ceph: add open export target session helper

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

2 files changed, 38 insertions, 15 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 7c00dd530bd1..f4f050a69a48 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -847,35 +847,56 @@ static int __open_session(struct ceph_mds_client *mdsc,
  *
  * called under mdsc->mutex
  */
+static struct ceph_mds_session *
+__open_export_target_session(struct ceph_mds_client *mdsc, int target)
+{
+        struct ceph_mds_session *session;
+
+        session = __ceph_lookup_mds_session(mdsc, target);
+        if (!session) {
+                session = register_session(mdsc, target);
+                if (IS_ERR(session))
+                        return session;
+        }
+        if (session->s_state == CEPH_MDS_SESSION_NEW ||
+            session->s_state == CEPH_MDS_SESSION_CLOSING)
+                __open_session(mdsc, session);
+
+        return session;
+}
+
+struct ceph_mds_session *
+ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
+{
+        struct ceph_mds_session *session;
+
+        dout("open_export_target_session to mds%d\n", target);
+
+        mutex_lock(&mdsc->mutex);
+        session = __open_export_target_session(mdsc, target);
+        mutex_unlock(&mdsc->mutex);
+
+        return session;
+}
+
 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
                                           struct ceph_mds_session *session)
 {
         struct ceph_mds_info *mi;
         struct ceph_mds_session *ts;
         int i, mds = session->s_mds;
-        int target;
 
         if (mds >= mdsc->mdsmap->m_max_mds)
                 return;
+
         mi = &mdsc->mdsmap->m_info[mds];
         dout("open_export_target_sessions for mds%d (%d targets)\n",
              session->s_mds, mi->num_export_targets);
 
         for (i = 0; i < mi->num_export_targets; i++) {
-                target = mi->export_targets[i];
-                ts = __ceph_lookup_mds_session(mdsc, target);
-                if (!ts) {
-                        ts = register_session(mdsc, target);
-                        if (IS_ERR(ts))
-                                return;
-                }
-                if (session->s_state == CEPH_MDS_SESSION_NEW ||
-                    session->s_state == CEPH_MDS_SESSION_CLOSING)
-                        __open_session(mdsc, session);
-                else
-                        dout(" mds%d target mds%d %p is %s\n", session->s_mds,
-                             i, ts, session_state_name(ts->s_state));
-                ceph_put_mds_session(ts);
+                ts = __open_export_target_session(mdsc, mi->export_targets[i]);
+                if (!IS_ERR(ts))
+                        ceph_put_mds_session(ts);
         }
 }
 
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 4c053d099ae4..68288917c737 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -383,6 +383,8 @@ extern void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
 extern void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc,
                                  struct ceph_msg *msg);
 
+extern struct ceph_mds_session *
+ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target);
 extern void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
                                           struct ceph_mds_session *session);