3 files changed, 24 insertions, 4 deletions

diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 1bf384307d15..a1423c66df04 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -462,7 +462,11 @@ __nsm_find(const struct sockaddr_in *sin,
         list_for_each(pos, &nsm_handles) {
                 nsm = list_entry(pos, struct nsm_handle, sm_link);
 
-                if (!nlm_cmp_addr(&nsm->sm_addr, sin))
+                if (hostname && nsm_use_hostnames) {
+                        if (strlen(nsm->sm_name) != hostname_len
+                         || memcmp(nsm->sm_name, hostname, hostname_len))
+                                continue;
+                } else if (!nlm_cmp_addr(&nsm->sm_addr, sin))
                         continue;
                 atomic_inc(&nsm->sm_count);
                 goto out;
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 626b6c116a6d..709cf7c80545 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -47,6 +47,7 @@ nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
         }
 
         memset(&args, 0, sizeof(args));
+        args.mon_name = nsm->sm_name;
         args.addr = nsm->sm_addr.sin_addr.s_addr;
         args.prog = NLM_PROGRAM;
         args.vers = 3;
@@ -150,7 +151,7 @@ nsm_create(void)
 static u32 *
 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 {
-        char    buffer[20];
+        char    buffer[20], *name;
 
         /*
          * Use the dotted-quad IP address of the remote host as
@@ -158,8 +159,13 @@ xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
          * hostname first for whatever remote hostname it receives,
          * so this works alright.
          */
-        sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
-        if (!(p = xdr_encode_string(p, buffer))
+        if (nsm_use_hostnames) {
+                name = argp->mon_name;
+        } else {
+                sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
+                name = buffer;
+        }
+        if (!(p = xdr_encode_string(p, name))
          || !(p = xdr_encode_string(p, utsname()->nodename)))
                 return ERR_PTR(-EIO);
         *p++ = htonl(argp->prog);
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 3cc369e5693f..a3b7602cd383 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -61,6 +61,7 @@ static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
 static unsigned long            nlm_grace_period;
 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
 static int                      nlm_udpport, nlm_tcpport;
+int                             nsm_use_hostnames = 0;
 
 /*
  * Constants needed for the sysctl interface.
@@ -395,6 +396,14 @@ static ctl_table nlm_sysctls[] = {
                 .extra1         = (int *) &nlm_port_min,
                 .extra2         = (int *) &nlm_port_max,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "nsm_use_hostnames",
+                .data           = &nsm_use_hostnames,
+                .maxlen         = sizeof(int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
         { .ctl_name = 0 }
 };
 
@@ -483,6 +492,7 @@ module_param_call(nlm_udpport, param_set_port, param_get_int,
                   &nlm_udpport, 0644);
 module_param_call(nlm_tcpport, param_set_port, param_get_int,
                   &nlm_tcpport, 0644);
+module_param(nsm_use_hostnames, bool, 0644);
 
 /*
  * Initialising and terminating the module.