Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752859AbdFZMSl (ORCPT ); Mon, 26 Jun 2017 08:18:41 -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 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 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-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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1118 Lines: 37 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); } } -- 2.9.4