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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1990DC433DF for ; Mon, 10 Aug 2020 16:36:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA3092076B for ; Mon, 10 Aug 2020 16:36:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YV9tEoXX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727850AbgHJQgf (ORCPT ); Mon, 10 Aug 2020 12:36:35 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:25290 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727833AbgHJQgd (ORCPT ); Mon, 10 Aug 2020 12:36:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597077392; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=E7cstcAHVFGfhscj0UF342G+MM1KSXqD/P1R9pHujqc=; b=YV9tEoXXLoSBTdBZfXyA4yI1CoocsTaPyuKoLd5zCJ0+APuQJlyDbVBinKQLjQOHIsgaCy YwVjaGHPW0pAJTzPozfHWeeJqNQTgHxss/MW0KgigVlofmtWgVKU0IrmCQDvwxSzmO2weR kfF5B3rFnRRY7GQF5XnvvZNabRkZfmU= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-385-xDURFU1uNju7tJRYeiawDQ-1; Mon, 10 Aug 2020 12:36:30 -0400 X-MC-Unique: xDURFU1uNju7tJRYeiawDQ-1 Received: by mail-ej1-f69.google.com with SMTP id m18so4101078ejl.5 for ; Mon, 10 Aug 2020 09:36:30 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=E7cstcAHVFGfhscj0UF342G+MM1KSXqD/P1R9pHujqc=; b=pzb1N7bVEMuVdan5OFCeKlsvqRigM2jaILJPe2ycppzrvljY8cYMlqygU1slzSNiPE 6CKYHgcQ1xH6ycLjArypZonB6yEH+v/jodnMJv4CvBXsKL/p2UZp2WjWT2F46hGihsQA hpFhkmixnGkfSJd7YZGjog5mWUogj7ziQFxkzYz6Yf7I+OARH4IV2zwZ+b1xNNqOgFj+ QFxjAjS0CrWtPrMEgA4r4eShwA/wl4ONYkmCzK4QZ8mLkqBVi2h9iO8giH97gF7oSu9V 2hjpkpDJQvNaLepiYUM3wMMEgo4nrw5m6bVmPbT0LTqUlOHtng0fJSbtHpvfbZfbCBmt tYSA== X-Gm-Message-State: AOAM5314KDgPr4SMYkWxI91XKtY3tNDGembas2dfZ+XxRzllLWtrUfwl mBhQKVLTucAfshdt44kSDdL5pM2wzSyxeH8KIvWIxyXnutbIqrKzhW+2AU0915vvUg21xKYq9AE 9CpbWCrTLGGquxdM705DTHya6n6AAMXbxgoA1 X-Received: by 2002:a17:906:a4b:: with SMTP id x11mr23475872ejf.83.1597077389406; Mon, 10 Aug 2020 09:36:29 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxxf3SVX6ZuISdp8oMWj+mkcjWbaPxLFNRh9thEVecTra/0s+AaKG5bkamyJTprqlXgn7eVTDeevbLYmrbh9t0= X-Received: by 2002:a17:906:a4b:: with SMTP id x11mr23475853ejf.83.1597077389176; Mon, 10 Aug 2020 09:36:29 -0700 (PDT) MIME-Version: 1.0 References: <447452.1596109876@warthog.procyon.org.uk> <1851200.1596472222@warthog.procyon.org.uk> <667820.1597072619@warthog.procyon.org.uk> <672169.1597074488@warthog.procyon.org.uk> In-Reply-To: <672169.1597074488@warthog.procyon.org.uk> From: David Wysochanski Date: Mon, 10 Aug 2020 12:35:53 -0400 Message-ID: Subject: Re: [GIT PULL] fscache rewrite -- please drop for now To: David Howells Cc: Steve French , Linus Torvalds , Alexander Viro , Matthew Wilcox , Christoph Hellwig , Jeff Layton , Trond Myklebust , Anna Schumaker , Steve French , Eric Van Hensbergen , linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs , CIFS , ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, linux-fsdevel , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Mon, Aug 10, 2020 at 11:48 AM David Howells wrote: > > Steve French wrote: > > > cifs.ko also can set rsize quite small (even 1K for example, although > > that will be more than 10x slower than the default 4MB so hopefully no > > one is crazy enough to do that). > > You can set rsize < PAGE_SIZE? > > > I can't imagine an SMB3 server negotiating an rsize or wsize smaller than > > 64K in today's world (and typical is 1MB to 8MB) but the user can specify a > > much smaller rsize on mount. If 64K is an adequate minimum, we could change > > the cifs mount option parsing to require a certain minimum rsize if fscache > > is selected. > > I've borrowed the 256K granule size used by various AFS implementations for > the moment. A 512-byte xattr can thus hold a bitmap covering 1G of file > space. > > Is it possible to make the granule size configurable, then reject a registration if the size is too small or not a power of 2? Then a netfs using the API could try to set equal to rsize, and then error out with a message if the registration was rejected.