4 files changed, 232 insertions, 89 deletions

diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index a0cda062bc33..8e6b8d3c7410 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -289,35 +289,73 @@ downdelay
 fail_over_mac
 
         Specifies whether active-backup mode should set all slaves to
-        the same MAC address (the traditional behavior), or, when
-        enabled, change the bond's MAC address when changing the
-        active interface (i.e., fail over the MAC address itself).
-
-        Fail over MAC is useful for devices that cannot ever alter
-        their MAC address, or for devices that refuse incoming
-        broadcasts with their own source MAC (which interferes with
-        the ARP monitor).
-
-        The down side of fail over MAC is that every device on the
-        network must be updated via gratuitous ARP, vs. just updating
-        a switch or set of switches (which often takes place for any
-        traffic, not just ARP traffic, if the switch snoops incoming
-        traffic to update its tables) for the traditional method.  If
-        the gratuitous ARP is lost, communication may be disrupted.
-
-        When fail over MAC is used in conjuction with the mii monitor,
-        devices which assert link up prior to being able to actually
-        transmit and receive are particularly susecptible to loss of
-        the gratuitous ARP, and an appropriate updelay setting may be
-        required.
-
-        A value of 0 disables fail over MAC, and is the default.  A
-        value of 1 enables fail over MAC.  This option is enabled
-        automatically if the first slave added cannot change its MAC
-        address.  This option may be modified via sysfs only when no
-        slaves are present in the bond.
-
-        This option was added in bonding version 3.2.0.
+        the same MAC address at enslavement (the traditional
+        behavior), or, when enabled, perform special handling of the
+        bond's MAC address in accordance with the selected policy.
+
+        Possible values are:
+
+        none or 0
+
+                This setting disables fail_over_mac, and causes
+                bonding to set all slaves of an active-backup bond to
+                the same MAC address at enslavement time.  This is the
+                default.
+
+        active or 1
+
+                The "active" fail_over_mac policy indicates that the
+                MAC address of the bond should always be the MAC
+                address of the currently active slave.  The MAC
+                address of the slaves is not changed; instead, the MAC
+                address of the bond changes during a failover.
+
+                This policy is useful for devices that cannot ever
+                alter their MAC address, or for devices that refuse
+                incoming broadcasts with their own source MAC (which
+                interferes with the ARP monitor).
+
+                The down side of this policy is that every device on
+                the network must be updated via gratuitous ARP,
+                vs. just updating a switch or set of switches (which
+                often takes place for any traffic, not just ARP
+                traffic, if the switch snoops incoming traffic to
+                update its tables) for the traditional method.  If the
+                gratuitous ARP is lost, communication may be
+                disrupted.
+
+                When this policy is used in conjuction with the mii
+                monitor, devices which assert link up prior to being
+                able to actually transmit and receive are particularly
+                susecptible to loss of the gratuitous ARP, and an
+                appropriate updelay setting may be required.
+
+        follow or 2
+
+                The "follow" fail_over_mac policy causes the MAC
+                address of the bond to be selected normally (normally
+                the MAC address of the first slave added to the bond).
+                However, the second and subsequent slaves are not set
+                to this MAC address while they are in a backup role; a
+                slave is programmed with the bond's MAC address at
+                failover time (and the formerly active slave receives
+                the newly active slave's MAC address).
+
+                This policy is useful for multiport devices that
+                either become confused or incur a performance penalty
+                when multiple ports are programmed with the same MAC
+                address.
+
+
+        The default policy is none, unless the first slave cannot
+        change its MAC address, in which case the active policy is
+        selected by default.
+
+        This option may be modified via sysfs only when no slaves are
+        present in the bond.
+
+        This option was added in bonding version 3.2.0.  The "follow"
+        policy was added in bonding version 3.3.0.
 
