[PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[Monam Agarwal]

This patchset uses following coccinelle script to replace
rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

@@
expression E;
@@
- rcu_assign_pointer(
+ RCU_INIT_POINTER(
E, NULL)

Monam Agarwal (9):
  net/ethernet: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/net/ethernet/broadcom/bnx2.c
  net/ethernet: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
  net: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/net/macvtap.c
  net: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/net/ppp/pptp.c
  net/wireless: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/net/wireless/ath/carl9170/main.c
  scsi: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,
    NULL) in drivers/scsi/libfc/fc_libfc.c
  target: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, 
       NULL) in drivers/target/tcm_fc/tfc_sess.c
  vhost: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,  
      NULL) in drivers/vhost/net.c
  vhost: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,  
      NULL) in drivers/vhost/test.c

 drivers/net/ethernet/broadcom/bnx2.c               |    2 +-
 drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c |    4 ++--
 drivers/net/macvtap.c                              |    8 ++++----
 drivers/net/ppp/pptp.c                             |    2 +-
 drivers/net/wireless/ath/carl9170/main.c           |   12 ++++++------
 drivers/scsi/libfc/fc_libfc.c                      |    4 ++--
 drivers/target/tcm_fc/tfc_sess.c                   |    2 +-
 drivers/vhost/net.c                                |    2 +-
 drivers/vhost/test.c                               |    2 +-
 9 files changed, 19 insertions(+), 19 deletions(-)

-- 
1.7.9.5

[PATCH 1/9] net/ethernet: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/net/ethernet/broadcom/bnx2.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/net/ethernet/broadcom/bnx2.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index 965c723..5eab730 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -409,7 +409,7 @@ static int bnx2_unregister_cnic(struct net_device *dev)
 	mutex_lock(&bp->cnic_lock);
 	cp->drv_state = 0;
 	bnapi->cnic_present = 0;
-	rcu_assign_pointer(bp->cnic_ops, NULL);
+	RCU_INIT_POINTER(bp->cnic_ops, NULL);
 	mutex_unlock(&bp->cnic_lock);
 	synchronize_rcu();
 	return 0;
-- 
1.7.9.5

[PATCH 2/9] net/ethernet: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
index da5a5d9..a7ec886 100644
--- a/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
+++ b/drivers/net/ethernet/chelsio/cxgb3/cxgb3_offload.c
@@ -1300,7 +1300,7 @@ int cxgb3_offload_activate(struct adapter *adapter)
 
 out_free_l2t:
 	t3_free_l2t(L2DATA(dev));
-	rcu_assign_pointer(dev->l2opt, NULL);
+	RCU_INIT_POINTER(dev->l2opt, NULL);
 out_free:
 	kfree(t);
 	return err;
@@ -1328,7 +1328,7 @@ void cxgb3_offload_deactivate(struct adapter *adapter)
 	rcu_read_lock();
 	d = L2DATA(tdev);
 	rcu_read_unlock();
-	rcu_assign_pointer(tdev->l2opt, NULL);
+	RCU_INIT_POINTER(tdev->l2opt, NULL);
 	call_rcu(&d->rcu_head, clean_l2_data);
 	if (t->nofail_skb)
 		kfree_skb(t->nofail_skb);
-- 
1.7.9.5

[PATCH 3/9] net: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/net/macvtap.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/net/macvtap.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 1b7082d..7c88d13 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -145,8 +145,8 @@ static void macvtap_put_queue(struct macvtap_queue *q)
 	if (vlan) {
 		int index = get_slot(vlan, q);
 
-		rcu_assign_pointer(vlan->taps[index], NULL);
-		rcu_assign_pointer(q->vlan, NULL);
+		RCU_INIT_POINTER(vlan->taps[index], NULL);
+		RCU_INIT_POINTER(q->vlan, NULL);
 		sock_put(&q->sk);
 		--vlan->numvtaps;
 	}
@@ -223,8 +223,8 @@ static void macvtap_del_queues(struct net_device *dev)
 					      lockdep_is_held(&macvtap_lock));
 		if (q) {
 			qlist[j++] = q;
-			rcu_assign_pointer(vlan->taps[i], NULL);
-			rcu_assign_pointer(q->vlan, NULL);
+			RCU_INIT_POINTER(vlan->taps[i], NULL);
+			RCU_INIT_POINTER(q->vlan, NULL);
 			vlan->numvtaps--;
 		}
 	}
-- 
1.7.9.5

[PATCH 4/9] net: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/net/ppp/pptp.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/net/ppp/pptp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 89f829f..ede899c 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -162,7 +162,7 @@ static void del_chan(struct pppox_sock *sock)
 {
 	spin_lock(&chan_lock);
 	clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap);
-	rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], NULL);
+	RCU_INIT_POINTER(callid_sock[sock->proto.pptp.src_addr.call_id], NULL);
 	spin_unlock(&chan_lock);
 	synchronize_rcu();
 }
-- 
1.7.9.5

