libceph: add function that reset client's entity addr

This function also re-open connections to OSD/MON, and re-send in-flight
OSD requests after re-opening connections to OSD.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/ceph_common.c

@@ -694,6 +694,14 @@ void ceph_destroy_client(struct ceph_client *client)
 }
 EXPORT_SYMBOL(ceph_destroy_client);
 
+void ceph_reset_client_addr(struct ceph_client *client)
+{
+	ceph_messenger_reset_nonce(&client->msgr);
+	ceph_monc_reopen_session(&client->monc);
+	ceph_osdc_reopen_osds(&client->osdc);
+}
+EXPORT_SYMBOL(ceph_reset_client_addr);
+
 /*
  * true if we have the mon map (and have thus joined the cluster)
  */

net/ceph/messenger.c

@@ -3031,6 +3031,12 @@ static void con_fault(struct ceph_connection *con)
 }
 
 
+void ceph_messenger_reset_nonce(struct ceph_messenger *msgr)
+{
+	u32 nonce = le32_to_cpu(msgr->inst.addr.nonce) + 1000000;
+	msgr->inst.addr.nonce = cpu_to_le32(nonce);
+	encode_my_addr(msgr);
+}
 
 /*
  * initialize a new messenger instance

net/ceph/mon_client.c

@@ -213,6 +213,13 @@ static void reopen_session(struct ceph_mon_client *monc)
 	__open_session(monc);
 }
 
+void ceph_monc_reopen_session(struct ceph_mon_client *monc)
+{
+	mutex_lock(&monc->mutex);
+	reopen_session(monc);
+	mutex_unlock(&monc->mutex);
+}
+
 static void un_backoff(struct ceph_mon_client *monc)
 {
 	monc->hunt_mult /= 2; /* reduce by 50% */

net/ceph/osd_client.c

@@ -5086,6 +5086,24 @@ out_put_req:
 }
 EXPORT_SYMBOL(ceph_osdc_call);
 
+/*
+ * reset all osd connections
+ */
+void ceph_osdc_reopen_osds(struct ceph_osd_client *osdc)
+{
+	struct rb_node *n;
+
+	down_write(&osdc->lock);
+	for (n = rb_first(&osdc->osds); n; ) {
+		struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
+
+		n = rb_next(n);
+		if (!reopen_osd(osd))
+			kick_osd_requests(osd);
+	}
+	up_write(&osdc->lock);
+}
+
 /*
  * init, shutdown
  */