From patchwork Mon Jun 26 12:10:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 9809297 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 654C5603F3 for ; Mon, 26 Jun 2017 12:18:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6BD5B28583 for ; Mon, 26 Jun 2017 12:18:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 60AA928585; Mon, 26 Jun 2017 12:18:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0B6AA28584 for ; Mon, 26 Jun 2017 12:18:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752804AbdFZMST (ORCPT ); Mon, 26 Jun 2017 08:18:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37224 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752792AbdFZMSI (ORCPT ); Mon, 26 Jun 2017 08:18:08 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C50B94E4C6; Mon, 26 Jun 2017 12:18:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C50B94E4C6 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ming.lei@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com C50B94E4C6 Received: from localhost (ovpn-12-86.pek2.redhat.com [10.72.12.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id BA9EB60BE6; Mon, 26 Jun 2017 12:17:59 +0000 (UTC) From: Ming Lei To: Jens Axboe , Christoph Hellwig , Huang Ying , Andrew Morton , Alexander Viro Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Ming Lei Subject: [PATCH v2 31/51] fs/buffer.c: use bvec iterator to truncate the bio Date: Mon, 26 Jun 2017 20:10:14 +0800 Message-Id: <20170626121034.3051-32-ming.lei@redhat.com> In-Reply-To: <20170626121034.3051-1-ming.lei@redhat.com> References: <20170626121034.3051-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 26 Jun 2017 12:18:08 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Once multipage bvec is enabled, the last bvec may include more than one page, this patch use bvec_get_last_page() to truncate the bio. Signed-off-by: Ming Lei --- fs/buffer.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 1910f539770b..53b8a29f4525 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3055,8 +3055,7 @@ void guard_bio_eod(int op, struct bio *bio) unsigned truncated_bytes; /* * 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(). + * even though multipage bvec is supported. */ struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; @@ -3085,7 +3084,10 @@ void guard_bio_eod(int op, struct bio *bio) /* ..and clear the end of the buffer for reads */ if (op == REQ_OP_READ) { - zero_user(bvec->bv_page, bvec->bv_offset + bvec->bv_len, + struct bio_vec bv; + + bvec_get_last_page(bvec, &bv); + zero_user(bv.bv_page, bv.bv_offset + bv.bv_len, truncated_bytes); } }