s3: Add connections_forall_read()

In a cluster, this makes a large difference: For r/w traverse, we have to do a
fetch_locked on every record which for most users of connections_forall is just
overkill.

source3/include/proto.h

@@ -431,6 +431,10 @@ int connections_forall(int (*fn)(struct db_record *rec,
 				 const struct connections_data *data,
 				 void *private_data),
 		       void *private_data);
+int connections_forall_read(int (*fn)(const struct connections_key *key,
+				      const struct connections_data *data,
+				      void *private_data),
+			    void *private_data);
 bool connections_init(bool rw);
 
 /* The following definitions come from lib/dbwrap_util.c  */

source3/lib/conn_tdb.c

@@ -121,6 +121,48 @@ int connections_forall(int (*fn)(struct db_record *rec,
 	return ctx->traverse(ctx, conn_traverse_fn, (void *)&state);
 }
 
+struct conn_traverse_read_state {
+	int (*fn)(const struct connections_key *key,
+		  const struct connections_data *data,
+		  void *private_data);
+	void *private_data;
+};
+
+static int connections_forall_read_fn(struct db_record *rec,
+				      void *private_data)
+{
+	struct conn_traverse_read_state *state =
+		(struct conn_traverse_read_state *)private_data;
+
+	if ((rec->key.dsize != sizeof(struct connections_key))
+	    || (rec->value.dsize != sizeof(struct connections_data))) {
+		return 0;
+	}
+	return state->fn((const struct connections_key *)rec->key.dptr,
+			 (const struct connections_data *)rec->value.dptr,
+			 state->private_data);
+}
+
+int connections_forall_read(int (*fn)(const struct connections_key *key,
+				      const struct connections_data *data,
+				      void *private_data),
+			    void *private_data)
+{
+	struct db_context *ctx;
+	struct conn_traverse_read_state state;
+
+	ctx = connections_db_ctx(false);
+	if (ctx == NULL) {
+		return -1;
+	}
+
+	state.fn = fn;
+	state.private_data = private_data;
+
+	return ctx->traverse_read(ctx, connections_forall_read_fn,
+				  (void *)&state);
+}
+
 bool connections_init(bool rw)
 {
 	return (connections_db_ctx(rw) != NULL);

source3/smbd/sesssetup.c

@@ -1356,8 +1356,7 @@ static void reply_sesssetup_and_X_spnego(struct smb_request *req)
  a new session setup with VC==0 is ignored.
 ****************************************************************************/
 
-static int shutdown_other_smbds(struct db_record *rec,
+static int shutdown_other_smbds(const struct connections_key *key,
-				const struct connections_key *key,
 				const struct connections_data *crec,
 				void *private_data)
 {
@@ -1394,7 +1393,7 @@ static void setup_new_vc_session(void)
 	invalidate_all_vuids();
 #endif
 	if (lp_reset_on_zero_vc()) {
-		connections_forall(shutdown_other_smbds,
+		connections_forall_read(shutdown_other_smbds,
 			CONST_DISCARD(void *,
 			client_addr(get_client_fd(),addr,sizeof(addr))));
 	}

source3/utils/net_status.c

@@ -151,8 +151,7 @@ static int collect_pid(struct db_record *rec, void *private_data)
 	return 0;
 }
 
-static int show_share_parseable(struct db_record *rec,
+static int show_share_parseable(const struct connections_key *key,
-				const struct connections_key *key,
 				const struct connections_data *crec,
 				void *state)
 {
@@ -205,7 +204,7 @@ static int net_status_shares_parseable(struct net_context *c, int argc, const ch
 	db->traverse_read(db, collect_pid, &ids);
 	TALLOC_FREE(db);
 
-	connections_forall(show_share_parseable, &ids);
+	connections_forall_read(show_share_parseable, &ids);
 
 	SAFE_FREE(ids.entries);
 

source3/utils/smbcontrol.c

@@ -259,8 +259,7 @@ cleanup:
 	ptrace(PTRACE_DETACH, pid, NULL, NULL);
 }
 
-static int stack_trace_connection(struct db_record *rec,
+static int stack_trace_connection(const struct connections_key *key,
-				  const struct connections_key *key,
 				  const struct connections_data *crec,
 				  void *priv)
 {
@@ -291,7 +290,7 @@ static bool do_daemon_stack_trace(struct messaging_context *msg_ctx,
 		 */
 		print_stack_trace(dest, &count);
 	} else {
-		connections_forall(stack_trace_connection, &count);
+		connections_forall_read(stack_trace_connection, &count);
 	}
 
 	return True;

source3/utils/status.c

@@ -232,8 +232,7 @@ static void print_brl(struct file_id id,
 	TALLOC_FREE(share_mode);
 }
 
-static int traverse_fn1(struct db_record *rec,
+static int traverse_fn1(const struct connections_key *key,
-			const struct connections_key *key,
 			const struct connections_data *crec,
 			void *state)
 {
@@ -447,7 +446,7 @@ static int traverse_sessionid(struct db_record *db, void *state)
 		d_printf("\nService      pid     machine       Connected at\n");
 		d_printf("-------------------------------------------------------\n");
 
-		connections_forall(traverse_fn1, NULL);
+		connections_forall_read(traverse_fn1, NULL);
 
 		d_printf("\n");
 

source3/web/statuspage.c

@@ -182,8 +182,7 @@ static void print_share_mode(const struct share_mode_entry *e,
 
 
 /* kill off any connections chosen by the user */
-static int traverse_fn1(struct db_record *rec,
+static int traverse_fn1(const struct connections_key *key,
-			const struct connections_key *key,
 			const struct connections_data *crec,
 			void *private_data)
 {
@@ -199,8 +198,7 @@ static int traverse_fn1(struct db_record *rec,
 }
 
 /* traversal fn for showing machine connections */
-static int traverse_fn2(struct db_record *rec,
+static int traverse_fn2(const struct connections_key *key,
-                        const struct connections_key *key,
                         const struct connections_data *crec,
                         void *private_data)
 {
@@ -224,8 +222,7 @@ static int traverse_fn2(struct db_record *rec,
 }
 
 /* traversal fn for showing share connections */
-static int traverse_fn3(struct db_record *rec,
+static int traverse_fn3(const struct connections_key *key,
-                        const struct connections_key *key,
                         const struct connections_data *crec,
                         void *private_data)
 {
@@ -325,7 +322,7 @@ void status_page(void)
 		PID_or_Machine = 0;
 	}
 
-	connections_forall(traverse_fn1, NULL);
+	connections_forall_read(traverse_fn1, NULL);
 
 	initPid2Machine ();
 
@@ -415,7 +412,7 @@ void status_page(void)
 	}
 	printf("</tr>\n");
 
-	connections_forall(traverse_fn2, NULL);
+	connections_forall_read(traverse_fn2, NULL);
 
 	printf("</table><p>\n");
 
@@ -424,7 +421,7 @@ void status_page(void)
 	printf("<tr><th>%s</th><th>%s</th><th>%s</th><th>%s</th><th>%s</th><th>%s</th></tr>\n\n",
 		_("Share"), _("User"), _("Group"), _("PID"), _("Client"), _("Date"));
 
-	connections_forall(traverse_fn3, NULL);
+	connections_forall_read(traverse_fn3, NULL);
 
 	printf("</table><p>\n");