Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752255AbdHJLQY (ORCPT ); Thu, 10 Aug 2017 07:16:24 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:39662 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750868AbdHJLQW (ORCPT ); Thu, 10 Aug 2017 07:16:22 -0400 Date: Thu, 10 Aug 2017 04:16:16 -0700 From: Christoph Hellwig To: Ming Lei Cc: Jens Axboe , Christoph Hellwig , Huang Ying , Andrew Morton , Alexander Viro , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 05/49] fs/buffer: comment on direct access to bvec table Message-ID: <20170810111616.GC20308@infradead.org> References: <20170808084548.18963-1-ming.lei@redhat.com> <20170808084548.18963-6-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170808084548.18963-6-ming.lei@redhat.com> User-Agent: Mutt/1.8.3 (2017-05-23) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 516 Lines: 12 > + /* > + * It is safe to truncate the last bvec in the following way > + * even though multipage bvec is supported, but we need to > + * fix the parameters passed to zero_user(). > + */ > + struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; A 'we need to fix XXX' comment isn't very useful. Just fix it in the series (which I suspect you're going to do anyway). Also a bio_last_vec helper might be nice for something like this and documents properly converted places much better than these comments.