Merge branch 'stable/for-jens-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git...

Merge branch 'stable/for-jens-4.2' of git://git./linux/kernel/git/konrad/xen into for-linus

Konrad writes:

"There are three bugs that have been found in the xen-blkfront (and
backend). Two of them have the stable tree CC-ed. They have been found
where an guest is migrating to a host that is missing
'feature-persistent' support (from one that has it enabled). We end up
hitting an BUG() in the driver code."