Ceph » CephFS

My memory on this code starts to be somewhat blurry, but looking at git log (in mainline) the following 4 patches seem to be relevant to this issue:

d557c48db730 ("ceph: quota: add counter for snaprealms with quota")
e3161f17d926 ("ceph: quota: cache inode pointer in ceph_snap_realm")
0eb6bbe4d9cf ("ceph: fix root quota realm check")
2596366907f8 ("ceph: don't check quota for snap inode")

Looking at the Ubuntu kernel, I see that it only includes backports of 2 of them (d557c48db730 and 0eb6bbe4d9cf).

Commit e3161f17d926 in particular is optimizing the realms hierarchy walkthrough. Picking this patch should fix that warning, I believe.

Sounds good. Anything I can do to support the process?

Michael Robertson wrote:

Sounds good. Anything I can do to support the process?

I believe that the best thing to do is to open a bug report in Ubuntu and see if they can get these missing patches backported into the appropriate kernel.

I've done a quick test and, after compiling the bionic kernel 4.15.0-96.97 (the latest released), I can reproduce the issue. Cherry-picking the 2 missing commits (2596366907f8 and e3161f17d926) fixes it.

Cool, thanks guys.
I reviewed Ubuntu bug reporting guidelines, and created Launchpad account.
The bug report requires a package name - Would that be "ceph" in this case?

Michael Robertson wrote:

Cool, thanks guys.
I reviewed Ubuntu bug reporting guidelines, and created Launchpad account.
The bug report requires a package name - Would that be "ceph" in this case?

From your description, I believe it would be 'linux-azure': https://launchpad.net/ubuntu/xenial/+source/linux-azure

Thanks Luis, I appreciate the help.

https://bugs.launchpad.net/ubuntu/+source/linux-meta-azure/+bug/1875884

I think that's all we can do here. Do with this ticket as you will.

Hmm, they are requesting details on how to reproduce the problem. I don't think they would appreciate me directing them to create an AKS cluster and install Rook, which is the only way I currently know. :)
Have you a simple testcase setup I can share? I'll check through the ceph docs to see what I can find.

Michael Robertson wrote:

Hmm, they are requesting details on how to reproduce the problem. I don't think they would appreciate me directing them to create an AKS cluster and install Rook, which is the only way I currently know. :)
Have you a simple testcase setup I can share? I'll check through the ceph docs to see what I can find.

Sure, something like this will reproduce the issue:

# mount -t ceph <mon>:<port>:/ /mnt/ceph -o name=admin,secret=<my-secret>
# mkdir /mnt/ceph/quotadir
# setfattr -n ceph.quota.max_files -v 10 /mnt/ceph/quotadir
# umount /mnt/ceph
# mount -t ceph <mon>:<port>:/quotadir /mnt/ceph -o name=admin,secret=<my-secret> # <== Note the 'quotadir' here!!!
# touch /mnt/ceph/newfile