From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Kleikamp Subject: Re: [Acl-Devel] Status of ACL patches regarding inclusion in the standard kernel? Date: Tue, 8 Oct 2002 15:37:17 -0500 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <200210081537.17153.shaggy@austin.ibm.com> References: <3DA33606.9050702@tls.msk.ru> <20021008200417.GB100396@dhcp-uaus08-128-212.sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: Tobias Burnus , acl-devel@bestbits.at, linux-fsdevel@vger.kernel.org Return-path: To: spencer.shepler@sun.com, Spencer Shepler , Michael Tokarev In-Reply-To: <20021008200417.GB100396@dhcp-uaus08-128-212.sun.com> List-Id: linux-fsdevel.vger.kernel.org On Tuesday 08 October 2002 15:04, Spencer Shepler wrote: > On Tue, Michael Tokarev wrote: > > Just a random thought (sorry if it was discussed before) - I don't > > see why every filesystem with it's own unique layout etc should > > store ACLs as xattrs - there may be different implementation > > especially for ACLs but no xattrs at all (at the beginning of the > > "ACL era", almost everyone agreed that ACL/xattrs subsystem should > > be more-or-less universal, allowing many different layouts/concepts > > (think NTFS ACLs vs POSIX ACLs) to be used). Well, conversion > > routines may exists (if at all possible), but in some cases this > > will be an overkill. > > This would certainly be true of NFSv4 where ACLs are part of the > semantically defined attributes and are not part of the xattr space. > Using [gs]et_posic_acl() would make the translation job > straightforward for the NFS client/server. The xattr space is broken down into namespaces that the fs's are free to handle any way they wish, so even though the ACL's may come in as an xattr, the fs can store it any way it chooses. This is where I argue that IF we have a separate ACL interface, there's no need to require that the xattr interface be used to store the ACL, but since most filesystems will use xattrs, we should have a generic function that stores/retrieves the ACL in the form of an xattr (and caches the ACL for fast access). If we decide NOT to have a separate ACL interface, the filesystem would then deal with the ACL's based on the xattr namespace. It has the freedom to actually store the ACL as an xattr, or in some other fashion. In this case, I still argue for a generic get_posix_acl (not a file operation) that calls the fs's get_xattr. I don't see a need for every fs to implement this function. -- David Kleikamp IBM Linux Technology Center