bonding: simplify and use RCU protection for 3ad xmit path

The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb
(bonding: initial RCU conversion) has convert the roundrobin, active-backup, broadcast and xor xmit path to rcu protection, the performance will be better for these mode, so this time, convert xmit path for 3ad mode.

Suggested-by Nikolay Aleksandrov <[email protected]>

Suggested-by Veaceslav Falico <[email protected]>

Signed-off-by Ding Tianhong <[email protected]>

Signed-off-by Wang Yufen <[email protected]>

Cc Nikolay Aleksandrov <[email protected]>

Cc Veaceslav Falico <[email protected]>

---
drivers/net/bonding/bond_3ad.c | 32 ++++++++++++++------------------ drivers/net/bonding/bonding.h | 32 +++++++++++++++++++++++++++++++-

2 files changed, 45 insertions(+), 19 deletions(-)

drivers/net/bonding/bond_3ad.c +14 -17

index 0d8f427..13f1deb 100644
@@ -143,7 +143,7 @@ static inline struct bonding *__get_bond_by_port(struct port *port)
 */
 static inline struct port *__get_first_port(struct bonding *bond)
 {
-	struct slave *first_slave = bond_first_slave(bond);
+	struct slave *first_slave = bond_first_slave_rcu(bond);
 
 	return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL;
 }

@@ -163,7 +163,7 @@ static inline struct port *__get_next_port(struct port *port)
 	// If there's no bond for this port, or this is the last slave
 	if (bond == NULL)
 		return NULL;
-	slave_next = bond_next_slave(bond, slave);
+	slave_next = bond_next_slave_rcu(bond, slave);
 	if (!slave_next || bond_is_first_slave(bond, slave_next))
 		return NULL;
 

@@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info)
 
 int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 {
-	struct slave *slave, *start_at;
 	struct bonding *bond = netdev_priv(dev);
+	struct slave *slave;
 	int slave_agg_no;
 	int slaves_in_agg;
 	int agg_id;
-	int i;
 	struct ad_info ad_info;
 	int res = 1;
 
-	read_lock(&bond->lock);
 	if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
 		pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n",
 			 dev->name);

@@ -2444,13 +2442,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 
 	slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg);
 
-	bond_for_each_slave(bond, slave) {
+	bond_for_each_slave_rcu(bond, slave) {
 		struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
 		if (agg && (agg->aggregator_identifier == agg_id)) {
-			slave_agg_no--;
-			if (slave_agg_no < 0)
-				break;
+			if (--slave_agg_no < 0) {
+				if (SLAVE_IS_OK(slave)) {
+					res = bond_dev_queue_xmit(bond,
+						skb, slave->dev);
+					goto out;
+				}
+			}
 		}
 	}
 

@@ -2460,23 +2462,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 		goto out;
 	}
 
-	start_at = slave;
-
-	bond_for_each_slave_from(bond, slave, i, start_at) {
-		int slave_agg_id = 0;
+	bond_for_each_slave_rcu(bond, slave) {
 		struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
-		if (agg)
-			slave_agg_id = agg->aggregator_identifier;
-
-		if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) {
+		if (SLAVE_IS_OK(slave) && agg &&
+			agg->aggregator_identifier == agg_id) {
 			res = bond_dev_queue_xmit(bond, skb, slave->dev);
 			break;
 		}
 	}
 

out:

drivers/net/bonding/bond_3ad.c +0 -1

-	read_unlock(&bond->lock);

	if (res) {
		/* no suitable interface, frame not sent */
		kfree_skb(skb);

drivers/net/bonding/bonding.h +12 -1

index f7ab161..f013b12 100644
@@ -74,13 +74,34 @@
 /* slave list primitives */
 #define bond_to_slave(ptr) list_entry(ptr, struct slave, list)
 
+/* slave list primitives, Caller must hold rcu_read_lock */
+#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list)
+
+/* bond_is_empty return NULL if slave list is empty*/
+#define bond_is_empty(bond) \
+	(list_empty(&(bond)->slave_list))
+
+/* bond_is_empty_rcu return NULL if slave list is empty*/
+#define bond_is_empty_rcu(bond) \
+	(!list_first_or_null_rcu(&(bond)->slave_list, struct slave, list))
+
 /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */
 #define bond_first_slave(bond) \
 	list_first_entry_or_null(&(bond)->slave_list, struct slave, list)
 #define bond_last_slave(bond) \
-	(list_empty(&(bond)->slave_list) ? NULL : \
+	(bond_is_empty(bond) ? NULL : \
 					   bond_to_slave((bond)->slave_list.prev))

drivers/net/bonding/bonding.h +10 -0

+
 #define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list)
 #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list)
 

