From d219face9059f38ad187bde133451a2a308fdb7c Mon Sep 17 00:00:00 2001 From: Krishnamraju Eraparaju Date: Tue, 4 Feb 2020 14:42:30 +0530 Subject: RDMA/iw_cxgb4: initiate CLOSE when entering TERM As per draft-hilland-iwarp-verbs-v1.0, sec 6.2.3, always initiate a CLOSE when entering into TERM state. In c4iw_modify_qp(), disconnect operation should only be performed when the modify_qp call is invoked from ib_core. And all other internal modify_qp calls(invoked within iw_cxgb4) that needs 'disconnect' should call c4iw_ep_disconnect() explicitly after modify_qp. Otherwise, deadlocks like below can occur: Call Trace: schedule+0x2f/0xa0 schedule_preempt_disabled+0xa/0x10 __mutex_lock.isra.5+0x2d0/0x4a0 c4iw_ep_disconnect+0x39/0x430 => tries to reacquire ep lock again c4iw_modify_qp+0x468/0x10d0 rx_data+0x218/0x570 => acquires ep lock process_work+0x5f/0x70 process_one_work+0x1a7/0x3b0 worker_thread+0x30/0x390 kthread+0x112/0x130 ret_from_fork+0x35/0x40 Fixes: d2c33370ae73 ("RDMA/iw_cxgb4: Always disconnect when QP is transitioning to TERMINATE state") Link: https://lore.kernel.org/r/20200204091230.7210-1-krishna2@chelsio.com Signed-off-by: Krishnamraju Eraparaju Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/cxgb4/cm.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/infiniband/hw/cxgb4/cm.c') diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index ee1182f9b627..d69dece3b1d5 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -3036,6 +3036,10 @@ static int terminate(struct c4iw_dev *dev, struct sk_buff *skb) C4IW_QP_ATTR_NEXT_STATE, &attrs, 1); } + /* As per draft-hilland-iwarp-verbs-v1.0, sec 6.2.3, + * when entering the TERM state the RNIC MUST initiate a CLOSE. + */ + c4iw_ep_disconnect(ep, 1, GFP_KERNEL); c4iw_put_ep(&ep->com); } else pr_warn("TERM received tid %u no ep/qp\n", tid); -- cgit v1.2.3-59-g8ed1b