LU-16213 kfilnd: Allow one HELLO in-flight per peer

[fs/lustre-release.git] / lnet / klnds / kfilnd / kfilnd.h

diff --git a/lnet/klnds/kfilnd/kfilnd.h b/lnet/klnds/kfilnd/kfilnd.h
index 64b126e..076085d 100644 (file)
--- a/lnet/klnds/kfilnd/kfilnd.h
+++ b/lnet/klnds/kfilnd/kfilnd.h
@@ -234,23 +234,53 @@ struct kfilnd_peer {
        u16 kp_version;
        u32 kp_local_session_key;
        u32 kp_remote_session_key;
+       atomic_t kp_hello_pending;
+       time64_t kp_hello_ts;
 };
 
-static inline bool kfilnd_peer_is_new_peer(struct kfilnd_peer *kp)
+/* Sets kp_hello_sending
+ * Returns true if it was already set
+ * Returns false otherwise
+ */
+static inline bool kfilnd_peer_set_check_hello_pending(struct kfilnd_peer *kp)
 {
-       return kp->kp_version == 0;
+       return (atomic_cmpxchg(&kp->kp_hello_pending, 0, 1) == 1);
+}
+
+static inline void kfilnd_peer_clear_hello_pending(struct kfilnd_peer *kp)
+{
+       atomic_set(&kp->kp_hello_pending, 0);
 }
 
-static inline void kfilnd_peer_set_version(struct kfilnd_peer *kp,
-                                          u16 version)
+static inline bool kfilnd_peer_is_new_peer(struct kfilnd_peer *kp)
 {
-       kp->kp_version = version;
+       return kp->kp_version == 0;
 }
 
-static inline void kfilnd_peer_set_remote_session_key(struct kfilnd_peer *kp,
-                                                     u32 session_key)
+/* Peer needs hello if it is not up to date and there is not already a hello
+ * in flight.
+ *
+ * If hello was sent more than LND timeout seconds ago, and we never received a
+ * response, then send another one.
+ */
+static inline bool kfilnd_peer_needs_hello(struct kfilnd_peer *kp)
 {
-       kp->kp_remote_session_key = session_key;
+       if (atomic_read(&kp->kp_hello_pending) == 0) {
+               if (kfilnd_peer_is_new_peer(kp))
+                       return true;
+       } else if (ktime_before(kp->kp_hello_ts + lnet_get_lnd_timeout(),
+                               ktime_get_seconds())) {
+               /* Sent hello but never received reply */
+               CDEBUG(D_NET,
+                      "No response from %s(%p):0x%llx after %lld\n",
+                      libcfs_nid2str(kp->kp_nid), kp, kp->kp_addr,
+                      ktime_sub(ktime_get_seconds(), kp->kp_hello_ts));
+
+               kfilnd_peer_clear_hello_pending(kp);
+               return true;
+       }
+
+       return false;
 }
 
 struct kfilnd_fab {
@@ -700,6 +730,7 @@ struct kfilnd_transaction {
        enum kfilnd_msg_type msg_type;
 };
 
-int kfilnd_send_hello_request(struct kfilnd_dev *dev, int cpt, lnet_nid_t nid);
+int kfilnd_send_hello_request(struct kfilnd_dev *dev, int cpt,
+                             struct kfilnd_peer *kp);
 
 #endif /* _KFILND_ */