Subject: Re: [PATCH net] bonding: set primary_reselect in LB and AB mode

From: Jay Vosburgh <[email-masked]>
Date: Fri, 15 Nov 2013 10:02:45 -0800

Ding Tianhong <[email-masked]> wrote:

>The primary_reselect only reselection for the primary slave,
>but the primary slave only support for ALB, TLB and AB mode,
>so we sould set the primary_reselect for these mode.
>
>to fix this: Add a check for ALB, TLB and AB mode in
>bonding_store_primary_reselect, avoid to select active slave
>again in other modes.

	I don't believe that setting primary_reselect in a
!USES_PRIMARY() mode has any negative effects.  It doesn't do anything,
but also doesn't break anything.  Is there a case that setting
primary_reselect causes misbehavior in a !USES_PRIMARY() mode?

	Presuming that primary_reselect doesn't break things, this just
adds an ordering limitation when configuring bonding (mode must be set
prior to primary_reselect).  I don't believe this change adds any value,
and may break existing configuration scripts.

	-J

>Signed-off-by: Ding Tianhong <[email-masked]>
>---
> drivers/net/bonding/bond_sysfs.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
>diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
>index 47749c9..cac2291 100644
>--- a/drivers/net/bonding/bond_sysfs.c
>+++ b/drivers/net/bonding/bond_sysfs.c
>@@ -1141,6 +1141,13 @@ static ssize_t bonding_store_primary_reselect(struct device *d,
> 	if (!rtnl_trylock())
> 		return restart_syscall();
>
>+	if (!USES_PRIMARY(bond->params.mode)) {
>+		pr_info("%s: Unable to set primary reselect; %s is in mode %d\n",
>+			bond->dev->name, bond->dev->name, bond->params.mode);
>+		ret = -EINVAL;
>+		goto out;
>+	}
>+
> 	new_value = bond_parse_parm(buf, pri_reselect_tbl);
> 	if (new_value < 0)  {
> 		pr_err("%s: Ignoring invalid primary_reselect value %.*s.\n",
>-- 
>1.7.12

---
	-Jay Vosburgh, IBM Linux Technology Center, [email-masked]