IPoIB: Disable NAPI while CQ is being drained
If NAPI is enabled while IPoIB's CQ is being drained, it creates a
race on priv->ibwc between ipoib_poll() and ipoib_drain_cq(), leading
to memory corruption.
The solution is to enable/disable NAPI in ipoib_ib_dev_{open/stop}()
instead of in ipoib_{open/stop}(), and sync NAPI on the INITIALIZED
flag instead on the ADMIN_UP flag. This way NAPI will be disabled when
ipoib_drain_cq() is called.
This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=1587>.
Signed-off-by: Yossi Etigin <yosefe@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index da60827..e7e5adf 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -685,7 +685,8 @@
queue_delayed_work(ipoib_workqueue, &priv->ah_reap_task,
round_jiffies_relative(HZ));
- set_bit(IPOIB_FLAG_INITIALIZED, &priv->flags);
+ if (!test_and_set_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
+ napi_enable(&priv->napi);
return 0;
}
@@ -804,7 +805,8 @@
struct ipoib_tx_buf *tx_req;
int i;
- clear_bit(IPOIB_FLAG_INITIALIZED, &priv->flags);
+ if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
+ napi_disable(&priv->napi);
ipoib_cm_dev_stop(dev);