commit 991fb3f7 "dev: always advertise rx_flags changes via netlink"
introduced rtnl notification from __dev_set_promiscuity(),
which can be called in atomic context.

Steps to reproduce:
ip tuntap add dev tap1 mode tap
ifconfig tap1 up
tcpdump -nei tap1 &
ip tuntap del dev tap1 mode tap

[  271.627994] device tap1 left promiscuous mode
[  271.639897] BUG: sleeping function called from invalid context at mm/slub.c:940
[  271.664491] in_atomic(): 1, irqs_disabled(): 0, pid: 3394, name: ip
[  271.677525] INFO: lockdep is turned off.
[  271.690503] CPU: 0 PID: 3394 Comm: ip Tainted: G        W    3.12.0-rc3+ #73
[  271.703996] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
[  271.731254]  ffffffff81a58506 ffff8807f0d57a58 ffffffff817544e5 ffff88082fa0f428
[  271.760261]  ffff8808071f5f40 ffff8807f0d57a88 ffffffff8108bad1 ffffffff81110ff8
[  271.790683]  0000000000000010 00000000000000d0 00000000000000d0 ffff8807f0d57af8
[  271.822332] Call Trace:
[  271.838234]  [<ffffffff817544e5>] dump_stack+0x55/0x76
[  271.854446]  [<ffffffff8108bad1>] __might_sleep+0x181/0x240
[  271.870836]  [<ffffffff81110ff8>] ? rcu_irq_exit+0x68/0xb0
[  271.887076]  [<ffffffff811a80be>] kmem_cache_alloc_node+0x4e/0x2a0
[  271.903368]  [<ffffffff810b4ddc>] ? vprintk_emit+0x1dc/0x5a0
[  271.919716]  [<ffffffff81614d67>] ? __alloc_skb+0x57/0x2a0
[  271.936088]  [<ffffffff810b4de0>] ? vprintk_emit+0x1e0/0x5a0
[  271.952504]  [<ffffffff81614d67>] __alloc_skb+0x57/0x2a0
[  271.968902]  [<ffffffff8163a0b2>] rtmsg_ifinfo+0x52/0x100
[  271.985302]  [<ffffffff8162ac6d>] __dev_notify_flags+0xad/0xc0
[  272.001642]  [<ffffffff8162ad0c>] __dev_set_promiscuity+0x8c/0x1c0
[  272.017917]  [<ffffffff81731ea5>] ? packet_notifier+0x5/0x380
[  272.033961]  [<ffffffff8162b109>] dev_set_promiscuity+0x29/0x50
[  272.049855]  [<ffffffff8172e937>] packet_dev_mc+0x87/0xc0
[  272.065494]  [<ffffffff81732052>] packet_notifier+0x1b2/0x380
[  272.080915]  [<ffffffff81731ea5>] ? packet_notifier+0x5/0x380
[  272.096009]  [<ffffffff81761c66>] notifier_call_chain+0x66/0x150
[  272.110803]  [<ffffffff8108503e>] __raw_notifier_call_chain+0xe/0x10
[  272.125468]  [<ffffffff81085056>] raw_notifier_call_chain+0x16/0x20
[  272.139984]  [<ffffffff81620190>] call_netdevice_notifiers_info+0x40/0x70
[  272.154523]  [<ffffffff816201d6>] call_netdevice_notifiers+0x16/0x20
[  272.168552]  [<ffffffff816224c5>] rollback_registered_many+0x145/0x240
[  272.182263]  [<ffffffff81622641>] rollback_registered+0x31/0x40
[  272.195369]  [<ffffffff816229c8>] unregister_netdevice_queue+0x58/0x90
[  272.208230]  [<ffffffff81547ca0>] __tun_detach+0x140/0x340
[  272.220686]  [<ffffffff81547ed6>] tun_chr_close+0x36/0x60
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Jiri noted, currently we first do all bonding-specific initialization
(specifically - bond_select_active_slave(bond)) before we actually attach
the slave (so that it becomes visible through bond_for_each_slave() and
friends). This might result in bond_select_active_slave() not seeing the
first/new slave and, thus, not actually selecting an active slave.

