[PATCH] bonding: documentation and code cleanup for resend_igmp

Improves the documentation about how IGMP resend parameter
works, fix two missing checks and coding style issues.

Signed-off-by: Flavio Leitner <redacted>
---
 Documentation/networking/bonding.txt |   13 +++++++++++--
 drivers/net/bonding/bond_main.c      |   12 +++++++-----
 drivers/net/bonding/bond_sysfs.c     |   10 +++++-----
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 1f45bd8..683ef76 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt

@@ -770,8 +770,17 @@ resend_igmp
 	a failover event. One membership report is issued immediately after
 	the failover, subsequent packets are sent in each 200ms interval.
 
-	The valid range is 0 - 255; the default value is 1. This option
-	was added for bonding version 3.7.0.
+	The valid range is 0 - 255; the default value is 1. A value of 0
+	prevents the IGMP membership report to be issued due the failover
+	event.
+
+	This option is useful for bonding modes balance-rr or 0,
+	active-backup or 1, balance-tlb or 5, balance-alb or 6, which a
+	failover can move the IGMP traffic from one slave to another.
+	Therefore, the switch must be notified with an extra IGMP report
+	to start forwarding the IGMP traffic over the new selected slave.
+
+	This option was added for bonding version 3.7.0.
 
 3. Configuring Bonding Devices
 ==============================

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 6dc4284..86a8001 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c

@@ -852,7 +852,7 @@ static void bond_resend_igmp_join_requests(struct bonding *bond)
 static void bond_resend_igmp_join_requests_delayed(struct work_struct *work)
 {
 	struct bonding *bond = container_of(work, struct bonding,
-							mcast_work.work);
+					    mcast_work.work);
 	bond_resend_igmp_join_requests(bond);
 }
 

@@ -1172,10 +1172,12 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
 	}
 
 	/* resend IGMP joins since active slave has changed or
-	 * all were sent on curr_active_slave */
-	if (((USES_PRIMARY(bond->params.mode) && new_active) ||
-	     bond->params.mode == BOND_MODE_ROUNDROBIN) &&
-	    netif_running(bond->dev)) {
+	 * all were sent on curr_active_slave.
+	 * resend only if bond is brought up with the affected
+	 * bonding modes and the retransmission is enabled */
+	if (netif_running(bond->dev) && (bond->params.resend_igmp > 0) &&
+	    ((USES_PRIMARY(bond->params.mode) && new_active) ||
+	     bond->params.mode == BOND_MODE_ROUNDROBIN)) {
 		bond->igmp_retrans = bond->params.resend_igmp;
 		queue_delayed_work(bond->wq, &bond->mcast_work, 0);
 	}

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 4059bfc..a32848a 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c

@@ -1539,8 +1539,8 @@ static DEVICE_ATTR(all_slaves_active, S_IRUGO | S_IWUSR,
  * Show and set the number of IGMP membership reports to send on link failure
  */
 static ssize_t bonding_show_resend_igmp(struct device *d,
-					 struct device_attribute *attr,
-					 char *buf)
+					struct device_attribute *attr,
+					char *buf)
 {
 	struct bonding *bond = to_bond(d);
 

@@ -1548,8 +1548,8 @@ static ssize_t bonding_show_resend_igmp(struct device *d,
 }
 
 static ssize_t bonding_store_resend_igmp(struct device *d,
-					  struct device_attribute *attr,
-					  const char *buf, size_t count)
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
 {
 	int new_value, ret = count;
 	struct bonding *bond = to_bond(d);

@@ -1561,7 +1561,7 @@ static ssize_t bonding_store_resend_igmp(struct device *d,
 		goto out;
 	}
 
-	if (new_value < 0) {
+	if (new_value < 0 || new_value > 255) {
 		pr_err("%s: Invalid resend_igmp value %d not in range 0-255; rejected.\n",
 		       bond->dev->name, new_value);
 		ret = -EINVAL;

-- 
1.7.4

On Wed, 2011-05-25 at 11:44 -0300, Flavio Leitner wrote:

Grammar nit - "prevents the ICMP membership report from being issued in
response to the failover event."  Or "prevents issuing of the IGMP
membership report in response to a failover event."

+
+	This option is useful for bonding modes balance-rr or 0,
+	active-backup or 1, balance-tlb or 5, balance-alb or 6, which a
+	failover can move the IGMP traffic from one slave to another.
+	Therefore, the switch must be notified with an extra IGMP report
+	to start forwarding the IGMP traffic over the new selected slave.

