From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932736AbcEQBah (ORCPT ); Mon, 16 May 2016 21:30:37 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34565 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932581AbcEQB1H (ORCPT ); Mon, 16 May 2016 21:27:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Lyakas , Filipe Manana , David Sterba Subject: [PATCH 4.5 095/101] btrfs: do not write corrupted metadata blocks to disk Date: Mon, 16 May 2016 18:21:40 -0700 Message-Id: <20160517011510.189264863@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160517011506.359924439@linuxfoundation.org> References: <20160517011506.359924439@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Lyakas commit 0f805531daa2ebfb5706422dc2ead1cff9e53e65 upstream. csum_dirty_buffer was issuing a warning in case the extent buffer did not look alright, but was still returning success. Let's return error in this case, and also add an additional sanity check on the extent buffer header. The caller up the chain may BUG_ON on this, for example flush_epd_write_bio will, but it is better than to have a silent metadata corruption on disk. Signed-off-by: Alex Lyakas Reviewed-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -513,9 +513,20 @@ static int csum_dirty_buffer(struct btrf eb = (struct extent_buffer *)page->private; if (page != eb->pages[0]) return 0; + found_start = btrfs_header_bytenr(eb); - if (WARN_ON(found_start != start || !PageUptodate(page))) - return 0; + /* + * Please do not consolidate these warnings into a single if. + * It is useful to know what went wrong. + */ + if (WARN_ON(found_start != start)) + return -EUCLEAN; + if (WARN_ON(!PageUptodate(page))) + return -EUCLEAN; + + ASSERT(memcmp_extent_buffer(eb, fs_info->fsid, + btrfs_header_fsid(), BTRFS_FSID_SIZE) == 0); + return csum_tree_block(fs_info, eb, 0); }