@@ -93,6 +114,15 @@
 	(bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \
 					  bond_to_slave((pos)->list.prev))
 
+/* Since bond_first/last_slave_rcu can return NULL, these can return NULL too */
+#define bond_next_slave_rcu(bond, pos) \
+	(bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \
+					 bond_to_slave_rcu((pos)->list.next))
+
+#define bond_prev_slave_rcu(bond, pos) \
+	(bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \
+					  bond_to_slave_rcu((pos)->list.prev))
+
 /**
 * bond_for_each_slave_from - iterate the slaves list from a starting point
 * @bond:	the bond holding this list.

Signature · 1 line

1.8.2.1

Really?

No. Again - take a look at list_first_or_null_rcu. And its comments.

I'm sorry that I'm acting that negatively... But if that gets accepted - I'll have days of nightmares.

Try to understand how RCU works, please, before sending patches using it.

Quoted 142 lines · Ding Tianhong

The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb
(bonding: initial RCU conversion) has convert the roundrobin, active-backup, broadcast and xor xmit path to rcu protection, the performance will be better for these mode, so this time, convert xmit path for 3ad mode.

Suggested-by Nikolay Aleksandrov <[email protected]>

Suggested-by Veaceslav Falico <[email protected]>

Signed-off-by Ding Tianhong <[email protected]>

Signed-off-by Wang Yufen <[email protected]>

Cc Nikolay Aleksandrov <[email protected]>

Cc Veaceslav Falico <[email protected]>

---
drivers/net/bonding/bond_3ad.c | 32 ++++++++++++++------------------ drivers/net/bonding/bonding.h | 32 +++++++++++++++++++++++++++++++-

2 files changed, 45 insertions(+), 19 deletions(-)

drivers/net/bonding/bond_3ad.c +1 -1

index 0d8f427..13f1deb 100644
@@ -143,7 +143,7 @@ static inline struct bonding 
 *__get_bond_by_port(struct port *port)
 */
 static inline struct port *__get_first_port(struct bonding *bond)
 {
- struct slave *first_slave = bond_first_slave(bond);
+ struct slave *first_slave = bond_first_slave_rcu(bond);
 
 return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL;

}

drivers/net/bonding/bond_3ad.c +2 -4

@@ -163,7 +163,7 @@ static inline struct port *__get_next_port(struct 
 port *port)
 // If there's no bond for this port, or this is the last slave
 if (bond == NULL)
 return NULL;
- slave_next = bond_next_slave(bond, slave);
+ slave_next = bond_next_slave_rcu(bond, slave);
 if (!slave_next || bond_is_first_slave(bond, slave_next))
 return NULL;

@@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct 
 bonding *bond, struct ad_info *ad_info)
 
 int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 {
- struct slave *slave, *start_at;
 struct bonding *bond = netdev_priv(dev);
+ struct slave *slave;
 int slave_agg_no;
 int slaves_in_agg;
 int agg_id;
- int i;
 struct ad_info ad_info;
 int res = 1;
 
- read_lock(&bond->lock);
 if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
 pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n",

dev->name);

drivers/net/bonding/bond_3ad.c +11 -12

@@ -2444,13 +2442,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, 
 struct net_device *dev)
 
 slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg);
 
- bond_for_each_slave(bond, slave) {
+ bond_for_each_slave_rcu(bond, slave) {
 struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
 if (agg && (agg->aggregator_identifier == agg_id)) {
- slave_agg_no--;
- if (slave_agg_no < 0)
- break;
+ if (--slave_agg_no < 0) {
+ if (SLAVE_IS_OK(slave)) {
+ res = bond_dev_queue_xmit(bond,
+ skb, slave->dev);
+ goto out;
+ }
+ }
 }
 }

@@ -2460,23 +2462,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, 
 struct net_device *dev)
 goto out;
 }
 
