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=-5.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 96F53C4361B for ; Tue, 15 Dec 2020 03:19:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D38422475 for ; Tue, 15 Dec 2020 03:19:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726898AbgLODTV (ORCPT ); Mon, 14 Dec 2020 22:19:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726886AbgLODTA (ORCPT ); Mon, 14 Dec 2020 22:19:00 -0500 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9585C06179C for ; Mon, 14 Dec 2020 19:18:20 -0800 (PST) Received: by mail-pl1-x641.google.com with SMTP id r4so10195152pls.11 for ; Mon, 14 Dec 2020 19:18:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=x0F4e7e8J+VvKx26V8nuLlBsAEt7nzUZe1QX+0WOrZI=; b=MqehWWdECBfcy09hKHbVwBWV3Wg8cAoFYJzpCQkTfIfUaVG5dG8h/UMRJfToYrRuPb w1e1VfIscbIr+nSDeUJJCIKQhiFGPi24shyg10hdKusCE/Y3b+4GpjIuiYInowiCFThq g7uuGHAu/Re3fmXw7mdFFKg5dk+KA5PkdpNB7drpJcCCexbI/col4A6/i0OoNzK3Qbe6 7/vC8Ws0H1JDbLO460Bb0KkmuXrxYgvHWbsc/6p1ca86g6+/vIQAgz280Vb+WAizulY7 ydM3+xIiri12FgfoM0QTaF2fVN4opYZhQOLmjVKkjthfPes7N/5utXUrZM2sEg0zisTu BENA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=x0F4e7e8J+VvKx26V8nuLlBsAEt7nzUZe1QX+0WOrZI=; b=JzIeT/pAZCsFY8T40ou61CWQmgoPAT//3LNIUMrnfBJB1cay872NyFi3FCX38RHinY E2y/vofmBWF33IeMN4ylYg4/ikfbVZ9Y/TSD22fajRpOdZPhzWzwy0EPd34LsvxHMWio HJ2nD4LCC9UGsEcaOoPcGVu4vOI+JJWpSJCb3lEdNckZvmbR0miIpW26Vd7LMLcQKk4Y euKOEJkCgJbngNfxMQ45JQ4p1r8RfkZcdFNqv8Ba6B86LI8cKyQJChtr3xz763nAei2+ 3o9q6rBkFOTzmfYfVnWU10A0Q7oAnL96TIUr87SXpTgi+jSD6XgH9YOjq/qZpPAtlXhL u1bg== X-Gm-Message-State: AOAM532o/ZnuxFCu86B52EOB2c3o3PsBDT35AiYeXHSG+CDxpGAAup2M Fg4lq0N8Q+4gYNvdl0HNkA9nHQ== X-Google-Smtp-Source: ABdhPJyLAnVndemEaMwEL9ZPFp/FJzydb6o6UC59mdfPy13MPNnUS984np59pd8NYPwHr7iVBIOk7w== X-Received: by 2002:a17:90a:970b:: with SMTP id x11mr28106576pjo.16.1608002300280; Mon, 14 Dec 2020 19:18:20 -0800 (PST) Received: from [192.168.1.134] ([66.219.217.173]) by smtp.gmail.com with ESMTPSA id a141sm21678462pfa.189.2020.12.14.19.18.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Dec 2020 19:18:19 -0800 (PST) Subject: Re: [PATCHSET v3 0/4] fs: Support for LOOKUP_NONBLOCK / RESOLVE_NONBLOCK To: Linus Torvalds Cc: linux-fsdevel , Al Viro References: <20201214191323.173773-1-axboe@kernel.dk> From: Jens Axboe Message-ID: <7ac6a45f-26b2-ef4a-8941-f3bffcf03900@kernel.dk> Date: Mon, 14 Dec 2020 20:18:18 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 12/14/20 8:06 PM, Linus Torvalds wrote: > On Mon, Dec 14, 2020 at 11:13 AM Jens Axboe wrote: >> >> I'm pretty happy with this at this point. The core change is very simple, >> and the users end up being trivial too. > > It does look very simple. Agree, hard to imagine it being much simpler than this. > It strikes me that io_statx would be another user of this. But it > obviously depends on what the actual io_uring users do.. Indeed, I did mention that in my email from the other thread earlier today, and I think it's potentially an even bigger deal than nonblock open. Lots of workloads are very stat intensive. So I did do that: https://git.kernel.dk/cgit/linux-block/log/?h=nonblock-path-lookup it's the top three patches there. Basically all local file systems are fine with AT_STATX_LOOKUP just basically mapping to LOOKUP_NONBLOCK, various (mostly) networked file systems like to do revalidation and other kinds of communication as part of getattr. Hence the second patch there is needed to have some: if (query_flags & AT_STATX_NONBLOCK) return -EAGAIN; constructs in there to avoid it in the nonblock path. Outside of that, it's very trivial and just works. I didn't include it in this posting to avoid detracting from the core work, but I definitely think we should be doing that as well. -- Jens Axboe