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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 3cce735..3b37812 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -857,6 +857,7 @@ enum {
                                 * so shrink_page_list() would not recurse into,
                                 * and potentially deadlock on, this drbd worker.
                                 */
+       DISCONNECT_SENT,        /* Currently the last bit in this 32bit word */
 };
 
 struct drbd_bitmap; /* opaque for drbd_conf */

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index df9965d..7b48653 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -659,6 +659,9 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
                        goto abort;
                }
 
+               if (mask.conn == C_MASK && val.conn == C_DISCONNECTING)
+                       set_bit(DISCONNECT_SENT, &mdev->flags);
+
                wait_event(mdev->state_wait,
                        (rv = _req_st_cond(mdev, mask, val)));
 

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 55c359a..64e6a61 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -534,7 +534,6 @@ static int drbd_recv(struct drbd_conf *mdev, void *buf, size_t size)
                                dev_err(DEV, "sock_recvmsg returned %d\n", rv);
                        break;
                } else if (rv == 0) {
-                       dev_info(DEV, "sock was shut down by peer\n");
                        break;
                } else  {
                        /* signal came in, or peer/link went down,
@@ -547,9 +546,21 @@ static int drbd_recv(struct drbd_conf *mdev, void *buf, size_t size)
 
        set_fs(oldfs);
 
+       if (rv == 0) {
+               if (test_bit(DISCONNECT_SENT, &mdev->flags)) {
+                       long t; /* time_left */
+                       t = wait_event_timeout(mdev->state_wait, mdev->state.conn < C_CONNECTED,
+                                              mdev->net_conf->ping_timeo * HZ/10);
+                       if (t)
+                               goto out;
+               }
+               dev_info(DEV, "sock was shut down by peer\n");
+       }
+
        if (rv != size)
                drbd_force_state(mdev, NS(conn, C_BROKEN_PIPE));
 
+out:
        return rv;
 }
 
@@ -760,6 +771,7 @@ static int drbd_connect(struct drbd_conf *mdev)
 
        D_ASSERT(!mdev->data.socket);
 
+       clear_bit(DISCONNECT_SENT, &mdev->flags);
        if (drbd_request_state(mdev, NS(conn, C_WF_CONNECTION)) < SS_SUCCESS)
                return -2;
 
@@ -4680,6 +4692,13 @@ int drbd_asender(struct drbd_thread *thi)
                        received += rv;
                        buf      += rv;
                } else if (rv == 0) {
+                       if (test_bit(DISCONNECT_SENT, &mdev->flags)) {
+                               long t; /* time_left */
+                               t = wait_event_timeout(mdev->state_wait, mdev->state.conn < C_CONNECTED,
+                                                      mdev->net_conf->ping_timeo * HZ/10);
+                               if (t)
+                                       break;
+                       }
                        dev_err(DEV, "meta connection shut down by peer.\n");
                        goto reconnect;
                } else if (rv == -EAGAIN) {