From 8edc3affc0770886c7bfb3436b0fdd09bce13167 Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Sat, 4 Mar 2017 08:57:33 -0800 Subject: 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: Dmitry Vyukov Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller --- net/rds/connection.c | 1 + net/rds/rds.h | 6 +++--- net/rds/tcp.c | 4 ++-- 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/rds/connection.c b/net/rds/connection.c index 0e04dcceb1d4..1fa75ab7b733 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -429,6 +429,7 @@ void rds_conn_destroy(struct rds_connection *conn) */ rds_cong_remove_conn(conn); + put_net(conn->c_net); kmem_cache_free(rds_conn_slab, conn); spin_lock_irqsave(&rds_conn_lock, flags); diff --git a/net/rds/rds.h b/net/rds/rds.h index 39518ef7af4d..82d38ccf5e8b 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -147,7 +147,7 @@ struct rds_connection { /* Protocol version */ unsigned int c_version; - possible_net_t c_net; + struct net *c_net; struct list_head c_map_item; unsigned long c_map_queued; @@ -162,13 +162,13 @@ struct rds_connection { static inline struct net *rds_conn_net(struct rds_connection *conn) { - return read_pnet(&conn->c_net); + return conn->c_net; } static inline 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 diff --git a/net/rds/tcp.c b/net/rds/tcp.c index a973d3b4dff0..65c8e3b3b710 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -529,7 +529,7 @@ static void rds_tcp_kill_sock(struct net *net) flush_work(&rtn->rds_tcp_accept_w); spin_lock_irq(&rds_tcp_conn_lock); 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) continue; @@ -584,7 +584,7 @@ static void rds_tcp_sysctl_reset(struct net *net) spin_lock_irq(&rds_tcp_conn_lock); 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) continue; -- cgit v1.2.3-59-g8ed1b