From: Animesh K Trivedi Date: Tue, 28 Sep 2010 14:44:02 +0000 (+0000) Subject: RDMA/iwcm: Fix hang in uninterruptible wait on cm_id destroy X-Git-Tag: firefly_0821_release~7613^2~3618^2^8~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=26012f0750dd73348b0a0a680a4bee2715d4a334;p=firefly-linux-kernel-4.4.55.git RDMA/iwcm: Fix hang in uninterruptible wait on cm_id destroy A process can get stuck in an uninterruptible wait in the kernel while destroying a cm_id when iw_cm_connect() fails: For example, When creation of a PD fails but the user continues with an attempt to connect to the server without checking the return value, in iw_cm_connect() a NULL qp is found so the call fails. However the IWCM_F_CONNECT_WAIT bit is not cleared. destroy_cm_id() then waits forever for IWCM_F_CONNECT_WAIT to be cleared. The same problem exists on the passive side with the accept call. Fix this by clearing the bit and waking up any waiters in the appropriate spots. Signed-off-by: Animesh Trivedi Acked-by: Steve Wise Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c index bfead5bc25f6..2a1e9ae134b4 100644 --- a/drivers/infiniband/core/iwcm.c +++ b/drivers/infiniband/core/iwcm.c @@ -506,6 +506,8 @@ int iw_cm_accept(struct iw_cm_id *cm_id, qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn); if (!qp) { spin_unlock_irqrestore(&cm_id_priv->lock, flags); + clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags); + wake_up_all(&cm_id_priv->connect_wait); return -EINVAL; } cm_id->device->iwcm->add_ref(qp); @@ -565,6 +567,8 @@ int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param) qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn); if (!qp) { spin_unlock_irqrestore(&cm_id_priv->lock, flags); + clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags); + wake_up_all(&cm_id_priv->connect_wait); return -EINVAL; } cm_id->device->iwcm->add_ref(qp);