[SRU][Xenial][PATCH 0/6] Backport Ceph CRUSH_TUNABLES5 support

[Billy Olsen]

From: Billy Olsen <billy.olsen at gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1728739

[Impact]
Attempting to use the kernel rbd driver to mount images from a
Jewel (Xenial) or Luminous (Artful & Pike Ubuntu Cloud Archive)
server causes the mount to fail. This is due to Ceph's addition
of new CRUSH_TUNABLES5 feature which is not understood by the
4.4 kernel client.

[Fix]
Backport the 5 original patches (clean cherry-picks) that added
CRUSH_TUNABLES5 support in the upstream 4.5 kernel. Also backport
an additional patch that allows the client to understand the new
v7 format of the MOSDOpReply message.

- https://www.spinics.net/lists/ceph-devel/msg28421.html
- https://www.spinics.net/lists/ceph-devel/msg28458.html

[Test Case]
1. Deploy a Jewel/Luminous Ceph Cluster with crush tunables set
   to optimal.
2. Create an RBD image suitable for kernel client:
   $ rbd create --pool rbd --image-feature layering --size 1G test
3. Map rbd device to local server node:
   $ rbd map --pool rbd test

[Regression Potential]
Minimal. Code is limited to kernel rbd driver and new code should
primarily affect clients connecting to clusters with the new
tunables options.

[Notes]
Only applicable to Xenial LTS kernel 4.4 since code was included
in the 4.5 kernel.

Ilya Dryomov (6):
  crush: ensure bucket id is valid before indexing buckets array
  crush: ensure take bucket value is valid
  crush: add chooseleaf_stable tunable
  crush: decode and initialize chooseleaf_stable
  libceph: advertise support for TUNABLES5
  libceph: MOSDOpReply v7 encoding

 include/linux/ceph/ceph_features.h | 16 +++++++++++++++-
 include/linux/crush/crush.h        |  8 +++++++-
 net/ceph/crush/mapper.c            | 33 ++++++++++++++++++++++++++-------
 net/ceph/osd_client.c              | 10 ++++++++++
 net/ceph/osdmap.c                  | 19 ++++++++++++++-----
 5 files changed, 72 insertions(+), 14 deletions(-)

-- 
2.14.1