X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B691B385800B
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1638959896;
	bh=99V3CLD0JY8Y6iFzNy2c1Z5dL33wtj8O/f8NA0x13MY=;
	h=Date:From:To:Subject:References:In-Reply-To:List-Id:
	 List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe:
	 Reply-To:From;
	b=tKwbYJrtQ4hlUNi2EpWcqbqf1F6xrF26z1CVpOo2q0eLwLSZS3B2KYUuUnSvwtDwQ
	 tLig1Ei3wBf+QG1D+GiFj2RbghIO4bT8IehT0o/EBqXZuPv/1DLn6ZOfAye8RN3akJ
	 kC1k60fvwr1lhiQ8HxH9gDQujmSQdVud7qmwQFXE=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 080273858D28
Authentication-Results: sourceware.org;
 dmarc=fail (p=none dis=none) header.from=cygwin.com
Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=cygwin.com
Date: Wed, 8 Dec 2021 11:37:39 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: vboxsharedfs - Too many levels of symbolic links
Message-ID: <YbCK8/w9KfjB+b/N@calimero.vinschen.de>
Mail-Followup-To: cygwin AT cygwin DOT com
References: <Ya+WvmECA+zAbuV9 AT calimero DOT vinschen DOT de>
 <20211208172008 DOT 01b11239c374604abf638a19 AT nifty DOT ne DOT jp>
MIME-Version: 1.0
Content-Disposition: inline
In-Reply-To: <20211208172008.01b11239c374604abf638a19@nifty.ne.jp>
X-Provags-ID: V03:K1:naXLOUaNLIEvTYkzVBBcwvyy7+BZMTj1X9OC6T7KBsuT0h+/F8T
 qnByBctPu5Y7DNPXmYdnIfqRf13VhYdAarNbat8NwV/Mb0Q6GuiP0ON0SN0zTN2ufjUaOdw
 i7qwFpM0wwpGWRstCgVqyB4uvFS0yKkbWq6nN/rwXAZ3THudWD6P/e/D9xnaRC3Mmer5xSq
 HhZGTCc6bXzVIHHqrDplg==
X-UI-Out-Filterresults: notjunk:1;V03:K0:CZWP6kRHw7s=:NN5tlS8PafHtsG0E7ymb14
 AghgjGa/apJxeRYvwR2HCi4y+ykh/fkQ7rux2C9rALrmq/9JSYHltulhKLRovv8qlLweVe9Ek
 VtSjlHccv0BShTpa20xtCG0BEE5AY/nGhAwoREkeJPybZBVZPRlNxHqoJB8iqpJtwpfbR11ij
 x3azmlBAObGXqQvIQuuRLDP4JibFGJx1S4AU7Zb3A/GJAX4pqcnxjmANMPg+QsdYaiSyf2WzL
 i3i1UmSWChnMoDJN8EDF9tnkuLZ3mStGS1HFdRqnXLUIkzFePt6WUvAOm62oRD1bo+cIFQa7j
 9HFaK4AWGQgDlmLfTPEdlokjlbKlFgn3bzz89RiGKHatJ7q7kQZRKH1QqgyOKqXkYu4Zc/yCl
 U+wZl8XxBdInVXm9bJbeFIU+Xog+mZgPFoO04/shrppQsTEu1r5o0GRdkkHxR9vE6uw5gt13A
 VKL+rk3Rh0j0Wa3RzUhZFvcG1G9A6IRafqp+hhKHUEM7lEyx0EqUP07B1T627ZuKQWYsBDtnB
 5YIZFeP0+q+xk4m1Np4mxpMRFi9hi8R1k75Ter2ydXs0gCWsFJc0h3YiCgEMhcq6Of+fJDzay
 ++FWaQobFGyz9DUBVSaiKs8+nabBOwspdRkRM06o1ZEOQ24QCqo71OV/2lK+M0XN/+T7NRF1j
 uQ2tRi0/7Cq7ZtQmGKh9EFvD+hGzcXgF/FiEuHbUyw3lOBc8KG/KvwXTMiyjlvfObZuAQfi6m
 FQoZ7ueXJnDoIDgt
X-Spam-Status: No, score=-99.4 required=5.0 tests=BAYES_00,
 GOOD_FROM_CORINNA_CYGWIN, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE,
 RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NEUTRAL,
 TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.29
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>
Reply-To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
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>

On Dec  8 17:20, Takashi Yano wrote:
> On Tue, 7 Dec 2021 18:15:42 +0100
> Corinna Vinschen wrote:
> > Hi Takashi,
> > 
> > ----- Forwarded message from Corinna Vinschen <corinna-cygwin AT cygwin DOT com> -----
> > > The idea of the GFPNBH call is to short-circuit the path_conv handling
> > > in case we have native Windows symlinks in the path.  My example above
> > > was only considering what comes out of the `if ((pc_flags & ...) { ... }
> > > ' expression starting in line 3485 (assuming "b" is a native symlink).
> > > 
> > > What I mean is this: Your patch disregards the entire string returned by
> > > GFPNBH, if the returned path is an UNC path, no matter what.
> > > 
> > > But what if the incoming path already *was* an UNC path, and potentially
> > > contains native symlinks?  In that case you have no reason to disregard
> > > the resulting path from GFPNBH.
> > > 
> > > And if it was a drive letter path, wouldn't it be nicer to just convert
> > > the UNC path prefix back to the drive letter and keep the rest of the
> > > final path intact?
> > > 
> > > However, both of these scenarios require extra code, which isn't that
> > > important for now, so, never mind.
> > ----- End forwarded message -----
> > 
> > What I meant is something like the below (entirely untested).  Yeah, I'm
> > not sure myself, if it's worth the effort...
> > [...]
> I confirmed that your patch works nicely.
> 
> ...except when the drive is created by subst using UNC path,
> e.g. subst w: \\server\share.
> 
> In this case, WNetGetConnectionW() fails with ERROR_NO_NET_OR_BAD_PATH.
> 
> So, I modified your patch a bit.
> 
> What about attached patch?

Oh, great!  GetVolumePathNameW is the function I somehow missed when
looking into the Microsoft docs yesterday, so thanks for modifying the
patch this way.

Please push.


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