From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:43668 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388449AbeGWNa6 (ORCPT ); Mon, 23 Jul 2018 09:30:58 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 46465ACB5 for ; Mon, 23 Jul 2018 12:29:59 +0000 (UTC) Date: Mon, 23 Jul 2018 14:29:51 +0200 From: David Sterba To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2] btrfs: extent-tree: Remove dead alignment check Message-ID: <20180723122951.GJ26141@twin.jikos.cz> Reply-To: dsterba@suse.cz References: <20180723064729.9236-1-wqu@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180723064729.9236-1-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Jul 23, 2018 at 02:47:29PM +0800, Qu Wenruo wrote: > In find_free_extent() under checks: tag, we have the following code > > ------ > search_start = ALIGN(offset, fs_info->stripesize); > /* move on to the next group */ > if (search_start + num_bytes > > block_group->key.objectid + block_group->key.offset) { > btrfs_add_free_space(block_group, offset, num_bytes); > goto loop; > } > if (offset < search_start) > btrfs_add_free_space(block_group, offset, > search_start - offset); > BUG_ON(offset > search_start); > ------ > > However ALIGN() is rounding up, thus @search_start >= @offset and that > BUG_ON() will never be triggered. > > Signed-off-by: Qu Wenruo Reviewed-by: David Sterba