From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751784AbeEQS1O (ORCPT ); Thu, 17 May 2018 14:27:14 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48868 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbeEQS1N (ORCPT ); Thu, 17 May 2018 14:27:13 -0400 Date: Thu, 17 May 2018 11:26:38 -0700 From: Matthew Wilcox To: Jeff Layton Cc: viro@zeniv.linux.org.uk, jack@suse.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, lurodriguez@suse.de Subject: Re: [PATCH v2] vfs: avoid dereferencing pointers in iterate_supers callbacks Message-ID: <20180517182638.GD26718@bombadil.infradead.org> References: <20180517154646.18751-1-jlayton@kernel.org> <20180517174336.18529-1-jlayton@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180517174336.18529-1-jlayton@kernel.org> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 17, 2018 at 01:43:36PM -0400, Jeff Layton wrote: > @@ -107,12 +109,10 @@ static void fdatawait_one_bdev(struct block_device *bdev, void *arg) > */ > void ksys_sync(void) > { > - int nowait = 0, wait = 1; > - > wakeup_flusher_threads(WB_REASON_SYNC); > iterate_supers(sync_inodes_one_sb, NULL); > - iterate_supers(sync_fs_one_sb, &nowait); > - iterate_supers(sync_fs_one_sb, &wait); > + iterate_supers(sync_fs_one_sb, NULL); > + iterate_supers(sync_fs_one_sb, (void *)1UL); I think this is actually less clear. How about: void *wait = (void *)1UL; iterate_supers(sync_fs_one_sb, !wait); iterate_supers(sync_fs_one_sb, wait);