ctdb-recoverd: Handle cancellation when releasing recovery lock

If the recovery lock is in the process of being taken then free the
cluster mutex handle but leave the recovery lock handle in place.
This allows ctdb_recovery_lock() to fail.

Note that this isn't yet live because rec->recovery_lock_handle is
still only set at the completion of the attempt to take the lock.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13617

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>

diff --git a/ctdb/server/ctdb_recoverd.c b/ctdb/server/ctdb_recoverd.c
index 6a02110153578c7a9331a80e6ed6f0321e90b071..d0eceee62f9f833a194c9804c912d0923f8e7bb4 100644 (file)
--- a/ctdb/server/ctdb_recoverd.c
+++ b/ctdb/server/ctdb_recoverd.c
@@ -980,6 +980,20 @@ static void ctdb_recovery_unlock(struct ctdb_recoverd *rec)
                return;
        }
 
+       if (! rec->recovery_lock_handle->done) {
+               /*
+                * Taking of recovery lock still in progress.  Free
+                * the cluster mutex handle to release it but leave
+                * the recovery lock handle in place to allow taking
+                * of the lock to fail.
+                */
+               D_NOTICE("Cancelling recovery lock\n");
+               TALLOC_FREE(rec->recovery_lock_handle->h);
+               rec->recovery_lock_handle->done = true;
+               rec->recovery_lock_handle->locked = false;
+               return;
+       }
+
        D_NOTICE("Releasing recovery lock\n");
        TALLOC_FREE(rec->recovery_lock_handle);
 }