From 8adcceba11c91f02ee2aa2d85a7a6d12e8f20120 Mon Sep 17 00:00:00 2001
From: Daeho Jeong <daeho.jeong@samsung.com>
Date: Mon, 5 Sep 2016 22:56:10 -0400
Subject: [PATCH] ext4: reinforce check of i_dtime when clearing high fields of
 uid and gid

commit 93e3b4e6631d2a74a8cf7429138096862ff9f452 upstream.

Now, ext4_do_update_inode() clears high 16-bit fields of uid/gid
of deleted and evicted inode to fix up interoperability with old
kernels. However, it checks only i_dtime of an inode to determine
whether the inode was deleted and evicted, and this is very risky,
because i_dtime can be used for the pointer maintaining orphan inode
list, too. We need to further check whether the i_dtime is being
used for the orphan inode list even if the i_dtime is not NULL.

We found that high 16-bit fields of uid/gid of inode are unintentionally
and permanently cleared when the inode truncation is just triggered,
but not finished, and the inode metadata, whose high uid/gid bits are
cleared, is written on disk, and the sudden power-off follows that
in order.

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Hobin Woo <hobin.woo@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
Reading git-format-patch failed