Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933232AbcL0QJc (ORCPT ); Tue, 27 Dec 2016 11:09:32 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:35119 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932573AbcL0QHP (ORCPT ); Tue, 27 Dec 2016 11:07:15 -0500 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-block@vger.kernel.org, Christoph Hellwig , Ming Lei , Alexander Viro , linux-fsdevel@vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)) Subject: [PATCH v1 50/54] fs/buffer.c: use bvec iterator to truncate the bio Date: Wed, 28 Dec 2016 00:04:59 +0800 Message-Id: <1482854706-14128-19-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1482854706-14128-1-git-send-email-tom.leiming@gmail.com> References: <1482854706-14128-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1602 Lines: 51 For making multipage bvec working well. Signed-off-by: Ming Lei --- fs/buffer.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 63d2f40c21fd..014892593f57 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3063,8 +3063,7 @@ 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]; @@ -3087,15 +3086,21 @@ void guard_bio_eod(int op, struct bio *bio) /* Uhhuh. We've got a bio that straddles the device size! */ truncated_bytes = bio->bi_iter.bi_size - (maxsector << 9); - /* Truncate the bio.. */ - bio->bi_iter.bi_size -= truncated_bytes; - bvec->bv_len -= truncated_bytes; - /* ..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, - truncated_bytes); + struct bvec_iter start = BVEC_ITER_ALL_INIT; + struct bvec_iter iter; + struct bio_vec bv; + + start.bi_bvec_done = bvec->bv_len - truncated_bytes; + + __bvec_for_each_sp_bvec(bv, bvec, iter, start) + zero_user(bv.bv_page, bv.bv_offset, bv.bv_len); } + + /* Truncate the bio.. */ + bio->bi_iter.bi_size -= truncated_bytes; + bvec->bv_len -= truncated_bytes; } static int submit_bh_wbc(int op, int op_flags, struct buffer_head *bh, -- 2.7.4