This adds support for the upcoming aes256k key type in CephX that is

based on Kerberos 5 and brings a bunch of assorted CephFS fixes from
Ethan and Sam.  One of Sam's patches in particular undoes a change in
the fscrypt area that had an inadvertent side effect of making CephFS
behave as if mounted with wsize=4096 and leading to the corresponding
degradation in performance, especially for sequential writes.

One RBD and two CephFS fixes which address potential oopses. The RBD

thing is more of a rare edge case that pops up in our CI, while the two
CephFS scenarios are regressions that were reported by users and can be
triggered trivially in normal operation.  All marked for stable.

A bunch of libceph fixes split evenly between memory safety and

implementation correctness issues (all marked for stable) and a change
in maintainers for CephFS: Slava and Alex have formally taken over
Xiubo's role.

We have a patch that adds an initial set of tracepoints to the MDS

client from Max, a fix that hardens osdmap parsing code from myself
(marked for stable) and a few assorted fixups.

A patch to make sparse read handling work in msgr2 secure mode from

Slava and a couple of fixes from Ziming and myself to avoid operating
on potentially invalid memory, all marked for stable.

Some messenger improvements from Eric and Max, a patch to address the

issue (also affected userspace) of incorrect permissions being granted
to users who have access to multiple different CephFS instances within
the same cluster from Kotresh and a bunch of assorted CephFS fixes from
Slava.

A fix for a race condition around r_parent tracking that took a long

time to track down from Alex and some fixes for potential crashes on
accessing invalid memory from Max and myself.  All marked for stable.

A one-liner that leads to a startling (but also very much rational)

performance improvement in cases where an IMA policy with rules that
are based on fsmagic matching is enforced, an encryption-related fixup
that addresses generic/397 and other fstest failures and a couple of
cleanups in CephFS.

A small CephFS encryption-related fix and a dead code cleanup.

A fix for a memory leak from Antoine (marked for stable) and two

cleanups from Liang and Slava, all in CephFS.