From 07ef56781cce43bbc1c382b8596de3c1312d0f4b Mon Sep 17 00:00:00 2001
From: Avan Thakkar <athakkar@redhat.com>
Date: Tue, 27 Aug 2024 13:12:06 +0530
Subject: [PATCH] doc: cmount_path documentation for CEPHFS nfs exports

Signed-off-by: Avan Thakkar <athakkar@redhat.com>
(cherry picked from commit d38858da360afdaf15b331d89ddd72c689465dfe)
---
 doc/mgr/nfs.rst | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/doc/mgr/nfs.rst b/doc/mgr/nfs.rst
index 5181a651b75..ec020311a19 100644
--- a/doc/mgr/nfs.rst
+++ b/doc/mgr/nfs.rst
@@ -283,7 +283,7 @@ Create CephFS Export
 
 .. code:: bash
 
-    $ ceph nfs export create cephfs --cluster-id <cluster_id> --pseudo-path <pseudo_path> --fsname <fsname> [--readonly] [--path=/path/in/cephfs] [--client_addr <value>...] [--squash <value>] [--sectype <value>...]
+    $ ceph nfs export create cephfs --cluster-id <cluster_id> --pseudo-path <pseudo_path> --fsname <fsname> [--readonly] [--path=/path/in/cephfs] [--client_addr <value>...] [--squash <value>] [--sectype <value>...] [--cmount_path <value>]
 
 This creates export RADOS objects containing the export block, where
 
@@ -318,6 +318,11 @@ values may be separated by a comma (example: ``--sectype krb5p,krb5i``). The
 server will negotatiate a supported security type with the client preferring
 the supplied methods left-to-right.
 
+``<cmount_path>`` specifies the path within the ceph filesystem to mount this export on. It is
+allowed to be any complete path hierarchy between ``/`` and the ``EXPORT {path}``. (i.e. if ``EXPORT { Path }`` parameter is ``/foo/bar`` then cmount_path could be ``/``, ``/foo`` or ``/foo/bar``).
+!! If this and the other ``EXPORT { FSAL {} }`` options are the same between multiple exports, those exports will share a single cephfs client.
+If not specified, the default is ``/``.
+
 .. note:: Specifying values for sectype that require Kerberos will only function on servers
           that are configured to support Kerberos. Setting up NFS-Ganesha to support Kerberos
           can be found here `Kerberos setup for NFS Ganesha in Ceph <https://github.com/nfs-ganesha/nfs-ganesha/wiki/Kerberos-setup-for-NFS-Ganesha-in-Ceph>`_.
@@ -478,9 +483,9 @@ For example,::
      ],
      "fsal": {
        "name": "CEPH",
-       "user_id": "nfs.mynfs.1",
        "fs_name": "a",
-       "sec_label_xattr": ""
+       "sec_label_xattr": "",
+       "cmount_path": "/"
      },
      "clients": []
    }
@@ -494,6 +499,8 @@ provided JSON should fully describe the new state of the export (just
 as when creating a new export), with the exception of the
 authentication credentials, which will be carried over from the
 previous state of the export where possible.
+The ``user_id`` in the ``fsal`` block should not be modified or mentioned in the JSON file as it is auto-generated for CephFS exports.
+It's auto-generated in the format ``nfs.<cluster_id>.<fs_name>.<hash_id>``.
 
 ::
 
@@ -515,9 +522,9 @@ previous state of the export where possible.
      ],
      "fsal": {
        "name": "CEPH",
-       "user_id": "nfs.mynfs.1",
        "fs_name": "a",
-       "sec_label_xattr": ""
+       "sec_label_xattr": "",
+       "cmount_path": "/"
      },
      "clients": []
    }
-- 
2.39.5