diff options
| author | Michael S. Tsirkin <mst@mellanox.co.il> | 2006-03-20 10:08:25 -0800 |
|---|---|---|
| committer | Roland Dreier <rolandd@cisco.com> | 2006-03-20 10:08:25 -0800 |
| commit | dc05980dd736bfbe5b2524b463e5f098e67a64e9 (patch) | |
| tree | 87f212e24ee4362a5e670418b32bd0c959d3f1c6 /drivers/infiniband | |
| parent | bf17c1c7cc9250d7c3c01b0ae898aefa1853535a (diff) | |
| download | blackbird-op-linux-dc05980dd736bfbe5b2524b463e5f098e67a64e9.tar.gz blackbird-op-linux-dc05980dd736bfbe5b2524b463e5f098e67a64e9.zip | |
IB/mad: Fix oopsable race on device removal
Fix an oopsable race debugged by Eli Cohen <eli@mellanox.co.il>:
After removing the port from port_list, ib_mad_port_close flushes
port_priv->wq before destroying the special QPs. This means that a
completion event could arrive, and queue a new work in this work queue
after flush.
This patch also removes an unnecessary flush_workqueue():
destroy_workqueue() already includes a flush.
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/mad.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c index 16549add8e8f..f7854b65fd55 100644 --- a/drivers/infiniband/core/mad.c +++ b/drivers/infiniband/core/mad.c @@ -2364,8 +2364,12 @@ static void timeout_sends(void *data) static void ib_mad_thread_completion_handler(struct ib_cq *cq, void *arg) { struct ib_mad_port_private *port_priv = cq->cq_context; + unsigned long flags; - queue_work(port_priv->wq, &port_priv->work); + spin_lock_irqsave(&ib_mad_port_list_lock, flags); + if (!list_empty(&port_priv->port_list)) + queue_work(port_priv->wq, &port_priv->work); + spin_unlock_irqrestore(&ib_mad_port_list_lock, flags); } /* @@ -2677,18 +2681,23 @@ static int ib_mad_port_open(struct ib_device *device, } INIT_WORK(&port_priv->work, ib_mad_completion_handler, port_priv); + spin_lock_irqsave(&ib_mad_port_list_lock, flags); + list_add_tail(&port_priv->port_list, &ib_mad_port_list); + spin_unlock_irqrestore(&ib_mad_port_list_lock, flags); + ret = ib_mad_port_start(port_priv); if (ret) { printk(KERN_ERR PFX "Couldn't start port\n"); goto error9; } - spin_lock_irqsave(&ib_mad_port_list_lock, flags); - list_add_tail(&port_priv->port_list, &ib_mad_port_list); - spin_unlock_irqrestore(&ib_mad_port_list_lock, flags); return 0; error9: + spin_lock_irqsave(&ib_mad_port_list_lock, flags); + list_del_init(&port_priv->port_list); + spin_unlock_irqrestore(&ib_mad_port_list_lock, flags); + destroy_workqueue(port_priv->wq); error8: destroy_mad_qp(&port_priv->qp_info[1]); @@ -2725,11 +2734,9 @@ static int ib_mad_port_close(struct ib_device *device, int port_num) printk(KERN_ERR PFX "Port %d not found\n", port_num); return -ENODEV; } - list_del(&port_priv->port_list); + list_del_init(&port_priv->port_list); spin_unlock_irqrestore(&ib_mad_port_list_lock, flags); - /* Stop processing completions. */ - flush_workqueue(port_priv->wq); destroy_workqueue(port_priv->wq); destroy_mad_qp(&port_priv->qp_info[1]); destroy_mad_qp(&port_priv->qp_info[0]); |
