[Cluster-devel] [PATCH dlm/next 1/6] fs: dlm: remove lock dependency warning

[Alexander Aring <aahringo@redhat.com>]

During my experiments to make dlm robust against tcpkill application I
was able to run sometimes in a circular lock dependency warning between
clusters_root.subsys.su_mutex and con->sock_mutex. We don't need to
held the sock_mutex when getting the mark value which held the
clusters_root.subsys.su_mutex. This patch moves the specific handling
just before the sock_mutex will be held.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/lowcomms.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 1bf1808bfa6b0..24f5e55313d83 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -971,6 +971,10 @@ static void sctp_connect_to_sock(struct connection *con)
 		return;
 	}
 
+	result = dlm_comm_mark(con->nodeid, &mark);
+	if (result < 0)
+		return;
+
 	mutex_lock(&con->sock_mutex);
 
 	/* Some odd races can cause double-connects, ignore them */
@@ -995,11 +999,6 @@ static void sctp_connect_to_sock(struct connection *con)
 	if (result < 0)
 		goto socket_err;
 
-	/* set skb mark */
-	result = dlm_comm_mark(con->nodeid, &mark);
-	if (result < 0)
-		goto bind_err;
-
 	sock_set_mark(sock->sk, mark);
 
 	con->rx_action = receive_from_sock;
@@ -1072,6 +1071,10 @@ static void tcp_connect_to_sock(struct connection *con)
 		return;
 	}
 
+	result = dlm_comm_mark(con->nodeid, &mark);
+	if (result < 0)
+		return;
+
 	mutex_lock(&con->sock_mutex);
 	if (con->retries++ > MAX_CONNECT_RETRIES)
 		goto out;
@@ -1086,11 +1089,6 @@ static void tcp_connect_to_sock(struct connection *con)
 	if (result < 0)
 		goto out_err;
 
-	/* set skb mark */
-	result = dlm_comm_mark(con->nodeid, &mark);
-	if (result < 0)
-		goto out_err;
-
 	sock_set_mark(sock->sk, mark);
 
 	memset(&saddr, 0, sizeof(saddr));
-- 
2.26.2