[PATCH v3] bonding: "primary_reselect" with "failure" is not working properly

[PATCH v3] bonding: "primary_reselect" with "failure" is not working properly

[Mazhar Rana]

From: Mazhar Rana <mazhar.rana@cyberoam.com>

When "primary_reselect" is set to "failure", primary interface should
not become active until current active slave is down. But if we set first
member of bond device as a "primary" interface and "primary_reselect"
is set to "failure" then whenever primary interface's link get back(up)
it become active slave even if current active slave is still up.

With this patch, "bond_find_best_slave" will not traverse members if
primary interface is not candidate for failover/reselection and current
active slave is still up.

Signed-off-by: Mazhar Rana <mazhar.rana@cyberoam.com>
Signed-off-by: Jay Vosburgh <j.vosburgh@gmail.com>
---

v1->v2: 
return "curr" instead of "bond->curr_active_slave".

v2->v3: 
To make code more clear, replaced function bond_should_change_active
with bond_choose_primary_or_current which will return slave device.

 drivers/net/bonding/bond_main.c | 51 +++++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 17 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 19eb990..317a494 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -689,40 +689,57 @@ out:
 
 }
 
-static bool bond_should_change_active(struct bonding *bond)
+static struct slave *bond_choose_primary_or_current(struct bonding *bond)
 {
 	struct slave *prim = rtnl_dereference(bond->primary_slave);
 	struct slave *curr = rtnl_dereference(bond->curr_active_slave);
 
-	if (!prim || !curr || curr->link != BOND_LINK_UP)
-		return true;
+	if (!prim || prim->link != BOND_LINK_UP) {
+		if (!curr || curr->link != BOND_LINK_UP)
+			return NULL;
+		return curr;
+	}
+
 	if (bond->force_primary) {
 		bond->force_primary = false;
-		return true;
+		return prim;
+	}
+
+	if (!curr || curr->link != BOND_LINK_UP)
+		return prim;
+
+	/* At this point, prim and curr are both up */
+	switch (bond->params.primary_reselect) {
+	case BOND_PRI_RESELECT_ALWAYS:
+		return prim;
+	case BOND_PRI_RESELECT_BETTER:
+		if (prim->speed < curr->speed)
+			return curr;
+		if (prim->speed == curr->speed && prim->duplex <= curr->duplex)
+			return curr;
+		return prim;
+	case BOND_PRI_RESELECT_FAILURE:
+		return curr;
+	default:
+		netdev_err(bond->dev, "impossible primary_reselect %d\n",
+			   bond->params.primary_reselect);
+		return curr;
 	}
-	if (bond->params.primary_reselect == BOND_PRI_RESELECT_BETTER &&
-	    (prim->speed < curr->speed ||
-	     (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
-		return false;
-	if (bond->params.primary_reselect == BOND_PRI_RESELECT_FAILURE)
-		return false;
-	return true;
 }
 
 /**
- * find_best_interface - select the best available slave to be the active one
+ * bond_find_best_slave - select the best available slave to be the active one
  * @bond: our bonding struct
  */
 static struct slave *bond_find_best_slave(struct bonding *bond)
 {
-	struct slave *slave, *bestslave = NULL, *primary;
+	struct slave *slave, *bestslave = NULL;
 	struct list_head *iter;
 	int mintime = bond->params.updelay;
 
-	primary = rtnl_dereference(bond->primary_slave);
-	if (primary && primary->link == BOND_LINK_UP &&
-	    bond_should_change_active(bond))
-		return primary;
+	slave = bond_choose_primary_or_current(bond);
+	if (slave)
+		return slave;
 
 	bond_for_each_slave(bond, slave, iter) {
 		if (slave->link == BOND_LINK_UP)
-- 
1.9.1

Re: [PATCH v3] bonding: "primary_reselect" with "failure" is not working properly

[Jay Vosburgh]

Mazhar Rana <ranamazharp@gmail.com> wrote:

>From: Mazhar Rana <mazhar.rana@cyberoam.com>
>
>When "primary_reselect" is set to "failure", primary interface should
>not become active until current active slave is down. But if we set first
>member of bond device as a "primary" interface and "primary_reselect"
>is set to "failure" then whenever primary interface's link get back(up)
>it become active slave even if current active slave is still up.
>
>With this patch, "bond_find_best_slave" will not traverse members if
>primary interface is not candidate for failover/reselection and current
>active slave is still up.
>
>Signed-off-by: Mazhar Rana <mazhar.rana@cyberoam.com>
>Signed-off-by: Jay Vosburgh <j.vosburgh@gmail.com>

	I don't believe I posted a Signed-off-by, so you really
shouldn't include one for me without it being explicitly stated.

