DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 51KKbTaJ419447
Authentication-Results: delorie.com; dmarc=pass (p=none dis=none) header.from=cygwin.com
Authentication-Results: delorie.com; spf=pass smtp.mailfrom=cygwin.com
DKIM-Filter: OpenDKIM Filter v2.11.0 delorie.com 51KKbTaJ419447
Authentication-Results: delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=FKs4DTv/
X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 3439C3858401
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1740083847;
	bh=uPu6p5thnns1cvZA892vrb+cjFLYaYoJov+NzR6D5hc=;
	h=Date:To:Subject:References:In-Reply-To:List-Id:List-Unsubscribe:
	 List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	 From;
	b=FKs4DTv/LQPyD9/Obyb+qejhcbiLFHreXTUgZksN5VO1COAfwoAQET4zFGEHwxmaf
	 bRn2XP/C0uy0t4qvPsG8p7PkCT2jp6jOV5ISmTg415XCzjasuKKTkwfGMDMZfgJl/x
	 pBWUGciXFFeSNsehVKtzBqY+K7Yv0zcdf24xxICQ=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1C6D13858D20
Date: Thu, 20 Feb 2025 21:36:37 +0100
To: cygwin AT cygwin DOT com
Subject: Re: [regression-3.6] coreutils mkdir broken on UNC paths
Message-ID: <Z7eSVamMjrs5XsBm@calimero.vinschen.de>
Mail-Followup-To: cygwin AT cygwin DOT com
References: <CALXu0UdHbasuyBiVZveyvJ1+K168QKBu0wn_cEVG8z+zfqQQeg AT mail DOT gmail DOT com>
 <CAPJSo4XR+vG=RLrOwdo=TsVhLj+qRhDdu0CFrnDZn4Z0oSoqhQ AT mail DOT gmail DOT com>
 <Z7dgP35hc_jd_dK7 AT calimero DOT vinschen DOT de>
 <CAPJSo4WrUzuGyTzz=Pp8oPnnbcawLNGZBb5dCE67AazVh8B2bA AT mail DOT gmail DOT com>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <CAPJSo4WrUzuGyTzz=Pp8oPnnbcawLNGZBb5dCE67AazVh8B2bA@mail.gmail.com>
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Corinna Vinschen via Cygwin <cygwin AT cygwin DOT com>
Reply-To: cygwin AT cygwin DOT com
Cc: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
Content-Type: text/plain; charset="utf-8"
Errors-To: cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 51KKbTaJ419447

On Feb 20 19:24, Lionel Cons via Cygwin wrote:
> On Thu, 20 Feb 2025 at 18:09, Corinna Vinschen via Cygwin
> <cygwin AT cygwin DOT com> wrote:
> >
> > On Feb 20 17:37, Lionel Cons via Cygwin wrote:
> > > On Thu, 20 Feb 2025 at 14:56, Cedric Blancher via Cygwin
> > > <cygwin AT cygwin DOT com> wrote:
> > > >
> > > > Good afternoon!
> > > >
> > > > Cygwin 3.6.0-0.378.g78fb13d21f4f.x86_64, Cygwin coreutils package 9.6-1
> > > >
> > > > coreutils mkdir is broken on UNC paths:
> > > >
> > > > mkdir -p -- "//ember.data4.local/afs/disk11/builds/bash/install_root/usr/local/bin"
> > > > mkdir: cannot create directory ‘//ember.data4.local’: Read-only file system
> > > >
> > > > This happens because you cannot do a "cd .." in
> > > > //ember.data4.local/afs, because "afs" is the UNC prefix for that
> > > > filesystem.
> > >
> > > No, it happens because mkdir "//ember.data4.local" returns "Read-only
> > > file system". If Cygwin would just return EEXIST if this mount exists,
> > > then this whole mkdir -p would work.
> >
> > You know exactly what Cygwin is doing wrong, great!
> 
> Sorry, it has been a very long day, and I did not communicate my point
> precisely.
> My point is that mkdir("//ember.data4.local") for a share should in my
> opinion not return EROFS, because the share already exists.
> 
> Looking at the code:
> int
> fhandler_base::mkdir (mode_t)
> {
>  if (exists ())
>    set_errno (EEXIST);
>  else
>    set_errno (EROFS);
>  return -1;
> }
> 
> My guess is that exists() fails. The why? and how? I do not know.

And here's the problem.  It works fine for me on all shares, be it SMB,
Samba, or NFS:

https://cygwin.com/pipermail/cygwin/2025-February/257438.html

> Maybe the hostname resolution in fhandler_netdrive::exists() failed?

If so, it would be a problem on your side.
Does `nslookup ember.data4.local' return a valid address?

I just pushed a patch to print a debug statement in strace output
to see what error code GetAddrInfoW returned.

The next test release cygwin-3.6.0-0.380-gdf307349a09e, due in an hour
or so, will contain that patch.  Rerun mkdir as above under strace and
send the full trace output as attachment.


Corinna

-- 
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