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=-5.8 required=3.0 tests=BAYES_00,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 064C9C3526C for ; Sun, 20 Dec 2020 01:38:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFE6823A9C for ; Sun, 20 Dec 2020 01:38:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727112AbgLTBii (ORCPT ); Sat, 19 Dec 2020 20:38:38 -0500 Received: from new2-smtp.messagingengine.com ([66.111.4.224]:57189 "EHLO new2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726570AbgLTBii (ORCPT ); Sat, 19 Dec 2020 20:38:38 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailnew.nyi.internal (Postfix) with ESMTP id A992E580280; Sat, 19 Dec 2020 20:37:51 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Sat, 19 Dec 2020 20:37:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=themaw.net; h= message-id:subject:from:to:cc:date:in-reply-to:references :content-type:mime-version:content-transfer-encoding; s=fm2; bh= wYkrXGX5bqF3rN0X4kPI6tvW8uypdLSLd/RGKSp8NGI=; b=AW9vxUFmmnUjjRM1 sAhFm/AOebjHh093xhh+CDRhXmvAhwfPOTAA4tcMCaDOBixt3OMgoFhudOqN/Ndb mnTLQmw3uhldFVfaSklFx9ckadObbRNU3CTuBKK3d/a7xsjngyYUMhRjrZETid6V 0QvPgYDWvf/eA038pabT+Gx9uoCBxiHjHb3NW5KTamkqINpQrUcWOnWhZSv0glKX UHxXTeYFgWehTYggAkRR5kExGAjbAC6aZrynHI7MX2onz5vuy2ygk70YG4y24eKf /PM9Fy6WR2xin/SwcW+jZpWQtwu6H1qtygYdPYX6vvvqkvEuIEC0/7WNbZ45m7ZU VyrQhg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=wYkrXGX5bqF3rN0X4kPI6tvW8uypdLSLd/RGKSp8N GI=; b=VITYEP9H1vPEW464PbO8MypkDAT+WN11nSzfbm17OsBedsFk6CdFh98Oc 994R8KCqkaYTnZqeCJcsZOvPiw0cYFKa4UPOAl6iodZk9wtJOD+0YOqix+lpOLjT /dEQwUEwoVrhS8jHrQjqjiJByJan8JslIc1CdDNiI+XLKrcZoNf3DSEN/Bb+OAO4 K28vNzJEoYZAoML0oLmS2NK7iYF/VVJOCRA1CDejdMWBm8CpltJE+6x3XipI2gBg BN80JB/aqpt3z9GAML+7nda9hN2sTJf01MfJkdRtcWaqrZ/KhAkNT7Dh+0TlO3xn UYfPAGtv1nq1hpouOT8kY/3UVMV4w== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrudelledgfeeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepkffuhffvffgjfhgtfggggfesthejredttderjeenucfhrhhomhepkfgrnhcu mfgvnhhtuceorhgrvhgvnhesthhhvghmrgifrdhnvghtqeenucggtffrrghtthgvrhhnpe effeettedvgeduvdevfeevfeettdffudduheeuiefhueevgfevheffledugefgjeenucfk phepuddtiedrieelrddvgeejrddvtdehnecuvehluhhsthgvrhfuihiivgeptdenucfrrg hrrghmpehmrghilhhfrhhomheprhgrvhgvnhesthhhvghmrgifrdhnvght X-ME-Proxy: Received: from mickey.themaw.net (106-69-247-205.dyn.iinet.net.au [106.69.247.205]) by mail.messagingengine.com (Postfix) with ESMTPA id 3E51224005B; Sat, 19 Dec 2020 20:37:45 -0500 (EST) Message-ID: <352f587fe4e24a8bea5f841b5f93df92164072d0.camel@themaw.net> Subject: Re: [PATCH v2 0/6] kernfs: proposed locking and concurrency improvement From: Ian Kent To: Tejun Heo Cc: Greg KH , Fox Chen , akpm@linux-foundation.org, dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu, ricklind@linux.vnet.ibm.com, sfr@canb.auug.org.au, viro@zeniv.linux.org.uk Date: Sun, 20 Dec 2020 09:37:42 +0800 In-Reply-To: References: <67a3012a6a215001c8be9344aee1c99897ff8b7e.camel@themaw.net> <37c339831d4e7f3c6db88fbca80c6c2bd835dff2.camel@themaw.net> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-1.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2020-12-20 at 07:52 +0800, Ian Kent wrote: > On Sat, 2020-12-19 at 11:23 -0500, Tejun Heo wrote: > > Hello, > > > > On Sat, Dec 19, 2020 at 03:08:13PM +0800, Ian Kent wrote: > > > And looking further I see there's a race that kernfs can't do > > > anything > > > about between kernfs_refresh_inode() and > > > fs/inode.c:update_times(). > > > > Do kernfs files end up calling into that path tho? Doesn't look > > like > > it to > > me but if so yeah we'd need to override the update_time for kernfs. You are correct, update_time() will only be called during symlink following and only to update atime. So this isn't sufficient to update the inode attributes to reflect changes make by things like kernfs_setattr() or when the directory link count changes ... Sigh!