dlm: fix wake_up() calls for pending remove

This patch move the wake_up() call at the point when a remove message
completed. Before it was only when a remove message was going to be
sent. The possible waiter in wait_pending_remove() waits until a remove
is done if the resource name matches with the per ls variable
ls->ls_remove_name. If this is the case we must wait until a pending
remove is done which is indicated if DLM_WAIT_PENDING_COND() returns
false which will always be the case when ls_remove_len and
ls_remove_name are unset to indicate that a remove is not going on
anymore.

Fixes: 21d9ac1 ("fs: dlm: use event based wait for pending remove")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

Author: Alexander Aring

fs/dlm/lock.c

@@ -1810,7 +1810,6 @@ static void shrink_bucket(struct dlm_ls *ls, int b)
 		memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
 		spin_unlock(&ls->ls_remove_spin);
 		spin_unlock(&ls->ls_rsbtbl[b].lock);
-		wake_up(&ls->ls_remove_wait);
 
 		send_remove(r);
 
@@ -1819,6 +1818,7 @@ static void shrink_bucket(struct dlm_ls *ls, int b)
 		ls->ls_remove_len = 0;
 		memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
 		spin_unlock(&ls->ls_remove_spin);
+		wake_up(&ls->ls_remove_wait);
 
 		dlm_free_rsb(r);
 	}
@@ -4096,7 +4096,6 @@ static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
 	memcpy(ls->ls_remove_name, name, DLM_RESNAME_MAXLEN);
 	spin_unlock(&ls->ls_remove_spin);
 	spin_unlock(&ls->ls_rsbtbl[b].lock);
-	wake_up(&ls->ls_remove_wait);
 
 	rv = _create_message(ls, sizeof(struct dlm_message) + len,
 			     dir_nodeid, DLM_MSG_REMOVE, &ms, &mh);
@@ -4112,6 +4111,7 @@ static void send_repeat_remove(struct dlm_ls *ls, char *ms_name, int len)
 	ls->ls_remove_len = 0;
 	memset(ls->ls_remove_name, 0, DLM_RESNAME_MAXLEN);
 	spin_unlock(&ls->ls_remove_spin);
+	wake_up(&ls->ls_remove_wait);
 }
 
 static int receive_request(struct dlm_ls *ls, struct dlm_message *ms)