1 files changed, 44 insertions, 3 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 40d41a2831d7..e1bd933629fe 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -9,6 +9,7 @@
 #include <linux/seq_file.h>
 #include <linux/hash.h>
 #include <linux/string.h>
+#include <net/sock.h>
 
 #define RPCDBG_FACILITY RPCDBG_AUTH
 
@@ -375,6 +376,44 @@ void svcauth_unix_purge(void)
         cache_purge(&ip_map_cache);
 }
 
+static inline struct ip_map *
+ip_map_cached_get(struct svc_rqst *rqstp)
+{
+        struct ip_map *ipm = rqstp->rq_sock->sk_info_authunix;
+        if (ipm != NULL) {
+                if (!cache_valid(&ipm->h)) {
+                        /*
+                         * The entry has been invalidated since it was
+                         * remembered, e.g. by a second mount from the
+                         * same IP address.
+                         */
+                        rqstp->rq_sock->sk_info_authunix = NULL;
+                        cache_put(&ipm->h, &ip_map_cache);
+                        return NULL;
+                }
+                cache_get(&ipm->h);
+        }
+        return ipm;
+}
+
+static inline void
+ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
+{
+        struct svc_sock *svsk = rqstp->rq_sock;
+
+        if (svsk->sk_sock->type == SOCK_STREAM && svsk->sk_info_authunix == NULL)
+                svsk->sk_info_authunix = ipm;   /* newly cached, keep the reference */
+        else
+                cache_put(&ipm->h, &ip_map_cache);
+}
+
+void
+svcauth_unix_info_release(void *info)
+{
+        struct ip_map *ipm = info;
+        cache_put(&ipm->h, &ip_map_cache);
+}
+
 static int
 svcauth_unix_set_client(struct svc_rqst *rqstp)
 {
@@ -384,8 +423,10 @@ svcauth_unix_set_client(struct svc_rqst *rqstp)
         if (rqstp->rq_proc == 0)
                 return SVC_OK;
 
-        ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
-                            rqstp->rq_addr.sin_addr);
+        ipm = ip_map_cached_get(rqstp);
+        if (ipm == NULL)
+                ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
+                                    rqstp->rq_addr.sin_addr);
 
         if (ipm == NULL)
                 return SVC_DENIED;
@@ -400,7 +441,7 @@ svcauth_unix_set_client(struct svc_rqst *rqstp)
                 case 0:
                         rqstp->rq_client = &ipm->m_client->h;
                         kref_get(&rqstp->rq_client->ref);
-                        cache_put(&ipm->h, &ip_map_cache);
+                        ip_map_cached_put(rqstp, ipm);
                         break;
         }
         return SVC_OK;