From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.9]:55084 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S944108AbcJaPfc (ORCPT ); Mon, 31 Oct 2016 11:35:32 -0400 Date: Mon, 31 Oct 2016 08:35:30 -0700 From: Christoph Hellwig To: Ming Lei Cc: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , "Kirill A . Shutemov" , Alexander Viro , Kent Overstreet Subject: Re: [PATCH 19/60] fs/buffer: comment on direct access to bvec table Message-ID: <20161031153530.GJ30919@infradead.org> References: <1477728600-12938-1-git-send-email-tom.leiming@gmail.com> <1477728600-12938-20-git-send-email-tom.leiming@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1477728600-12938-20-git-send-email-tom.leiming@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: I think we'll just need a version zero_fill_bio with a length argument and let that handle all the bvec access. I have vague memories that Kent posted one a while ago, Ccing him. On Sat, Oct 29, 2016 at 04:08:18PM +0800, Ming Lei wrote: > Signed-off-by: Ming Lei > --- > fs/buffer.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/buffer.c b/fs/buffer.c > index b205a629001d..81c3793948b4 100644 > --- a/fs/buffer.c > +++ b/fs/buffer.c > @@ -3018,8 +3018,13 @@ static void end_bio_bh_io_sync(struct bio *bio) > void guard_bio_eod(int op, struct bio *bio) > { > sector_t maxsector; > - struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; > 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(). > + */ > + struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1]; > > maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9; > if (!maxsector) > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html ---end quoted text---