Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758384AbcDEMmq (ORCPT ); Tue, 5 Apr 2016 08:42:46 -0400 Received: from zimbra13.linbit.com ([212.69.166.240]:57289 "EHLO zimbra13.linbit.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751670AbcDEMmo (ORCPT ); Tue, 5 Apr 2016 08:42:44 -0400 Date: Tue, 5 Apr 2016 14:42:38 +0200 From: Lars Ellenberg To: Ming Lei Cc: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , Boaz Harrosh , Philipp Reisner , drbd-dev@lists.linbit.com Subject: Re: [PATCH 03/27] block: drbd: remove impossible failure handling Message-ID: <20160405124238.GV3078@soda.linbit> Mail-Followup-To: Ming Lei , Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , Boaz Harrosh , Philipp Reisner , drbd-dev@lists.linbit.com References: <1459857443-20611-1-git-send-email-tom.leiming@gmail.com> <1459857443-20611-4-git-send-email-tom.leiming@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1459857443-20611-4-git-send-email-tom.leiming@gmail.com> 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 Content-Length: 475 Lines: 19 On Tue, Apr 05, 2016 at 07:56:48PM +0800, Ming Lei wrote: > For a non-cloned bio, bio_add_page() only returns failure when > the io vec table is full, but in that case, bio->bi_vcnt can't > be zero at all. > > So remove the impossible failure handling. Before the immutable bvecs, we did in fact see this trigger in the wild. On "strange" deployments. But for the current implementation of bio_add_page(), you are correct, this is impossible now. Ack. Thanks, Lars