Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932244Ab1DLOiq (ORCPT ); Tue, 12 Apr 2011 10:38:46 -0400 Received: from kroah.org ([198.145.64.141]:57729 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932369Ab1DLOii (ORCPT ); Tue, 12 Apr 2011 10:38:38 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Tue Apr 12 07:35:56 2011 Message-Id: <20110412143556.196623410@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Tue, 12 Apr 2011 07:35:06 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Goldwyn Rodrigues , jlbec Subject: [077/105] Treat writes as new when holes span across page boundaries In-Reply-To: <20110412143613.GA19478@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1481 Lines: 44 2.6.38-stable review patch. If anyone has any objections, please let us know. ------------------ From: Goldwyn Rodrigues commit 272b62c1f0f6f742046e45b50b6fec98860208a0 upstream. When a hole spans across page boundaries, the next write forces a read of the block. This could end up reading existing garbage data from the disk in ocfs2_map_page_blocks. This leads to non-zero holes. In order to avoid this, mark the writes as new when the holes span across page boundaries. Signed-off-by: Goldwyn Rodrigues Signed-off-by: jlbec Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/aops.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1026,6 +1026,12 @@ static int ocfs2_prepare_page_for_write( ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, &cluster_start, &cluster_end); + /* treat the write as new if the a hole/lseek spanned across + * the page boundary. + */ + new = new | ((i_size_read(inode) <= page_offset(page)) && + (page_offset(page) <= user_pos)); + if (page == wc->w_target_page) { map_from = user_pos & (PAGE_CACHE_SIZE - 1); map_to = map_from + user_len; -- 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/