From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 1/2] block: move the padding adjustment to blk_rq_map_sg Date: Tue, 08 Apr 2008 10:49:22 +0900 Message-ID: <47FACF22.4010104@gmail.com> References: <47FA061A.8000107@gmail.com> <20080407221103Y.tomof@acm.org> <47FA2090.4040005@gmail.com> <20080408083526P.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wf-out-1314.google.com ([209.85.200.168]:39294 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752667AbYDHBta (ORCPT ); Mon, 7 Apr 2008 21:49:30 -0400 Received: by wf-out-1314.google.com with SMTP id 28so1741172wff.4 for ; Mon, 07 Apr 2008 18:49:29 -0700 (PDT) In-Reply-To: <20080408083526P.fujita.tomonori@lab.ntt.co.jp> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: FUJITA Tomonori Cc: linux-scsi@vger.kernel.org, tomof@acm.org, James.Bottomley@HansenPartnership.com, jens.axboe@oracle.com Hello, FUJITA Tomonori wrote: >>> The current code does padding only for requests that we call >>> __blk_rq_map_user (bio_copy_user) for. You meant that if we create a >>> new flag like REQ_NEED_PADDING and set it in blk_rq_map_user, >>> blk_rq_map_sg can do padding only when it was set. >> Yeap, that's what I meant. > > Thanks, I see. Then, I have one question: blk_rq_map_user_iov doesn't > padding, thus libata still needs to adjust scatter list, right? Yes but it doesn't, so blk_rq_map_user_iov() path is essentially broken regarding padding at the moment. :-( -- tejun