wenli xie reported a buffer cache deadlock when an overlayfs is mounted
atop xfs and overlayfs tries to replace a single-nlink file with a
whiteout file. This test reproduces that deadlock.
Reported-by: wenli xie <wlxie7296@gmail.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>