* [PATCH 4/5] bonding: restructure and simplify bond_for_each_slave_next()
@ 2013-08-28 4:21 Ding Tianhong
2013-08-29 14:25 ` Nikolay Aleksandrov
0 siblings, 1 reply; 3+ messages in thread
From: Ding Tianhong @ 2013-08-28 4:21 UTC (permalink / raw)
To: Jay Vosburgh, Andy Gospodarek, David S. Miller,
Nikolay Aleksandrov, Veaceslav Falico, Netdev
remove the wordy int and add bond_for_each_slave_next_rcu().
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
---
drivers/net/bonding/bond_alb.c | 3 +--
drivers/net/bonding/bond_main.c | 6 ++----
drivers/net/bonding/bonding.h | 19 +++++++++++++++----
3 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 3a5db7b..d266c56 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -383,7 +383,6 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond)
{
struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
struct slave *rx_slave, *slave, *start_at;
- int i = 0;
if (bond_info->next_rx_slave)
start_at = bond_info->next_rx_slave;
@@ -392,7 +391,7 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond)
rx_slave = NULL;
- bond_for_each_slave_from(bond, slave, i, start_at) {
+ bond_for_each_slave_from(bond, slave, start_at) {
if (SLAVE_IS_OK(slave)) {
if (!rx_slave) {
rx_slave = slave;
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 4264a76..8c9902a 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -904,7 +904,6 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
struct slave *new_active, *old_active;
struct slave *bestslave = NULL;
int mintime = bond->params.updelay;
- int i;
new_active = bond->curr_active_slave;
@@ -923,7 +922,7 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
/* remember where to stop iterating over the slaves */
old_active = new_active;
- bond_for_each_slave_from(bond, new_active, i, old_active) {
+ bond_for_each_slave_from(bond, new_active, old_active) {
if (new_active->link == BOND_LINK_UP) {
return new_active;
} else if (new_active->link == BOND_LINK_BACK &&
@@ -2891,7 +2890,6 @@ do_failover:
static void bond_ab_arp_probe(struct bonding *bond)
{
struct slave *slave, *next_slave;
- int i;
read_lock(&bond->curr_slave_lock);
@@ -2923,7 +2921,7 @@ static void bond_ab_arp_probe(struct bonding *bond)
/* search for next candidate */
next_slave = bond_next_slave(bond, bond->current_arp_slave);
- bond_for_each_slave_from(bond, slave, i, next_slave) {
+ bond_for_each_slave_from(bond, slave, next_slave) {
if (IS_UP(slave->dev)) {
slave->link = BOND_LINK_BACK;
bond_set_slave_active_flags(slave);
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index ecb5d1d..7670584 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -119,14 +119,25 @@
* bond_for_each_slave_from - iterate the slaves list from a starting point
* @bond: the bond holding this list.
* @pos: current slave.
- * @cnt: counter for max number of moves
* @start: starting point.
*
* Caller must hold bond->lock
*/
-#define bond_for_each_slave_from(bond, pos, cnt, start) \
- for (cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \
- cnt++, pos = bond_next_slave(bond, pos))
+#define bond_for_each_slave_from(bond, pos, start) \
+ for (pos = bond_next_slave(bond, start); pos && pos != start; \
+ pos = bond_next_slave(bond, pos))
+
+/**
+ * bond_for_each_slave_from_rcu - iterate the slaves list from a starting point
+ * @bond: the bond holding this list.
+ * @pos: current slave.
+ * @start: starting point.
+ *
+ * Caller must hold rcu_read_lock
+ */
+#define bond_for_each_slave_from_rcu(bond, pos, start) \
+ for (pos = bond_next_slave_rcu(bond, start); pos && pos != start; \
+ pos = bond_next_slave_rcu(bond, pos))
/**
* bond_for_each_slave - iterate over all slaves
--
1.8.2.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH 4/5] bonding: restructure and simplify bond_for_each_slave_next()
2013-08-28 4:21 [PATCH 4/5] bonding: restructure and simplify bond_for_each_slave_next() Ding Tianhong
@ 2013-08-29 14:25 ` Nikolay Aleksandrov
2013-08-30 3:37 ` Ding Tianhong
0 siblings, 1 reply; 3+ messages in thread
From: Nikolay Aleksandrov @ 2013-08-29 14:25 UTC (permalink / raw)
To: Ding Tianhong
Cc: Jay Vosburgh, Andy Gospodarek, David S. Miller, Veaceslav Falico,
Netdev
On 08/28/2013 06:21 AM, Ding Tianhong wrote:
> remove the wordy int and add bond_for_each_slave_next_rcu().
