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 DF9CDC6379F for ; Sat, 18 Feb 2023 16:24:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229606AbjBRQYc (ORCPT ); Sat, 18 Feb 2023 11:24:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjBRQYb (ORCPT ); Sat, 18 Feb 2023 11:24:31 -0500 Received: from mail-wr1-x434.google.com (mail-wr1-x434.google.com [IPv6:2a00:1450:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F5BB2D78; Sat, 18 Feb 2023 08:24:30 -0800 (PST) Received: by mail-wr1-x434.google.com with SMTP id c12so941568wrx.12; Sat, 18 Feb 2023 08:24:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=nNG/ZkOCIrrfrgO8M6bqZE57VLyTtK7ATZ3OMgUqmyA=; b=SopmrsAD92rtqJgzUbDjMoG/uvyDq05yQOviGlTdjGdHdGw/vno8LqBLWm6hacs0Ys FI/eAQNM1rpK2yh9uniWFbJiVTw+MOI/07Btn1TALCpmoAymBUhBmB+l5+wkzvkVznoN KaxDGgs8YVFrsHkL2ugCuUYSlfc84ViA11PhyrlIAysK3tJZrjAR6SfnbZUVTQHKGGhQ jriTfdvlzLvUzlbokfsvKuz7gAoc6OwKp5fLWCE1xhmpqp9eOdGhE3eg9MWf6JQpOuAj zvf24okaPnMjgQ0MUmmvMJ1ZSqItPeDi/g2Dz1Dfjs30G/2ICD9CMMaUZfJWOEjx4yCE YUgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=nNG/ZkOCIrrfrgO8M6bqZE57VLyTtK7ATZ3OMgUqmyA=; b=eDq0KVVOIOKGrFK6mweKPsHONst6ZNqYTDXJZ0R8o2hqsi0P64fmfnKsUVYWlqAb8s S+NhLBPymKr7hW53EgDNh4a7js5Dvskbpimq6HuUJXCRgVCt3J2pACL5rInFRXSIbHLB bBpqAtgTPB+DogyMsLZGP4WAcEucMWQRCy//hTeAdglsHKd18yehMoZlcdVa3OLNTsh8 ZcxJI9a+XqKSeTsG3wy2RMdEFBVUMtUUxGCDLqzbKplw6u3j88kUmtQ+osS/0q8+fI9m L+NwTgD6Jcu1T/7/WaB1UyNKrrAQ7VUC2C4U8HEvk2H/kx1QC8xcuVjDuEPBmsjFE5mw Sbvw== X-Gm-Message-State: AO0yUKXuEQdPFas+ZDxlknzHjSvOjrOvZmbimycrivO6KzGr6NTddbdt PYoP10dG5bjHsk8VYk2NtUlevlXmC7ZiEj5DMPE= X-Google-Smtp-Source: AK7set+IJQedZgNv3Xg8eCsBCe8oByqYF768XCrPeeTCvF0MpLXSOAbCa6NGgA6L59XPm2UqqDvTyj06v0wWeXkvT60= X-Received: by 2002:a5d:6e8a:0:b0:2c5:50db:e9fc with SMTP id k10-20020a5d6e8a000000b002c550dbe9fcmr46111wrz.674.1676737468580; Sat, 18 Feb 2023 08:24:28 -0800 (PST) MIME-Version: 1.0 References: <20230124023834.106339-1-ericvh@kernel.org> <20230218003323.2322580-1-ericvh@kernel.org> <20230218003323.2322580-5-ericvh@kernel.org> In-Reply-To: From: Eric Van Hensbergen Date: Sat, 18 Feb 2023 10:24:17 -0600 Message-ID: Subject: Re: [PATCH v4 04/11] fs/9p: Remove unnecessary superblock flags To: asmadeus@codewreck.org Cc: Eric Van Hensbergen , v9fs-developer@lists.sourceforge.net, rminnich@gmail.com, lucho@ionkov.net, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux_oss@crudebyte.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org That's fair -- and it didn't seem to hurt anything to have DIRSYNC at the moment, so I can drop this patch if we think its too much noise. I guess it was more of a reaction the filesystem implicitly setting mount flags which might override whatever the user intended. FWIW SB_SYNCHRONOUS did seem to have an effect on behavior (although I didn't specifically track down where) -- I noticed this because the problems Christian found seemed to go away if I mounted the filesystem with sync (which basically ended up overriding aspects of the cache configuration I guess). -eric On Sat, Feb 18, 2023 at 3:34 AM wrote: > > Eric Van Hensbergen wrote on Sat, Feb 18, 2023 at 12:33:16AM +0000: > > These flags just add unnecessary extra operations. > > When 9p is run without cache, it inherently implements > > these options so we don't need them in the superblock > > (which ends up sending extraneous fsyncs, etc.). User > > can still request these options on mount, but we don't > > need to set them as default. > > Hm, I don't see where they'd add any operations -- if you have time > would you mind pointing me at some? > > As far as I can see, it's just about 'sync' or 'dirsync' in /proc/mounts > and the ST_SYNCHRONOUS statvfs flag; that looks harmless to me and it > looks more correct to keep to me. > > (Sorry, didn't take the time to actually try taking a trace; I've > checked the flag itself and the IS_SYNC/IS_DIRSYNC -> inode_needs_sync > wrappers and that only seems used by specific filesystems who'd care > about users setting the mount options, not the other way aorund.) > > -- > Dominique