[dm-devel] [PATCH 5/6] libmultipath: Introduce timedlock()

[Bart Van Assche]

Introduce the function timedlock(). Ensure that the value of the
"depth" member value is incorrect if pthread_mutex_timedlock()
times out.

Signed-off-by: Bart Van Assche <bart.vanassche at sandisk.com>
---
 libmultipath/lock.h | 11 +++++++++++
 multipathd/cli.c    |  3 +--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/libmultipath/lock.h b/libmultipath/lock.h
index dc83336..9808480 100644
--- a/libmultipath/lock.h
+++ b/libmultipath/lock.h
@@ -18,6 +18,17 @@ static inline void lock(struct mutex_lock *a)
 	pthread_mutex_lock(&a->mutex);
 }
 
+static inline int timedlock(struct mutex_lock *a, struct timespec *tmo)
+{
+	int r;
+
+	a->depth++;
+	r = pthread_mutex_timedlock(&a->mutex, tmo);
+	if (r)
+		a->depth--;
+	return r;
+}
+
 static inline void unlock(struct mutex_lock *a)
 {
 	a->depth--;
diff --git a/multipathd/cli.c b/multipathd/cli.c
index 9597736..9a19728 100644
--- a/multipathd/cli.c
+++ b/multipathd/cli.c
@@ -487,8 +487,7 @@ parse_cmd (char * cmd, char ** reply, int * len, void * data, int timeout )
 
 		pthread_cleanup_push(cleanup_lock, &vecs->lock);
 		if (tmo.tv_sec) {
-			vecs->lock.depth++;
-			r = pthread_mutex_timedlock(&vecs->lock.mutex, &tmo);
+			r = timedlock(&vecs->lock, &tmo);
 		} else {
 			lock(&vecs->lock);
 			r = 0;
-- 
2.9.2