From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56594 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934868AbcJTPyp (ORCPT ); Thu, 20 Oct 2016 11:54:45 -0400 Subject: Patch "ext4: unmap metadata when zeroing blocks" has been added to the 4.8-stable tree To: jack@suse.cz, gregkh@linuxfoundation.org, tytso@mit.edu Cc: , From: Date: Thu, 20 Oct 2016 17:54:05 +0200 Message-ID: <147697884599204@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ext4: unmap metadata when zeroing blocks to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-unmap-metadata-when-zeroing-blocks.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 9b623df614576680cadeaa4d7e0b5884de8f7c17 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 30 Sep 2016 02:02:29 -0400 Subject: ext4: unmap metadata when zeroing blocks From: Jan Kara commit 9b623df614576680cadeaa4d7e0b5884de8f7c17 upstream. When zeroing blocks for DAX allocations, we also have to unmap aliases in the block device mappings. Otherwise writeback can overwrite zeros with stale data from block device page cache. Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -647,11 +647,19 @@ found: /* * We have to zeroout blocks before inserting them into extent * status tree. Otherwise someone could look them up there and - * use them before they are really zeroed. + * use them before they are really zeroed. We also have to + * unmap metadata before zeroing as otherwise writeback can + * overwrite zeros with stale data from block device. */ if (flags & EXT4_GET_BLOCKS_ZERO && map->m_flags & EXT4_MAP_MAPPED && map->m_flags & EXT4_MAP_NEW) { + ext4_lblk_t i; + + for (i = 0; i < map->m_len; i++) { + unmap_underlying_metadata(inode->i_sb->s_bdev, + map->m_pblk + i); + } ret = ext4_issue_zeroout(inode, map->m_lblk, map->m_pblk, map->m_len); if (ret) { Patches currently in stable-queue which might be from jack@suse.cz are queue-4.8/ext4-allow-dax-writeback-for-hole-punch.patch queue-4.8/mm-filemap-don-t-plant-shadow-entries-without-radix-tree-node.patch queue-4.8/reiserfs-unlock-superblock-before-calling-reiserfs_quota_on_mount.patch queue-4.8/ext4-unmap-metadata-when-zeroing-blocks.patch queue-4.8/jbd2-fix-lockdep-annotation-in-add_transaction_credits.patch