Bug 2049272

Summary:	mgr/nfs: allow dynamic updates of CephFS NFS exports
Product:	[Red Hat Storage] Red Hat Ceph Storage	Reporter:	Ram Raja <rraja>
Component:	Ceph-Mgr Plugins	Assignee:	Ram Raja <rraja>
Ceph-Mgr Plugins sub component:	orchestrator	QA Contact:	Hemanth Kumar <hyelloji>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	high
Priority:	unspecified	CC:	adking, akraj, ceph-eng-bugs, fpantano, gfarnum, gfidente, ngangadh, tserlin, vereddy
Version:	5.1	Keywords:	Rebase
Target Milestone:	---
Target Release:	5.2
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	ceph-16.2.8-2.el8cp	Doc Type:	Enhancement
Doc Text:	.CephFS NFS export can be dynamically updated using the `ceph nfs export apply` command Previously, when updating a CephFS NFS export, the NFS-Ganesha servers were always restarted. This temporarily affected all the client connections served by the ganesha servers including those exports that were not updated. With this release, a CephFS NFS export can now be dynamically updated using the `ceph nfs export apply` command. The NFS servers are no longer restarted every time a CephFS NFS export is updated.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-08-09 17:37:27 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1961115, 2071977, 2102272

Description Ram Raja 2022-02-01 20:06:02 UTC

Description of problem:
You can update a CephFS NFS export using `ceph nfs export apply` CLI. But this always restarts the NFS Ganesha servers, and temporarily affects all the NFS clients served by the NFS servers. Many of the export field updates do not need the NFS servers to be restarted. These exports updates can be dynamic. The mgr/nfs module's apply_export() needs to be modified to allow dynamic updates of CephFS NFS exports.


Use case:
OpenStack Manila's CephFS NFS driver currently allows dynamic client access updates of manila shares (CephFS NFS exports). It wants to use the `ceph nfs export` interfaces to  manage the exports and expects the exports' client access updates to be dynamic.

Comment 1 RHEL Program Management 2022-02-01 20:06:08 UTC

Please specify the severity of this bug. Severity is defined here:
https://bugzilla.redhat.com/page.cgi?id=fields.html#bug_severity.

Comment 4 Ram Raja 2022-03-29 16:46:10 UTC

The feature was merged in master and pacific (should be available in 16.2.8). Quincy backport is pending.
You can see the following tracker ticker for more details,
https://tracker.ceph.com/issues/54025
https://tracker.ceph.com/issues/54987

Comment 9 Ram Raja 2022-06-16 22:10:24 UTC

Steps to test:

- create a NFS cluster using cephadm
# ceph nfs cluster create nfs-ganesha

- create a CephFS subvolume
# ceph fs volume create a
# ceph fs subvolume create a subvol00
# ceph fs subvolume getpath a subvol00
/volumes/_nogroup/subvol00/ce8c002b-5f6e-4db5-8189-7bec6aceb39f

- create a read-write NFS export for the subvolume path
# ceph nfs export create cephfs nfs-ganesha /cephfs a /volumes/_nogroup/subvol00/ce8c002b-5f6e-4db5-8189-7bec6aceb39f


- mount export
# mount.nfs4 192.168.0.14:/cephfs /mnt/nfs/
where 192.168.0.14 is the ganesha server IP and /cephfs is pseudo path of export

- from the mount point perform writes

- note the PID of NFS server

- update NFS export's access type from read-write  to read-only
# ceph nfs export get nfs-ganesha /cephfs > export1.conf
# sed -i 's/RW/RO/g' export1.conf
# ceph nfs export apply nfs-ganesha -i export1.conf

- try writing from NFS mountpoint. It'll say it's a read-only file system

- check the PID of NFS server. It shouldn't have changed. This confirms that the NFS server was not restarted when the NFS export was reloaded.

Comment 17 errata-xmlrpc 2022-08-09 17:37:27 UTC

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 Security, Bug Fix, 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-2022:5997