An implementation of CoDel AQM, from Kathleen Nichols and Van Jacobson.

http://queue.acm.org/detail.cfm?id=2209336

This AQM main input is no longer queue size in bytes or packets, but the
delay packets stay in (FIFO) queue.

As we don't have infinite memory, we still can drop packets in enqueue()
in case of massive load, but mean of CoDel is to drop packets in
dequeue(), using a control law based on two simple parameters :

target : target sojourn time (default 5ms)
interval : width of moving time window (default 100ms)

Based on initial work from Dave Taht.

Refactored to help future codel inclusion as a plugin for other linux
qdisc (FQ_CODEL, ...), like RED.

include/net/codel.h contains codel algorithm as close as possible than
Kathleen reference.

net/sched/sch_codel.c contains the linux qdisc specific glue.

Separate structures permit a memory efficient implementation of fq_codel
(to be sent as a separate work) : Each flow has its own struct
codel_vars.

timestamps are taken at enqueue() time with 1024 ns precision, allowing
a range of 2199 seconds in queue, and 100Gb links support. iproute2 uses
usec as base unit.

Selected packets are dropped, unless ECN is enabled and packets can get
ECN mark instead.

Tested from 2Mb to 10Gb speeds with no particular problems, on ixgbe and
tg3 drivers (BQL enabled).

Usage: tc qdisc ... codel [ limit PACKETS ] [ target TIME ]
                          [ interval TIME ] [ ecn ]

qdisc codel 10: parent 1:1 limit 2000p target 3.0ms interval 60.0ms ecn
 Sent 13347099587 bytes 8815805 pkt (dropped 0, overlimits 0 requeues 0)
 rate 202365Kbit 16708pps backlog 113550b 75p requeues 0
  count 116 lastcount 98 ldelay 4.3ms dropping drop_next 816us
  maxpacket 1514 ecn_mark 84399 drop_overlimit 0

CoDel must be seen as a base module, and should be used keeping in mind
there is still a FIFO queue. So a typical setup will probably need a
hierarchy of several qdiscs and packet classifiers to be able to meet
whatever constraints a user might have.

One possible example would be to use fq_codel, which combines Fair
Queueing and CoDel, in replacement of sfq / sfq_red.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDave Taht <dave.taht@bufferbloat.net>
Cc: Kathleen Nichols <nichols@pollere.com>
Cc: Van Jacobson <van@pollere.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add an optimized boolean function to check if
2 ethernet addresses are the same.

This is to avoid any confusion about compare_ether_addr_64bits
returning an unsigned, and not being able to use the
compare_ether_addr_64bits function for sorting ala memcmp.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It actually works on the input queue and will use its read mem
routines, thus it's better to have in in the tcp_input.c file.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ETHTOOL_GMODULEINFO returns a new struct ethtool_modinfo that will return the
type and size of plug-in module eeprom (such as SFP+) for parsing
by userland program.

ETHTOOL_GMODULEEEPROM returns the raw eeprom information
using the existing ethtool_eeprom structture to return the data
Signed-off-by: NStuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>

Add a boolean function to check if 2 ethernet addresses
are the same.

This is to avoid any confusion about compare_ether_addr
returning an unsigned, and not being able to use the
compare_ether_addr function for sorting ala memcmp.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

can be used e.g. for ingress traffic policing or
to detect when a host/port consumes more bandwidth than expected.

This is done by optionally making cost to mean
"cost per 16-byte-chunk-of-data" instead of "cost per packet".
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The target allows you to create rules in the "raw" and "mangle" tables
which set the skbuff mark by means of hash calculation within a given
range. The nfmark can influence the routing method (see "Use netfilter
MARK value as routing key") and can also be used by other subsystems to
change their behaviour.

[ Part of this patch has been refactorized and modified by Pablo Neira Ayuso ]
Signed-off-by: NHans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch adds the flags parameter to ipv6_find_hdr. This flags
allows us to:

* know if this is a fragment.
* stop at the AH header, so the information contained in that header
  can be used for some specific packet handling.

This patch also adds the offset parameter for inspection of one
inner IPv6 header that is contained in error messages.
Signed-off-by: NHans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch removes ip_queue support which was marked as obsolete
years ago. The nfnetlink_queue modules provides more advanced
user-space packet queueing mechanism.

