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authorSowmini Varadhan <sowmini.varadhan@oracle.com>2018-01-04 06:53:00 -0800
committerDavid S. Miller <davem@davemloft.net>2018-01-05 13:39:18 -0500
commit3db6e0d172c94bd9953a1347c55ffb64b1d2e74f (patch)
tree67f61aa4784da3fba56aa43e3626d3f3b6562c78 /net/rds/tcp_send.c
parentc90ecbfaf50d2d7db25c531d9169be7e47435f3f (diff)
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_send.c')
-rw-r--r--net/rds/tcp_send.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c
index dc860d1bb608..73c74763ca72 100644
--- a/net/rds/tcp_send.c
+++ b/net/rds/tcp_send.c
@@ -202,8 +202,11 @@ void rds_tcp_write_space(struct sock *sk)
tc->t_last_seen_una = rds_tcp_snd_una(tc);
rds_send_path_drop_acked(cp, rds_tcp_snd_una(tc), rds_tcp_is_acked);
- if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf)
+ rcu_read_lock();
+ if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf &&
+ !test_bit(RDS_DESTROY_PENDING, &cp->cp_flags))
queue_delayed_work(rds_wq, &cp->cp_send_w, 0);
+ rcu_read_unlock();
out:
read_unlock_bh(&sk->sk_callback_lock);