>
> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
> ---
> drivers/net/bonding/bond_alb.c | 3 +--
> drivers/net/bonding/bond_main.c | 6 ++----
> drivers/net/bonding/bonding.h | 19 +++++++++++++++----
> 3 files changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
> index 3a5db7b..d266c56 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -383,7 +383,6 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond)
> {
> struct alb_bond_info *bond_info = &(BOND_ALB_INFO(bond));
> struct slave *rx_slave, *slave, *start_at;
> - int i = 0;
>
> if (bond_info->next_rx_slave)
> start_at = bond_info->next_rx_slave;
> @@ -392,7 +391,7 @@ static struct slave *rlb_next_rx_slave(struct bonding *bond)
>
> rx_slave = NULL;
>
> - bond_for_each_slave_from(bond, slave, i, start_at) {
> + bond_for_each_slave_from(bond, slave, start_at) {
> if (SLAVE_IS_OK(slave)) {
> if (!rx_slave) {
> rx_slave = slave;
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 4264a76..8c9902a 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -904,7 +904,6 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
> struct slave *new_active, *old_active;
> struct slave *bestslave = NULL;
> int mintime = bond->params.updelay;
> - int i;
>
> new_active = bond->curr_active_slave;
>
> @@ -923,7 +922,7 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
> /* remember where to stop iterating over the slaves */
> old_active = new_active;
>
> - bond_for_each_slave_from(bond, new_active, i, old_active) {
> + bond_for_each_slave_from(bond, new_active, old_active) {
> if (new_active->link == BOND_LINK_UP) {
> return new_active;
> } else if (new_active->link == BOND_LINK_BACK &&
> @@ -2891,7 +2890,6 @@ do_failover:
> static void bond_ab_arp_probe(struct bonding *bond)
> {
> struct slave *slave, *next_slave;
> - int i;
>
> read_lock(&bond->curr_slave_lock);
>
> @@ -2923,7 +2921,7 @@ static void bond_ab_arp_probe(struct bonding *bond)
>
> /* search for next candidate */
> next_slave = bond_next_slave(bond, bond->current_arp_slave);
> - bond_for_each_slave_from(bond, slave, i, next_slave) {
> + bond_for_each_slave_from(bond, slave, next_slave) {
> if (IS_UP(slave->dev)) {
> slave->link = BOND_LINK_BACK;
> bond_set_slave_active_flags(slave);
> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
> index ecb5d1d..7670584 100644
> --- a/drivers/net/bonding/bonding.h
> +++ b/drivers/net/bonding/bonding.h
> @@ -119,14 +119,25 @@
> * bond_for_each_slave_from - iterate the slaves list from a starting point
> * @bond: the bond holding this list.
> * @pos: current slave.
> - * @cnt: counter for max number of moves
> * @start: starting point.
> *
> * Caller must hold bond->lock
> */
> -#define bond_for_each_slave_from(bond, pos, cnt, start) \
> - for (cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \
> - cnt++, pos = bond_next_slave(bond, pos))
> +#define bond_for_each_slave_from(bond, pos, start) \
> + for (pos = bond_next_slave(bond, start); pos && pos != start; \
> + pos = bond_next_slave(bond, pos))
> +
> +/**
> + * bond_for_each_slave_from_rcu - iterate the slaves list from a starting point
> + * @bond: the bond holding this list.
> + * @pos: current slave.
> + * @start: starting point.
> + *
> + * Caller must hold rcu_read_lock
> + */
> +#define bond_for_each_slave_from_rcu(bond, pos, start) \
> + for (pos = bond_next_slave_rcu(bond, start); pos && pos != start; \
> + pos = bond_next_slave_rcu(bond, pos))
>
One question here: what if "start" gets deleted while we're traversing the list,
could this lead to an infinite loop ?
> /**
> * bond_for_each_slave - iterate over all slaves
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 4/5] bonding: restructure and simplify bond_for_each_slave_next()
2013-08-29 14:25 ` Nikolay Aleksandrov
@ 2013-08-30 3:37 ` Ding Tianhong
0 siblings, 0 replies; 3+ messages in thread
From: Ding Tianhong @ 2013-08-30 3:37 UTC (permalink / raw)
To: Nikolay Aleksandrov
Cc: Jay Vosburgh, Andy Gospodarek, David S. Miller, Veaceslav Falico,
Netdev
>> slave->link = BOND_LINK_BACK;
>> bond_set_slave_active_flags(slave);
>> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
>> index ecb5d1d..7670584 100644
>> --- a/drivers/net/bonding/bonding.h
>> +++ b/drivers/net/bonding/bonding.h
>> @@ -119,14 +119,25 @@
>> * bond_for_each_slave_from - iterate the slaves list from a starting point
>> * @bond: the bond holding this list.
>> * @pos: current slave.
>> - * @cnt: counter for max number of moves
>> * @start: starting point.
>> *
>> * Caller must hold bond->lock
>> */
>> -#define bond_for_each_slave_from(bond, pos, cnt, start) \
>> - for (cnt = 0, pos = start; pos && cnt < (bond)->slave_cnt; \
>> - cnt++, pos = bond_next_slave(bond, pos))
>> +#define bond_for_each_slave_from(bond, pos, start) \
>> + for (pos = bond_next_slave(bond, start); pos && pos != start; \
>> + pos = bond_next_slave(bond, pos))
>> +
>> +/**
>> + * bond_for_each_slave_from_rcu - iterate the slaves list from a starting point
>> + * @bond: the bond holding this list.
>> + * @pos: current slave.
>> + * @start: starting point.
>> + *
>> + * Caller must hold rcu_read_lock
>> + */
>> +#define bond_for_each_slave_from_rcu(bond, pos, start) \
>> + for (pos = bond_next_slave_rcu(bond, start); pos && pos != start; \
>> + pos = bond_next_slave_rcu(bond, pos))
>>
> One question here: what if "start" gets deleted while we're traversing the list,
> could this lead to an infinite loop ?
>
agree, so the start should not be delete while traversing the list, the func should not run
without protection.
>> /**
>> * bond_for_each_slave - iterate over all slaves
>>
>
>
> .
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-08-30 3:37 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-08-28 4:21 [PATCH 4/5] bonding: restructure and simplify bond_for_each_slave_next() Ding Tianhong
2013-08-29 14:25 ` Nikolay Aleksandrov
2013-08-30 3:37 ` Ding Tianhong
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).