From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753316Ab3EIU2S (ORCPT ); Thu, 9 May 2013 16:28:18 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:34322 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752590Ab3EIU2R (ORCPT ); Thu, 9 May 2013 16:28:17 -0400 Date: Thu, 9 May 2013 21:28:15 +0100 From: Al Viro To: Linus Torvalds Cc: Linux Kernel Mailing List , linux-fsdevel Subject: Re: [git pull] more vfs.git stuff Message-ID: <20130509202815.GH25399@ZenIV.linux.org.uk> References: <20130509192655.GG25399@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 09, 2013 at 01:12:43PM -0700, Linus Torvalds wrote: > On Thu, May 9, 2013 at 12:26 PM, Al Viro wrote: > > Regression fix from Geert + yet another open-coded kernel_read(). > > Hmm. I get one more commit - a racy usbmon thing. Oops - pull stats not updated... My apologies. > Which looks fine per > se, but would look even better if it just made mmap_active an atomic_t > instead, wouldn't you say? The only place checking that sucker is in a fairly large area protected by ->b_lock (in mon_bin_event()); I really don't want to dig deep enough to tell if having it changed right after it had been checked is safe. OTOH, from a cursory look through that code it appears that the whole map_count thing is completely misguided - it seems to assume that ->open() is called for each VMA, including the one created by mmap(2). Sigh... OK, it might make more sense to drop that last commit for now. It's obviously more broken in mmap-related code than just a buggered locking for counter and it probably doesn't make much sense to patch just that one. And I'll have several more fixes of similar turds tomorrow, when mchehab finishes testing videobuf ones. Up to you, really.