- start_at = slave;
-
- bond_for_each_slave_from(bond, slave, i, start_at) {
- int slave_agg_id = 0;
+ bond_for_each_slave_rcu(bond, slave) {
 struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
- if (agg)
- slave_agg_id = agg->aggregator_identifier;
-
- if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) {
+ if (SLAVE_IS_OK(slave) && agg &&
+ agg->aggregator_identifier == agg_id) {
 res = bond_dev_queue_xmit(bond, skb, slave->dev);
 break;
 }
 }
 

out:
- read_unlock(&bond->lock);
if (res) {
/* no suitable interface, frame not sent */
kfree_skb(skb);

drivers/net/bonding/bonding.h +14 -1

index f7ab161..f013b12 100644
@@ -74,13 +74,34 @@
 /* slave list primitives */
 #define bond_to_slave(ptr) list_entry(ptr, struct slave, list)
 
+/* slave list primitives, Caller must hold rcu_read_lock */
+#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list)
+
+/* bond_is_empty return NULL if slave list is empty*/
+#define bond_is_empty(bond) \
+ (list_empty(&(bond)->slave_list))
+
+/* bond_is_empty_rcu return NULL if slave list is empty*/
+#define bond_is_empty_rcu(bond) \
+ (!list_first_or_null_rcu(&(bond)->slave_list, struct slave, list))
+
 /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */
 #define bond_first_slave(bond) \
 list_first_entry_or_null(&(bond)->slave_list, struct slave, list)
 #define bond_last_slave(bond) \
- (list_empty(&(bond)->slave_list) ? NULL : \
+ (bond_is_empty(bond) ? NULL : \
 bond_to_slave((bond)->slave_list.prev))
 
+/**
+ * IMPORTANT: bond_first/last_slave_rcu can return NULL in case of 

an empty list
+ * Caller must hold rcu_read_lock
+ */

drivers/net/bonding/bonding.h line 103

Quoted 5 lines

drivers/net/bonding/bonding.h +5 -0

+#define bond_first_slave_rcu(bond) \
+ list_first_or_null_rcu(&(bond)->slave_list, struct slave, list)
+#define bond_last_slave_rcu(bond) \
+ (bond_is_empty_rcu(bond) ? NULL : \
+ bond_to_slave_rcu((bond)->slave_list.prev))

Really?

No. Again - take a look at list_first_or_null_rcu. And its comments.

I'm sorry that I'm acting that negatively... But if that gets accepted - I'll have days of nightmares.

Try to understand how RCU works, please, before sending patches using it.

Quoted 26 lines

+
#define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list) #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list)

drivers/net/bonding/bonding.h +1 -0

@@ -93,6 +114,15 @@
 (bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \
 bond_to_slave((pos)->list.prev))
 
+/* Since bond_first/last_slave_rcu can return NULL, these can return 

NULL too */

drivers/net/bonding/bonding.h +8 -0

+#define bond_next_slave_rcu(bond, pos) \
+ (bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \
+ bond_to_slave_rcu((pos)->list.next))
+
+#define bond_prev_slave_rcu(bond, pos) \
+ (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \
+ bond_to_slave_rcu((pos)->list.prev))
+

/**
* bond_for_each_slave_from - iterate the slaves list from a starting point
* @bond: the bond holding this list.

Signature · 1 line

1.8.2.1

Signature · 3 lines

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

Quoted 151 lines · Veaceslav Falico

Quoted 142 lines · Ding Tianhong

The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb
(bonding: initial RCU conversion) has convert the roundrobin, active-backup, broadcast and xor xmit path to rcu protection, the performance will be better for these mode, so this time, convert xmit path for 3ad mode.

Suggested-by Nikolay Aleksandrov <[email protected]>

Suggested-by Veaceslav Falico <[email protected]>

Signed-off-by Ding Tianhong <[email protected]>

Signed-off-by Wang Yufen <[email protected]>

Cc Nikolay Aleksandrov <[email protected]>

Cc Veaceslav Falico <[email protected]>

---
drivers/net/bonding/bond_3ad.c | 32 ++++++++++++++------------------ drivers/net/bonding/bonding.h | 32 +++++++++++++++++++++++++++++++-

2 files changed, 45 insertions(+), 19 deletions(-)

drivers/net/bonding/bond_3ad.c +1 -1

index 0d8f427..13f1deb 100644
@@ -143,7 +143,7 @@ static inline struct bonding 
 *__get_bond_by_port(struct port *port)
 */
 static inline struct port *__get_first_port(struct bonding *bond)
 {
- struct slave *first_slave = bond_first_slave(bond);
+ struct slave *first_slave = bond_first_slave_rcu(bond);
 
 return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL;

