Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757700Ab0GBHGF (ORCPT ); Fri, 2 Jul 2010 03:06:05 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:34859 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754000Ab0GBHGB (ORCPT ); Fri, 2 Jul 2010 03:06:01 -0400 Date: Fri, 2 Jul 2010 03:05:48 -0400 From: "hch@infradead.org" To: Andreas Dilger Cc: Neil Brown , "Aneesh Kumar K. V" , "hch@infradead.org" , "viro@zeniv.linux.org.uk" , "adilger@sun.com" , "corbet@lwn.net" , "serue@us.ibm.com" , "hooanon05@yahoo.co.jp" , "bfields@fieldses.org" , "linux-fsdevel@vger.kernel.org" , "sfrench@us.ibm.com" , "philippe.deniel@CEA.FR" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH -V14 0/11] Generic name to handle and open by handle syscalls Message-ID: <20100702070548.GA6959@infradead.org> References: <1276621981-2774-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <871vbn2mk9.fsf@linux.vnet.ibm.com> <20100702064108.64034561@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 929 Lines: 13 On Thu, Jul 01, 2010 at 10:02:29PM -0600, Andreas Dilger wrote: > I'd like to be able to use this interface to implement the distributed open call proposed by the POSIX HECWG. This allows one client to do the path traversal, broadcast the file handle to the (maybe) 1M processes in the job via MPI, and then the other clients can open the file by handle without doing 1M times the full path traversal (which might be 10's of RPCs per process). The proposal is doomed anyway. If we allow any sort of open by handle system call for unprivilegued users we need to do reconnect the dentry to the dcache path anyway (reconnect_path), which is more expensive than a normal path lookup. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/