bonding: add an option to fail when any of arp_ip_target is inaccessible
Currently, we fail only when all of the ips in arp_ip_target are gone.
However, in some situations we might need to fail if even one host from
arp_ip_target becomes unavailable.
All situations, obviously, rely on the idea that we need *completely*
functional network, with all interfaces/addresses working correctly.
One real world example might be:
vlans on top on bond (hybrid port). If bond and vlans have ips assigned
and we have their peers monitored via arp_ip_target - in case of switch
misconfiguration (trunk/access port), slave driver malfunction or
tagged/untagged traffic dropped on the way - we will be able to switch
to another slave.
Though any other configuration needs that if we need to have access to all
arp_ip_targets.
This patch adds this possibility by adding a new parameter -
arp_all_targets (both as a module parameter and as a sysfs knob). It can be
set to:
0 or any (the default) - which works exactly as it's working now -
the slave is up if any of the arp_ip_targets are up.
1 or all - the slave is up if all of the arp_ip_targets are up.
This parameter can be changed on the fly (via sysfs), and requires the mode
to be active-backup and arp_validate to be enabled (it obeys the
arp_validate config on which slaves to validate).
Internally it's done through:
1) Add target_last_arp_rx[BOND_MAX_ARP_TARGETS] array to slave struct. It's
an array of jiffies, meaning that slave->target_last_arp_rx[i] is the
last time we've received arp from bond->params.arp_targets[i] on this
slave.
2) If we successfully validate an arp from bond->params.arp_targets[i] in
bond_validate_arp() - update the slave->target_last_arp_rx[i] with the
current jiffies value.
3) When getting slave's last_rx via slave_last_rx(), we return the oldest
time when we've received an arp from any address in
bond->params.arp_targets[].
If the value of arp_all_targets == 0 - we still work the same way as
before.
Also, update the documentation to reflect the new parameter.
v3->v4:
Kill the forgotten rtnl_unlock(), rephrase the documentation part to be
more clear, don't fail setting arp_all_targets if arp_validate is not set -
it has no effect anyway but can be easier to set up. Also, print a warning
if the last arp_ip_target is removed while the arp_interval is on, but not
the arp_validate.
v2->v3:
Use _bh spinlock, remove useless rtnl_lock() and use jiffies for new
arp_ip_target last arp, instead of slave_last_rx(). On bond_enslave(),
use the same initialization value for target_last_arp_rx[] as is used
for the default last_arp_rx, to avoid useless interface flaps.
Also, instead of failing to remove the last arp_ip_target just print a
warning - otherwise it might break existing scripts.
v1->v2:
Correctly handle adding/removing hosts in arp_ip_target - we need to
shift/initialize all slave's target_last_arp_rx. Also, don't fail module
loading on arp_all_targets misconfiguration, just disable it, and some
minor style fixes.
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index ece57f1..dc36a3d 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -443,6 +443,44 @@
static DEVICE_ATTR(arp_validate, S_IRUGO | S_IWUSR, bonding_show_arp_validate,
bonding_store_arp_validate);
+/*
+ * Show and set arp_all_targets.
+ */
+static ssize_t bonding_show_arp_all_targets(struct device *d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct bonding *bond = to_bond(d);
+ int value = bond->params.arp_all_targets;
+
+ return sprintf(buf, "%s %d\n", arp_all_targets_tbl[value].modename,
+ value);
+}
+
+static ssize_t bonding_store_arp_all_targets(struct device *d,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct bonding *bond = to_bond(d);
+ int new_value;
+
+ new_value = bond_parse_parm(buf, arp_all_targets_tbl);
+ if (new_value < 0) {
+ pr_err("%s: Ignoring invalid arp_all_targets value %s\n",
+ bond->dev->name, buf);
+ return -EINVAL;
+ }
+ pr_info("%s: setting arp_all_targets to %s (%d).\n",
+ bond->dev->name, arp_all_targets_tbl[new_value].modename,
+ new_value);
+
+ bond->params.arp_all_targets = new_value;
+
+ return count;
+}
+
+static DEVICE_ATTR(arp_all_targets, S_IRUGO | S_IWUSR,
+ bonding_show_arp_all_targets, bonding_store_arp_all_targets);
/*
* Show and store fail_over_mac. User only allowed to change the
@@ -590,10 +628,11 @@
struct device_attribute *attr,
const char *buf, size_t count)
{
- __be32 newtarget;
- int i = 0, ret = -EINVAL;
struct bonding *bond = to_bond(d);
- __be32 *targets;
+ struct slave *slave;
+ __be32 newtarget, *targets;
+ unsigned long *targets_rx;
+ int ind, i, j, ret = -EINVAL;
targets = bond->params.arp_targets;
newtarget = in_aton(buf + 1);
@@ -611,8 +650,8 @@
goto out;
}
- i = bond_get_targets_ip(targets, 0); /* first free slot */
- if (i == -1) {
+ ind = bond_get_targets_ip(targets, 0); /* first free slot */
+ if (ind == -1) {
pr_err("%s: ARP target table is full!\n",
bond->dev->name);
goto out;
@@ -620,7 +659,12 @@
pr_info("%s: adding ARP target %pI4.\n", bond->dev->name,
&newtarget);
- targets[i] = newtarget;
+ /* not to race with bond_arp_rcv */
+ write_lock_bh(&bond->lock);
+ bond_for_each_slave(bond, slave, i)
+ slave->target_last_arp_rx[ind] = jiffies;
+ targets[ind] = newtarget;
+ write_unlock_bh(&bond->lock);
} else if (buf[0] == '-') {
if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
pr_err("%s: invalid ARP target %pI4 specified for removal\n",
@@ -628,18 +672,32 @@
goto out;
}
- i = bond_get_targets_ip(targets, newtarget);
- if (i == -1) {
- pr_info("%s: unable to remove nonexistent ARP target %pI4.\n",
+ ind = bond_get_targets_ip(targets, newtarget);
+ if (ind == -1) {
+ pr_err("%s: unable to remove nonexistent ARP target %pI4.\n",
bond->dev->name, &newtarget);
goto out;
}
+ if (ind == 0 && !targets[1] && bond->params.arp_interval)
+ pr_warn("%s: removing last arp target with arp_interval on\n",
+ bond->dev->name);
+
pr_info("%s: removing ARP target %pI4.\n", bond->dev->name,
&newtarget);
- for (; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
+
+ write_lock_bh(&bond->lock);
+ bond_for_each_slave(bond, slave, i) {
+ targets_rx = slave->target_last_arp_rx;
+ j = ind;
+ for (; (j < BOND_MAX_ARP_TARGETS-1) && targets[j+1]; j++)
+ targets_rx[j] = targets_rx[j+1];
+ targets_rx[j] = 0;
+ }
+ for (i = ind; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
targets[i] = targets[i+1];
targets[i] = 0;
+ write_unlock_bh(&bond->lock);
} else {
pr_err("no command found in arp_ip_targets file for bond %s. Use +<addr> or -<addr>.\n",
bond->dev->name);
@@ -1623,6 +1681,7 @@
&dev_attr_mode.attr,
&dev_attr_fail_over_mac.attr,
&dev_attr_arp_validate.attr,
+ &dev_attr_arp_all_targets.attr,
&dev_attr_arp_interval.attr,
&dev_attr_arp_ip_target.attr,
&dev_attr_downdelay.attr,