From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH] block: add a bi_error field to struct bio Date: Fri, 24 Jul 2015 10:36:45 -0600 Message-ID: <55B2699D.6010400@kernel.dk> References: <1437398977-8492-1-git-send-email-hch@lst.de> <1437398977-8492-2-git-send-email-hch@lst.de> <55AFE643.5000704@kernel.dk> <55B01252.90004@kernel.dk> <20150724104946.GA25145@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150724104946.GA25145@lst.de> Sender: linux-raid-owner@vger.kernel.org To: Christoph Hellwig Cc: "Martin K. Petersen" , Neil Brown , Liu Bo , linux-raid@vger.kernel.org, dm-devel@redhat.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-raid.ids On 07/24/2015 04:49 AM, Christoph Hellwig wrote: > On Wed, Jul 22, 2015 at 03:59:46PM -0600, Jens Axboe wrote: >> One possible solution would be to shrink bi_flags to an unsigned int, no >> problems fitting that in. Then we could stuff bi_error in that (new) hole, >> and we would end up having the same size again. > > As long as we use set/test/clear_bt on bi_flags that won't work unfortunately. Right, I don't think we need to do that though. If you look at the flags usage, it's all over the map. Some use test/set_bit, some set it just by OR'ing the mask. There's no reason we can't make this work without relying on set/test_bit, and then shrink it to an unsigned int. -- Jens Axboe