More nits.  How about (with some added guesses on my part about
direction)

This option is useful for bonding modes balance-rr (0), active-backup
(1), balance-tlb (5) and balance-alb (6), in which a failover can switch
the outgoing IGMP traffic from one slave to another.  Therefore a fresh
IGMP report must be issued to cause the switch to forward the incoming
IGMP traffic over the newly selected slave.

rick jones

On 05/25/2011 02:19 PM, Rick Jones wrote:

On Wed, 2011-05-25 at 11:44 -0300, Flavio Leitner wrote:

quoted

Improves the documentation about how IGMP resend parameter
works, fix two missing checks and coding style issues.

Signed-off-by: Flavio Leitner <redacted>
---
 Documentation/networking/bonding.txt |   13 +++++++++++--
 drivers/net/bonding/bond_main.c      |   12 +++++++-----
 drivers/net/bonding/bond_sysfs.c     |   10 +++++-----
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 1f45bd8..683ef76 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt

@@ -770,8 +770,17 @@ resend_igmp
 	a failover event. One membership report is issued immediately after
 	the failover, subsequent packets are sent in each 200ms interval.
 
-	The valid range is 0 - 255; the default value is 1. This option
-	was added for bonding version 3.7.0.
+	The valid range is 0 - 255; the default value is 1. A value of 0
+	prevents the IGMP membership report to be issued due the failover
+	event.

Grammar nit - "prevents the ICMP membership report from being issued in
response to the failover event."  Or "prevents issuing of the IGMP
membership report in response to a failover event."

I like the first suggestion. I'll update the patch fixing the ICMP
typo.

quoted

+
+	This option is useful for bonding modes balance-rr or 0,
+	active-backup or 1, balance-tlb or 5, balance-alb or 6, which a
+	failover can move the IGMP traffic from one slave to another.
+	Therefore, the switch must be notified with an extra IGMP report
+	to start forwarding the IGMP traffic over the new selected slave.

More nits.  How about (with some added guesses on my part about
direction)

This option is useful for bonding modes balance-rr (0), active-backup
(1), balance-tlb (5) and balance-alb (6), in which a failover can switch
the outgoing IGMP traffic from one slave to another.  Therefore a fresh
IGMP report must be issued to cause the switch to forward the incoming
IGMP traffic over the newly selected slave.

It's also better. thanks. However, the failover can switch both
incoming and outgoing IGMP traffic so I'd leave it generic as before.
For instance:

This option is useful for bonding modes balance-rr (0), active-backup
(1), balance-tlb (5) and balance-alb (6), in which a failover can switch
the IGMP traffic from one slave to another.  Therefore a fresh IGMP
report must be issued to cause the switch to forward the incoming
IGMP traffic over the newly selected slave.

What do you think?

thanks,
fbl

quoted

Grammar nit - "prevents the ICMP membership report from being issued in
response to the failover event."  Or "prevents issuing of the IGMP
membership report in response to a failover event."

I like the first suggestion. I'll update the patch fixing the ICMP
typo.

Petards, petards, everywhere - and why are they all pointing at me :)

quoted

quoted

+
+	This option is useful for bonding modes balance-rr or 0,
+	active-backup or 1, balance-tlb or 5, balance-alb or 6, which a
+	failover can move the IGMP traffic from one slave to another.
+	Therefore, the switch must be notified with an extra IGMP report
+	to start forwarding the IGMP traffic over the new selected slave.

More nits.  How about (with some added guesses on my part about
direction)

This option is useful for bonding modes balance-rr (0), active-backup
(1), balance-tlb (5) and balance-alb (6), in which a failover can switch
the outgoing IGMP traffic from one slave to another.  Therefore a fresh
IGMP report must be issued to cause the switch to forward the incoming
IGMP traffic over the newly selected slave.

It's also better. thanks. However, the failover can switch both
incoming and outgoing IGMP traffic so I'd leave it generic as before.
For instance:

This option is useful for bonding modes balance-rr (0), active-backup
(1), balance-tlb (5) and balance-alb (6), in which a failover can switch
the IGMP traffic from one slave to another.  Therefore a fresh IGMP
report must be issued to cause the switch to forward the incoming
IGMP traffic over the newly selected slave.

What do you think?

I'm find with leaving it generic.

rick jones