 lacp_rate
 
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 51e0f2de42c6..5b4af3cc2a44 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -100,7 +100,7 @@ static char *xmit_hash_policy = NULL;
 static int arp_interval = BOND_LINK_ARP_INTERV;
 static char *arp_ip_target[BOND_MAX_ARP_TARGETS] = { NULL, };
 static char *arp_validate = NULL;
-static int fail_over_mac = 0;
+static char *fail_over_mac = NULL;
 struct bond_params bonding_defaults;
 
 module_param(max_bonds, int, 0);
@@ -136,8 +136,8 @@ module_param_array(arp_ip_target, charp, NULL, 0);
 MODULE_PARM_DESC(arp_ip_target, "arp targets in n.n.n.n form");
 module_param(arp_validate, charp, 0);
 MODULE_PARM_DESC(arp_validate, "validate src/dst of ARP probes: none (default), active, backup or all");
-module_param(fail_over_mac, int, 0);
-MODULE_PARM_DESC(fail_over_mac, "For active-backup, do not set all slaves to the same MAC.  0 of off (default), 1 for on.");
+module_param(fail_over_mac, charp, 0);
+MODULE_PARM_DESC(fail_over_mac, "For active-backup, do not set all slaves to the same MAC.  none (default), active or follow");
 
 /*----------------------------- Global variables ----------------------------*/
 
@@ -190,6 +190,13 @@ struct bond_parm_tbl arp_validate_tbl[] = {
 {       NULL,                   -1},
 };
 
+struct bond_parm_tbl fail_over_mac_tbl[] = {
+{       "none",                 BOND_FOM_NONE},
+{       "active",               BOND_FOM_ACTIVE},
+{       "follow",               BOND_FOM_FOLLOW},
+{       NULL,                   -1},
+};
+
 /*-------------------------- Forward declarations ---------------------------*/
 
 static void bond_send_gratuitous_arp(struct bonding *bond);
@@ -973,6 +980,82 @@ static void bond_mc_swap(struct bonding *bond, struct slave *new_active, struct
         }
 }
 
+/*
+ * bond_do_fail_over_mac
+ *
+ * Perform special MAC address swapping for fail_over_mac settings
+ *
+ * Called with RTNL, bond->lock for read, curr_slave_lock for write_bh.
+ */
+static void bond_do_fail_over_mac(struct bonding *bond,
+                                  struct slave *new_active,
+                                  struct slave *old_active)
+{
+        u8 tmp_mac[ETH_ALEN];
+        struct sockaddr saddr;
+        int rv;
+
+        switch (bond->params.fail_over_mac) {
+        case BOND_FOM_ACTIVE:
+                if (new_active)
+                        memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
+                               new_active->dev->addr_len);
+                break;
+        case BOND_FOM_FOLLOW:
+                /*
+                 * if new_active && old_active, swap them
+                 * if just old_active, do nothing (going to no active slave)
+                 * if just new_active, set new_active to bond's MAC
+                 */
+                if (!new_active)
+                        return;
+
+                write_unlock_bh(&bond->curr_slave_lock);
+                read_unlock(&bond->lock);
+
+                if (old_active) {
+                        memcpy(tmp_mac, new_active->dev->dev_addr, ETH_ALEN);
+                        memcpy(saddr.sa_data, old_active->dev->dev_addr,
+                               ETH_ALEN);
+                        saddr.sa_family = new_active->dev->type;
+                } else {
+                        memcpy(saddr.sa_data, bond->dev->dev_addr, ETH_ALEN);
+                        saddr.sa_family = bond->dev->type;
+                }
+
+                rv = dev_set_mac_address(new_active->dev, &saddr);
+                if (rv) {
+                        printk(KERN_ERR DRV_NAME
+                               ": %s: Error %d setting MAC of slave %s\n",
+                               bond->dev->name, -rv, new_active->dev->name);
+                        goto out;
+                }
+
+                if (!old_active)
+                        goto out;
+
+                memcpy(saddr.sa_data, tmp_mac, ETH_ALEN);
+                saddr.sa_family = old_active->dev->type;
+
+                rv = dev_set_mac_address(old_active->dev, &saddr);
+                if (rv)
+                        printk(KERN_ERR DRV_NAME
+                               ": %s: Error %d setting MAC of slave %s\n",
+                               bond->dev->name, -rv, new_active->dev->name);
+out:
+                read_lock(&bond->lock);
+                write_lock_bh(&bond->curr_slave_lock);
+                break;
+        default:
+                printk(KERN_ERR DRV_NAME
+                       ": %s: bond_do_fail_over_mac impossible: bad policy %d\n",
+                       bond->dev->name, bond->params.fail_over_mac);
+                break;
+        }
+
+}
+
+
 /**
  * find_best_interface - select the best available slave to be the active one
  * @bond: our bonding struct
@@ -1040,7 +1123,8 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
  * because it is apparently the best available slave we have, even though its
  * updelay hasn't timed out yet.
  *
- * Warning: Caller must hold curr_slave_lock for writing.
+ * If new_active is not NULL, caller must hold bond->lock for read and
+ * curr_slave_lock for write_bh.
  */
 void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
 {
@@ -1107,12 +1191,9 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
                         bond_set_slave_active_flags(new_active);
                 }
 
