From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752755AbYIVId5 (ORCPT ); Mon, 22 Sep 2008 04:33:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751851AbYIVIdt (ORCPT ); Mon, 22 Sep 2008 04:33:49 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:60306 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751630AbYIVIds (ORCPT ); Mon, 22 Sep 2008 04:33:48 -0400 Date: Mon, 22 Sep 2008 01:33:38 -0700 From: Andrew Morton To: Krishna Kumar Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: do_generic_file_read() never gets a NULL 'filp' argument Message-Id: <20080922013338.8e1c10ff.akpm@linux-foundation.org> In-Reply-To: <20080922061610.20158.86022.sendpatchset@localhost.localdomain> References: <20080922061610.20158.86022.sendpatchset@localhost.localdomain> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 22 Sep 2008 11:46:10 +0530 Krishna Kumar wrote: > From: Krishna Kumar > > The 'filp' argument to do_generic_file_read() is never NULL. > How did you verify this? NFS used to like passing NULL file*'s into VFS functions. I don't recall whether it affected do_generic_file_read(). > mm/filemap.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff -ruNp 2.6.27-rc7-org/mm/filemap.c 2.6.27-rc7-new/mm/filemap.c > --- 2.6.27-rc7-org/mm/filemap.c 2008-09-17 12:53:25.000000000 +0530 > +++ 2.6.27-rc7-new/mm/filemap.c 2008-09-17 12:53:59.000000000 +0530 > @@ -1186,8 +1186,7 @@ out: > ra->prev_pos |= prev_offset; > > *ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset; > - if (filp) > - file_accessed(filp); > + file_accessed(filp); > } > > int file_read_actor(read_descriptor_t *desc, struct page *page,