On Sun, Aug 13, 2023 at 7:13 PM Martin Wege <martin.l.w...@gmail.com> wrote:
>
> On Sun, Aug 13, 2023 at 12:43 AM Roland Mainz via Cygwin
> <cygwin@cygwin.com> wrote:
> >
> > On Fri, Aug 11, 2023 at 10:55 AM Corinna Vinschen via Cygwin
> > <cygwin@cygwin.com> wrote:
> > [snip]
> > > On Aug 11 10:25, Martin Wege wrote:
> > > > Cygwin somehow breaks unmounting of network shares, but ONLY if the
> > > > net use /delete happens in a bash shell script.
> > > >
> > > > Example:
> > > > Mount SMB network share on Z:
> > > > Do not touch Z:!
> > > >
> > > > Then do a net use /delete in a bash script:
> > > > net use Z: /delete
> > > > Systemfehler 1794 aufgetreten.
> > > > Der Redirector wird verwendet und kann nicht aus dem Speicher entfernt
> > > > werden.
> > > >
> > > > If I execute the net use Z: /delete in an interactive bash shell it
> > > > works.
> > > >
> > > > Can anyone explain this?
> > >
> > > Something is wrong on your side, but no, I can't explain it. It's
> > > not related to Cygwin:
> > >
> > > $ cat > b.sh <<EOF
> > > #!/bin/bash
> > > net use Z: /delete
> > > EOF
> > > $ chmod +x b.sh
> > > $ net use Z: \\\\server\\share
> > > The command completed successfully.
> > >
> > > B:[~]$ ./b.sh
> > > Z: was deleted successfully.
> >
> > I think it's the problem that a shell keeps a fd open to the shell
> > script's file.
> >
> > Example:
> > ---- snip ----
> > $ cat shellfd.ksh
> > #!/bin/ksh93
> > # shell script printing the fd which the shell
> > # process has open right now
> > ls -l /proc/$$/fd/
> > true # needed here so ksh93 doesn't make a tail optimisation
> > exit 0
> > $ bash shellfd.ksh
> > total 0
> > lrwx------ 1 test001 users 64 Aug 13 00:26 0 -> /dev/pts/7
> > lrwx------ 1 test001 users 64 Aug 13 00:26 1 -> /dev/pts/7
> > lrwx------ 1 test001 users 64 Aug 13 00:26 2 -> /dev/pts/7
> > lr-x------ 1 test001 users 64 Aug 13 00:26 255 ->
> > /cygdrive/h/tmp/shellfd.ksh
> > $ ksh93 shellfd.ksh
> > total 0
> > lrwx------ 1 test001 users 64 Aug 13 00:26 0 -> /dev/pts/7
> > lrwx------ 1 test001 users 64 Aug 13 00:26 1 -> /dev/pts/7
> > lr-x------ 1 test001 users 64 Aug 13 00:26 10 -> /cygdrive/h/tmp/shellfd.ksh
> > lrwx------ 1 test001 users 64 Aug 13 00:26 2 -> /dev/pts/7
> > ---- snip ----
> >
> > So both bash4 an ksh93 keep a fd to the shell script ("shellfd.ksh")
> > around (I even tried /usr/bin/shcomp to make shell bytecode, but the
> > issue remains...)
> >
> > And here comes the nasty part: If shellfd.ksh is on a network
> > filesystem (in my test setup my home dir, mounted at H:), then in some
> > cases (I do not know why) a $ net use Z: /delete # will fail with
> > error #1794 if both network filesystems are from the same server.
> >
> > This is NOT the same as the script tries to unmount the filesystem it
> > is residing on - Z: is mounted separately, and a different exported
> > directory than H:, and yet I can reproduce that issue (after around
> > 30-40 experiments, until I remembered that ksh93 keeps a fd to the
> > script open).
> >
> > This sounds a lot like a Windows bug.
> >
> > Martin: Do you have more than one network filesystem mounted on your
> > machine ?
>
> Yes, usually 12-14 filesystems mounted per machine. This includes user
> directories, and several directories where the software and production
> data come from. I still have to test whether putting software on a
> local disk solves the problem. Maybe I should better call this a
> workaround for a silly Windows restriction.
Yeah, putting software on a local disk allows me to do a successful
net use Z: /delete
So what do we do now? File a bug at Microsoft support, and they fix
that for Windows 12 in 2038?
Thanks,
Martin
--
Problem reports: https://cygwin.com/problems.html
FAQ: https://cygwin.com/faq/
Documentation: https://cygwin.com/docs.html
Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