-                /* when bonding does not set the slave MAC address, the bond MAC
-                 * address is the one of the active slave.
-                 */
                 if (new_active && bond->params.fail_over_mac)
-                        memcpy(bond->dev->dev_addr,  new_active->dev->dev_addr,
-                                new_active->dev->addr_len);
+                        bond_do_fail_over_mac(bond, new_active, old_active);
+
                 bond->send_grat_arp = bond->params.num_grat_arp;
                 if (bond->curr_active_slave &&
                         test_bit(__LINK_STATE_LINKWATCH_PENDING,
@@ -1137,7 +1218,7 @@ void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
  * - The primary_slave has got its link back.
  * - A slave has got its link back and there's no old curr_active_slave.
  *
- * Warning: Caller must hold curr_slave_lock for writing.
+ * Caller must hold bond->lock for read and curr_slave_lock for write_bh.
  */
 void bond_select_active_slave(struct bonding *bond)
 {
@@ -1384,14 +1465,14 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                         printk(KERN_WARNING DRV_NAME
                                ": %s: Warning: The first slave device "
                                "specified does not support setting the MAC "
-                               "address. Enabling the fail_over_mac option.",
+                               "address. Setting fail_over_mac to active.",
                                bond_dev->name);
-                        bond->params.fail_over_mac = 1;
-                } else if (!bond->params.fail_over_mac) {
+                        bond->params.fail_over_mac = BOND_FOM_ACTIVE;
+                } else if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
                         printk(KERN_ERR DRV_NAME
                                 ": %s: Error: The slave device specified "
                                 "does not support setting the MAC address, "
-                                "but fail_over_mac is not enabled.\n"
+                                "but fail_over_mac is not set to active.\n"
                                 , bond_dev->name);
                         res = -EOPNOTSUPP;
                         goto err_undo_flags;
@@ -1498,6 +1579,10 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 
         bond_compute_features(bond);
 
+        write_unlock_bh(&bond->lock);
+
+        read_lock(&bond->lock);
+
         new_slave->last_arp_rx = jiffies;
 
         if (bond->params.miimon && !bond->params.use_carrier) {
@@ -1574,6 +1659,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                 }
         }
 
+        write_lock_bh(&bond->curr_slave_lock);
+
         switch (bond->params.mode) {
         case BOND_MODE_ACTIVEBACKUP:
                 bond_set_slave_inactive_flags(new_slave);
@@ -1621,9 +1708,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
                 break;
         } /* switch(bond_mode) */
 
+        write_unlock_bh(&bond->curr_slave_lock);
+
         bond_set_carrier(bond);
 
-        write_unlock_bh(&bond->lock);
+        read_unlock(&bond->lock);
 
         res = bond_create_slave_symlinks(bond_dev, slave_dev);
         if (res)
@@ -1647,6 +1736,10 @@ err_unset_master:
 
 err_restore_mac:
         if (!bond->params.fail_over_mac) {
+                /* XXX TODO - fom follow mode needs to change master's
+                 * MAC if this slave's MAC is in use by the bond, or at
+                 * least print a warning.
+                 */
                 memcpy(addr.sa_data, new_slave->perm_hwaddr, ETH_ALEN);
                 addr.sa_family = slave_dev->type;
                 dev_set_mac_address(slave_dev, &addr);
@@ -1701,20 +1794,18 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
                 return -EINVAL;
         }
 
