From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99FB0C6FA82 for ; Sat, 10 Sep 2022 19:48:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229560AbiIJTsY (ORCPT ); Sat, 10 Sep 2022 15:48:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229904AbiIJTsH (ORCPT ); Sat, 10 Sep 2022 15:48:07 -0400 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [IPv6:2a03:a000:7:0:5054:ff:fe1c:15ff]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B538627B3D; Sat, 10 Sep 2022 12:47:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Gf3iMQ+MIqgx3+mJysjCBke8D/E+r5JbUH6683x5+Og=; b=j6Iq4VK9au7hbkSuQKBGdDG9GP mwAGx/98LQc7paRsL14lJtePAQ6KABmyGEiCoqpgJSj2UbqQxSTMRrQ5/Taiug3UjN4Oc/5CfoX58 sN7/z/u2sbh1TbDVON/fsTWzC0NSpnpSWPxv18dHXrUjI0Z0zc+9RuIkgErQjwhFBHEHxF7LpN2Zd GYbt9za+SxMF6DJXFWMYVDkY4hXexaztbWaQuLMKeJmDQZlnthkZ0Pm4O1zb2IoZbzipYbmpee0MF MgZ+XhfrOFTa+OgKZMEtnZ0iNfbAxXLFUg1vjLVO1eP2OSYy/kjJEVwjO0UsIHYbKGHhei/dZagQB M9E8wObQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.95 #2 (Red Hat Linux)) id 1oX6RN-00EPHP-Rk; Sat, 10 Sep 2022 19:46:57 +0000 Date: Sat, 10 Sep 2022 20:46:57 +0100 From: Al Viro To: NeilBrown Cc: Jeff Layton , Trond Myklebust , "bfields@fieldses.org" , "zohar@linux.ibm.com" , "djwong@kernel.org" , "xiubli@redhat.com" , "brauner@kernel.org" , "linux-api@vger.kernel.org" , "linux-xfs@vger.kernel.org" , "david@fromorbit.com" , "fweimer@redhat.com" , "linux-kernel@vger.kernel.org" , "chuck.lever@oracle.com" , "linux-man@vger.kernel.org" , "linux-nfs@vger.kernel.org" , "tytso@mit.edu" , "jack@suse.cz" , "linux-ext4@vger.kernel.org" , "linux-btrfs@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "lczerner@redhat.com" , "adilger.kernel@dilger.ca" , "ceph-devel@vger.kernel.org" Subject: Re: [man-pages RFC PATCH v4] statx, inode: document the new STATX_INO_VERSION field Message-ID: References: <20220907111606.18831-1-jlayton@kernel.org> <166255065346.30452.6121947305075322036@noble.neil.brown.name> <79aaf122743a295ddab9525d9847ac767a3942aa.camel@kernel.org> <20220907125211.GB17729@fieldses.org> <771650a814ab1ff4dc5473d679936b747d9b6cf5.camel@kernel.org> <8a71986b4fb61cd9b4adc8b4250118cbb19eec58.camel@hammerspace.com> <166259764365.30452.5588074352157110414@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <166259764365.30452.5588074352157110414@noble.neil.brown.name> Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Thu, Sep 08, 2022 at 10:40:43AM +1000, NeilBrown wrote: > We do hold i_rwsem today. I'm working on changing that. Preserving > atomic directory changeinfo will be a challenge. The only mechanism I > can think if is to pass a "u64*" to all the directory modification ops, > and they fill in the version number at the point where it is incremented > (inode_maybe_inc_iversion_return()). The (nfsd) caller assumes that > "before" was one less than "after". If you don't want to internally > require single increments, then you would need to pass a 'u64 [2]' to > get two iversions back. Are you serious? What kind of boilerplate would that inflict on the filesystems not, er, opting in for that... scalability improvement experiment?