From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751636Ab0LTCV6 (ORCPT ); Sun, 19 Dec 2010 21:21:58 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:52454 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160Ab0LTCV4 (ORCPT ); Sun, 19 Dec 2010 21:21:56 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [RFC 5/5] truncate: Remove unnecessary page release Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , linux-mm , LKML , Nick Piggin , Al Viro In-Reply-To: <02ab98b3a1450f7a1c31edc48ccc57e887cee900.1292604746.git.minchan.kim@gmail.com> References: <02ab98b3a1450f7a1c31edc48ccc57e887cee900.1292604746.git.minchan.kim@gmail.com> Message-Id: <20101220112227.E566.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Mon, 20 Dec 2010 11:21:52 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > This patch series changes remove_from_page_cache's page ref counting > rule. page cache ref count is decreased in remove_from_page_cache. > So we don't need call again in caller context. > > Cc: Nick Piggin > Cc: Al Viro > Cc: linux-mm@kvack.org > Signed-off-by: Minchan Kim > --- > mm/truncate.c | 1 - > 1 files changed, 0 insertions(+), 1 deletions(-) > > diff --git a/mm/truncate.c b/mm/truncate.c > index 9ee5673..8decb93 100644 > --- a/mm/truncate.c > +++ b/mm/truncate.c > @@ -114,7 +114,6 @@ truncate_complete_page(struct address_space *mapping, struct page *page) > * calls cleancache_put_page (and note page->mapping is now NULL) > */ > cleancache_flush_page(mapping, page); > - page_cache_release(page); /* pagecache ref */ > return 0; Do we _always_ have stable page reference here? IOW, I can assume cleancache_flush_page() doesn't cause NULL deref?