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=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Date: Thu, 28 Aug 2014 21:00:41 +0400
From: Andrey Repin <anrdaemon@yandex.ru>
Reply-To: cygwin@cygwin.com
Message-ID: <1833268701.20140828210041@yandex.ru>
To: Corinna Vinschen <cygwin@cygwin.com>
Subject: ACL behavior in Cygwin // Re: (call-process ...) hangs in emacs
In-Reply-To: <20140828141036.GW20700@calimero.vinschen.de>
References: <53E3F2AE.7030608@redhat.com> <53E4D01B.9010005@cornell.edu> <53F1F154.1020702@cornell.edu> <53FB87DC.2050908@cornell.edu> <87wq9v9j2y.fsf@Rainer.invalid> <53FD0662.5050208@cornell.edu> <20140827084245.GD20700@calimero.vinschen.de> <17910052714.20140828010203@yandex.ru> <20140828100112.GQ20700@calimero.vinschen.de> <187704841.20140828172337@yandex.ru> <20140828141036.GW20700@calimero.vinschen.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

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@yandex.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