[ Upstream commit b355516f450703c9015316e429b66a93dfff0e6f ]
If the DLM lowcomms stack is shut down before any DLM traffic can be generated, flush_workqueue() and destroy_workqueue() can be called on empty send and/or recv workqueues.
Insert guard conditionals to only call flush_workqueue() and destroy_workqueue() on workqueues that are not NULL.
Signed-off-by: David Windsor dwindsor@redhat.com Signed-off-by: David Teigland teigland@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/dlm/lowcomms.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 114ebfe30929..3951d39b9b75 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -1628,8 +1628,10 @@ static void clean_writequeues(void)
static void work_stop(void) { - destroy_workqueue(recv_workqueue); - destroy_workqueue(send_workqueue); + if (recv_workqueue) + destroy_workqueue(recv_workqueue); + if (send_workqueue) + destroy_workqueue(send_workqueue); }
static int work_start(void) @@ -1689,13 +1691,17 @@ static void work_flush(void) struct hlist_node *n; struct connection *con;
- flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); do { ok = 1; foreach_conn(stop_conn); - flush_workqueue(recv_workqueue); - flush_workqueue(send_workqueue); + if (recv_workqueue) + flush_workqueue(recv_workqueue); + if (send_workqueue) + flush_workqueue(send_workqueue); for (i = 0; i < CONN_HASH_SIZE && ok; i++) { hlist_for_each_entry_safe(con, n, &connection_hash[i], list) {