drbd: Ignore the exit code of a fence-peer handler if it returns too late

In case the connection was established and lost again before
the a fence-peer handler returns, ignore the exit code of this
instance. (And use the exit code of the later started instance)

Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@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 f943aac..f104328 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -832,6 +832,7 @@ struct drbd_tconn {                 /* is a resource from the config file */
        unsigned susp_nod:1;            /* IO suspended because no data */
        unsigned susp_fen:1;            /* IO suspended because fence peer handler runs */
        struct mutex cstate_mutex;      /* Protects graceful disconnects */
+       unsigned int connect_cnt;       /* Inc each time a connection is established */
 
        unsigned long flags;
        struct net_conf *net_conf;      /* content protected by rcu */

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 0936d6a..e25803b 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -417,6 +417,7 @@ static enum drbd_fencing_p highest_fencing_policy(struct drbd_tconn *tconn)
 
 bool conn_try_outdate_peer(struct drbd_tconn *tconn)
 {
+       unsigned int connect_cnt;
        union drbd_state mask = { };
        union drbd_state val = { };
        enum drbd_fencing_p fp;
@@ -428,6 +429,10 @@ bool conn_try_outdate_peer(struct drbd_tconn *tconn)
                return false;
        }
 
+       spin_lock_irq(&tconn->req_lock);
+       connect_cnt = tconn->connect_cnt;
+       spin_unlock_irq(&tconn->req_lock);
+
        fp = highest_fencing_policy(tconn);
        switch (fp) {
        case FP_NOT_AVAIL:
@@ -492,8 +497,14 @@ bool conn_try_outdate_peer(struct drbd_tconn *tconn)
           here, because we might were able to re-establish the connection in the
           meantime. */
        spin_lock_irq(&tconn->req_lock);
-       if (tconn->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &tconn->flags))
-               _conn_request_state(tconn, mask, val, CS_VERBOSE);
+       if (tconn->cstate < C_WF_REPORT_PARAMS && !test_bit(STATE_SENT, &tconn->flags)) {
+               if (tconn->connect_cnt != connect_cnt)
+                       /* In case the connection was established and droped
+                          while the fence-peer handler was running, ignore it */
+                       conn_info(tconn, "Ignoring fence-peer exit code\n");
+               else
+                       _conn_request_state(tconn, mask, val, CS_VERBOSE);
+       }
        spin_unlock_irq(&tconn->req_lock);
 
        return conn_highest_pdsk(tconn) <= D_OUTDATED;

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 90c5be2..216d47b 100644 (file)
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1115,8 +1115,10 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
                drbd_thread_restart_nowait(&mdev->tconn->receiver);
 
        /* Resume AL writing if we get a connection */
-       if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)
+       if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED) {
                drbd_resume_al(mdev);
+               mdev->tconn->connect_cnt++;
+       }
 
        /* remember last attach time so request_timer_fn() won't
         * kill newly established sessions while we are still trying to thaw