LU-13883 lnet: Lookup lpni after discovery

[fs/lustre-release.git] / lnet / lnet / peer.c

diff --git a/lnet/lnet/peer.c b/lnet/lnet/peer.c
index 9a6780c..6ec793b 100644 (file)
--- a/lnet/lnet/peer.c
+++ b/lnet/lnet/peer.c
@@ -1357,6 +1357,16 @@ LNetPrimaryNID(lnet_nid_t nid)
                rc = lnet_discover_peer_locked(lpni, cpt, true);
                if (rc)
                        goto out_decref;
+               /* The lpni (or lp) for this NID may have changed and our ref is
+                * the only thing keeping the old one around. Release the ref
+                * and lookup the lpni again
+                */
+               lnet_peer_ni_decref_locked(lpni);
+               lpni = lnet_find_peer_ni_locked(nid);
+               if (!lpni) {
+                       rc = -ENOENT;
+                       goto out_unlock;
+               }
                lp = lpni->lpni_peer_net->lpn_peer;
 
                /* Only try once if discovery is disabled */
@@ -2063,6 +2073,26 @@ __must_hold(&lp->lp_lock)
        return rc;
 }
 
+/* Add the message to the peer's lp_dc_pendq and queue the peer for discovery */
+void
+lnet_peer_queue_message(struct lnet_peer *lp, struct lnet_msg *msg)
+{
+       /* The discovery thread holds net_lock/EX and lp_lock when it splices
+        * the lp_dc_pendq onto a local list for resending. Thus, we do the same
+        * when adding to the list and queuing the peer to ensure that we do not
+        * strand any messages on the lp_dc_pendq. This scheme ensures the
+        * message will be resent even if the peer is already being discovered.
+        * Therefore we needn't check the return value of
+        * lnet_peer_queue_for_discovery(lp).
+        */
+       lnet_net_lock(LNET_LOCK_EX);
+       spin_lock(&lp->lp_lock);
+       list_add_tail(&msg->msg_list, &lp->lp_dc_pendq);
+       spin_unlock(&lp->lp_lock);
+       lnet_peer_queue_for_discovery(lp);
+       lnet_net_unlock(LNET_LOCK_EX);
+}
+
 /*
  * Queue a peer for the attention of the discovery thread.  Call with
  * lnet_net_lock/EX held. Returns 0 if the peer was queued, and