[PATCH 5/9] net/wireless: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/net/wireless/ath/carl9170/main.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/net/wireless/ath/carl9170/main.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c
index f06e069..5518592 100644
--- a/drivers/net/wireless/ath/carl9170/main.c
+++ b/drivers/net/wireless/ath/carl9170/main.c
@@ -446,7 +446,7 @@ static void carl9170_op_stop(struct ieee80211_hw *hw)
 
 	mutex_lock(&ar->mutex);
 	if (IS_ACCEPTING_CMD(ar)) {
-		rcu_assign_pointer(ar->beacon_iter, NULL);
+		RCU_INIT_POINTER(ar->beacon_iter, NULL);
 
 		carl9170_led_set_state(ar, 0);
 
@@ -678,7 +678,7 @@ unlock:
 		vif_priv->active = false;
 		bitmap_release_region(&ar->vif_bitmap, vif_id, 0);
 		ar->vifs--;
-		rcu_assign_pointer(ar->vif_priv[vif_id].vif, NULL);
+		RCU_INIT_POINTER(ar->vif_priv[vif_id].vif, NULL);
 		list_del_rcu(&vif_priv->list);
 		mutex_unlock(&ar->mutex);
 		synchronize_rcu();
@@ -716,7 +716,7 @@ static void carl9170_op_remove_interface(struct ieee80211_hw *hw,
 	WARN_ON(vif_priv->enable_beacon);
 	vif_priv->enable_beacon = false;
 	list_del_rcu(&vif_priv->list);
-	rcu_assign_pointer(ar->vif_priv[id].vif, NULL);
+	RCU_INIT_POINTER(ar->vif_priv[id].vif, NULL);
 
 	if (vif == main_vif) {
 		rcu_read_unlock();
@@ -1258,7 +1258,7 @@ static int carl9170_op_sta_add(struct ieee80211_hw *hw,
 		}
 
 		for (i = 0; i < CARL9170_NUM_TID; i++)
-			rcu_assign_pointer(sta_info->agg[i], NULL);
+			RCU_INIT_POINTER(sta_info->agg[i], NULL);
 
 		sta_info->ampdu_max_len = 1 << (3 + sta->ht_cap.ampdu_factor);
 		sta_info->ht_sta = true;
@@ -1285,7 +1285,7 @@ static int carl9170_op_sta_remove(struct ieee80211_hw *hw,
 			struct carl9170_sta_tid *tid_info;
 
 			tid_info = rcu_dereference(sta_info->agg[i]);
-			rcu_assign_pointer(sta_info->agg[i], NULL);
+			RCU_INIT_POINTER(sta_info->agg[i], NULL);
 
 			if (!tid_info)
 				continue;
@@ -1398,7 +1398,7 @@ static int carl9170_op_ampdu_action(struct ieee80211_hw *hw,
 			spin_unlock_bh(&ar->tx_ampdu_list_lock);
 		}
 
-		rcu_assign_pointer(sta_info->agg[tid], NULL);
+		RCU_INIT_POINTER(sta_info->agg[tid], NULL);
 		rcu_read_unlock();
 
 		ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
-- 
1.7.9.5

[PATCH 6/9] scsi: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/scsi/libfc/fc_libfc.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/scsi/libfc/fc_libfc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index b773512..ee74eec 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -297,9 +297,9 @@ void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
 	BUG_ON(type >= FC_FC4_PROV_SIZE);
 	mutex_lock(&fc_prov_mutex);
 	if (prov->recv)
-		rcu_assign_pointer(fc_passive_prov[type], NULL);
+		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
 	else
-		rcu_assign_pointer(fc_active_prov[type], NULL);
+		RCU_INIT_POINTER(fc_active_prov[type], NULL);
 	mutex_unlock(&fc_prov_mutex);
 	synchronize_rcu();
 }
-- 
1.7.9.5

[PATCH 7/9] target: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/target/tcm_fc/tfc_sess.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/target/tcm_fc/tfc_sess.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c
index 3269213..95fb826 100644
--- a/drivers/target/tcm_fc/tfc_sess.c
+++ b/drivers/target/tcm_fc/tfc_sess.c
@@ -110,7 +110,7 @@ static void ft_tport_delete(struct ft_tport *tport)
 	ft_sess_delete_all(tport);
 	lport = tport->lport;
 	BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
-	rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);
+	RCU_INIT_POINTER(lport->prov[FC_TYPE_FCP], NULL);
 
 	tpg = tport->tpg;
 	if (tpg) {
-- 
1.7.9.5

[PATCH 8/9] vhost: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in drivers/vhost/net.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/vhost/net.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 882a51f..b243e06 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -556,7 +556,7 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
 	sock = rcu_dereference_protected(vq->private_data,
 					 lockdep_is_held(&vq->mutex));
 	vhost_net_disable_vq(n, vq);
-	rcu_assign_pointer(vq->private_data, NULL);
+	RCU_INIT_POINTER(vq->private_data, NULL);
 	mutex_unlock(&vq->mutex);
 	return sock;
 }
-- 
1.7.9.5

