From 143b72d69965034b247d0b18a09476c0330d8cbc Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 14 Jun 2018 11:52:34 -0700 Subject: [PATCH] rds: avoid unenecessary cong_update in loop transport commit f1693c63ab133d16994cc50f773982b5905af264 upstream. Loop transport which is self loopback, remote port congestion update isn't relevant. Infact the xmit path already ignores it. Receive path needs to do the same. Reported-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com Reviewed-by: Sowmini Varadhan Signed-off-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/loop.c | 1 + net/rds/rds.h | 5 +++++ net/rds/recv.c | 5 +++++ 3 files changed, 11 insertions(+) diff --git a/net/rds/loop.c b/net/rds/loop.c index 6b12b68541ae9..05cab8c5a3791 100644 --- a/net/rds/loop.c +++ b/net/rds/loop.c @@ -191,4 +191,5 @@ struct rds_transport rds_loop_transport = { .inc_copy_to_user = rds_message_inc_copy_to_user, .inc_free = rds_loop_inc_free, .t_name = "loopback", + .t_type = RDS_TRANS_LOOP, }; diff --git a/net/rds/rds.h b/net/rds/rds.h index 42af715b63fca..1b4050a0f7ba8 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -381,6 +381,11 @@ struct rds_notifier { int n_status; }; +/* Available as part of RDS core, so doesn't need to participate + * in get_preferred transport etc + */ +#define RDS_TRANS_LOOP 3 + /** * struct rds_transport - transport specific behavioural hooks * diff --git a/net/rds/recv.c b/net/rds/recv.c index bd82522534fc5..f60a704b3ab53 100644 --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -76,6 +76,11 @@ static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk, return; rs->rs_rcv_bytes += delta; + + /* loop transport doesn't send/recv congestion updates */ + if (rs->rs_transport->t_type == RDS_TRANS_LOOP) + return; + now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs); rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d "