NFS: Add implid to sysfs

The Linux NFS server added support for returning this information during
an EXCHANGE_ID in Linux v6.13. This is something and admin might want to
query, so let's add it to sysfs.

Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Link: https://lore.kernel.org/r/20250207204225.594002-2-anna@kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
index 7b59a40d40c061a41b0fbde91aa006314f02c1fb..b30401b2c939a1dac676dde12453614a6758fb5e 100644 (file)
--- a/fs/nfs/sysfs.c
+++ b/fs/nfs/sysfs.c
@@ -272,6 +272,38 @@ out:
 
 static struct kobj_attribute nfs_sysfs_attr_shutdown = __ATTR_RW(shutdown);
 
+#if IS_ENABLED(CONFIG_NFS_V4_1)
+static ssize_t
+implid_domain_show(struct kobject *kobj, struct kobj_attribute *attr,
+                               char *buf)
+{
+       struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
+       struct nfs41_impl_id *impl_id = server->nfs_client->cl_implid;
+
+       if (!impl_id || strlen(impl_id->domain) == 0)
+               return 0; //sysfs_emit(buf, "");
+       return sysfs_emit(buf, "%s\n", impl_id->domain);
+}
+
+static struct kobj_attribute nfs_sysfs_attr_implid_domain = __ATTR_RO(implid_domain);
+
+
+static ssize_t
+implid_name_show(struct kobject *kobj, struct kobj_attribute *attr,
+                               char *buf)
+{
+       struct nfs_server *server = container_of(kobj, struct nfs_server, kobj);
+       struct nfs41_impl_id *impl_id = server->nfs_client->cl_implid;
+
+       if (!impl_id || strlen(impl_id->name) == 0)
+               return 0; //sysfs_emit(buf, "");
+       return sysfs_emit(buf, "%s\n", impl_id->name);
+}
+
+static struct kobj_attribute nfs_sysfs_attr_implid_name = __ATTR_RO(implid_name);
+
+#endif /* IS_ENABLED(CONFIG_NFS_V4_1) */
+
 #define RPC_CLIENT_NAME_SIZE 64
 
 void nfs_sysfs_link_rpc_client(struct nfs_server *server,
@@ -309,6 +341,32 @@ static struct kobj_type nfs_sb_ktype = {
        .child_ns_type = nfs_netns_object_child_ns_type,
 };
 
+#if IS_ENABLED(CONFIG_NFS_V4_1)
+static void nfs_sysfs_add_nfsv41_server(struct nfs_server *server)
+{
+       int ret;
+
+       if (!server->nfs_client->cl_implid)
+               return;
+
+       ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_implid_domain.attr,
+                                          nfs_netns_server_namespace(&server->kobj));
+       if (ret < 0)
+               pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
+                       server->s_sysfs_id, ret);
+
+       ret = sysfs_create_file_ns(&server->kobj, &nfs_sysfs_attr_implid_name.attr,
+                                  nfs_netns_server_namespace(&server->kobj));
+       if (ret < 0)
+               pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
+                       server->s_sysfs_id, ret);
+}
+#else /* CONFIG_NFS_V4_1 */
+static inline void nfs_sysfs_add_nfsv41_server(struct nfs_server *server)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
 void nfs_sysfs_add_server(struct nfs_server *server)
 {
        int ret;
@@ -325,6 +383,8 @@ void nfs_sysfs_add_server(struct nfs_server *server)
        if (ret < 0)
                pr_warn("NFS: sysfs_create_file_ns for server-%d failed (%d)\n",
                        server->s_sysfs_id, ret);
+
+       nfs_sysfs_add_nfsv41_server(server);
 }
 EXPORT_SYMBOL_GPL(nfs_sysfs_add_server);