Commit 3a8db798 authored Oct 08, 2016 by Marcelo Ricardo Leitner Committed by David Teigland Oct 10, 2016

dlm: free workqueues after the connections



After backporting commit ee44b4bc ("dlm: use sctp 1-to-1 API")
series to a kernel with an older workqueue which didn't use RCU yet, it
was noticed that we are freeing the workqueues in dlm_lowcomms_stop()
too early as free_conn() will try to access that memory for canceling
the queued works if any.

This issue was introduced by commit 0d737a8c as before it such
attempt to cancel the queued works wasn't performed, so the issue was
not present.

This patch fixes it by simply inverting the free order.

Cc: stable@vger.kernel.org
Fixes: 0d737a8c ("dlm: fix race while closing connections")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>

parent c8d2bc9b

fs/dlm/lowcomms.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -1656,16 +1656,12 @@ void dlm_lowcomms_stop(void)
		mutex_lock(&connections_lock);
		dlm_allow_conn = 0;
		foreach_conn(stop_conn);
		clean_writequeues();
		foreach_conn(free_conn);
		mutex_unlock(&connections_lock);

		work_stop();

		mutex_lock(&connections_lock);
		clean_writequeues();

		foreach_conn(free_conn);

		mutex_unlock(&connections_lock);
		kmem_cache_destroy(con_cache);
		}

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