fs: dlm: fix race setting stop tx flag

[ Upstream commit bce6bc07619627064c3b997e13298de4882dddd4 ]

This patch sets the stop tx flag before we commit the dlm message.
This flag will report about unexpected transmissions after we
send the DLM_FIN message out, which should be the last message sent.
When we commit the dlm fin message, it could be that we already
got an ack back and the CLOSED state change already happened.
We should not set this flag when we are in CLOSED state. To avoid this
race we simply set the tx flag before the state change can be in
progress by moving it before dlm_midcomms_commit_mhandle().

Cc: stable@vger.kernel.org
Fixes: 9c99c76781ff ("fs: dlm: add reliable connection if reconnect")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c
index d976c2009b185ad72712ed03405738040f3a6a4b..b2a25a33a14888405c07c28db364d10f9f0ba335 100644 (file)
--- a/fs/dlm/midcomms.c
+++ b/fs/dlm/midcomms.c
@@ -406,6 +406,7 @@ static int dlm_send_fin(struct midcomms_node *node,
        if (!mh)
                return -ENOMEM;
 
+       set_bit(DLM_NODE_FLAG_STOP_TX, &node->flags);
        mh->ack_rcv = ack_rcv;
 
        m_header = (struct dlm_header *)ppc;
@@ -417,7 +418,6 @@ static int dlm_send_fin(struct midcomms_node *node,
 
        pr_debug("sending fin msg to node %d\n", node->nodeid);
        dlm_midcomms_commit_mhandle(mh, NULL, 0);
-       set_bit(DLM_NODE_FLAG_STOP_TX, &node->flags);
 
        return 0;
 }