Commit 81ddb41f authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

RDMA/cm: Allow ib_send_cm_rej() to be done under lock 

The first thing ib_send_cm_rej() does is obtain the lock, so use the usual
unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

While here simplify some of the logic in the implementation.

Link: https://lore.kernel.org/r/20200310092545.251365-14-leon@kernel.org


Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 87cabf3e

drivers/infiniband/core/cm.c

+52 −40
Original line number Diff line number Diff line
@@ -87,6 +87,10 @@ static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv, 
			       const void *private_data, u8 private_data_len);

static int cm_send_drep_locked(struct cm_id_private *cm_id_priv,

			       void *private_data, u8 private_data_len);

static int cm_send_rej_locked(struct cm_id_private *cm_id_priv,

			      enum ib_cm_rej_reason reason, void *ari,

			      u8 ari_length, const void *private_data,

			      u8 private_data_len);



static struct ib_client cm_client = {

	.name   = "cm",
@@ -1060,11 +1064,11 @@ retest: 
	case IB_CM_REQ_SENT:

	case IB_CM_MRA_REQ_RCVD:

		ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);

		spin_unlock_irq(&cm_id_priv->lock);

		ib_send_cm_rej(cm_id, IB_CM_REJ_TIMEOUT,

		cm_send_rej_locked(cm_id_priv, IB_CM_REJ_TIMEOUT,

				   &cm_id_priv->id.device->node_guid,

			       sizeof cm_id_priv->id.device->node_guid,

				   sizeof(cm_id_priv->id.device->node_guid),

				   NULL, 0);

		spin_unlock_irq(&cm_id_priv->lock);

		break;

	case IB_CM_REQ_RCVD:

		if (err == -ENOMEM) {
@@ -1072,9 +1076,10 @@ retest: 
			cm_reset_to_idle(cm_id_priv);

			spin_unlock_irq(&cm_id_priv->lock);

		} else {

			cm_send_rej_locked(cm_id_priv,

					   IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,

					   NULL, 0);

			spin_unlock_irq(&cm_id_priv->lock);

			ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,

				       NULL, 0, NULL, 0);

		}

		break;

	case IB_CM_REP_SENT:
@@ -1084,9 +1089,9 @@ retest: 
	case IB_CM_MRA_REQ_SENT:

	case IB_CM_REP_RCVD:

	case IB_CM_MRA_REP_SENT:

		cm_send_rej_locked(cm_id_priv, IB_CM_REJ_CONSUMER_DEFINED, NULL,

				   0, NULL, 0);

		spin_unlock_irq(&cm_id_priv->lock);

		ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED,

			       NULL, 0, NULL, 0);

		break;

	case IB_CM_ESTABLISHED:

		if (cm_id_priv->qp_type == IB_QPT_XRC_TGT) {
@@ -2899,65 +2904,72 @@ out: 
	return -EINVAL;

}



int ib_send_cm_rej(struct ib_cm_id *cm_id,

		   enum ib_cm_rej_reason reason,

		   void *ari,

		   u8 ari_length,

		   const void *private_data,

static int cm_send_rej_locked(struct cm_id_private *cm_id_priv,

			      enum ib_cm_rej_reason reason, void *ari,

			      u8 ari_length, const void *private_data,

			      u8 private_data_len)

{

	struct cm_id_private *cm_id_priv;

	struct ib_mad_send_buf *msg;

	unsigned long flags;

	int ret;



	lockdep_assert_held(&cm_id_priv->lock);



	if ((private_data && private_data_len > IB_CM_REJ_PRIVATE_DATA_SIZE) ||

	    (ari && ari_length > IB_CM_REJ_ARI_LENGTH))

		return -EINVAL;



	cm_id_priv = container_of(cm_id, struct cm_id_private, id);



	spin_lock_irqsave(&cm_id_priv->lock, flags);

	switch (cm_id->state) {

	switch (cm_id_priv->id.state) {

	case IB_CM_REQ_SENT:

	case IB_CM_MRA_REQ_RCVD:

	case IB_CM_REQ_RCVD:

	case IB_CM_MRA_REQ_SENT:

	case IB_CM_REP_RCVD:

	case IB_CM_MRA_REP_SENT:

		ret = cm_alloc_msg(cm_id_priv, &msg);

		if (!ret)

			cm_format_rej((struct cm_rej_msg *) msg->mad,

				      cm_id_priv, reason, ari, ari_length,

				      private_data, private_data_len);



		cm_reset_to_idle(cm_id_priv);

		ret = cm_alloc_msg(cm_id_priv, &msg);

		if (ret)

			return ret;

		cm_format_rej((struct cm_rej_msg *)msg->mad, cm_id_priv, reason,

			      ari, ari_length, private_data, private_data_len);

		break;

	case IB_CM_REP_SENT:

	case IB_CM_MRA_REP_RCVD:

		ret = cm_alloc_msg(cm_id_priv, &msg);

		if (!ret)

			cm_format_rej((struct cm_rej_msg *) msg->mad,

				      cm_id_priv, reason, ari, ari_length,

				      private_data, private_data_len);



		cm_enter_timewait(cm_id_priv);

		ret = cm_alloc_msg(cm_id_priv, &msg);

		if (ret)

			return ret;

		cm_format_rej((struct cm_rej_msg *)msg->mad, cm_id_priv, reason,

			      ari, ari_length, private_data, private_data_len);

		break;

	default:

		pr_debug("%s: local_id %d, cm_id->state: %d\n", __func__,

			 be32_to_cpu(cm_id_priv->id.local_id), cm_id->state);

		ret = -EINVAL;

		goto out;

			 be32_to_cpu(cm_id_priv->id.local_id),

			 cm_id_priv->id.state);

		return -EINVAL;

	}



	if (ret)

		goto out;



	ret = ib_post_send_mad(msg, NULL);

	if (ret)

	if (ret) {

		cm_free_msg(msg);

		return ret;

	}



out:	spin_unlock_irqrestore(&cm_id_priv->lock, flags);

	return 0;

}



int ib_send_cm_rej(struct ib_cm_id *cm_id, enum ib_cm_rej_reason reason,

		   void *ari, u8 ari_length, const void *private_data,

		   u8 private_data_len)

{

	struct cm_id_private *cm_id_priv =

		container_of(cm_id, struct cm_id_private, id);

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&cm_id_priv->lock, flags);

	ret = cm_send_rej_locked(cm_id_priv, reason, ari, ari_length,

				 private_data, private_data_len);

	spin_unlock_irqrestore(&cm_id_priv->lock, flags);

	return ret;

}

EXPORT_SYMBOL(ib_send_cm_rej);

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