From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Kacur Subject: Re: [PATCH] input: remove BKL from uinput open function Date: Sun, 31 Jan 2010 00:07:18 +0100 Message-ID: <520f0cf11001301507k20e3cf8dqa73026e12f3a1767@mail.gmail.com> References: <1264800197-29523-1-git-send-email-cascardo@holoscopio.com> <201001300741.20954.arnd@arndb.de> <20100130072205.GA30378@core.coreip.homeip.net> <201001302257.09354.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from mail-ew0-f228.google.com ([209.85.219.228]:65022 "EHLO mail-ew0-f228.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753673Ab0A3XHU (ORCPT ); Sat, 30 Jan 2010 18:07:20 -0500 In-Reply-To: <201001302257.09354.arnd@arndb.de> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Arnd Bergmann Cc: Dmitry Torokhov , Thadeu Lima de Souza Cascardo , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org On Sat, Jan 30, 2010 at 10:57 PM, Arnd Bergmann wrote: > On Saturday 30 January 2010, Dmitry Torokhov wrote: >> On Sat, Jan 30, 2010 at 07:41:20AM +0100, Arnd Bergmann wrote: >> > The change looks good, but the same driver also uses the BKL in the >> > default_llseek function. It would be nice to get rid of that in the >> > same patch, e.g. by adding a ".llseek = generic_file_llseek," line >> > in the file_operations, or making it call nonseekable_open() if the >> > driver does not require seek to do anything. >> > >> >> I am afraid you mixed up the drivers, I don't see uinput implementing >> seek... > > Sorry, I should have been clearer, but not implementing llseek > is the problem I was referring to: When a driver has no explicit > .llseek operation in its file operations and does not call > nonseekable_open from its open operation, the VFS layer will > implicitly use default_llseek, which takes the BKL. We're > in the process of changing drivers not to do this, one by one > so we can kill the BKL in the end. > I know we've discussed this before, but why wouldn't the following make more sense? .llseek = no_llseek,