Fix this by moving all the bond-related init part after we've actually
completely initialized and linked (via bond_master_upper_dev_link()) the
new slave.

Also, remove the bond_(de/a)ttach_slave(), it's useless to have functions
to ++/-- one int.

After this we have all the initialization of the new slave *before*
linking, and all the stuff that needs to be done on bonding *after* it. It
has also a bonus effect - we can remove the locking on the new slave init
completely, and only use it for bond_select_active_slave().
Reported-by: NJiri Pirko <jiri@resnulli.us>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Acked-by: Ding Tianhong@huawei.com
Reviewed-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

no longer needed since bond_option_active_slave_set() can be used
instead.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds two new hash policy modes which use skb_flow_dissect:
3 - Encapsulated layer 2+3
4 - Encapsulated layer 3+4
There should be a good improvement for tunnel users in those modes.
It also changes the old hash functions to:
hash ^= (__force u32)flow.dst ^ (__force u32)flow.src;
hash ^= (hash >> 16);
hash ^= (hash >> 8);

Where hash will be initialized either to L2 hash, that is
SRCMAC[5] XOR DSTMAC[5], or to flow->ports which should be extracted
from the upper layer. Flow's dst and src are also extracted based on the
xmit policy either directly from the buffer or by using skb_flow_dissect,
but in both cases if the protocol is IPv6 then dst and src are obtained by
ipv6_addr_hash() on the real addresses. In case of a non-dissectable
packet, the algorithms fall back to L2 hashing.
The bond_set_mode_ops() function is now obsolete and thus deleted
because it was used only to set the proper hash policy. Also we trim a
pointer from struct bonding because we no longer need to keep the hash
function, now there's only a single hash function - bond_xmit_hash that
works based on bond->params.xmit_policy.

The hash function and skb_flow_dissect were suggested by Eric Dumazet.
The layer names were suggested by Andy Gospodarek, because I suck at
semantics.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we rely on rtnl locking in bond_set_rx_mode(), however it's not
always the case:

RTNL: assertion failed at drivers/net/bonding/bond_main.c (3391)
...
 [<ffffffff81651ca5>] dump_stack+0x54/0x74
 [<ffffffffa029e717>] bond_set_rx_mode+0xc7/0xd0 [bonding]
 [<ffffffff81553af7>] __dev_set_rx_mode+0x57/0xa0
 [<ffffffff81557ff8>] __dev_mc_add+0x58/0x70
 [<ffffffff81558020>] dev_mc_add+0x10/0x20
 [<ffffffff8161e26e>] igmp6_group_added+0x18e/0x1d0
 [<ffffffff81186f76>] ? kmem_cache_alloc_trace+0x236/0x260
 [<ffffffff8161f80f>] ipv6_dev_mc_inc+0x29f/0x320
 [<ffffffff8161f9e7>] ipv6_sock_mc_join+0x157/0x260
...

Fix this by using RCU primitives.
Reported-by: NJoe Lawrence <joe.lawrence@stratus.com>
Tested-by: NJoe Lawrence <joe.lawrence@stratus.com>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recently grabbed this report:
https://bugzilla.redhat.com/show_bug.cgi?id=1005567

Of an issue in which the bonding driver, with an attached vlan encountered the
following errors when bond0 was taken down and back up:

dummy1: promiscuity touches roof, set promiscuity failed. promiscuity feature of
device might be broken.

