Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758223Ab3DXMVF (ORCPT ); Wed, 24 Apr 2013 08:21:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39548 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757731Ab3DXMVD (ORCPT ); Wed, 24 Apr 2013 08:21:03 -0400 Date: Wed, 24 Apr 2013 14:21:00 +0200 From: Jan Kara To: Gu Zheng Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel , Al Viro , Jens Subject: Re: [PATCH] mm/filemap.c: fix criteria of calling iov_shorten() in generic_file_direct_write() Message-ID: <20130424122100.GA21962@quack.suse.cz> References: <51764857.5010808@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51764857.5010808@cn.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2020 Lines: 52 On Tue 23-04-13 16:37:43, Gu Zheng wrote: > From 35947e6535d92c54cf523470cc8811e8b5fee3e5 Mon Sep 17 00:00:00 2001 > From: Gu Zheng > Date: Tue, 23 Apr 2013 16:09:04 +0800 > Subject: [PATCH] mm/filemap.c: fix criteria of calling iov_shorten() in generic_file_direct_write() > > generic_file_direct_write() compares 'count'(the max count we actually can write) > with 'ocount'(the count we request to write) to see if there is need to call > iov_shorten() to reduce number of segments and the iovec's length. If the > 'count' is equal or greater than 'ocount', there is no need to call iov_shorten() > indeed. So the judgement should be changed: > 'if (count != ocount)' --> 'if (count < ocount)' Thanks for the patch but it shouldn't be really possible that count > ocount, should it? So your patch doesn't really fix anything. Or am I missing something? Honza > > Signed-off-by: Gu Zheng > --- > mm/filemap.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index e1979fd..c566b9c 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2183,7 +2183,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, > size_t write_len; > pgoff_t end; > > - if (count != ocount) > + if (count < ocount) > *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count); > > write_len = iov_length(iov, *nr_segs); > -- > 1.7.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Jan Kara SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/