Commits
Sowmini Varadhan committed 80ad0d4a7a7
rds: rds_cong_queue_updates needs to defer the congestion update transmission
When the RDS transport is TCP, we cannot inline the call to rds_send_xmit
from rds_cong_queue_update because
(a) we are already holding the sock_lock in the recv path, and
will deadlock when tcp_setsockopt/tcp_sendmsg try to get the sock
lock
(b) cong_queue_update does an irqsave on the rds_cong_lock, and this
will trigger warnings (for a good reason) from functions called
out of sock_lock.
This patch reverts the change introduced by
2fa57129d ("RDS: Bypass workqueue when queueing cong updates").
The patch has been verified for both RDS/TCP as well as RDS/RDMA
to ensure that there are not regressions for either transport:
- for verification of RDS/TCP a client-server unit-test was used,
with the server blocked in gdb and thus unable to drain its rcvbuf,
eventually triggering a RDS congestion update.
- for RDS/RDMA, the standard IB regression tests were used
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>