The error occurs because, during __bond_release_one, if we release our last
slave, we take on a random mac address and issue a NETDEV_CHANGEADDR
notification.  With an attached vlan, the vlan may see that the vlan and bond
mac address were in sync, but no longer are.  This triggers a call to dev_uc_add
and dev_set_rx_mode, which enables IFF_PROMISC on the bond device.  Then, when
we complete __bond_release_one, we use the current state of the bond flags to
determine if we should decrement the promiscuity of the releasing slave.  But
since the bond changed promiscuity state during the release operation, we
incorrectly decrement the slave promisc count when it wasn't in promiscuous mode
to begin with, causing the above error

Fix is pretty simple, just cache the bonding flags at the start of the function
and use those when determining the need to set promiscuity.

This is also needed for the ALLMULTI flag

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Mark Wu <wudxw@linux.vnet.ibm.com>
CC: "David S. Miller" <davem@davemloft.net>
Reported-by: NMark Wu <wudxw@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After commit 1f718f0f ("bonding: populate
neighbour's private on enslave"), we've moved the actual 'linking' in the
end of the function - so that, once linked, the slave is ready to be used,
and is not still in the process of enslaving.

However, 802.3ad verified if it's the first slave by looking at the

if (bond_first_slave(bond) == new_slave)

which, because we've moved the linking to the end, became broken - on the
first slave bond_first_slave(bond) returns NULL.

Fix this by verifying if the prev_slave, that equals bond_last_slave(), is
actually populated - if it is - then it's not the first slave, and vice
versa.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also, remove the same functionality from bonding - it will be already done
for any device that links to its lower/upper neighbour.

The links will be created for dev's kobject, and will look like
lower_eth0 for lower device eth0 and upper_bridge0 for upper device
bridge0.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

And all the initialization.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't really need it, and it's really hard to RCUify the list->prev.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we verify if we have slaves by checking if bond->slave_list is
empty. Create a define bond_has_slaves() and use it, a bit more readable
and easier to change in the future.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently it uses the hard-to-rcuify bond_for_each_slave_from(), and also
it doesn't check every slave for disrepencies between the actual
IS_UP(slave) and the slave->link == BOND_LINK_UP, but only till we find the
next suitable slave.

Fix this by using bond_for_each_slave() and storing the first good slave in
*before till we find the current_arp_slave, after that we store the first good
slave in new_slave. If new_slave is empty - use the slave stored in before,
and if it's also empty - then we didn't find any suitable slave.

Also, in the meanwhile, check for each slave status.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bond_find_best_slave() does not have to be balanced - i.e. return the slave
that is *after* some other slave, but rather return the best slave that
suits, except of bond->primary_slave - in which case we just return it if
it's suitable.

After that we just look through all the slaves and return either first up
slave or the slave whose link came back earliest.

We also don't care about curr_active_slave lock cause we use it in
bond_should_change_active() only and there we take it right away - i.e. it
won't go away.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're safe agains removal there, cause we use neighbours primitives.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It needs a list_head *iter, so add it wherever needed. Use both non-rcu and
rcu variants.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We only use it in rollback scenarios and can easily use the standart
bond_for_each_dev() instead.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the new provided function when attaching the lower slave to populate
its ->private with struct slave *new_slave. Also, move it to the end to
be able to 'find' it only after it was completely initialized, and
deinitialize in the first place on release.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, we distinguish neighbours (first-level linked devices) from
non-neighbours by the neighbour bool in the netdev_adjacent. This could be
quite time-consuming in case we would like to traverse *only* through
neighbours - cause we'd have to traverse through all devices and check for
this flag, and in a (quite common) scenario where we have lots of vlans on
top of bridge, which is on top of a bond - the bonding would have to go
through all those vlans to get its upper neighbour linked devices.

This situation is really unpleasant, cause there are already a lot of cases
when a device with slaves needs to go through them in hot path.

To fix this, introduce a new upper/lower device lists structure -
adj_list, which contains only the neighbours. It works always in
pair with the all_adj_list structure (renamed from upper/lower_dev_list),
i.e. both of them contain the same links, only that all_adj_list contains
also non-neighbour device links. It's really a small change visible,
currently, only for __netdev_adjacent_dev_insert/remove(), and doesn't
change the main linked logic at all.

