Description of problem:
Creating cephfs subvolumes with a quota, and then using ganesha to export them with --cmount_path="/" shows the full size of the volume on the client - not the quota'd size. This could lead to unexpected failures which from the NFS client side would be difficult to diagnose.
Version-Release number of selected component (if applicable):
registry-proxy.engineering.redhat.com/rh-osbs/rhceph:7-125
ceph version 18.2.0-118.el9cp
nfs-ganesha-5.6-3.el9cp.x86_64
How reproducible:
Issue seen on all clients
Steps to Reproduce:
1. Create a cluster with cephfs and ganesha
2. Define a cephfs subvolume with a quota
3. Create an export that uses the subvolume
4. mount on a client
5. Use df to confirm the usage information, and du to confirm that the client mount is actually empty
Actual results:
[root@nfs-client-01 ~]# df -h /mnt/nfs
Filesystem Size Used Avail Use% Mounted on
172.18.200.10:/nfs-client-01 5.9T 8.3G 5.9T 1% /mnt/nfs
[root@nfs-client-01 ~]# du -h --max-depth 0 /mnt/nfs
6.5K /mnt/nfs
8.3G used, and yet 6.5K - indicating the quota is not honoured.
Expected results:
On older builds the mount showed the quota'd value - and when capacity was exceeded EIO triggered as normal.
Additional info:
I'll attach configs for the subvolume, and export
This is due to the client-sharing changes to reduce memory consumption.
Users can use a non-client-sharing config as a work-around to get subvolume quotas.
We will take this on for 7.1.
Thanks Kaleb. How does that look from an ODF perspective? I mean within ODF the PVC is quota'd, but if the mount doesn't show it - could that lead to problems?
Also, can you provide an example of the nfs export create command that works with quotas so this case tracks the issue and the workaround...or failing that a link to the docs? I couldn't find cmount_path in the upstream docs?
Comment 22Goutham Pacha Ravi
2025-08-27 22:27:36 UTC
*** Bug 2356271 has been marked as a duplicate of this bug. ***
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (Moderate: Red Hat Ceph Storage 9.0 Security and Enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHSA-2026:1536