bonding: introduce primary_reselect option
In some cases there is not desirable to switch back to primary interface when
it's link recovers and rather stay with currently active one. We need to avoid
packetloss as much as we can in some cases. This is solved by introducing
primary_reselect option. Note that enslaved primary slave is set as current
active no matter what.
Patch modified by Jay Vosburgh as follows: fixed bug in action
after change of option setting via sysfs, revised the documentation
update, and bumped the bonding version number.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 69c5b15..19d57d5 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -94,6 +94,7 @@
static int use_carrier = 1;
static char *mode;
static char *primary;
+static char *primary_reselect;
static char *lacp_rate;
static char *ad_select;
static char *xmit_hash_policy;
@@ -126,6 +127,14 @@
"6 for balance-alb");
module_param(primary, charp, 0);
MODULE_PARM_DESC(primary, "Primary network device to use");
+module_param(primary_reselect, charp, 0);
+MODULE_PARM_DESC(primary_reselect, "Reselect primary slave "
+ "once it comes up; "
+ "0 for always (default), "
+ "1 for only if speed of primary is "
+ "better, "
+ "2 for only on active slave "
+ "failure");
module_param(lacp_rate, charp, 0);
MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner "
"(slow/fast)");
@@ -200,6 +209,13 @@
{ NULL, -1},
};
+const struct bond_parm_tbl pri_reselect_tbl[] = {
+{ "always", BOND_PRI_RESELECT_ALWAYS},
+{ "better", BOND_PRI_RESELECT_BETTER},
+{ "failure", BOND_PRI_RESELECT_FAILURE},
+{ NULL, -1},
+};
+
struct bond_parm_tbl ad_select_tbl[] = {
{ "stable", BOND_AD_STABLE},
{ "bandwidth", BOND_AD_BANDWIDTH},
@@ -1070,6 +1086,25 @@
}
+static bool bond_should_change_active(struct bonding *bond)
+{
+ struct slave *prim = bond->primary_slave;
+ struct slave *curr = bond->curr_active_slave;
+
+ if (!prim || !curr || curr->link != BOND_LINK_UP)
+ return true;
+ if (bond->force_primary) {
+ bond->force_primary = false;
+ return true;
+ }
+ 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
@@ -1094,7 +1129,8 @@
}
if ((bond->primary_slave) &&
- bond->primary_slave->link == BOND_LINK_UP) {
+ bond->primary_slave->link == BOND_LINK_UP &&
+ bond_should_change_active(bond)) {
new_active = bond->primary_slave;
}
@@ -1678,8 +1714,10 @@
if (USES_PRIMARY(bond->params.mode) && bond->params.primary[0]) {
/* if there is a primary slave, remember it */
- if (strcmp(bond->params.primary, new_slave->dev->name) == 0)
+ if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
bond->primary_slave = new_slave;
+ bond->force_primary = true;
+ }
}
write_lock_bh(&bond->curr_slave_lock);
@@ -3201,11 +3239,14 @@
}
if (USES_PRIMARY(bond->params.mode)) {
- seq_printf(seq, "Primary Slave: %s\n",
+ seq_printf(seq, "Primary Slave: %s",
(bond->primary_slave) ?
bond->primary_slave->dev->name : "None");
+ if (bond->primary_slave)
+ seq_printf(seq, " (primary_reselect %s)",
+ pri_reselect_tbl[bond->params.primary_reselect].modename);
- seq_printf(seq, "Currently Active Slave: %s\n",
+ seq_printf(seq, "\nCurrently Active Slave: %s\n",
(curr) ? curr->dev->name : "None");
}
@@ -4646,7 +4687,7 @@
static int bond_check_params(struct bond_params *params)
{
- int arp_validate_value, fail_over_mac_value;
+ int arp_validate_value, fail_over_mac_value, primary_reselect_value;
/*
* Convert string parameters.
@@ -4945,6 +4986,20 @@
primary = NULL;
}
+ if (primary && primary_reselect) {
+ primary_reselect_value = bond_parse_parm(primary_reselect,
+ pri_reselect_tbl);
+ if (primary_reselect_value == -1) {
+ pr_err(DRV_NAME
+ ": Error: Invalid primary_reselect \"%s\"\n",
+ primary_reselect ==
+ NULL ? "NULL" : primary_reselect);
+ return -EINVAL;
+ }
+ } else {
+ primary_reselect_value = BOND_PRI_RESELECT_ALWAYS;
+ }
+
if (fail_over_mac) {
fail_over_mac_value = bond_parse_parm(fail_over_mac,
fail_over_mac_tbl);
@@ -4976,6 +5031,7 @@
params->use_carrier = use_carrier;
params->lacp_fast = lacp_fast;
params->primary[0] = 0;
+ params->primary_reselect = primary_reselect_value;
params->fail_over_mac = fail_over_mac_value;
if (primary) {