Also, add some comments a fix a name collision in
netdev_for_each_upper_dev_rcu() and rework the naming by the following
rules:

netdev_(all_)(upper|lower)_*

If "all_" is present, then we work with the whole list of upper/lower
devices, otherwise - only with direct neighbours. Uninline functions - to
get better stack traces.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

running bonding in ALB mode requires that learning packets be sent periodically,
so that the switch knows where to send responding traffic.  However, depending
on switch configuration, there may not be any need to send traffic at the
default rate of 3 packets per second, which represents little more than wasted
data.  Allow the ALB learning packet interval to be made configurable via sysfs
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Acked-by: NAcked-by: Veaceslav Falico <vfalico@redhat.com>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndy Gospodarek <andy@greyhouse.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We make bond_arp_rcv global so it can be used in bond_sysfs if the bond
interface is up and arp_interval is being changed to a positive value
and cleared otherwise as per Jay's suggestion.
This also fixes a problem where bond_arp_rcv was set even though
arp_validate was disabled while the bond was up by unsetting recv_probe
in bond_store_arp_validate and respectively setting it if enabled.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NMarcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bond_compute_features is always called with RTNL held, so we can safely
drop the read bond->lock.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're protected by RTNL so nothing can happen and we can safely drop the
read bond->lock.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We don't have to release all slaves when closing the bond dev, so remove
the outdated comment and the braces around the left single statement.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch aims to remove a use of the bond->lock for mutual exclusion
which will later allow easier migration to RCU of the users of this
functionality. We use RTNL as a synchronizing mechanism since it's
always held when send_peer_notif is set, and when it is decremented from
the notifier function. We can also drop some locking, and fix the
leakage of the send_peer_notif counter.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

They're simply annoying and will spam dmesg constantly if we hit them, so
convert to pr_debug so that we still can access them in case of debugging.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there are no real users of vlan_list/current_alb_vlan, only the
helpers which maintain them, so remove them.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We always hold the rtnl_lock() in __bond_release_one(), so use
vlan_uses_dev() instead of bond_vlan_used().

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, bond_has_this_ip() is aware only of vlan upper devices, and thus
will return false if the address is associated with the upper bridge or any
other device, and thus will break the arp logic.

Fix this by using the upper device list. For every upper device we verify
if the address associated with it is our address, and if yes - return true.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, bond_arp_send_all() is aware only of vlans, which breaks
configurations like bond <- bridge (or any other 'upper' device) with IP
(which is quite a common scenario for virt setups).

To fix this we convert the bond_arp_send_all() to first verify if the rt
device is the bond itself, and if not - to go through its list of upper
vlans and their respectiv upper devices (if the vlan's upper device matches
- tag the packet), if still not found - go through all of our upper list
devices to see if any of them match the route device for the target. If the
match is a vlan device - we also save its vlan_id and tag it in
bond_arp_send().

Also, clean the function a bit to be more readable.

CC: Vlad Yasevich <vyasevic@redhat.com>
CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to return a negative error code in the add bond vlan ids error
handling case instead of 0, as done elsewhere in this function.

Introduced by commit 1ff412ad.
(bonding: change the bond's vlan syncing functions with the standard ones)
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In case of bond_add_vlan() failure currently we'll have the vlan's
refcnt bumped up in all slaves, but it will never go down because it
failed to get added to the bond, so properly unwind the added vlan if
bond_add_vlan fails.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now we have vlan_vids_add/del_by_dev() which serve the same purpose as
bond's bond_add/del_vlans_on_slave() with the good side effect of
reverting the changes if one of the additions fails.
There's only 1 change in the behaviour of enslave: if adding of the
vlans to the slave fails, we'll fail the enslaving because otherwise we
might delete some vlan that wasn't added by the bonding.
The only way this may happen is with ENOMEM currently, so we're in trouble
anyway.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Acked-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise, on neighbour creation, bond_neigh_init() will be called with a
foreign netdev.
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're already protected by RTNL lock, so nothing can happen to bond/its
slaves, and thus the locking is useless here (both bond->lock and
bond->curr_active_slave).