}

drivers/net/bonding/bond_3ad.c +2 -4

@@ -163,7 +163,7 @@ static inline struct port 
 *__get_next_port(struct port *port)
 // If there's no bond for this port, or this is the last slave
 if (bond == NULL)
 return NULL;
- slave_next = bond_next_slave(bond, slave);
+ slave_next = bond_next_slave_rcu(bond, slave);
 if (!slave_next || bond_is_first_slave(bond, slave_next))
 return NULL;

@@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct 
 bonding *bond, struct ad_info *ad_info)
 
 int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 {
- struct slave *slave, *start_at;
 struct bonding *bond = netdev_priv(dev);
+ struct slave *slave;
 int slave_agg_no;
 int slaves_in_agg;
 int agg_id;
- int i;
 struct ad_info ad_info;
 int res = 1;
 
- read_lock(&bond->lock);
 if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
 pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n",

dev->name);

drivers/net/bonding/bond_3ad.c +11 -12

@@ -2444,13 +2442,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, 
 struct net_device *dev)
 
 slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg);
 
- bond_for_each_slave(bond, slave) {
+ bond_for_each_slave_rcu(bond, slave) {
 struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
 if (agg && (agg->aggregator_identifier == agg_id)) {
- slave_agg_no--;
- if (slave_agg_no < 0)
- break;
+ if (--slave_agg_no < 0) {
+ if (SLAVE_IS_OK(slave)) {
+ res = bond_dev_queue_xmit(bond,
+ skb, slave->dev);
+ goto out;
+ }
+ }
 }
 }

@@ -2460,23 +2462,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, 
 struct net_device *dev)
 goto out;
 }
 
- start_at = slave;
-
- bond_for_each_slave_from(bond, slave, i, start_at) {
- int slave_agg_id = 0;
+ bond_for_each_slave_rcu(bond, slave) {
 struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
- if (agg)
- slave_agg_id = agg->aggregator_identifier;
-
- if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) {
+ if (SLAVE_IS_OK(slave) && agg &&
+ agg->aggregator_identifier == agg_id) {
 res = bond_dev_queue_xmit(bond, skb, slave->dev);
 break;
 }
 }
 

out:
- read_unlock(&bond->lock);
if (res) {
/* no suitable interface, frame not sent */
kfree_skb(skb);

drivers/net/bonding/bonding.h +14 -1

index f7ab161..f013b12 100644
@@ -74,13 +74,34 @@
 /* slave list primitives */
 #define bond_to_slave(ptr) list_entry(ptr, struct slave, list)
 
+/* slave list primitives, Caller must hold rcu_read_lock */
+#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list)
+
+/* bond_is_empty return NULL if slave list is empty*/
+#define bond_is_empty(bond) \
+ (list_empty(&(bond)->slave_list))
+
+/* bond_is_empty_rcu return NULL if slave list is empty*/
+#define bond_is_empty_rcu(bond) \
+ (!list_first_or_null_rcu(&(bond)->slave_list, struct slave, list))
+
 /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */
 #define bond_first_slave(bond) \
 list_first_entry_or_null(&(bond)->slave_list, struct slave, list)
 #define bond_last_slave(bond) \
- (list_empty(&(bond)->slave_list) ? NULL : \
+ (bond_is_empty(bond) ? NULL : \
 bond_to_slave((bond)->slave_list.prev))
 
+/**
+ * IMPORTANT: bond_first/last_slave_rcu can return NULL in case of 

an empty list
+ * Caller must hold rcu_read_lock
+ */

drivers/net/bonding/bonding.h line 103

Quoted 5 lines

drivers/net/bonding/bonding.h +5 -0

+#define bond_first_slave_rcu(bond) \
+ list_first_or_null_rcu(&(bond)->slave_list, struct slave, list)
+#define bond_last_slave_rcu(bond) \
+ (bond_is_empty_rcu(bond) ? NULL : \
+ bond_to_slave_rcu((bond)->slave_list.prev))

Really?

Quoted 7 lines

No. Again - take a look at list_first_or_null_rcu. And its comments.

I'm sorry that I'm acting that negatively... But if that gets accepted - I'll have days of nightmares.