-        mac_addr_differ = memcmp(bond_dev->dev_addr,
-                                 slave->perm_hwaddr,
-                                 ETH_ALEN);
-        if (!mac_addr_differ && (bond->slave_cnt > 1)) {
-                printk(KERN_WARNING DRV_NAME
-                       ": %s: Warning: the permanent HWaddr of %s - "
-                       "%s - is still in use by %s. "
-                       "Set the HWaddr of %s to a different address "
-                       "to avoid conflicts.\n",
-                       bond_dev->name,
-                       slave_dev->name,
-                       print_mac(mac, slave->perm_hwaddr),
-                       bond_dev->name,
-                       slave_dev->name);
+        if (!bond->params.fail_over_mac) {
+                mac_addr_differ = memcmp(bond_dev->dev_addr, slave->perm_hwaddr,
+                                         ETH_ALEN);
+                if (!mac_addr_differ && (bond->slave_cnt > 1))
+                        printk(KERN_WARNING DRV_NAME
+                               ": %s: Warning: the permanent HWaddr of %s - "
+                               "%s - is still in use by %s. "
+                               "Set the HWaddr of %s to a different address "
+                               "to avoid conflicts.\n",
+                               bond_dev->name, slave_dev->name,
+                               print_mac(mac, slave->perm_hwaddr),
+                               bond_dev->name, slave_dev->name);
         }
 
         /* Inform AD package of unbinding of slave. */
@@ -1841,7 +1932,7 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
         /* close slave before restoring its mac address */
         dev_close(slave_dev);
 
-        if (!bond->params.fail_over_mac) {
+        if (bond->params.fail_over_mac != BOND_FOM_ACTIVE) {
                 /* restore original ("permanent") mac address */
                 memcpy(addr.sa_data, slave->perm_hwaddr, ETH_ALEN);
                 addr.sa_family = slave_dev->type;
@@ -3164,7 +3255,8 @@ static void bond_info_show_master(struct seq_file *seq)
 
         if (bond->params.mode == BOND_MODE_ACTIVEBACKUP &&
             bond->params.fail_over_mac)
-                seq_printf(seq, " (fail_over_mac)");
+                seq_printf(seq, " (fail_over_mac %s)",
+                   fail_over_mac_tbl[bond->params.fail_over_mac].modename);
 
         seq_printf(seq, "\n");
 
@@ -4092,10 +4184,10 @@ static int bond_set_mac_address(struct net_device *bond_dev, void *addr)
         dprintk("bond=%p, name=%s\n", bond, (bond_dev ? bond_dev->name : "None"));
 
         /*
-         * If fail_over_mac is enabled, do nothing and return success.
-         * Returning an error causes ifenslave to fail.
+         * If fail_over_mac is set to active, do nothing and return
+         * success.  Returning an error causes ifenslave to fail.
          */
-        if (bond->params.fail_over_mac)
+        if (bond->params.fail_over_mac == BOND_FOM_ACTIVE)
                 return 0;
 
         if (!is_valid_ether_addr(sa->sa_data)) {
@@ -4600,7 +4692,7 @@ int bond_parse_parm(const char *buf, struct bond_parm_tbl *tbl)
 
 static int bond_check_params(struct bond_params *params)
 {
-        int arp_validate_value;
+        int arp_validate_value, fail_over_mac_value;
 
         /*
          * Convert string parameters.
@@ -4875,10 +4967,23 @@ static int bond_check_params(struct bond_params *params)
                 primary = NULL;
         }
 
-        if (fail_over_mac && (bond_mode != BOND_MODE_ACTIVEBACKUP))
-                printk(KERN_WARNING DRV_NAME
-                       ": Warning: fail_over_mac only affects "
-                       "active-backup mode.\n");
+        if (fail_over_mac) {
+                fail_over_mac_value = bond_parse_parm(fail_over_mac,
+                                                      fail_over_mac_tbl);
+                if (fail_over_mac_value == -1) {
+                        printk(KERN_ERR DRV_NAME
+                               ": Error: invalid fail_over_mac \"%s\"\n",
+                               arp_validate == NULL ? "NULL" : arp_validate);
+                        return -EINVAL;
+                }
+
+                if (bond_mode != BOND_MODE_ACTIVEBACKUP)
+                        printk(KERN_WARNING DRV_NAME
+                               ": Warning: fail_over_mac only affects "
+                               "active-backup mode.\n");
+        } else {
+                fail_over_mac_value = BOND_FOM_NONE;
+        }
 
