On Wed, Aug 02, 2023 at 05:41:28PM +0200, Christoph Hellwig wrote:

Just like get_tree_bdev needs to drop s_umount when opening the main
device, we need to do the same for the ext4 log device to avoid a
potential lock order reversal with s_unmount for the mark_dead path.

It might be preferable to just drop s_umount over ->fill_super entirely,
but that will require a fairly massive audit first, so we'll do the easy
version here first.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Theodore Ts'o <tytso@mit.edu>