This patch also removes capability code included in SELinux that
refers to ip_queue. Otherwise, we break compilation.

Several warning has been sent regarding this to the mailing list
in the past month without anyone rising the hand to stop this
with some strong argument.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Explicit helper attachment via the CT target is broken with NAT
if non-standard ports are used. This problem was hidden behind
the automatic helper assignment routine. Thus, it becomes more
noticeable now that we can disable the automatic helper assignment
with Eric Leblond's:

9e8ac5a netfilter: nf_ct_helper: allow to disable automatic helper assignment

Basically, nf_conntrack_alter_reply asks for looking up the helper
up if NAT is enabled. Unfortunately, we don't have the conntrack
template at that point anymore.

Since we don't want to rely on the automatic helper assignment,
we can skip the second look-up and stick to the helper that was
attached by iptables. With the CT target, the user is in full
control of helper attachment, thus, the policy is to trust what
the user explicitly configures via iptables (no automatic magic
anymore).

Interestingly, this bug was hidden by the automatic helper look-up
code. But it can be easily trigger if you attach the helper in
a non-standard port, eg.

iptables -I PREROUTING -t raw -p tcp --dport 8888 \
	-j CT --helper ftp

And you disabled the automatic helper assignment.

I added the IPS_HELPER_BIT that allows us to differenciate between
a helper that has been explicitly attached and those that have been
automatically assigned. I didn't come up with a better solution
(having backward compatibility in mind).
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

	Allow master and backup servers to use many threads
for sync traffic. Add sysctl var "sync_ports" to define the
number of threads. Every thread will use single UDP port,
thread 0 will use the default port 8848 while last thread
will use port 8848+sync_ports-1.

	The sync traffic for connections is scheduled to many
master threads based on the cp address but one connection is
always assigned to same thread to avoid reordering of the
sync messages.

	Remove ip_vs_sync_switch_mode because this check
for sync mode change is still risky. Instead, check for mode
change under sync_buff_lock.

	Make sure the backup socks do not block on reading.

Special thanks to Aleksey Chudov for helping in all tests.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Tested-by: NAleksey Chudov <aleksey.chudov@gmail.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

	Add two new sysctl vars to control the sync rate with the
main idea to reduce the rate for connection templates because
currently it depends on the packet rate for controlled connections.
This mechanism should be useful also for normal connections
with high traffic.

sync_refresh_period: in seconds, difference in reported connection
	timer that triggers new sync message. It can be used to
	avoid sync messages for the specified period (or half of
	the connection timeout if it is lower) if connection state
	is not changed from last sync.

sync_retries: integer, 0..3, defines sync retries with period of
	sync_refresh_period/8. Useful to protect against loss of
	sync messages.

	Allow sysctl_sync_threshold to be used with
sysctl_sync_period=0, so that only single sync message is sent
if sync_refresh_period is also 0.

	Add new field "sync_endtime" in connection structure to
hold the reported time when connection expires. The 2 lowest
bits will represent the retry count.

	As the sysctl_sync_period now can be 0 use ACCESS_ONCE to
avoid division by zero.

	Special thanks to Aleksey Chudov for being patient with me,
for his extensive reports and helping in all tests.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Tested-by: NAleksey Chudov <aleksey.chudov@gmail.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

	High rate of sync messages in master can lead to
overflowing the socket buffer and dropping the messages.
Fixed sleep of 1 second without wakeup events is not suitable
for loaded masters,

	Use delayed_work to schedule sending for queued messages
and limit the delay to IPVS_SYNC_SEND_DELAY (20ms). This will
reduce the rate of wakeups but to avoid sending long bursts we
wakeup the master thread after IPVS_SYNC_WAKEUP_RATE (8) messages.

	Add hard limit for the queued messages before sending
by using "sync_qlen_max" sysctl var. It defaults to 1/32 of
the memory pages but actually represents number of messages.
It will protect us from allocating large parts of memory
when the sending rate is lower than the queuing rate.

	As suggested by Pablo, add new sysctl var
"sync_sock_size" to configure the SNDBUF (master) or
RCVBUF (slave) socket limit. Default value is 0 (preserve
system defaults).

