ceph-disk: mount xfs with inode64 by default

We did this forever ago with mkcephfs, but ceph-disk didn't.  Note that for
modern XFS this option is obsolete, but for older kernels it was not the
default.

Backport: firefly
Signed-off-by: Sage Weil <sage@redhat.com>
mon: prevent cache pools being used CephFS

Fixes two things:
 * EC pools are now permissible if they have a cache overlay
 * Pools are not permissible if they are a cache tier.

Fixes: #9435

Signed-off-by: John Spray <john.spray@redhat.com>
mon: forbid tier changes when in use by FS

* Removing tiers from a base pool in use by CephFS is forbidden.
* Using CephFS pools as tiers is forbidden.

Signed-off-by: John Spray <john.spray@redhat.com>