tree 67f61aa4784da3fba56aa43e3626d3f3b6562c78
parent c90ecbfaf50d2d7db25c531d9169be7e47435f3f
author Sowmini Varadhan <sowmini.varadhan@oracle.com> 1515077580 -0800
committer David S. Miller <davem@davemloft.net> 1515177558 -0500

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>