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IB/cm: Randomize starting comm ID

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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: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Sean Hefty 2006-08-28 15:15:18 -07:00 committed by Roland Dreier
parent 2b3e258e5d
commit f06d265375
1 changed files with 16 additions and 8 deletions
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24
drivers/infiniband/core/cm.c
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@ -1,5 +1,5 @@
/* /*
* 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 Topspin Corporation. All rights reserved.
* Copyright (c) 2004, 2005 Voltaire Corporation. All rights reserved. * Copyright (c) 2004, 2005 Voltaire Corporation. All rights reserved.
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved. * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@ -41,6 +41,7 @@
#include <linux/idr.h> #include <linux/idr.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/pci.h> #include <linux/pci.h>
#include <linux/random.h>
#include <linux/rbtree.h> #include <linux/rbtree.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/workqueue.h> #include <linux/workqueue.h>
@ -73,6 +74,7 @@ static struct ib_cm {
struct rb_root remote_id_table; struct rb_root remote_id_table;
struct rb_root remote_sidr_table; struct rb_root remote_sidr_table;
struct idr local_id_table; struct idr local_id_table;
__be32 random_id_operand;
struct workqueue_struct *wq; struct workqueue_struct *wq;
} cm; } 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) static int cm_alloc_id(struct cm_id_private *cm_id_priv)
{ {
unsigned long flags; unsigned long flags;
int ret; int ret, id;
static int next_id; static int next_id;
do { do {
spin_lock_irqsave(&cm.lock, flags); spin_lock_irqsave(&cm.lock, flags);
ret = idr_get_new_above(&cm.local_id_table, cm_id_priv, next_id++, ret = idr_get_new_above(&cm.local_id_table, cm_id_priv,
(__force int *) &cm_id_priv->id.local_id); next_id++, &id);
spin_unlock_irqrestore(&cm.lock, flags); spin_unlock_irqrestore(&cm.lock, flags);
} while( (ret == -EAGAIN) && idr_pre_get(&cm.local_id_table, GFP_KERNEL) ); } 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; return ret;
} }
@ -316,7 +320,8 @@ static void cm_free_id(__be32 local_id)
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&cm.lock, 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); 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; 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) {
if (cm_id_priv->id.remote_id == remote_id) if (cm_id_priv->id.remote_id == remote_id)
atomic_inc(&cm_id_priv->refcount); 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); spin_unlock_irqrestore(&cm.lock, flags);
return NULL; return NULL;
} }
cm_id_priv = idr_find(&cm.local_id_table, cm_id_priv = idr_find(&cm.local_id_table, (__force int)
(__force int) timewait_info->work.local_id); (timewait_info->work.local_id ^
cm.random_id_operand));
if (cm_id_priv) { if (cm_id_priv) {
if (cm_id_priv->id.remote_id == remote_id) if (cm_id_priv->id.remote_id == remote_id)
atomic_inc(&cm_id_priv->refcount); 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_qp_table = RB_ROOT;
cm.remote_sidr_table = RB_ROOT; cm.remote_sidr_table = RB_ROOT;
idr_init(&cm.local_id_table); 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); idr_pre_get(&cm.local_id_table, GFP_KERNEL);
cm.wq = create_workqueue("ib_cm"); cm.wq = create_workqueue("ib_cm");