RFD: cygwin ACLs: NFS or POSIX model: ease in adapting to CIFS ACLs?

Linda Walsh cygwin@tlinx.org
Sun Dec 21 23:25:00 GMT 2014

I seem to remember that the cygwin ACL's were based on NFS acls not
the POSIX ACL's.  From this snippet I read on the Samba list,
it seems there are some "very difficult" [nightmarish] cases
where NFS causes CIFS compatibility problems.  Is this only
NFSv4 (does cygwin model v4 or v3?) that had these problems? 

Would it simplify anything for cygwin to be using POSIX
acl's -- in so much that those seem to be more
str8forward in functionality mapping?

I know nothing about NFS ACL's or how they are different from POSIX ACL's,
but wondered also if code in the linux kernel or samba projects might have
any useful bits to use in cygwin only from the basis of what this
person states about their compatibility?

It may also be this is a dead issue without someone to do the work, but
am just wondering if it is, in any fixes or enhancements to the Cygwin ACL
work something that might be good to consider as a direction for either,
new or maintenance (or both) work?

Just seems like code in samba that presents a CIFS UI/API
to the 'user' from a POSIX ACL UI/API backend,  might have
some similarities between cygwin code using CIFS to talk to
the OS and presenting a POSIX ACL UI/API to the 'user'?

-------- Original Message --------
Subject: 	Does Samba 4 actually respect Unix file acls?
Date: 	Sat, 20 Dec 2014 20:42:11 -0500
From: 	Nico Kadel-Garcia <nkadel@gmail.com>
To: 	Rufe Glick <rufe.glick@gmail.com>
CC: 	samba@lists.samba.org <samba@lists.samba.org>
References: 	<931136554.20141219124751@gmail.com>

On Fri, Dec 19, 2014 at 12:47 PM, Rufe Glick <rufe.glick@gmail.com> wrote:
> Hello,
> After researching the subject on the internet I concluded that Samba should 
> take into account Unix file acls. During my tests I found the opposite. 

I'm sorry, but exactly which set of "file acl's" are you referring to?
NFS v4, prehaps or Linux availaility? CIFS ACL's? Because I've got to
warn you, I pursued getting NFS, and CIFS clients to work well with
Samba and Netapps, with Linux and Windows clients, and it was a
clusterfutz to manage. 

RHEL didn't include decent GUI's to manage NFSv4 ACL's, the are 
profound hierarchy differences between CIFS and
NFSv4, and the edge cases were nightmarish.

Frankly, for most environments, the POSIX permissions are not only
vastly simpler, but the software compatibly is so much simpler as to
help make the code more stable and thus safer. I remember even Jeremy
Allison referring to the NFSv4 code in Samba as spaghetti code.

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