[PATCH 9/9] vhost: Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) in test.c

[Monam Agarwal]

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
---
 drivers/vhost/test.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c
index fc9a1d7..82b3744 100644
--- a/drivers/vhost/test.c
+++ b/drivers/vhost/test.c
@@ -128,7 +128,7 @@ static void *vhost_test_stop_vq(struct vhost_test *n,
 	mutex_lock(&vq->mutex);
 	private = rcu_dereference_protected(vq->private_data,
 					 lockdep_is_held(&vq->mutex));
-	rcu_assign_pointer(vq->private_data, NULL);
+	RCU_INIT_POINTER(vq->private_data, NULL);
 	mutex_unlock(&vq->mutex);
 	return private;
 }
-- 
1.7.9.5

Re: [PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[Arend van Spriel]

On 20/03/14 15:37, Monam Agarwal wrote:
> This patchset uses following coccinelle script to replace
> rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)
>
> @@
> expression E;
> @@
> - rcu_assign_pointer(
> + RCU_INIT_POINTER(
> E, NULL)

I am not very familiar with rcu functionality nor coccinelle, but it 
looks too generic. I would think only NULL assignments during 
initialization should use RCU_INIT_POINTER(). The first patch in the 
series does it in a function called unregister_...(). Is it really ok to 
do there?

Gr. AvS

Re: [PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[Paul E. McKenney]

On Thu, Mar 20, 2014 at 03:58:52PM +0100, Arend van Spriel wrote:
> On 20/03/14 15:37, Monam Agarwal wrote:
> >This patchset uses following coccinelle script to replace
> >rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)
> >
> >@@
> >expression E;
> >@@
> >- rcu_assign_pointer(
> >+ RCU_INIT_POINTER(
> >E, NULL)
> 
> I am not very familiar with rcu functionality nor coccinelle, but it
> looks too generic. I would think only NULL assignments during
> initialization should use RCU_INIT_POINTER(). The first patch in the
> series does it in a function called unregister_...(). Is it really
> ok to do there?

Hello, Arend,

The thing that rcu_assign_pointer() is doing is ensuring that the
initialization of a structure is carried out before storing a pointer
to that structure.  In the case of the NULL pointer, there is no
structure to initialize, so nothing need be ordered.

So, yes, rcu_assign_pointer(p, NULL) can always safely be converted to
RCU_INIT_POINTER(p, NULL).  ;-)

							Thanx, Paul

Re: [PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[Arend van Spriel]

On 03/20/14 16:06, Paul E. McKenney wrote:
> On Thu, Mar 20, 2014 at 03:58:52PM +0100, Arend van Spriel wrote:
>> On 20/03/14 15:37, Monam Agarwal wrote:
>>> This patchset uses following coccinelle script to replace
>>> rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)
>>>
>>> @@
>>> expression E;
>>> @@
>>> - rcu_assign_pointer(
>>> + RCU_INIT_POINTER(
>>> E, NULL)
>>
>> I am not very familiar with rcu functionality nor coccinelle, but it
>> looks too generic. I would think only NULL assignments during
>> initialization should use RCU_INIT_POINTER(). The first patch in the
>> series does it in a function called unregister_...(). Is it really
>> ok to do there?
>
> Hello, Arend,
>
> The thing that rcu_assign_pointer() is doing is ensuring that the
> initialization of a structure is carried out before storing a pointer
> to that structure.  In the case of the NULL pointer, there is no
> structure to initialize, so nothing need be ordered.
>
> So, yes, rcu_assign_pointer(p, NULL) can always safely be converted to
> RCU_INIT_POINTER(p, NULL).  ;-)

And so I learned something today. Thanks, Paul. I really should pick up 
reading rcu material again. It ended up in a dusty corner upstairs.

Thanks,
Arend

Re: [PATCH 0/9] Replace rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)

[David Miller]

From: Monam Agarwal <monamagarwal123@gmail.com>
Date: Thu, 20 Mar 2014 20:07:10 +0530

> This patchset uses following coccinelle script to replace
> rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x,NULL)
> 
> @@
> expression E;
> @@
> - rcu_assign_pointer(
> + RCU_INIT_POINTER(
> E, NULL)

None of the networking patches apply to my net-next tree, in fact
nearly all of these case are already using RCU_INIT_POINTER()
properly.