* check for dangling bucket name or type names referenced by the
  buckets/items in the crush map.
* also check for the references from Item(0, 0, 0) which does not
  necessarily exist in the crush map under testing. the rationale
  behind this is: the "ceph osd tree" will also print stray OSDs
  whose id is greater or equal to 0. so it would be useful to
  check if the crush map offers the type name indexed by "0"
  (the name of OSDs is always "OSD.{id}", so we don't need to
  look up the name of an OSD item in the crushmap).

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit b75384d)

* so one is able to verify that the "ceph osd tree" won't chock on the
  new crush map because of dangling name/type references

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit d6b46d4)

* the "osd tree dump" command enumerates all buckets/osds found in either the
  crush map or the osd map. but the newly set crushmap is not validated for
  the dangling references, so we need to check to see if any item in new crush
  map is referencing unknown type/name when a new crush map is sent to
  monitor, reject it if any.

Fixes: #11680
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit a955f36)

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit e640d89)

add an argument "max_id" for "--check-names" to check if any item
has an id greater or equal to given "max_id" in crush map.

Note: edited since we do not have the fix introduced in 46103b2 in
      hammer.

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit d0658dd)

Fixes: #11680
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit 22e6bd6)

* because "--check" also checks for the max_id

Note: edited since we do not have the fix introduced in 46103b2 in
      hammer.

Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit 9381d53)

so we don't need to call CrushTester::check_name_maps() in OSDMonitor.cc
anymore.

Fixes: #11680
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit c6e6348)