	Change the master thread to detect and block on
SNDBUF overflow, so that we do not drop messages when
the socket limit is low but the sync_qlen_max limit is
not reached. On ENOBUFS or other errors just drop the
messages.

	Change master thread to enter TASK_INTERRUPTIBLE
state early, so that we do not miss wakeups due to messages or
kthread_should_stop event.

Thanks to Pablo Neira Ayuso for his valuable feedback!
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NSimon Horman <horms@verge.net.au>

	As the goal is to mirror the inactconns/activeconns
counters in the backup server, make sure the cp->flags are
updated even if cp is still not bound to dest. If cp->flags
are not updated ip_vs_bind_dest will rely only on the initial
flags when updating the counters. To avoid mistakes and
complicated checks for protocol state rely only on the
IP_VS_CONN_F_INACTIVE bit when updating the counters.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Tested-by: NAleksey Chudov <aleksey.chudov@gmail.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>

this_cpu_inc() is IRQ safe and faster than
local_bh_disable()/__this_cpu_inc()/local_bh_enable(), at least on x86.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Reviewed-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch allows you to disable automatic conntrack helper
lookup based on TCP/UDP ports, eg.

echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper

[ Note: flows that already got a helper will keep using it even
  if automatic helper assignment has been disabled ]

Once this behaviour has been disabled, you have to explicitly
use the iptables CT target to attach helper to flows.

There are good reasons to stop supporting automatic helper
assignment, for further information, please read:

http://www.netfilter.org/news.html#2012-04-03

This patch also adds one message to inform that automatic helper
assignment is deprecated and it will be removed soon (this is
spotted only once, with the first flow that gets a helper attached
to make it as less annoying as possible).
Signed-off-by: NEric Leblond <eric@regit.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Make the return value explicitly true or false.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a somewhat generic framework for MDIO bus
multiplexers.  It is modeled on the I2C multiplexer.

The multiplexer is needed if there are multiple PHYs with the same
address connected to the same MDIO bus adepter, or if there is
insufficient electrical drive capability for all the connected PHY
devices.

Conceptually it could look something like this:

                   ------------------
                   | Control Signal |
                   --------+---------
                           |
 ---------------   --------+------
 | MDIO MASTER |---| Multiplexer |
 ---------------   --+-------+----
                     |       |
                     C       C
                     h       h
                     i       i
                     l       l
                     d       d
                     |       |
     ---------       A       B   ---------
     |       |       |       |   |       |
     | PHY@1 +-------+       +---+ PHY@1 |
     |       |       |       |   |       |
     ---------       |       |   ---------
     ---------       |       |   ---------
     |       |       |       |   |       |
     | PHY@2 +-------+       +---+ PHY@2 |
     |       |                   |       |
     ---------                   ---------

This framework configures the bus topology from device tree data.  The
mechanics of switching the multiplexer is left to device specific
drivers.

The follow-on patch contains a multiplexer driven by GPIO lines.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add of_mdio_find_bus() which allows an mii_bus to be located given its
associated the device tree node.

This is needed by the follow-on patch to add a driver for MDIO bus
multiplexers.

The of_mdiobus_register() function is modified so that the device tree
node is recorded in the mii_bus.  Then we can find it again by
iterating over all mdio_bus_class devices.

Because the OF device tree has now become an integral part of the
kernel, this can live in mdio_bus.c (which contains the needed
mdio_bus_class structure) instead of of_mdio.c.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neither compare_ether_addr() nor compare_ether_addr_64bits()
(as it can fall back to the former) have comparison semantics
like memcmp() where the sign of the return value indicates sort
order. We had a bug in the wireless code due to a blind memcmp
replacement because of this.

A cursory look suggests that the wireless bug was the only one
due to this semantic difference.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the recent changes for how we compute the skb truesize it occurs to me
we are probably going to have a lot of calls to skb_end_pointer -
skb->head.  Instead of running all over the place doing that it would make
more sense to just make it a separate inline skb_end_offset(skb) that way
we can return the correct value without having gcc having to do all the
optimization to cancel out skb->head - skb->head.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It appears some networks play bad games with the two bits reserved for
ECN. This can trigger false congestion notifications and very slow
transferts.

