Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail
From: Lumin Etherlight <lumin@etherlight.link>
Newsgroups: comp.os.linux.networking
Subject: Re: NFS locks debian12/debian13/Opensuse
Date: Mon, 16 Feb 2026 22:22:55 +0300
Organization: Etherlight Systems - https://etherlight.link
Lines: 47
Message-ID: <n0EkZDOMz/pmnwr6rCvXhRoTkcTqUmWC@etherlight.link>
References: <yga5x8byvvg.fsf@akutech.de>
MIME-Version: 1.0
Content-Type: text/plain
Injection-Date: Mon, 16 Feb 2026 19:23:11 +0000 (UTC)
Injection-Info: dont-email.me; posting-host="b10ea166bed6270de93099208a46a4f8"; logging-data="1229488"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX183F2dPqaPYphVzLj8hWfie"
User-Agent: Gnus/5.13 (Gnus v5.13)
Cancel-Lock: sha1:I3ezK6MBZvioWr5vyZH8EkkpNNE= sha1:SHAXLEIT0rpaTDWwjEm9EtLbx80=
Xref: csiph.com comp.os.linux.networking:8566

Ralf Fassel <ralfixx@gmx.de> writes:

> When I try to 'flock' a file in a directory on
> that share simultaneously on all 3 machines:

> - when the Opensuse machine holds the lock:
>   - the Debian-12 machine blocks as expected
>   - the Debian-13 machine fails with
>     % flock foobar sh -c 'echo start ; sleep 10 ; echo end'
>     flock: foobar: Input/output error

> Any hint why the Debian-13 fails when Opensuse
> holds the lock?  Any hint where to start to look
> for answers?

        I  would start  by trying  to build  and run
  different versions of  flock, from Linux utils[1],
  by building those versions  and seeing if the same
  issue holds.  Build the newest version, and run it
  on all machines, and try  to also build the oldest
  version you're  using and run it  on all machines.
  If issues  seem to get fixed  by some combination,
  then a bug report  against flock might be helpful.
  If the same issue still holds, then it probably is
  a kernel issue.

        If you  are up  for it, compile  and install
  different versions  of the  Linux kernel  on those
  machines and  OSes.  See  if that would  fixes the
  issue.  In  that case you can  probably report the
  issue against the Linux kernel.

        In all  cases, you should report  the issues
  to your distribution's  maintainers first, and not
  to the Linux upstream directly.

        If you  are system-programming-inclined, you
  can use strace  on flock to see  what system calls
  flock was  calling when the error  occurred, which
  might help you figure out the source of the issue,
  with the help of flock's source code.

[1]: https://www.kernel.org/pub/linux/utils/util-linux/


Best Regards,
Lumin Etherlight