Try to understand how RCU works, please, before sending patches using it.

I am sad to here that, I think I had good understand of rcu, but maybe miss something. #define bond_first_slave_rcu(bond) \
(bond_is_empty_rcu(bond) ? NULL : \
bond_to_slave_rcu((bond)->slave_list.next))

vs
list_first_or_null_rcu(&(bond)->slave_list, struct slave, list)

maybe the first one is confort you, but I think the second is racy and simple, maybe I still miss something, I need a coffee to clear up.

Quoted 32 lines

Quoted 27 lines

+
#define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list) #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list)

drivers/net/bonding/bonding.h +1 -0

@@ -93,6 +114,15 @@
 (bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \
 bond_to_slave((pos)->list.prev))
 
+/* Since bond_first/last_slave_rcu can return NULL, these can 

return NULL too */

drivers/net/bonding/bonding.h +8 -0

+#define bond_next_slave_rcu(bond, pos) \
+ (bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \
+ bond_to_slave_rcu((pos)->list.next))
+
+#define bond_prev_slave_rcu(bond, pos) \
+ (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \
+ bond_to_slave_rcu((pos)->list.prev))
+

/**
* bond_for_each_slave_from - iterate the slaves list from a starting point
* @bond: the bond holding this list.

Signature · 1 line

1.8.2.1

Signature · 3 lines

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html

Quoted 131 lines · Ding Tianhong

The commit 278b20837511776dc9d5f6ee1c7fabd5479838bb
(bonding: initial RCU conversion) has convert the roundrobin, active-backup, broadcast and xor xmit path to rcu protection, the performance will be better for these mode, so this time, convert xmit path for 3ad mode.

Suggested-by Nikolay Aleksandrov <[email protected]>

Suggested-by Veaceslav Falico <[email protected]>

Signed-off-by Ding Tianhong <[email protected]>

Signed-off-by Wang Yufen <[email protected]>

Cc Nikolay Aleksandrov <[email protected]>

Cc Veaceslav Falico <[email protected]>

---
drivers/net/bonding/bond_3ad.c | 32 ++++++++++++++------------------ drivers/net/bonding/bonding.h | 32 +++++++++++++++++++++++++++++++-

2 files changed, 45 insertions(+), 19 deletions(-)

drivers/net/bonding/bond_3ad.c +14 -17

index 0d8f427..13f1deb 100644
@@ -143,7 +143,7 @@ static inline struct bonding *__get_bond_by_port(struct port *port)
 */
 static inline struct port *__get_first_port(struct bonding *bond)
 {
-    struct slave *first_slave = bond_first_slave(bond);
+    struct slave *first_slave = bond_first_slave_rcu(bond);
 
    return first_slave ? &(SLAVE_AD_INFO(first_slave).port) : NULL;
 }

@@ -163,7 +163,7 @@ static inline struct port *__get_next_port(struct port *port)
    // If there's no bond for this port, or this is the last slave
    if (bond == NULL)
        return NULL;
-    slave_next = bond_next_slave(bond, slave);
+    slave_next = bond_next_slave_rcu(bond, slave);
    if (!slave_next || bond_is_first_slave(bond, slave_next))
        return NULL;
 

@@ -2417,16 +2417,14 @@ int bond_3ad_get_active_agg_info(struct bonding *bond, struct ad_info *ad_info)
 
 int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 {
-    struct slave *slave, *start_at;
    struct bonding *bond = netdev_priv(dev);
+    struct slave *slave;
    int slave_agg_no;
    int slaves_in_agg;
    int agg_id;
-    int i;
    struct ad_info ad_info;
    int res = 1;
 
-    read_lock(&bond->lock);
    if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
        pr_debug("%s: Error: __bond_3ad_get_active_agg_info failed\n",
             dev->name);

@@ -2444,13 +2442,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
 
    slave_agg_no = bond->xmit_hash_policy(skb, slaves_in_agg);
 
-    bond_for_each_slave(bond, slave) {
+    bond_for_each_slave_rcu(bond, slave) {
        struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
        if (agg && (agg->aggregator_identifier == agg_id)) {
-            slave_agg_no--;
-            if (slave_agg_no < 0)
-                break;
+            if (--slave_agg_no < 0) {
+                if (SLAVE_IS_OK(slave)) {
+                    res = bond_dev_queue_xmit(bond,
+                        skb, slave->dev);
+                    goto out;
+                }
+            }
        }
    }
 

