From: Roland Dreier <roland@xxxxxxxxxxxxxxx>
A couple of places in the CM do
spin_lock_irq(&cm_id_priv->lock);
...
if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
However when the underlying transport is RoCE, this leads to a sleeping function
being called with the lock held - the callchain is
cm_alloc_response_msg() ->
ib_create_ah_from_wc() ->
ib_init_ah_from_wc() ->
rdma_addr_find_l2_eth_by_grh() ->
rdma_resolve_ip()
and rdma_resolve_ip() starts out by doing
req = kzalloc(sizeof *req, GFP_KERNEL);
not to mention rdma_addr_find_l2_eth_by_grh() doing
wait_for_completion(&ctx.comp);
to wait for the task that rdma_resolve_ip() queues up.
Fix this by moving the AH creation out of the lock.
Signed-off-by: Roland Dreier <roland@xxxxxxxxxxxxxxx>
---
drivers/infiniband/core/cm.c | 63 +++++++++++++++++++++++++++++++-------------
1 file changed, 44 insertions(+), 19 deletions(-)
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 2b4d613a3474..f814c5035c74 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -373,11 +373,19 @@ static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
return ret;
}
-static int cm_alloc_response_msg(struct cm_port *port,
- struct ib_mad_recv_wc *mad_recv_wc,
- struct ib_mad_send_buf **msg)
+static struct ib_mad_send_buf *cm_alloc_response_msg_no_ah(struct cm_port *port,
+ struct ib_mad_recv_wc *mad_recv_wc)
+{
+ return ib_create_send_mad(port->mad_agent, 1, mad_recv_wc->wc->pkey_index,
+ 0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
+ GFP_ATOMIC,
+ IB_MGMT_BASE_VERSION);
+}
+
+static int cm_create_response_msg_ah(struct cm_port *port,
+ struct ib_mad_recv_wc *mad_recv_wc,
+ struct ib_mad_send_buf *msg)
{
- struct ib_mad_send_buf *m;
struct ib_ah *ah;
ah = ib_create_ah_from_wc(port->mad_agent->qp->pd, mad_recv_wc->wc,
@@ -385,27 +393,40 @@ static int cm_alloc_response_msg(struct cm_port *port,
if (IS_ERR(ah))
return PTR_ERR(ah);
- m = ib_create_send_mad(port->mad_agent, 1, mad_recv_wc->wc->pkey_index,
- 0, IB_MGMT_MAD_HDR, IB_MGMT_MAD_DATA,
- GFP_ATOMIC,
- IB_MGMT_BASE_VERSION);
- if (IS_ERR(m)) {
- rdma_destroy_ah(ah);
- return PTR_ERR(m);
- }
- m->ah = ah;
- *msg = m;
+ msg->ah = ah;
return 0;
}
static void cm_free_msg(struct ib_mad_send_buf *msg)
{
- rdma_destroy_ah(msg->ah);
+ if (msg->ah)
+ rdma_destroy_ah(msg->ah);
if (msg->context[0])
cm_deref_id(msg->context[0]);
ib_free_send_mad(msg);
}
+static int cm_alloc_response_msg(struct cm_port *port,
+ struct ib_mad_recv_wc *mad_recv_wc,
+ struct ib_mad_send_buf **msg)
+{
+ struct ib_mad_send_buf *m;
+ int ret;
+
+ m = cm_alloc_response_msg_no_ah(port, mad_recv_wc);
+ if (IS_ERR(m))
+ return PTR_ERR(m);
+
+ ret = cm_create_response_msg_ah(port, mad_recv_wc, m);
+ if (ret) {
+ cm_free_msg(m);
+ return ret;
+ }
+
+ *msg = m;
+ return 0;
+}
+
static void * cm_copy_private_data(const void *private_data,
u8 private_data_len)
{
@@ -2424,7 +2445,8 @@ static int cm_dreq_handler(struct cm_work *work)
case IB_CM_TIMEWAIT:
atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
counter[CM_DREQ_COUNTER]);
- if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
+ msg = cm_alloc_response_msg_no_ah(work->port, work->mad_recv_wc);
+ if (IS_ERR(msg))
goto unlock;
cm_format_drep((struct cm_drep_msg *) msg->mad, cm_id_priv,
@@ -2432,7 +2454,8 @@ static int cm_dreq_handler(struct cm_work *work)
cm_id_priv->private_data_len);
spin_unlock_irq(&cm_id_priv->lock);
- if (ib_post_send_mad(msg, NULL))
+ if (cm_create_response_msg_ah(work->port, work->mad_recv_wc, msg) ||
+ ib_post_send_mad(msg, NULL))
cm_free_msg(msg);
goto deref;
case IB_CM_DREQ_RCVD:
@@ -2980,7 +3003,8 @@ static int cm_lap_handler(struct cm_work *work)
case IB_CM_MRA_LAP_SENT:
atomic_long_inc(&work->port->counter_group[CM_RECV_DUPLICATES].
counter[CM_LAP_COUNTER]);
- if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
+ msg = cm_alloc_response_msg_no_ah(work->port, work->mad_recv_wc);
+ if (IS_ERR(msg))
goto unlock;
cm_format_mra((struct cm_mra_msg *) msg->mad, cm_id_priv,
@@ -2990,7 +3014,8 @@ static int cm_lap_handler(struct cm_work *work)
cm_id_priv->private_data_len);
spin_unlock_irq(&cm_id_priv->lock);
- if (ib_post_send_mad(msg, NULL))
+ if (cm_create_response_msg_ah(work->port, work->mad_recv_wc, msg) ||
+ ib_post_send_mad(msg, NULL))
cm_free_msg(msg);
goto deref;
case IB_CM_LAP_RCVD:
--
2.14.1
--
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