Re: [PATCH net] bonding: set default miimon value for non-arp modes if not set

From: Jarod Wilson <redacted>
Date: Wed, 18 Jul 2018 14:49:36 -0400

For some time now, if you load the bonding driver and configure bond
parameters via sysfs using minimal config options, such as specifying
nothing but the mode, relying on defaults for everything else, modes
that cannot use arp monitoring (802.3ad, balance-tlb, balance-alb) all
wind up with both arp_interval=0 (as it should be) and miimon=0, which
means the miimon monitor thread never actually runs. This is particularly
problematic for 802.3ad.

 ...

I believe this became a major issue as of commit 4d2c0cda0744, which for
802.3ad bonds, sets slave->link = BOND_LINK_DOWN, with a comment about
relying on link monitoring via miimon to set it correctly, but since the
miimon work queue never runs, the link just stays marked down.

If we simply tweak bond_option_mode_set() slightly, we can check for the
non-arp modes having no miimon value set, and insert BOND_DEFAULT_MIIMON,
which gets things back in full working order. This problem exists as far
back as 4.14, and might be worth fixing in all stable trees since, though
the work-around is to simply specify an miimon value yourself.

Reported-by: Bob Ball <redacted>

 ...

Signed-off-by: Jarod Wilson <redacted>

Applied and queued up for -stable, thank you.