From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] input: remove BKL from uinput open function Date: Sat, 30 Jan 2010 22:57:09 +0100 Message-ID: <201001302257.09354.arnd@arndb.de> References: <1264800197-29523-1-git-send-email-cascardo@holoscopio.com> <201001300741.20954.arnd@arndb.de> <20100130072205.GA30378@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from moutng.kundenserver.de ([212.227.126.171]:57567 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753414Ab0A3WZO (ORCPT ); Sat, 30 Jan 2010 17:25:14 -0500 In-Reply-To: <20100130072205.GA30378@core.coreip.homeip.net> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: Thadeu Lima de Souza Cascardo , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org 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. Arnd