logger: fix condition checking using locks during wait

kernel/brick_wait.h

@@ -0,0 +1,69 @@
+/*
+ * MARS Long Distance Replication Software
+ *
+ * This file is part of MARS project: http://schoebel.github.io/mars/
+ *
+ * Copyright (C) 2010-2014 Thomas Schoebel-Theuer
+ * Copyright (C) 2011-2014 1&1 Internet AG
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef BRICK_WAIT_H
+#define BRICK_WAIT_H
+
+/* compat to some elder kernels...
+ */
+#ifndef ___wait_cond_timeout
+#define ___wait_cond_timeout(x) (x)
+#define prepare_to_wait_event(a,b,c) (prepare_to_wait(a, b, c), 0)
+#endif
+
+/* Some code stolen from include/linux/wait.h
+ */
+#define brick_wait(wq, condition, timeout)				\
+({									\
+	__label__ __out;						\
+	wait_queue_t __wait;						\
+	long __ret = timeout;	/* explicit shadow */			\
+									\
+	might_sleep();							\
+	/* check in advance to avoid spinlocks in fastpath */		\
+	if (condition)							\
+		goto __out;						\
+									\
+	INIT_LIST_HEAD(&__wait.task_list);				\
+	__wait.flags = 0;						\
+									\
+	for (;;) {							\
+		long __int = prepare_to_wait_event(&wq, &__wait, TASK_INTERRUPTIBLE); \
+									\
+		if (__int) {						\
+			__ret = __int;					\
+			break;						\
+		}							\
+									\
+		__ret = schedule_timeout(__ret);			\
+									\
+		__set_current_state(TASK_RUNNING);			\
+		if (___wait_cond_timeout(condition))			\
+			break;						\
+	}								\
+	finish_wait(&wq, &__wait);					\
+__out:	__ret;								\
+})
+
+
+#endif

kernel/mars_trans_logger.c

@@ -36,6 +36,7 @@
 #include <linux/string.h>
 #include <linux/bio.h>
 
+#include "brick_wait.h"
 #include "mars.h"
 #include "lib_limiter.h"
 
@@ -2605,7 +2606,7 @@ void trans_logger_log(struct trans_logger_brick *brick)
 		int winner;
 		int nr;
 
-		wait_event_interruptible_timeout(
+		brick_wait(
 			brick->worker_event,
 			({
 				winner = _do_ranking(brick);
@@ -2771,7 +2772,7 @@ void wait_replay(struct trans_logger_brick *brick, struct trans_logger_mref_aspe
 	bool ok = false;
 	bool was_empty;
 
-	wait_event_interruptible_timeout(brick->worker_event,
+	brick_wait(brick->worker_event,
 					 atomic_read(&brick->replay_count) < max
 					 && (_has_conflict(brick, mref_a) ? conflicts++ : (ok = true), ok),
 					 60 * HZ);