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 2DEFBC76195 for ; Tue, 28 Mar 2023 05:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230140AbjC1FOq (ORCPT ); Tue, 28 Mar 2023 01:14:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbjC1FOn (ORCPT ); Tue, 28 Mar 2023 01:14:43 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C93010DE for ; Mon, 27 Mar 2023 22:14:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=c+upOLAl1tNic16x8Kml180+4+m4/ZhbaMD9TGfmxxs=; b=fKGRKKkajfjv/3r8kcgNgFQfnP ikAfkwv4pEVGu1o8CVFNaLzRiEME/UkqQWM+50kX8UwmxxNrySdrHVZiFVyVVCp6LHsCCMW4l7Aaq VISqY0jRfjcgpSbf4jTNXj0ZZAOaddN9RU8H40G+o/+e0hm2ZRSBdP5Q8piYFC6GEB1tOyl9leUqd AnLBLn2a3zmQokWbjKZokz7VD9V234oSaNtlzWAVDhdY6MVnLBK7puPV6n9WYqnjdGpb9nb+YSnc0 Rgmj1nu28F+MvOTyEcvGYg+N2heuu+xsfCm7o1kIB7WLirtaN+TGL4jxlkQsY0P4vg+qAfChjzgXG IvqkkaWQ==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1ph1fH-00DA9M-2y; Tue, 28 Mar 2023 05:14:35 +0000 Date: Mon, 27 Mar 2023 22:14:35 -0700 From: Luis Chamberlain To: Dominique Martinet Cc: Christian Schoenebeck , Eric Van Hensbergen , Josef Bacik , Jeff Layton , lucho@ionkov.net, v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, Amir Goldstein , Pankaj Raghav Subject: Re: 9p caching with cache=loose and cache=fscache Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 28, 2023 at 11:31:50AM +0900, Dominique Martinet wrote: > Luis Chamberlain wrote on Mon, Mar 27, 2023 at 10:39:54AM -0700: > > > I have fixed what > > > I hope to be my last bug with the new patch series so it should be > > > going into linux-next today. > > > > Nice, thanks, since kdevops relies on a host kernel though and we strive > > to have stability for that, I personally like to recommend distro > > kernels and so they're a few kernel releases out of date. So debian-testing > > is on 6.1 as of today for example. > > [...] > > - opts: "ro,trans=virtio,version=9p2000.L,posixacl,cache=loose" > > + opts: "ro,trans=virtio,version=9p2000.L,posixacl,cache=none" > > Yes, if you want something mostly coherent with the host, cache=none (or > cache=mmap if you need mmap, iirc linux build does for linking? if you > want to do that on guest...) is what you'll want to use on current > kernels. OK cool, we use 9p to build on the host and so all the guest has to do is just 'make modules_install install'. > > BTW the qemu wiki seems to suggest cache=loose and its why I used it on > > kdevops as a default. What about the following so to avoid folks running > > into similar issues? I can go and update the wiki too. > > I've added Christian in Cc for this point, he's more active on the qemu > side > (thread started here: > https://lkml.kernel.org/r/ZA0FEyOtRBvpIXbi@bombadil.infradead.org > ) > > I have no opinion on the current wording, the default is there for a > reason and it's a safe default (none), and cache=loose is clearly > described with "no attempts are made at consistency, intended for > exclusive, read-only mounts" which I think ought to be clear enough > (exclusive means not shared with the host), but if you think it's not > clear enough it probably isn't. It certainly was not. LUis