[PATCH v2 net-next 0/6] bonding: prepare to and add arp_all_targets

[Veaceslav Falico <vfalico@redhat.com>]

Hi,

This patchset does some cleanup, fixes a few flaws and adds a new parameter
to control whether the slave should stay up when any of arp_ip_targets are
up or all of them are up (i.e. if the slave should go down if even one
target from arp_ip_targets fail).

The patches 1-5 basicly prepare the bonding code to work properly with this
new parameter, however it's not depending on them.

All comments are really welcome.

v1->v2:

Drop "[1/6] bonding: verify if bond has ip only once on arp validate", per
Jay's advice, it's really useless as a standalone patch (though the change
itself will appear in 2/6).

Fix "[2/6] bonding: add helper function bond_get_targets_ip(targets, ip)",
per Nikolay's advice, to verify if source ip != 0.0.0.0, otherwise we might
update 'null' arp_ip_targets' last_rx. Also, address style.

Drop "[5/6] bonding: don't swap arp's ips on validation for backup slave",
per Jay's advice, though it does address cyclic failover issue - it
disables a good optimization. Instead, update the documentation and fix the
cyclic loop issue in the following patch.

Add "bonding: don't trust arp requests unless active slave really works",
this patch fixes the cyclic loop that occurs when we can't reach
arp_ip_target and fool ourselves with our own generated arp requests. It's
done by checking if we currently have a current active slave and if this
slave received at least one arp reply after its 'nomination' to active.

Add "bonding: doc: some details on backup slave arp validation",
this patch describes a bit more in detail how the backup slave arp
validation works.

Fix "[6/6] bonding: add an option to fail when any of arp_ip_target is
inaccessible", per Nikolay's advice, to 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.

Thanks!

Veaceslav Falico (6):
      bonding: add helper function bond_get_targets_ip(targets, ip)
      bonding: don't add duplicate targets to arp_ip_target
      bonding: don't validate arp if we don't have to
      bonding: don't trust arp requests unless active slave really works
      bonding: doc: some details on backup slave arp validation
      bonding: add an option to fail when any of arp_ip_target is inaccessible

 Documentation/networking/bonding.txt |   23 ++++++
 drivers/net/bonding/bond_main.c      |   70 ++++++++++++++----
 drivers/net/bonding/bond_sysfs.c     |  131 ++++++++++++++++++++++++---------
 drivers/net/bonding/bonding.h        |   46 +++++++++++-
 4 files changed, 218 insertions(+), 52 deletions(-)