Commit 8edc3aff authored by Sowmini Varadhan's avatar Sowmini Varadhan Committed by David S. Miller
Browse files

rds: tcp: Take explicit refcounts on struct net 



It is incorrect for the rds_connection to piggyback on the
sock_net() refcount for the netns because this gives rise to
a chicken-and-egg problem during rds_conn_destroy. Instead explicitly
take a ref on the net, and hold the netns down till the connection
tear-down is complete.

Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fa4c7fb2

net/rds/connection.c

+1 −0
Original line number Original line Diff line number Diff line
@@ -429,6 +429,7 @@ void rds_conn_destroy(struct rds_connection *conn) 
	 */

	 */

	rds_cong_remove_conn(conn);

	rds_cong_remove_conn(conn);





	put_net(conn->c_net);

	kmem_cache_free(rds_conn_slab, conn);

	kmem_cache_free(rds_conn_slab, conn);





	spin_lock_irqsave(&rds_conn_lock, flags);

	spin_lock_irqsave(&rds_conn_lock, flags);

net/rds/rds.h

+3 −3
Original line number Original line Diff line number Diff line
@@ -147,7 +147,7 @@ struct rds_connection { 




	/* Protocol version */

	/* Protocol version */

	unsigned int		c_version;

	unsigned int		c_version;

	possible_net_t		c_net;

	struct net		*c_net;





	struct list_head	c_map_item;

	struct list_head	c_map_item;

	unsigned long		c_map_queued;

	unsigned long		c_map_queued;
@@ -162,13 +162,13 @@ struct rds_connection { 
static inline

static inline

struct net *rds_conn_net(struct rds_connection *conn)

struct net *rds_conn_net(struct rds_connection *conn)

{

{

	return read_pnet(&conn->c_net);

	return conn->c_net;

}

}





static inline

static inline

void rds_conn_net_set(struct rds_connection *conn, struct net *net)

void rds_conn_net_set(struct rds_connection *conn, struct net *net)

{

{

	write_pnet(&conn->c_net, net);

	conn->c_net = get_net(net);

}

}





#define RDS_FLAG_CONG_BITMAP	0x01

#define RDS_FLAG_CONG_BITMAP	0x01

net/rds/tcp.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -529,7 +529,7 @@ static void rds_tcp_kill_sock(struct net *net) 
	flush_work(&rtn->rds_tcp_accept_w);

	flush_work(&rtn->rds_tcp_accept_w);

	spin_lock_irq(&rds_tcp_conn_lock);

	spin_lock_irq(&rds_tcp_conn_lock);

	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {

	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {

		struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);

		struct net *c_net = tc->t_cpath->cp_conn->c_net;





		if (net != c_net || !tc->t_sock)

		if (net != c_net || !tc->t_sock)

			continue;

			continue;
@@ -584,7 +584,7 @@ static void rds_tcp_sysctl_reset(struct net *net) 




	spin_lock_irq(&rds_tcp_conn_lock);

	spin_lock_irq(&rds_tcp_conn_lock);

	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {

	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {

		struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);

		struct net *c_net = tc->t_cpath->cp_conn->c_net;





		if (net != c_net || !tc->t_sock)

		if (net != c_net || !tc->t_sock)

			continue;

			continue;

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