Also, add ASSERT_RTNL() both to bond_set_rx_mode() and bond_hw_addr_swap()
to catch possible uses of it without RTNL locking.

This patch also saves us from a lockdep false-positive in
bond_set_rx_mode() vs bond_hw_addr_swap().

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we use a lot of time comparison math for arp_interval
comparisons, which are sometimes quite hard to read and understand.

All the time comparisons have one pattern:
(time - arp_interval_jiffies) <= jiffies <= (time + mod *
arp_interval_jiffies + arp_interval_jiffies/2)

Introduce a new helper - bond_time_in_interval(), which will do the math in
one place and, thus, will clean up the logical code. This helper introduces
a bit of overhead (by always calculating the jiffies from arp_interval),
however it's really not visible, considering that functions using it
usually run once in arp_interval milliseconds.

There are several lines slightly over 80 chars, however breaking them would
result in more hard-to-read code than several character after the 80 mark.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simple cleanup to not call slave_last_rx() on every time function. It won't
give any measurable boost - but looks cleaner and easier to understand.

There are no time-consuming functions in between these calls, so it's safe
to call it in the beginning only once.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Otherwise, on neighbour creation, bond_neigh_init() will be called with a
foreign netdev.
Signed-off-by: NVeaceslav Falico <vfalico@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch does the initial bonding conversion to RCU. After it the
following modes are protected by RCU alone: roundrobin, active-backup,
broadcast and xor. Modes ALB/TLB and 3ad still acquire bond->lock for
reading, and will be dealt with later. curr_active_slave needs to be
dereferenced via rcu in the converted modes because the only thing
protecting the slave after this patch is rcu_read_lock, so we need the
proper barrier for weakly ordered archs and to make sure we don't have
stale pointer. It's not tagged with __rcu yet because there's still work
to be done to remove the curr_slave_lock, so sparse will complain when
rcu_assign_pointer and rcu_dereference are used, but the alternative to use
rcu_dereference_protected would've created much bigger code churn which is
more difficult to test and review. That will be converted in time.

1. Active-backup mode
 1.1 Perf recording while doing iperf -P 4
  - old bonding: iperf spent 0.55% in bonding, system spent 0.29% CPU
                 in bonding
  - new bonding: iperf spent 0.29% in bonding, system spent 0.15% CPU
                 in bonding
 1.2. Bandwidth measurements
  - old bonding: 16.1 gbps consistently
  - new bonding: 17.5 gbps consistently

2. Round-robin mode
 2.1 Perf recording while doing iperf -P 4
  - old bonding: iperf spent 0.51% in bonding, system spent 0.24% CPU
                 in bonding
  - new bonding: iperf spent 0.16% in bonding, system spent 0.11% CPU
                 in bonding
 2.2 Bandwidth measurements
  - old bonding: 8 gbps (variable due to packet reorderings)
  - new bonding: 10 gbps (variable due to packet reorderings)

Of course the latency has improved in all converted modes, and moreover
while
doing enslave/release (since it doesn't affect tx anymore).

Also I've stress tested all modes doing enslave/release in a loop while
transmitting traffic.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I factored out the tx xmit code which relies on slave id in
bond_xmit_slave_id. It is global because later it can be used also in
3ad mode xmit. Unnecessary obvious comments are removed. Active-backup
mode is simplified because bond_dev_queue_xmit always consumes the skb.
bond_xmit_xor becomes one line because of bond_xmit_slave_id.
bond_for_each_slave_from is not used in bond_xmit_slave_id because later
when RCU is used we can avoid important race condition by using standard
rculist routines.
Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>