tree 097d2f21d367ae28eaa40fc5d1ee9519f8932687
parent bb9fbe2ddd6d6111c5fe5987fa1e71da7d2ab854
parent f2ebd477f141bc09b10fb8deb612a4d9b8999bba
author David S. Miller <davem@davemloft.net> 1390857170 -0800
committer David S. Miller <davem@davemloft.net> 1390857170 -0800

Merge branch 'bonding'

Veaceslav Falico says:

====================
bonding: fix locking in bond_ab_arp_prob

After the latest patches, on every call of bond_ab_arp_probe() without an
active slave I see the following warning:

[    7.912314] RTNL: assertion failed at net/core/dev.c (4494)
...
[    7.922495]  [<ffffffff817acc6f>] dump_stack+0x51/0x72
[    7.923714]  [<ffffffff8168795e>] netdev_master_upper_dev_get+0x6e/0x70
[    7.924940]  [<ffffffff816a2a66>] rtnl_link_fill+0x116/0x260
[    7.926143]  [<ffffffff817acc6f>] ? dump_stack+0x51/0x72
[    7.927333]  [<ffffffff816a350c>] rtnl_fill_ifinfo+0x95c/0xb90
[    7.928529]  [<ffffffff8167af2b>] ? __kmalloc_reserve+0x3b/0xa0
[    7.929681]  [<ffffffff8167bfcf>] ? __alloc_skb+0x9f/0x1e0
[    7.930827]  [<ffffffff816a3b64>] rtmsg_ifinfo+0x84/0x100
[    7.931960]  [<ffffffffa00bca07>] bond_ab_arp_probe+0x1a7/0x370 [bonding]
[    7.933133]  [<ffffffffa00bcd78>] bond_activebackup_arp_mon+0x1a8/0x2f0 [bonding]
...

It happens because in bond_ab_arp_probe() we change the flags of a slave
without holding the RTNL lock.

To fix this - remove the useless curr_active_lock, RCUify it and lock RTNL
while changing the slave's flags. Also, remove bond_ab_arp_probe() from
under any locks in bond_ab_arp_mon().
====================

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>