X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:reply-to:message-id:to:subject
	:in-reply-to:references:mime-version:content-type
	:content-transfer-encoding; q=dns; s=default; b=CajqLF/dDT0oAwyz
	JWuagy7CDakuaEHUKMdxPj5eFiyolFPAunKd8+rZSdS70Lr/NGlfN/PUTjvXHNbS
	vzVFYswclQirt3putCDkSVNZiBdtKAutz8RchyoJMmHm+OrZ/TIqcStHG6r5e814
	+USNSqD40mng9lOGiQ90oG1hFZQ=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:reply-to:message-id:to:subject
	:in-reply-to:references:mime-version:content-type
	:content-transfer-encoding; s=default; bh=swidslqQ0WZ8vnGSMrtNf+
	TI4ns=; b=Zr8zher/Fp5mE6Wlro99NJ/QFcTLY7Pvucwx3xCukjhy3nQgPYeKCl
	Dw+Cp/kwq/Zg3FgzyXlyGntwqQmPzRpBtmW4plBd8PPOs22tU1FEbYXOXlyiQWpW
	9fQO8IZqN3CPwnlL892HMtGWxTXtkLVBg2veRUpkAAH5egqfzleDY=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=3.6 required=5.0 tests=AWL,BAYES_50,FREEMAIL_FROM,KAM_THEBAT,SPF_SOFTFAIL autolearn=no version=3.3.2
X-HELO: smtpback.ht-systems.ru
Date: Thu, 28 Aug 2014 21:00:41 +0400
From: Andrey Repin <anrdaemon AT yandex DOT ru>
Reply-To: cygwin AT cygwin DOT com
Message-ID: <1833268701.20140828210041@yandex.ru>
To: Corinna Vinschen <cygwin AT cygwin DOT com>
Subject: ACL behavior in Cygwin // Re: (call-process ...) hangs in emacs
In-Reply-To: <20140828141036.GW20700@calimero.vinschen.de>
References: <53E3F2AE DOT 7030608 AT redhat DOT com> <53E4D01B DOT 9010005 AT cornell DOT edu> <53F1F154 DOT 1020702 AT cornell DOT edu> <53FB87DC DOT 2050908 AT cornell DOT edu> <87wq9v9j2y DOT fsf AT Rainer DOT invalid> <53FD0662 DOT 5050208 AT cornell DOT edu> <20140827084245 DOT GD20700 AT calimero DOT vinschen DOT de> <17910052714 DOT 20140828010203 AT yandex DOT ru> <20140828100112 DOT GQ20700 AT calimero DOT vinschen DOT de> <187704841 DOT 20140828172337 AT yandex DOT ru> <20140828141036 DOT GW20700 AT calimero DOT vinschen DOT de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-IsSubscribed: yes

Greetings, Corinna Vinschen!

>> > It's what "acl" means on Cygwin.  "acl" means that Windowsd ACLs are used
>> > and permissions are handled and converted to and from POSIX permissions.
>> > "noacl" means, Cygwin ignores all ACLs and fakes ownership and POSIX
>> > permissions only based only on filetype and DOS R/O attribute, as it has
>> > to on filesystems not supporting ACLs, like FAT/FAT32.
>> 
>> Got it.
>> It seems, Cygwin need a middle groung between these two for cases, where FS
>> support access control, but don't want to be mangled.

> I'm certainly not going to introduce another mount mode.

I didn't said it has to be mount mode... besides, it doesn't make sense to
implement YA mode to do what is already done, just a little different.

> What Cygwin could do is to perform ACL-based access checks independently of
> the "acl"/"noacl" mount mode on FSes supporting ACLs.  However, if you want
> ACLs, why not use the "acl" mount mode in the first place?

ACL inheritance, mostly. POSIX'ized permissions break inheritance on newly
created files, at times making these files inaccessible to native
applications, even though inheritance rules would allow it otherwise.

> Still, it *might* makes sense in some scenarios, even if the results of
> stat(2)/acl(2) may differ surprisingly from what access(2) returns.

> We can also simply try it out.  A patch to enable this behaviour is
> dead-simple.

> Here's the prerequisite:

>   Would more than one person want that *and* be willing to give this a
>   *thorough* testing?

I'd like to hear out expected behavior from this patch first.
I might be able to do some testing, but not in the nearest month, I'm afraid.
The "list of things to do" grew out of control, and I'm trying hard to make
it shorter.
If there's no other interested parties, let's put it on ice, until you come
back from your vacation?


--
WBR,
Andrey Repin (anrdaemon AT yandex DOT ru) 28.08.2014, <20:37>

Sorry for my terrible english...


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple