3 files changed, 13 insertions, 1 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 832503c7a00e..a525fdefccde 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -380,6 +380,9 @@ extern bool nfs4_disable_idmapping;
 extern unsigned short max_session_slots;
 extern unsigned short send_implementation_id;
 
+#define NFS4_CLIENT_ID_UNIQ_LEN         (64)
+extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
+
 /* nfs4sysctl.c */
 #ifdef CONFIG_SYSCTL
 int nfs4_register_sysctl(void);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index b5834abfcbff..9aa97112426f 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4068,9 +4068,13 @@ static unsigned int
 nfs4_init_uniform_client_string(const struct nfs_client *clp,
                                 char *buf, size_t len)
 {
+        char *nodename = clp->cl_rpcclient->cl_nodename;
+
+        if (nfs4_client_id_uniquifier[0] != '\0')
+                nodename = nfs4_client_id_uniquifier;
         return scnprintf(buf, len, "Linux NFSv%u.%u %s",
                                 clp->rpc_ops->version, clp->cl_minorversion,
-                                clp->cl_rpcclient->cl_nodename);
+                                nodename);
 }
 
 /**
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 056138d45c11..56f02a9bd6d3 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2662,6 +2662,7 @@ unsigned int nfs_idmap_cache_timeout = 600;
 bool nfs4_disable_idmapping = true;
 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
 unsigned short send_implementation_id = 1;
+char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
 
 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
@@ -2669,6 +2670,7 @@ EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
 EXPORT_SYMBOL_GPL(max_session_slots);
 EXPORT_SYMBOL_GPL(send_implementation_id);
+EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
 
 #define NFS_CALLBACK_MAXPORTNR (65535U)
 
@@ -2694,6 +2696,8 @@ static struct kernel_param_ops param_ops_portnr = {
 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
 module_param(nfs_idmap_cache_timeout, int, 0644);
 module_param(nfs4_disable_idmapping, bool, 0644);
+module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
+                        NFS4_CLIENT_ID_UNIQ_LEN, 0600);
 MODULE_PARM_DESC(nfs4_disable_idmapping,
                 "Turn off NFSv4 idmapping when using 'sec=sys'");
 module_param(max_session_slots, ushort, 0644);
@@ -2702,6 +2706,7 @@ MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
 module_param(send_implementation_id, ushort, 0644);
 MODULE_PARM_DESC(send_implementation_id,
                 "Send implementation ID with NFSv4.1 exchange_id");
+MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
 MODULE_ALIAS("nfs4");
 
 #endif /* CONFIG_NFS_V4 */