rpc: duplicate request cache for nfs

Duplicate request cache provides a mechanism for detecting
duplicate rpc requests from clients. DRC caches replies
and on duplicate requests, sends the cached reply instead of
re-processing the request.

Change-Id: I3d62a6c4aa86c92bf61f1038ca62a1a46bf1c303
BUG: 847624
Signed-off-by: Rajesh Amaravathi <rajesh@redhat.com>
Reviewed-on: http://review.gluster.org/4049
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

4 files changed, 63 insertions, 1 deletions

diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index 9375c5d407a..b44c1d0b370 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -1939,6 +1939,50 @@ out:
         return ret;
 }
 
+/**
+ * gf_sock_union_equal_addr - check if two given gf_sock_unions have same addr
+ *
+ * @param a - first sock union
+ * @param b - second sock union
+ * @return _gf_true if a and b have same ipv{4,6} addr, _gf_false otherwise
+ */
+gf_boolean_t
+gf_sock_union_equal_addr (union gf_sock_union *a,
+                          union gf_sock_union *b)
+{
+        if (!a || !b) {
+                gf_log ("common-utils", GF_LOG_ERROR, "Invalid arguments"
+                        " to gf_sock_union_equal_addr");
+                return _gf_false;
+        }
+
+        if (a->storage.ss_family != b->storage.ss_family)
+                return _gf_false;
+
+        switch (a->storage.ss_family) {
+        case AF_INET:
+                if (a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr)
+                        return _gf_true;
+                else
+                        return _gf_false;
+
+        case AF_INET6:
+                if (memcmp ((void *)(&a->sin6.sin6_addr),
+                            (void *)(&b->sin6.sin6_addr),
+                            sizeof (a->sin6.sin6_addr)))
+                        return _gf_false;
+                else
+                        return _gf_true;
+
+        default:
+                gf_log ("common-utils", GF_LOG_DEBUG,
+                        "Unsupported/invalid address family");
+                break;
+        }
+
+        return _gf_false;
+}
+
 /*Thread safe conversion function*/
 char *
 uuid_utoa (uuid_t uuid)
diff --git a/libglusterfs/src/common-utils.h b/libglusterfs/src/common-utils.h
index e1193031c9d..1fb36d658f7 100644
--- a/libglusterfs/src/common-utils.h
+++ b/libglusterfs/src/common-utils.h
@@ -557,6 +557,8 @@ char valid_internet_address (char *address, gf_boolean_t wildcard_acc);
 char valid_ipv4_wildcard_check (char *address);
 char valid_ipv6_wildcard_check (char *address);
 char valid_wildcard_internet_address (char *address);
+gf_boolean_t gf_sock_union_equal_addr (union gf_sock_union *a,
+                                       union gf_sock_union *b);
 
 char *uuid_utoa (uuid_t uuid);
 char *uuid_utoa_r (uuid_t uuid, char *dst);
diff --git a/libglusterfs/src/list.h b/libglusterfs/src/list.h
index 35fccdf25a5..7f3712b51b4 100644
--- a/libglusterfs/src/list.h
+++ b/libglusterfs/src/list.h
@@ -175,4 +175,16 @@ list_append_init (struct list_head *list, struct list_head *head)
 	     &pos->member != (head); 					\
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
+#define list_for_each_entry_reverse(pos, head, member)                  \
+	for (pos = list_entry((head)->prev, typeof(*pos), member);      \
+	     &pos->member != (head);                                    \
+	     pos = list_entry(pos->member.prev, typeof(*pos), member))
+
+
+#define list_for_each_entry_safe_reverse(pos, n, head, member)          \
+	for (pos = list_entry((head)->prev, typeof(*pos), member),      \
+	        n = list_entry(pos->member.prev, typeof(*pos), member); \
+	     &pos->member != (head);                                    \
+	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+
 #endif /* _LLIST_H */
diff --git a/libglusterfs/src/mem-types.h b/libglusterfs/src/mem-types.h
index 015cd1a3b0e..4c78f46071e 100644
--- a/libglusterfs/src/mem-types.h
+++ b/libglusterfs/src/mem-types.h
@@ -104,6 +104,10 @@ enum gf_common_mem_types_ {
         gf_common_mt_eh_t                 = 88,
         gf_common_mt_store_handle_t       = 89,
         gf_common_mt_store_iter_t         = 90,
-        gf_common_mt_end                  = 91
+        gf_common_mt_drc_client_t         = 91,
+        gf_common_mt_drc_globals_t        = 92,
+        gf_common_mt_drc_rbtree_node_t    = 93,
+        gf_common_mt_iov_base_t           = 94,
+        gf_common_mt_end                  = 95,
 };
 #endif