Pull libnvdimm fixes from Dan Williams:
- A collection of crash and deadlock fixes for DAX that are also tagged
for -stable. We will look to re-enable DAX pmd mappings in 4.5, but
for now 4.4 and -stable should disable it by default.
- A fixup to ext2 and ext4 to mirror the same warning emitted by XFS
when mounting with "-o dax"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
block: protect rw_page against device teardown
mm, dax: fix DAX deadlocks (COW fault)
dax: disable pmd mappings
ext2, ext4: warn when mounting with dax enabled
95803066c6