drbd: Avoid NetworkFailure state during disconnect

Disconnecting is a cluster wide state change. In case the peer node agrees
to the state transition, it sends back the fact on the meta-data connection
and closes both sockets.

In case the node node that initiated the state transfer sees the closing
action on the data-socket, before the P_STATE_CHG_REPLY packet, it was
going into one of the network failure states.

At least with the fencing option set to something else thatn "dont-care",
the unclean shutdown of the connection causes a short IO freeze or
a fence operation.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index b83398d..37ae87e 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -816,6 +816,7 @@ enum {
                                 * so shrink_page_list() would not recurse into,
                                 * and potentially deadlock on, this drbd worker.
                                 */
+       DISCONNECT_SENT,
 };
 
 struct drbd_tconn {                    /* is a resource from the config file */

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 0eefbeb..1a8f698 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -522,7 +522,6 @@ static int drbd_recv(struct drbd_tconn *tconn, void *buf, size_t size)
                                conn_err(tconn, "sock_recvmsg returned %d\n", rv);
                        break;
                } else if (rv == 0) {
-                       conn_info(tconn, "sock was shut down by peer\n");
                        break;
                } else  {
                        /* signal came in, or peer/link went down,
@@ -535,9 +534,25 @@ static int drbd_recv(struct drbd_tconn *tconn, void *buf, size_t size)
 
        set_fs(oldfs);
 
+       if (rv == 0) {
+               if (test_bit(DISCONNECT_SENT, &tconn->flags)) {
+                       long t;
+                       rcu_read_lock();
+                       t = rcu_dereference(tconn->net_conf)->ping_timeo * HZ/10;
+                       rcu_read_unlock();
+
+                       t = wait_event_timeout(tconn->ping_wait, tconn->cstate < C_WF_REPORT_PARAMS, t);
+
+                       if (t)
+                               goto out;
+               }
+               conn_info(tconn, "sock was shut down by peer\n");
+       }
+
        if (rv != size)
                conn_request_state(tconn, NS(conn, C_BROKEN_PIPE), CS_HARD);
 
+out:
        return rv;
 }
 
@@ -894,6 +909,7 @@ static int conn_connect(struct drbd_tconn *tconn)
                .door_bell = COMPLETION_INITIALIZER_ONSTACK(ad.door_bell),
        };
 
+       clear_bit(DISCONNECT_SENT, &tconn->flags);
        if (conn_request_state(tconn, NS(conn, C_WF_CONNECTION), CS_VERBOSE) < SS_SUCCESS)
                return -2;
 
@@ -5316,6 +5332,18 @@ int drbd_asender(struct drbd_thread *thi)
                        received += rv;
                        buf      += rv;
                } else if (rv == 0) {
+                       if (test_bit(DISCONNECT_SENT, &tconn->flags)) {
+                               long t;
+                               rcu_read_lock();
+                               t = rcu_dereference(tconn->net_conf)->ping_timeo * HZ/10;
+                               rcu_read_unlock();
+
+                               t = wait_event_timeout(tconn->ping_wait,
+                                                      tconn->cstate < C_WF_REPORT_PARAMS,
+                                                      t);
+                               if (t)
+                                       break;
+                       }
                        conn_err(tconn, "meta connection shut down by peer.\n");
                        goto reconnect;
                } else if (rv == -EAGAIN) {

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index c16349a..4fda4e2 100644 (file)
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1742,6 +1742,9 @@ conn_cl_wide(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state v
                goto abort;
        }
 
+       if (val.conn == C_DISCONNECTING)
+               set_bit(DISCONNECT_SENT, &tconn->flags);
+
        wait_event(tconn->ping_wait, (rv = _conn_rq_cond(tconn, mask, val)));
        clear_bit(CONN_WD_ST_CHG_REQ, &tconn->flags);