From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754739AbaCRJn3 (ORCPT ); Tue, 18 Mar 2014 05:43:29 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:55050 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753462AbaCRJn1 (ORCPT ); Tue, 18 Mar 2014 05:43:27 -0400 Date: Tue, 18 Mar 2014 02:43:21 -0700 From: Christoph Hellwig To: NeilBrown Cc: "Michael Kerrisk (man-pages)" , "Aneesh Kumar K.V" , "linux-man@vger.kernel.org" , Linux-Fsdevel , lkml , Andreas Dilger , Christoph Hellwig Subject: Re: For review: open_by_name_at(2) man page Message-ID: <20140318094321.GA17024@infradead.org> References: <53271B69.3000305@gmail.com> <20140318090007.3adee3d0@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140318090007.3adee3d0@notabene.brown> User-Agent: Mutt/1.5.21 (2010-09-15) 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 On Tue, Mar 18, 2014 at 09:00:07AM +1100, NeilBrown wrote: > ESTALE is also returned if the filesystem does not support file-handle -> > file mappings. > On filesystems which don't provide export_operations (/sys /proc ubifs > romfs cramfs nfs coda ... several others) name_to_handle_at will produce a > generic handle using the 32 bit inode and 32 bit i_generation. Do we? Seems like the code is erroring out early if there are no export_ops? > Does it? My understanding from "man libblkid" (it is a while since I've read > the code) is that it either uses info in /dev/disks/by-* or reads directly > from the block devices (maybe using /sys to find them?) and interprets the > superblock to extract a UUID. It normally reads directly from disk, unless it has changed very recently.