diff options
author | Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2016-06-30 23:11:13 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-07-01 20:45:17 (GMT) |
commit | afb4164d91c7486a1d4ab098a1b88e27b5e25772 (patch) | |
tree | 9d1b76c3268d9c491fc9280237b62f7fb7a49892 /net/rds/tcp.c | |
parent | 02105b2ccdd6344146e0296172a9e0f17ff624ef (diff) | |
download | linux-afb4164d91c7486a1d4ab098a1b88e27b5e25772.tar.xz |
RDS: TCP: Refactor connection destruction to handle multiple paths
A single rds_connection may have multiple rds_conn_paths that have
to be carefully and correctly destroyed, for both rmmod and
netns-delete cases.
For both cases, we extract a single rds_tcp_connection for
each conn into a temporary list, and then invoke rds_conn_destroy()
which iteratively dismantles every path in the rds_connection.
For the netns deletion case, we additionally have to make sure
that we do not leave a socket in TIME_WAIT state, as this will
hold up the netns deletion. Thus we call rds_tcp_conn_paths_destroy()
to reset state quickly.
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/tcp.c')
-rw-r--r-- | net/rds/tcp.c | 46 |
1 files changed, 39 insertions, 7 deletions
diff --git a/net/rds/tcp.c b/net/rds/tcp.c index c6b47f6..b327727 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -323,6 +323,17 @@ static void rds_tcp_conn_free(void *arg) kmem_cache_free(rds_tcp_conn_slab, tc); } +static bool list_has_conn(struct list_head *list, struct rds_connection *conn) +{ + struct rds_tcp_connection *tc, *_tc; + + list_for_each_entry_safe(tc, _tc, list, t_tcp_node) { + if (tc->t_cpath->cp_conn == conn) + return true; + } + return false; +} + static void rds_tcp_destroy_conns(void) { struct rds_tcp_connection *tc, *_tc; @@ -330,8 +341,10 @@ static void rds_tcp_destroy_conns(void) /* avoid calling conn_destroy with irqs off */ spin_lock_irq(&rds_tcp_conn_lock); - list_splice(&rds_tcp_conn_list, &tmp_list); - INIT_LIST_HEAD(&rds_tcp_conn_list); + list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) { + if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) + list_move_tail(&tc->t_tcp_node, &tmp_list); + } spin_unlock_irq(&rds_tcp_conn_lock); list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) @@ -491,10 +504,30 @@ static struct pernet_operations rds_tcp_net_ops = { .size = sizeof(struct rds_tcp_net), }; +/* explicitly send a RST on each socket, thereby releasing any socket refcnts + * that may otherwise hold up netns deletion. + */ +static void rds_tcp_conn_paths_destroy(struct rds_connection *conn) +{ + struct rds_conn_path *cp; + struct rds_tcp_connection *tc; + int i; + struct sock *sk; + + for (i = 0; i < RDS_MPATH_WORKERS; i++) { + cp = &conn->c_path[i]; + tc = cp->cp_transport_data; + if (!tc->t_sock) + continue; + sk = tc->t_sock->sk; + sk->sk_prot->disconnect(sk, 0); + tcp_done(sk); + } +} + static void rds_tcp_kill_sock(struct net *net) { struct rds_tcp_connection *tc, *_tc; - struct sock *sk; LIST_HEAD(tmp_list); struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid); @@ -507,13 +540,12 @@ static void rds_tcp_kill_sock(struct net *net) if (net != c_net || !tc->t_sock) continue; - list_move_tail(&tc->t_tcp_node, &tmp_list); + if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) + list_move_tail(&tc->t_tcp_node, &tmp_list); } spin_unlock_irq(&rds_tcp_conn_lock); list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) { - sk = tc->t_sock->sk; - sk->sk_prot->disconnect(sk, 0); - tcp_done(sk); + rds_tcp_conn_paths_destroy(tc->t_cpath->cp_conn); rds_conn_destroy(tc->t_cpath->cp_conn); } } |