From: James Morris Subject: Re: [PATCH 0/4][RFC] NFSv3: implement extended attribute (XATTR) protocol Date: Tue, 22 Sep 2009 23:03:25 +1000 (EST) Message-ID: References: <4AB51538.7060201@schaufler-ca.com> <20090922124755.GA2886@infradead.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Casey Schaufler , Trond Myklebust , "J. Bruce Fields" , linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Christoph Hellwig Return-path: In-Reply-To: <20090922124755.GA2886@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, 22 Sep 2009, Christoph Hellwig wrote: > Note that the mapping should be really simple. Both the NFS protocol > and XFS implement the same IRIX-xattr format that has a numerical > namespace instead of the string prefix Linux has. If you just use the > same mapping as XFS it should not have interoperability problems. One issue may be that the IRIX protcol for listxattr includes a "attrlist_cursor_kern_t cursor" -- presumably to allow the client to index into large lists of xattrs. I'm going to guess that this doesn't happen much in practice, although to have interop with IRIX, we'd need to handle this in some useful way. Otherwise, yes, mapping to the IRIX protocol should be straightforward. We can use the side-protocol number+version to detect that we're talking to an IRIX box. - James -- James Morris