	In any event, I'm good with the patch, so:

Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>

	-J

>---
>
>v1->v2: 
>return "curr" instead of "bond->curr_active_slave".
>
>v2->v3: 
>To make code more clear, replaced function bond_should_change_active
>with bond_choose_primary_or_current which will return slave device.
>
> drivers/net/bonding/bond_main.c | 51 +++++++++++++++++++++++++++--------------
> 1 file changed, 34 insertions(+), 17 deletions(-)
>
>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>index 19eb990..317a494 100644
>--- a/drivers/net/bonding/bond_main.c
>+++ b/drivers/net/bonding/bond_main.c
>@@ -689,40 +689,57 @@ out:
> 
> }
> 
>-static bool bond_should_change_active(struct bonding *bond)
>+static struct slave *bond_choose_primary_or_current(struct bonding *bond)
> {
> 	struct slave *prim = rtnl_dereference(bond->primary_slave);
> 	struct slave *curr = rtnl_dereference(bond->curr_active_slave);
> 
>-	if (!prim || !curr || curr->link != BOND_LINK_UP)
>-		return true;
>+	if (!prim || prim->link != BOND_LINK_UP) {
>+		if (!curr || curr->link != BOND_LINK_UP)
>+			return NULL;
>+		return curr;
>+	}
>+
> 	if (bond->force_primary) {
> 		bond->force_primary = false;
>-		return true;
>+		return prim;
>+	}
>+
>+	if (!curr || curr->link != BOND_LINK_UP)
>+		return prim;
>+
>+	/* At this point, prim and curr are both up */
>+	switch (bond->params.primary_reselect) {
>+	case BOND_PRI_RESELECT_ALWAYS:
>+		return prim;
>+	case BOND_PRI_RESELECT_BETTER:
>+		if (prim->speed < curr->speed)
>+			return curr;
>+		if (prim->speed == curr->speed && prim->duplex <= curr->duplex)
>+			return curr;
>+		return prim;
>+	case BOND_PRI_RESELECT_FAILURE:
>+		return curr;
>+	default:
>+		netdev_err(bond->dev, "impossible primary_reselect %d\n",
>+			   bond->params.primary_reselect);
>+		return curr;
> 	}
>-	if (bond->params.primary_reselect == BOND_PRI_RESELECT_BETTER &&
>-	    (prim->speed < curr->speed ||
>-	     (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
>-		return false;
>-	if (bond->params.primary_reselect == BOND_PRI_RESELECT_FAILURE)
>-		return false;
>-	return true;
> }
> 
> /**
>- * find_best_interface - select the best available slave to be the active one
>+ * bond_find_best_slave - select the best available slave to be the active one
>  * @bond: our bonding struct
>  */
> static struct slave *bond_find_best_slave(struct bonding *bond)
> {
>-	struct slave *slave, *bestslave = NULL, *primary;
>+	struct slave *slave, *bestslave = NULL;
> 	struct list_head *iter;
> 	int mintime = bond->params.updelay;
> 
>-	primary = rtnl_dereference(bond->primary_slave);
>-	if (primary && primary->link == BOND_LINK_UP &&
>-	    bond_should_change_active(bond))
>-		return primary;
>+	slave = bond_choose_primary_or_current(bond);
>+	if (slave)
>+		return slave;
> 
> 	bond_for_each_slave(bond, slave, iter) {
> 		if (slave->link == BOND_LINK_UP)
>-- 
>1.9.1
>
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Re: [PATCH v3] bonding: "primary_reselect" with "failure" is not working properly

[David Miller]

From: Mazhar Rana <ranamazharp@gmail.com>
Date: Tue,  7 Jul 2015 15:04:50 +0530

> From: Mazhar Rana <mazhar.rana@cyberoam.com>
> 
> When "primary_reselect" is set to "failure", primary interface should
> not become active until current active slave is down. But if we set first
> member of bond device as a "primary" interface and "primary_reselect"
> is set to "failure" then whenever primary interface's link get back(up)
> it become active slave even if current active slave is still up.
> 
> With this patch, "bond_find_best_slave" will not traverse members if
> primary interface is not candidate for failover/reselection and current
> active slave is still up.
> 
> Signed-off-by: Mazhar Rana <mazhar.rana@cyberoam.com>
> Signed-off-by: Jay Vosburgh <j.vosburgh@gmail.com>

Applied, thanks.