         /* fill params struct with the proper values */
         params->mode = bond_mode;
@@ -4892,7 +4997,7 @@ static int bond_check_params(struct bond_params *params)
         params->use_carrier = use_carrier;
         params->lacp_fast = lacp_fast;
         params->primary[0] = 0;
-        params->fail_over_mac = fail_over_mac;
+        params->fail_over_mac = fail_over_mac_value;
 
         if (primary) {
                 strncpy(params->primary, primary, IFNAMSIZ);
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 7a61e9a14386..dd265c69b0df 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -50,6 +50,7 @@ extern struct bond_parm_tbl bond_mode_tbl[];
 extern struct bond_parm_tbl bond_lacp_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[];
 
 static int expected_refcount = -1;
 static struct class *netdev_class;
@@ -547,42 +548,37 @@ static ssize_t bonding_show_fail_over_mac(struct device *d, struct device_attrib
 {
         struct bonding *bond = to_bond(d);
 
-        return sprintf(buf, "%d\n", bond->params.fail_over_mac) + 1;
+        return sprintf(buf, "%s %d\n",
+                       fail_over_mac_tbl[bond->params.fail_over_mac].modename,
+                       bond->params.fail_over_mac);
 }
 
 static ssize_t bonding_store_fail_over_mac(struct device *d, struct device_attribute *attr, const char *buf, size_t count)
 {
         int new_value;
-        int ret = count;
         struct bonding *bond = to_bond(d);
 
         if (bond->slave_cnt != 0) {
                 printk(KERN_ERR DRV_NAME
                        ": %s: Can't alter fail_over_mac with slaves in bond.\n",
                        bond->dev->name);
-                ret = -EPERM;
-                goto out;
+                return -EPERM;
         }
 
-        if (sscanf(buf, "%d", &new_value) != 1) {
+        new_value = bond_parse_parm(buf, fail_over_mac_tbl);
+        if (new_value < 0) {
                 printk(KERN_ERR DRV_NAME
-                       ": %s: no fail_over_mac value specified.\n",
-                       bond->dev->name);
-                ret = -EINVAL;
-                goto out;
+                       ": %s: Ignoring invalid fail_over_mac value %s.\n",
+                       bond->dev->name, buf);
+                return -EINVAL;
         }
 
-        if ((new_value == 0) || (new_value == 1)) {
-                bond->params.fail_over_mac = new_value;
-                printk(KERN_INFO DRV_NAME ": %s: Setting fail_over_mac to %d.\n",
-                       bond->dev->name, new_value);
-        } else {
-                printk(KERN_INFO DRV_NAME
-                       ": %s: Ignoring invalid fail_over_mac value %d.\n",
-                       bond->dev->name, new_value);
-        }
-out:
-        return ret;
+        bond->params.fail_over_mac = new_value;
+        printk(KERN_INFO DRV_NAME ": %s: Setting fail_over_mac to %s (%d).\n",
+               bond->dev->name, fail_over_mac_tbl[new_value].modename,
+               new_value);
+
+        return count;
 }
 
 static DEVICE_ATTR(fail_over_mac, S_IRUGO | S_IWUSR, bonding_show_fail_over_mac, bonding_store_fail_over_mac);
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 8766b1213690..89fd9963db7a 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -248,6 +248,10 @@ static inline struct bonding *bond_get_bond_by_slave(struct slave *slave)
         return (struct bonding *)slave->dev->master->priv;
 }
 
+#define BOND_FOM_NONE                   0
+#define BOND_FOM_ACTIVE                 1
+#define BOND_FOM_FOLLOW                 2
+
 #define BOND_ARP_VALIDATE_NONE          0
 #define BOND_ARP_VALIDATE_ACTIVE        (1 << BOND_STATE_ACTIVE)
 #define BOND_ARP_VALIDATE_BACKUP        (1 << BOND_STATE_BACKUP)