@@ -2460,23 +2462,17 @@ int bond_3ad_xmit_xor(struct sk_buff *skb, struct net_device *dev)
        goto out;
    }
 
-    start_at = slave;
-
-    bond_for_each_slave_from(bond, slave, i, start_at) {
-        int slave_agg_id = 0;
+    bond_for_each_slave_rcu(bond, slave) {
        struct aggregator *agg = SLAVE_AD_INFO(slave).port.aggregator;
 
-        if (agg)
-            slave_agg_id = agg->aggregator_identifier;
-
-        if (SLAVE_IS_OK(slave) && agg && (slave_agg_id == agg_id)) {
+        if (SLAVE_IS_OK(slave) && agg &&
+            agg->aggregator_identifier == agg_id) {
            res = bond_dev_queue_xmit(bond, skb, slave->dev);
            break;
        }
    }
 

out:

drivers/net/bonding/bond_3ad.c +0 -1

-    read_unlock(&bond->lock);
    if (res) {
        /* no suitable interface, frame not sent */
        kfree_skb(skb);

drivers/net/bonding/bonding.h +12 -1

index f7ab161..f013b12 100644
@@ -74,13 +74,34 @@
 /* slave list primitives */
 #define bond_to_slave(ptr) list_entry(ptr, struct slave, list)
 
+/* slave list primitives, Caller must hold rcu_read_lock */
+#define bond_to_slave_rcu(ptr) list_entry_rcu(ptr, struct slave, list)
+
+/* bond_is_empty return NULL if slave list is empty*/
+#define bond_is_empty(bond) \
+    (list_empty(&(bond)->slave_list))
+
+/* bond_is_empty_rcu return NULL if slave list is empty*/
+#define bond_is_empty_rcu(bond) \
+    (!list_first_or_null_rcu(&(bond)->slave_list, struct slave, list))
+
 /* IMPORTANT: bond_first/last_slave can return NULL in case of an empty list */
 #define bond_first_slave(bond) \
    list_first_entry_or_null(&(bond)->slave_list, struct slave, list)
 #define bond_last_slave(bond) \
-    (list_empty(&(bond)->slave_list) ? NULL : \
+    (bond_is_empty(bond) ? NULL : \
                       bond_to_slave((bond)->slave_list.prev))

drivers/net/bonding/bonding.h line 103

Quoted 10 lines

drivers/net/bonding/bonding.h +9 -0

 
+/**
+ * IMPORTANT: bond_first/last_slave_rcu can return NULL in case of an empty list
+ * Caller must hold rcu_read_lock
+ */
+#define bond_first_slave_rcu(bond) \
+    list_first_or_null_rcu(&(bond)->slave_list, struct slave, list)
+#define bond_last_slave_rcu(bond) \
+    (bond_is_empty_rcu(bond) ? NULL : \
+                    bond_to_slave_rcu((bond)->slave_list.prev))

Really?

No. Again - take a look at list_first_or_null_rcu. And its comments.

I'm sorry that I'm acting that negatively... But if that gets accepted - I'll have days of nightmares.

Try to understand how RCU works, please, before sending patches using it.

Quoted 25 lines

drivers/net/bonding/bonding.h +10 -0

+
 #define bond_is_first_slave(bond, pos) ((pos)->list.prev == &(bond)->slave_list)
 #define bond_is_last_slave(bond, pos) ((pos)->list.next == &(bond)->slave_list)
 

@@ -93,6 +114,15 @@
    (bond_is_first_slave(bond, pos) ? bond_last_slave(bond) : \
                      bond_to_slave((pos)->list.prev))
 
+/* Since bond_first/last_slave_rcu can return NULL, these can return NULL too */
+#define bond_next_slave_rcu(bond, pos) \
+    (bond_is_last_slave(bond, pos) ? bond_first_slave_rcu(bond) : \
+                     bond_to_slave_rcu((pos)->list.next))
+
+#define bond_prev_slave_rcu(bond, pos) \
+    (bond_is_first_slave(bond, pos) ? bond_last_slave_rcu(bond) : \
+                      bond_to_slave_rcu((pos)->list.prev))
+
 /**
 * bond_for_each_slave_from - iterate the slaves list from a starting point
 * @bond:    the bond holding this list.

Signature · 1 line

1.8.2.1

.