bonding: alternate agg selection policies for 802.3ad

	This patch implements alternative aggregator selection policies
for 802.3ad.  The existing policy, now termed "stable," selects the active
aggregator by greatest bandwidth, and only reselects a new aggregator
if the active aggregator is entirely disabled (no more ports or all ports
down).

	This patch adds two new policies: bandwidth and count, selecting
the active aggregator by total bandwidth (like the stable policy) or by
the number of ports in the aggregator, respectively.  These two policies
also differ from the stable policy in that they will reselect the active
aggregator when availability-related changes occur in the bond (e.g.,
link state change).

	This permits "gang failover" within 802.3ad, allowing redundant
aggregators along parallel paths to always maintain the "best" aggregator
as the active aggregator (rather than having to wait for the active to
entirely fail).

	This patch also updates the driver version to 3.5.0.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 8788e3e33852..aaf2927b5c38 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -48,6 +48,7 @@ extern struct list_head bond_dev_list;
 extern struct bond_params bonding_defaults;
 extern struct bond_parm_tbl bond_mode_tbl[];
 extern struct bond_parm_tbl bond_lacp_tbl[];
+extern struct bond_parm_tbl ad_select_tbl[];
 extern struct bond_parm_tbl xmit_hashtype_tbl[];
 extern struct bond_parm_tbl arp_validate_tbl[];
 extern struct bond_parm_tbl fail_over_mac_tbl[];
@@ -944,6 +945,53 @@ out:
 }
 static DEVICE_ATTR(lacp_rate, S_IRUGO | S_IWUSR, bonding_show_lacp, bonding_store_lacp);
 
+static ssize_t bonding_show_ad_select(struct device *d,
+                                      struct device_attribute *attr,
+                                      char *buf)
+{
+        struct bonding *bond = to_bond(d);
+
+        return sprintf(buf, "%s %d\n",
+                ad_select_tbl[bond->params.ad_select].modename,
+                bond->params.ad_select);
+}
+
+
+static ssize_t bonding_store_ad_select(struct device *d,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t count)
+{
+        int new_value, ret = count;
+        struct bonding *bond = to_bond(d);
+
+        if (bond->dev->flags & IFF_UP) {
+                printk(KERN_ERR DRV_NAME
+                       ": %s: Unable to update ad_select because interface "
+                       "is up.\n", bond->dev->name);
+                ret = -EPERM;
+                goto out;
+        }
+
+        new_value = bond_parse_parm(buf, ad_select_tbl);
+
+        if (new_value != -1) {
+                bond->params.ad_select = new_value;
+                printk(KERN_INFO DRV_NAME
+                       ": %s: Setting ad_select to %s (%d).\n",
+                       bond->dev->name, ad_select_tbl[new_value].modename,
+                       new_value);
+        } else {
+                printk(KERN_ERR DRV_NAME
+                       ": %s: Ignoring invalid ad_select value %.*s.\n",
+                       bond->dev->name, (int)strlen(buf) - 1, buf);
+                ret = -EINVAL;
+        }
+out:
+        return ret;
+}
+
+static DEVICE_ATTR(ad_select, S_IRUGO | S_IWUSR, bonding_show_ad_select, bonding_store_ad_select);
+
 /*
  * Show and set the number of grat ARP to send after a failover event.
  */
@@ -1459,6 +1507,7 @@ static struct attribute *per_bond_attrs[] = {
         &dev_attr_downdelay.attr,
         &dev_attr_updelay.attr,
         &dev_attr_lacp_rate.attr,
+        &dev_attr_ad_select.attr,
         &dev_attr_xmit_hash_policy.attr,
         &dev_attr_num_grat_arp.attr,
         &dev_attr_num_unsol_na.attr,