libceph: move ceph_con_send() closed check under the con mutex

Take the con mutex before checking whether the connection is closed to
avoid racing with someone else closing it.

Signed-off-by: Sage Weil <sage@inktank.com>

1 files changed, 7 insertions, 9 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 1a3cb4a4f180..20e60a80bc29 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2453,22 +2453,20 @@ static void clear_standby(struct ceph_connection *con)
  */
 void ceph_con_send(struct ceph_connection *con, struct ceph_msg *msg)
 {
-        if (test_bit(CLOSED, &con->state)) {
-                dout("con_send %p closed, dropping %p\n", con, msg);
-                ceph_msg_put(msg);
-                return;
-        }
-
         /* set src+dst */
         msg->hdr.src = con->msgr->inst.name;
-
         BUG_ON(msg->front.iov_len != le32_to_cpu(msg->hdr.front_len));
-
         msg->needs_out_seq = true;
 
-        /* queue */
         mutex_lock(&con->mutex);
 
+        if (test_bit(CLOSED, &con->state)) {
+                dout("con_send %p closed, dropping %p\n", con, msg);
+                ceph_msg_put(msg);
+                mutex_unlock(&con->mutex);
+                return;
+        }
+
         BUG_ON(msg->con != NULL);
         msg->con = con->ops->get(con);
         BUG_ON(msg->con == NULL);