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Commit f06d2653 authored by Sean Hefty's avatar Sean Hefty Committed by Roland Dreier
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IB/cm: Randomize starting comm ID 



Randomize the starting local comm ID to avoid getting a rejected
connection due to a stale connection after a system reboot or
reloading of the ib_cm.

Signed-off-by: default avatarSean Hefty <sean.hefty@intel.com>
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 2b3e258e

drivers/infiniband/core/cm.c

+16 −8
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.

 * Copyright (c) 2004-2006 Intel Corporation.  All rights reserved.

 * Copyright (c) 2004 Topspin Corporation.  All rights reserved.

 * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.

 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -41,6 +41,7 @@ 
#include <linux/idr.h>

#include <linux/interrupt.h>

#include <linux/pci.h>

#include <linux/random.h>

#include <linux/rbtree.h>

#include <linux/spinlock.h>

#include <linux/workqueue.h>
@@ -73,6 +74,7 @@ static struct ib_cm { 
	struct rb_root remote_id_table;

	struct rb_root remote_sidr_table;

	struct idr local_id_table;

	__be32 random_id_operand;

	struct workqueue_struct *wq;

} cm;
@@ -299,15 +301,17 @@ static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av) 
static int cm_alloc_id(struct cm_id_private *cm_id_priv)

{

	unsigned long flags;

	int ret;

	int ret, id;

	static int next_id;



	do {

		spin_lock_irqsave(&cm.lock, flags);

		ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, next_id++,

					(__force int *) &cm_id_priv->id.local_id);

		ret = idr_get_new_above(&cm.local_id_table, cm_id_priv,

					next_id++, &id);

		spin_unlock_irqrestore(&cm.lock, flags);

	} while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) );



	cm_id_priv->id.local_id = (__force __be32) (id ^ cm.random_id_operand);

	return ret;

}
@@ -316,7 +320,8 @@ static void cm_free_id(__be32 local_id) 
	unsigned long flags;



	spin_lock_irqsave(&cm.lock, flags);

	idr_remove(&cm.local_id_table, (__force int) local_id);

	idr_remove(&cm.local_id_table,

		   (__force int) (local_id ^ cm.random_id_operand));

	spin_unlock_irqrestore(&cm.lock, flags);

}
@@ -324,7 +329,8 @@ static struct cm_id_private * cm_get_id(__be32 local_id, __be32 remote_id) 
{

	struct cm_id_private *cm_id_priv;



	cm_id_priv = idr_find(&cm.local_id_table, (__force int) local_id);

	cm_id_priv = idr_find(&cm.local_id_table,

			      (__force int) (local_id ^ cm.random_id_operand));

	if (cm_id_priv) {

		if (cm_id_priv->id.remote_id == remote_id)

			atomic_inc(&cm_id_priv->refcount);
@@ -2082,8 +2088,9 @@ static struct cm_id_private * cm_acquire_rejected_id(struct cm_rej_msg *rej_msg) 
			spin_unlock_irqrestore(&cm.lock, flags);

			return NULL;

		}

		cm_id_priv = idr_find(&cm.local_id_table,

				      (__force int) timewait_info->work.local_id);

		cm_id_priv = idr_find(&cm.local_id_table, (__force int)

				      (timewait_info->work.local_id ^

				       cm.random_id_operand));

		if (cm_id_priv) {

			if (cm_id_priv->id.remote_id == remote_id)

				atomic_inc(&cm_id_priv->refcount);
@@ -3360,6 +3367,7 @@ static int __init ib_cm_init(void) 
	cm.remote_qp_table = RB_ROOT;

	cm.remote_sidr_table = RB_ROOT;

	idr_init(&cm.local_id_table);

	get_random_bytes(&cm.random_id_operand, sizeof cm.random_id_operand);

	idr_pre_get(&cm.local_id_table, GFP_KERNEL);



	cm.wq = create_workqueue("ib_cm");