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 4CD55C6FA82 for ; Sat, 10 Sep 2022 23:00:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229785AbiIJXA0 (ORCPT ); Sat, 10 Sep 2022 19:00:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229565AbiIJXAY (ORCPT ); Sat, 10 Sep 2022 19:00:24 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1760727B36; Sat, 10 Sep 2022 16:00:24 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id C14851F385; Sat, 10 Sep 2022 23:00:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1662850822; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SEZa31fS3EA9aFsPGWU6D91+fQNEkWOjOiZMWEVbOm8=; b=D2nGQ+KmyoT+3CB9WFqrOvSdTCTC7vLDI6lvwiyiHKx1KRh/hVQcC1Kyz0pAWNWFH6DVsU oYPaZqJklzpxIdT0Kd5P9Oyjb0H9pGpXDZ3uFtk4/vxZx1JUV4VqaWxROrNytO57a7bi6i wlncE/a53qalNImF/4VgojhyTUI9QgM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1662850822; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SEZa31fS3EA9aFsPGWU6D91+fQNEkWOjOiZMWEVbOm8=; b=/7aLYuKDFocxpJ7Wq/t+4PhxPCMT/enTqz6zz/P8FeBaUvb/PmzRyHfFPSyewk9Cg5nGxr LoooUzXWIOKYwxCQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 48FBE133B7; Sat, 10 Sep 2022 23:00:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id iys6AP8WHWNKRgAAMHmgww (envelope-from ); Sat, 10 Sep 2022 23:00:15 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 From: "NeilBrown" To: "Al Viro" 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 In-reply-to: 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>, Date: Sun, 11 Sep 2022 09:00:10 +1000 Message-id: <166285081066.30452.6346804601094610224@noble.neil.brown.name> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Sun, 11 Sep 2022, Al Viro wrote: > 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? > Why would you think there would be any boiler plate? Only filesystems that opt in would need to do anything, and only when the caller asked (by passing a non-NULL array pointer). NeilBrown