- 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")
Signed-off-by: Krishnamraju Eraparaju <krishna2@xxxxxxxxxxx>
---
drivers/infiniband/hw/cxgb4/cm.c | 4 ++++
drivers/infiniband/hw/cxgb4/qp.c | 4 ++--
2 files changed, 6 insertions(+), 2 deletions(-)
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);
diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
index bbcac539777a..89ac2f9ae6dd 100644
--- a/drivers/infiniband/hw/cxgb4/qp.c
+++ b/drivers/infiniband/hw/cxgb4/qp.c
@@ -1948,10 +1948,10 @@ int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
qhp->attr.layer_etype = attrs->layer_etype;
qhp->attr.ecode = attrs->ecode;
ep = qhp->ep;
- c4iw_get_ep(&ep->com);
- disconnect = 1;
if (!internal) {
+ c4iw_get_ep(&ep->com);
terminate = 1;
+ disconnect = 1;
} else {
terminate = qhp->attr.send_term;
ret = rdma_fini(rhp, qhp, ep);
--
2.23.0.rc0
