From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra13.linbit.com (zimbra.linbit.com [212.69.161.123]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTPS id 03B451056331 for ; Tue, 5 Apr 2016 14:42:39 +0200 (CEST) Date: Tue, 5 Apr 2016 14:42:38 +0200 From: Lars Ellenberg To: Ming Lei Message-ID: <20160405124238.GV3078@soda.linbit> 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> Cc: linux-block@vger.kernel.org, Boaz Harrosh , Philipp Reisner , linux-kernel@vger.kernel.org, Jens Axboe , Christoph Hellwig , drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] [PATCH 03/27] block: drbd: remove impossible failure handling List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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