Commit 063c4c99 authored by Lars Marowsky-Bree's avatar Lars Marowsky-Bree Committed by David Teigland
Browse files

dlm: fix connection close handling 



Closing a connection to a node can create problems if there are
outstanding messages for that node.  The problems include dlm_send
spinning attempting to reconnect, or BUG from tcp_connect_to_sock()
attempting to use a partially closed connection.

To cleanly close a connection, we now first attempt to send any pending
messages, cancel any remaining workqueue work, and flag the connection
as closed to avoid reconnect attempts.

Signed-off-by: default avatarLars Marowsky-Bree <lmb@suse.de>
Signed-off-by: default avatarChristine Caulfield <ccaulfie@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent b5711b8e

fs/dlm/lowcomms.c

+13 −2
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ struct connection { 
#define CF_CONNECT_PENDING 3

#define CF_INIT_PENDING 4

#define CF_IS_OTHERCON 5

#define CF_CLOSE 6

	struct list_head writequeue;  /* List of outgoing writequeue_entries */

	spinlock_t writequeue_lock;

	int (*rx_action) (struct connection *);	/* What to do when active */
@@ -299,6 +300,8 @@ static void lowcomms_write_space(struct sock *sk) 


static inline void lowcomms_connect_sock(struct connection *con)

{

	if (test_bit(CF_CLOSE, &con->flags))

		return;

	if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))

		queue_work(send_workqueue, &con->swork);

}
@@ -1368,6 +1371,13 @@ int dlm_lowcomms_close(int nodeid) 
	log_print("closing connection to node %d", nodeid);

	con = nodeid2con(nodeid, 0);

	if (con) {

		clear_bit(CF_CONNECT_PENDING, &con->flags);

		clear_bit(CF_WRITE_PENDING, &con->flags);

		set_bit(CF_CLOSE, &con->flags);

		if (cancel_work_sync(&con->swork))

			log_print("canceled swork for node %d", nodeid);

		if (cancel_work_sync(&con->rwork))

			log_print("canceled rwork for node %d", nodeid);

		clean_one_writequeue(con);

		close_connection(con, true);

	}
@@ -1393,8 +1403,9 @@ static void process_send_sockets(struct work_struct *work) 


	if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {

		con->connect_action(con);

		set_bit(CF_WRITE_PENDING, &con->flags);

	}

	clear_bit(CF_WRITE_PENDING, &con->flags);

	if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags))

		send_to_sock(con);

}

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