LU-11128 ptlrpc: new request vs disconnect race

[fs/lustre-release.git] / lustre / ptlrpc / import.c

diff --git a/lustre/ptlrpc/import.c b/lustre/ptlrpc/import.c
index 241c1a7..8ca1dec 100644 (file)
--- a/lustre/ptlrpc/import.c
+++ b/lustre/ptlrpc/import.c
@@ -1665,13 +1665,38 @@ static int ptlrpc_disconnect_idle_interpret(const struct lu_env *env,
                                            void *data, int rc)
 {
        struct obd_import *imp = req->rq_import;
+       int connect = 0;
+
+       DEBUG_REQ(D_HA, req, "inflight=%d, refcount=%d: rc = %d\n",
+                 atomic_read(&imp->imp_inflight),
+                 atomic_read(&imp->imp_refcount), rc);
 
-       LASSERT(imp->imp_state == LUSTRE_IMP_CONNECTING);
        spin_lock(&imp->imp_lock);
-       IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_IDLE);
-       memset(&imp->imp_remote_handle, 0, sizeof(imp->imp_remote_handle));
+       /* DISCONNECT reply can be late and another connection can just
+        * be initiated. so we have to abort disconnection. */
+       if (req->rq_import_generation == imp->imp_generation &&
+           imp->imp_state != LUSTRE_IMP_CLOSED) {
+               LASSERTF(imp->imp_state == LUSTRE_IMP_CONNECTING,
+                        "%s\n", ptlrpc_import_state_name(imp->imp_state));
+               imp->imp_state = LUSTRE_IMP_IDLE;
+               memset(&imp->imp_remote_handle, 0,
+                      sizeof(imp->imp_remote_handle));
+               /* take our DISCONNECT into account */
+               if (atomic_read(&imp->imp_inflight) > 1) {
+                       imp->imp_generation++;
+                       imp->imp_initiated_at = imp->imp_generation;
+                       IMPORT_SET_STATE_NOLOCK(imp, LUSTRE_IMP_NEW);
+                       connect = 1;
+               }
+       }
        spin_unlock(&imp->imp_lock);
 
+       if (connect) {
+               rc = ptlrpc_connect_import(imp);
+               if (rc >= 0)
+                       ptlrpc_pinger_add_import(imp);
+       }
+
        return 0;
 }