diff options
| author |   Sowmini Varadhan <sowmini.varadhan@oracle.com> | 2018-01-04 06:53:00 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-01-05 13:39:18 -0500 |
| commit | 3db6e0d172c94bd9953a1347c55ffb64b1d2e74f (patch) | |
| tree | 67f61aa4784da3fba56aa43e3626d3f3b6562c78 /net/rds/tcp_recv.c | |
| parent | rds: Use atomic flag to track connections being destroyed (diff) | |
| download | linux-dev-3db6e0d172c94bd9953a1347c55ffb64b1d2e74f.tar.xz linux-dev-3db6e0d172c94bd9953a1347c55ffb64b1d2e74f.zip | |
rds: use RCU to synchronize work-enqueue with connection teardown
rds_sendmsg() can enqueue work on cp_send_w from process context, but
it should not enqueue this work if connection teardown has commenced
(else we risk enquing work after rds_conn_path_destroy() has assumed that
all work has been cancelled/flushed).
Similarly some other functions like rds_cong_queue_updates
and rds_tcp_data_ready are called in softirq context, and may end
up enqueuing work on rds_wq after rds_conn_path_destroy() has assumed
that all workqs are quiesced.
Check the RDS_DESTROY_PENDING bit and use rcu synchronization to avoid
all these races.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/tcp_recv.c')
| -rw-r--r-- | net/rds/tcp_recv.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/rds/tcp_recv.c b/net/rds/tcp_recv.c index e006ef8e6d40..dd707b9e73e5 100644 --- a/net/rds/tcp_recv.c +++ b/net/rds/tcp_recv.c @@ -321,8 +321,12 @@ void rds_tcp_data_ready(struct sock *sk) ready = tc->t_orig_data_ready; rds_tcp_stats_inc(s_tcp_data_ready_calls); - if (rds_tcp_read_sock(cp, GFP_ATOMIC) == -ENOMEM) - queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); + if (rds_tcp_read_sock(cp, GFP_ATOMIC) == -ENOMEM) { + rcu_read_lock(); + if (!test_bit(RDS_DESTROY_PENDING, &cp->cp_flags)) + queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); + rcu_read_unlock(); + } out: read_unlock_bh(&sk->sk_callback_lock); ready(sk); |