From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout1.samsung.com ([203.254.224.24]:41729 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753534AbbLXFuL (ORCPT ); Thu, 24 Dec 2015 00:50:11 -0500 From: Chao Yu To: 'Jaegeuk Kim' Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net References: <1450923320-41113-1-git-send-email-jaegeuk@kernel.org> <1450923320-41113-2-git-send-email-jaegeuk@kernel.org> In-reply-to: <1450923320-41113-2-git-send-email-jaegeuk@kernel.org> Subject: RE: [f2fs-dev] [PATCH 2/4] f2fs: return early when trying to read null nid Date: Thu, 24 Dec 2015 13:49:24 +0800 Message-id: <015401d13e0e$f214f8e0$d63eeaa0$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit Content-language: zh-cn Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hi Jaegeuk, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org] > Sent: Thursday, December 24, 2015 10:15 AM > To: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; > linux-f2fs-devel@lists.sourceforge.net > Cc: Jaegeuk Kim > Subject: [f2fs-dev] [PATCH 2/4] f2fs: return early when trying to read null nid > > If get_node_page() gets zero nid, we can return early without getting a wrong > page. For example, get_dnode_of_data() can try to do that. Good catch! > > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/node.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 341de5d..e17128d 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -1059,6 +1059,9 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid) > { > struct page *page; > int err; > + > + if (!nid) > + return ERR_PTR(-ENOENT); How about expand to check upper and lower boundary: if (check_nid_range) return ERR_PTR(-ENOENT); Thanks, > repeat: > page = grab_cache_page(NODE_MAPPING(sbi), nid); > if (!page) > -- > 2.5.4 (Apple Git-61) > > > ------------------------------------------------------------------------------ > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel