seems as if someone deleted the icon or the exe itself while other users
had the file open as well (we talk of around 15-20 people accessing the
same program normally).

AFAI understand deleting a desktop icon must not delete the file the
link points to ...

-

I figured out that the exe was somehow marked as "to be deleted as soon
as no smbd process accesses it anymore":

[2017/09/06 11:57:55.006868,  2] ../source3/smbd/open.c:1342(open_file)
  BUERO\userX opened file prog/wfibn.exe read=No write=No (numopen=8)
[2017/09/06 11:57:55.007039,  3]
../source3/smbd/smb2_server.c:3097(smbd_smb2_request_error_ex)
  smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1]
status[NT_STATUS_DELETE_PENDING] || at ../source3/smbd/smb2_create.c:293

As long as there were open sessions the file was there (with correct
permissions etc) but new connections were refused ("hey, it's gonna be
deleted in a few minutes anyway").

I suggested they should close all sessions at once ... then the file
actually was deleted and gone. cp-ied it back from a backup, after that
all (even the new) sessions were successful.

Now I tested if the binary works if set to readonly: yes, it does ...
and the users can't delete it now. Should work.

-

Is all this expected and normal behavior?

Am 2017-09-07 um 10:37 schrieb Stefan G. Weichinger via samba:
> Is all this expected and normal behavior?
*bump*

On Linux systems you can delete a file when some processes are accessing
that file. It will be really deleted once the last process free the file.
You can easily test that behaviour with a film or some music: you start
playing it, you delete it and the space would be deleted once no more
process access the file.

So it seems to me, whom is not Samba internal expert, a normal behaviour.

What I don't feel like a normal behaviour is how users could delete a file
they are not supposed to be allowed to.

Cheers

2017-09-10 18:23 GMT+02:00 Stefan G. Weichinger via samba <
samba at lists.samba.org>:
> Am 2017-09-07 um 10:37 schrieb Stefan G. Weichinger via samba:
>
> > Is all this expected and normal behavior?
>
> *bump*
>
>
>
>
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