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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 43730C2BA83 for ; Thu, 13 Feb 2020 09:50:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1762120848 for ; Thu, 13 Feb 2020 09:50:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="dro2BDY8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729728AbgBMJut (ORCPT ); Thu, 13 Feb 2020 04:50:49 -0500 Received: from mail-il1-f194.google.com ([209.85.166.194]:45287 "EHLO mail-il1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729653AbgBMJut (ORCPT ); Thu, 13 Feb 2020 04:50:49 -0500 Received: by mail-il1-f194.google.com with SMTP id p8so4406355iln.12 for ; Thu, 13 Feb 2020 01:50:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=IvHiB786hyXMz9+mRm3V1jaQi9rh7eAtkp5fjK9oQpc=; b=dro2BDY8dm9jeWkM6tJLCUicRS2wiaxHeuHw/Jo8PypTHwNBMstEpIyo6m825x6J1/ W7qATYCETJ8nOzLulY5tNGWI2aJCwHKd0Y6MaP8kddDYmcvcAuhqqGNprAdOzXaJWQLy pIWUQw0vnTlBRYQ6UIPNBdEr2Gj4bzsDZCARQ= 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=IvHiB786hyXMz9+mRm3V1jaQi9rh7eAtkp5fjK9oQpc=; b=bpqjxSqOzAHeuTwg27EqzwZsocOR4ktQ9DYBhk1WQYdVjE9dur28ybUZP0nZWq/9GM jSI7uXYaSuSmyhq4JXQArKM7J5k40HvVVqoCy0VtbIApSIEm1GdIOdqBrddHsiUIey5/ s2Z8jJd5oRWeCVQK9/2U1Z8rdyppDvsvV27UU3CQXH/rPLKROV1qW8UcK/dZDb02ClIg U/DAfe/NB/7yB94yMrAB4gN+RsEWih8+KfyFVQUORksDBKogwFs8Q/e0ZjlesXtUf0gj f7o51kARgaWg/pMZIJNkrt4IxBT1dZdehCJVhm/UwH5bJkiNVClPqPKckpEvd2xYmtKd FFww== X-Gm-Message-State: APjAAAUrr15Vn5BnJ5ZzsTWMUVGKt2wMqIWL6v98ix9gV59m8RbUlWSx TGoq9qgMt24/hKygAxPPJ2wzg9p6G0xDKF9IjQg6LQ== X-Google-Smtp-Source: APXvYqzPLyJuiUk2YFOhc26hrDS3dr/fVN/SUfieTZuZUy05TLW5Qd5IdMYr7oO8bYEjT0St9vYd2sTrYMX3nsEWWRA= X-Received: by 2002:a92:8847:: with SMTP id h68mr14775650ild.212.1581587447525; Thu, 13 Feb 2020 01:50:47 -0800 (PST) MIME-Version: 1.0 References: <1580536171-27838-1-git-send-email-qiwuchen55@gmail.com> <668fc86f-4214-f315-9b41-40368ba91022@fastmail.fm> <20200202020817.GA14887@cqw-OptiPlex-7050> In-Reply-To: From: Miklos Szeredi Date: Thu, 13 Feb 2020 10:50:36 +0100 Message-ID: Subject: Re: [PATCH] fuse: fix inode rwsem regression To: Bernd Schubert Cc: chenqiwu , linux-fsdevel@vger.kernel.org, chenqiwu , Matthew Wilcox Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Feb 2, 2020 at 10:18 PM Bernd Schubert wrote: > For network file systems it also common to globally enforce fuse > direct-io to reduce/avoid cache coherency issues - the application > typically doesn't ask for that on its own. And that is where this lock > is badly hurting. Hmm, maybe we should differentiate between > fuse-internal direct-io and application direct-io requests here? I'm not against optionally removing the locking for direct write. Theoretically that should be doable. But we need to be very careful about not breaking any assumptions in the kernel and libfuse code. Obviously this would need to be enabled with a flag (e.g. FOPEN_PARALLEL_WRITES). Thanks, Miklos