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/threads.c | |
| parent | c90ecbfaf50d2d7db25c531d9169be7e47435f3f (diff) | |
| download | linux-3db6e0d172c94bd9953a1347c55ffb64b1d2e74f.tar.bz2 | |
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/threads.c')
| -rw-r--r-- | net/rds/threads.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/net/rds/threads.c b/net/rds/threads.c index f121daa402c8..eb76db1360b0 100644 --- a/net/rds/threads.c +++ b/net/rds/threads.c @@ -87,8 +87,12 @@ void rds_connect_path_complete(struct rds_conn_path *cp, int curr) cp->cp_reconnect_jiffies = 0; set_bit(0, &cp->cp_conn->c_map_queued); - queue_delayed_work(rds_wq, &cp->cp_send_w, 0); - queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); + rcu_read_lock(); + if (!test_bit(RDS_DESTROY_PENDING, &cp->cp_flags)) { + queue_delayed_work(rds_wq, &cp->cp_send_w, 0); + queue_delayed_work(rds_wq, &cp->cp_recv_w, 0); + } + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(rds_connect_path_complete); @@ -133,7 +137,10 @@ void rds_queue_reconnect(struct rds_conn_path *cp) set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags); if (cp->cp_reconnect_jiffies == 0) { cp->cp_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies; - queue_delayed_work(rds_wq, &cp->cp_conn_w, 0); + rcu_read_lock(); + if (!test_bit(RDS_DESTROY_PENDING, &cp->cp_flags)) + queue_delayed_work(rds_wq, &cp->cp_conn_w, 0); + rcu_read_unlock(); return; } @@ -141,8 +148,11 @@ void rds_queue_reconnect(struct rds_conn_path *cp) rdsdebug("%lu delay %lu ceil conn %p for %pI4 -> %pI4\n", rand % cp->cp_reconnect_jiffies, cp->cp_reconnect_jiffies, conn, &conn->c_laddr, &conn->c_faddr); - queue_delayed_work(rds_wq, &cp->cp_conn_w, - rand % cp->cp_reconnect_jiffies); + rcu_read_lock(); + if (!test_bit(RDS_DESTROY_PENDING, &cp->cp_flags)) + queue_delayed_work(rds_wq, &cp->cp_conn_w, + rand % cp->cp_reconnect_jiffies); + rcu_read_unlock(); cp->cp_reconnect_jiffies = min(cp->cp_reconnect_jiffies * 2, rds_sysctl_reconnect_max_jiffies); |