Whenever ib_cm gets remove_one call, like when there is a hot-unplug
event, the driver should mark itself as going_down and confirm that no
new works are going to be queued for that device.
so, the order of the actions are:
1. mark the going_down bit.
2. flush the wq.
3. [make sure no new works for that device.]
4. unregister mad agent.
otherwise, works that are already queued can be scheduled after the mad
agent was freed.
Signed-off-by: Erez Shitrit <erezsh@xxxxxxxxxxxx>
---
drivers/infiniband/core/cm.c | 61 +++++++++++++++++++++++++++++++++++++++-----
1 file changed, 55 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index dbddddd..3a972eb 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -169,6 +169,7 @@ struct cm_device {
struct ib_device *ib_device;
struct device *device;
u8 ack_delay;
+ int going_down;
struct cm_port *port[0];
};
@@ -805,6 +806,11 @@ static void cm_enter_timewait(struct cm_id_private *cm_id_priv)
{
int wait_time;
unsigned long flags;
+ struct cm_device *cm_dev;
+
+ cm_dev = ib_get_client_data(cm_id_priv->id.device, &cm_client);
+ if (!cm_dev)
+ return;
spin_lock_irqsave(&cm.lock, flags);
cm_cleanup_timewait(cm_id_priv->timewait_info);
@@ -818,8 +824,14 @@ static void cm_enter_timewait(struct cm_id_private *cm_id_priv)
*/
cm_id_priv->id.state = IB_CM_TIMEWAIT;
wait_time = cm_convert_to_ms(cm_id_priv->av.timeout);
- queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
- msecs_to_jiffies(wait_time));
+
+ /* Check if the device started its remove_one */
+ spin_lock_irq(&cm.lock);
+ if (!cm_dev->going_down)
+ queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
+ msecs_to_jiffies(wait_time));
+ spin_unlock_irq(&cm.lock);
+
cm_id_priv->timewait_info = NULL;
}
@@ -3305,6 +3317,11 @@ static int cm_establish(struct ib_cm_id *cm_id)
struct cm_work *work;
unsigned long flags;
int ret = 0;
+ struct cm_device *cm_dev;
+
+ cm_dev = ib_get_client_data(cm_id->device, &cm_client);
+ if (!cm_dev)
+ return -ENODEV;
work = kmalloc(sizeof *work, GFP_ATOMIC);
if (!work)
@@ -3343,7 +3360,17 @@ static int cm_establish(struct ib_cm_id *cm_id)
work->remote_id = cm_id->remote_id;
work->mad_recv_wc = NULL;
work->cm_event.event = IB_CM_USER_ESTABLISHED;
- queue_delayed_work(cm.wq, &work->work, 0);
+
+ /* Check if the device started its remove_one */
+ spin_lock_irq(&cm.lock);
+ if (!cm_dev->going_down) {
+ queue_delayed_work(cm.wq, &work->work, 0);
+ } else {
+ kfree(work);
+ ret = -ENODEV;
+ }
+ spin_unlock_irq(&cm.lock);
+
out:
return ret;
}
@@ -3394,6 +3421,7 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent,
enum ib_cm_event_type event;
u16 attr_id;
int paths = 0;
+ int going_down = 0;
switch (mad_recv_wc->recv_buf.mad->mad_hdr.attr_id) {
case CM_REQ_ATTR_ID:
@@ -3452,7 +3480,19 @@ static void cm_recv_handler(struct ib_mad_agent *mad_agent,
work->cm_event.event = event;
work->mad_recv_wc = mad_recv_wc;
work->port = port;
- queue_delayed_work(cm.wq, &work->work, 0);
+
+ /* Check if the device started its remove_one */
+ spin_lock_irq(&cm.lock);
+ if (!port->cm_dev->going_down)
+ queue_delayed_work(cm.wq, &work->work, 0);
+ else
+ going_down = 1;
+ spin_unlock_irq(&cm.lock);
+
+ if (going_down) {
+ kfree(work);
+ ib_free_recv_mad(mad_recv_wc);
+ }
}
static int cm_init_qp_init_attr(struct cm_id_private *cm_id_priv,
@@ -3771,7 +3811,7 @@ static void cm_add_one(struct ib_device *ib_device)
cm_dev->ib_device = ib_device;
cm_get_ack_delay(cm_dev);
-
+ cm_dev->going_down = 0;
cm_dev->device = device_create(&cm_class, &ib_device->dev,
MKDEV(0, 0), NULL,
"%s", ib_device->name);
@@ -3864,14 +3904,23 @@ static void cm_remove_one(struct ib_device *ib_device)
list_del(&cm_dev->list);
write_unlock_irqrestore(&cm.device_lock, flags);
+ spin_lock_irq(&cm.lock);
+ cm_dev->going_down = 1;
+ spin_unlock_irq(&cm.lock);
+
for (i = 1; i <= ib_device->phys_port_cnt; i++) {
if (!rdma_cap_ib_cm(ib_device, i))
continue;
port = cm_dev->port[i-1];
ib_modify_port(ib_device, port->port_num, 0, &port_modify);
- ib_unregister_mad_agent(port->mad_agent);
+ /*
+ * We flush the queue here after the going_down set, this
+ * verify that no new works will be queued in the recv handler,
+ * after that we can call the unregister_mad_agent
+ */
flush_workqueue(cm.wq);
+ ib_unregister_mad_agent(port->mad_agent);
cm_remove_port_fs(port);
}
device_unregister(cm_dev->device);
--
1.7.11.3
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