Since RFC 3168 (6.1.1) forbids SYN packets to carry CT bits, we can
disable TCP ECN negociation if it happens we receive mangled CT bits in
the SYN packet.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Perry Lorier <perryl@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Wilmer van der Gaast <wilmer@google.com>
Cc: Ankur Jain <jankur@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Dave Täht <dave.taht@bufferbloat.net>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With multiple cards is hard to figure out which port caused trouble
int the layer2 routines (e.g. got a timeout).
Now we have the informations in the log output.
Signed-off-by: NKarsten Keil <kkeil@linux-pingi.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For certification test it is very useful to change the layer1
timer3 value on runtime.
Signed-off-by: NKarsten Keil <kkeil@linux-pingi.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To be full preemptiv safe, we cannot handle a L2 timeout in the timer
context itself, we should do all actions via the D-channel thread.
Signed-off-by: NKarsten Keil <kkeil@linux-pingi.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for a skb_head_is_locked helper function.  It is
meant to be used any time we are considering transferring the head from
skb->head to a paged frag.  If the head is locked it means we cannot remove
the head from the skb so it must be copied or we must take the skb as a
whole.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend tcp coalescing implementing it from tcp_queue_rcv(), the main
receiver function when application is not blocked in recvmsg().

Function tcp_queue_rcv() is moved a bit to allow its call from
tcp_data_queue()

This gives good results especially if GRO could not kick, and if skb
head is a fragment.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implementing the advanced early retransmit (sysctl_tcp_early_retrans==2).
Delays the fast retransmit by an interval of RTT/4. We borrow the
RTO timer to implement the delay. If we receive another ACK or send
a new packet, the timer is cancelled and restored to original RTO
value offset by time elapsed.  When the delayed-ER timer fires,
we enter fast recovery and perform fast retransmit.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements RFC 5827 early retransmit (ER) for TCP.
It reduces DUPACK threshold (dupthresh) if outstanding packets are
less than 4 to recover losses by fast recovery instead of timeout.

While the algorithm is simple, small but frequent network reordering
makes this feature dangerous: the connection repeatedly enter
false recovery and degrade performance. Therefore we implement
a mitigation suggested in the appendix of the RFC that delays
entering fast recovery by a small interval, i.e., RTT/4. Currently
ER is conservative and is disabled for the rest of the connection
after the first reordering event. A large scale web server
experiment on the performance impact of ER is summarized in
section 6 of the paper "Proportional Rate Reduction for TCP”,
IMC 2011. http://conferences.sigcomm.org/imc/2011/docs/p155.pdf

Note that Linux has a similar feature called THIN_DUPACK. The
differences are THIN_DUPACK do not mitigate reorderings and is only
used after slow start. Currently ER is disabled if THIN_DUPACK is
enabled. I would be happy to merge THIN_DUPACK feature with ER if
people think it's a good idea.

ER is enabled by sysctl_tcp_early_retrans:
  0: Disables ER

  1: Reduce dupthresh to packets_out - 1 when outstanding packets < 4.

  2: (Default) reduce dupthresh like mode 1. In addition, delay
     entering fast recovery by RTT/4.

Note: mode 2 is implemented in the third part of this patch series.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fix kernel doc typos in function names
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add ECN (Explicit Congestion Notification) marking capability to netem

tc qdisc add dev eth0 root netem drop 0.5 ecn

Instead of dropping packets, try to ECN mark them.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: NHagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

remove useless casts and rename variables for less confusion.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

L2TPv3 defines an IP encapsulation packet format where data is carried
directly over IP (no UDP). The kernel already has support for L2TP IP
encapsulation over IPv4 (l2tp_ip). This patch introduces support for
L2TP IP encapsulation over IPv6.

The implementation is derived from ipv6/raw and ipv4/l2tp_ip.
Signed-off-by: NChris Elston <celston@katalix.com>
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using
the netlink API. We already support unmanaged L2TPv3 tunnels over
IPv4. A patch to iproute2 to make use of this feature will be
submitted separately.
Signed-off-by: NChris Elston <celston@katalix.com>
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Checkpatch warns about the use of __attribute__((packed)). So use the
recommended __packed syntax instead.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

GRO can check if skb to be merged has its skb->head mapped to a page
fragment, instead of a kmalloc() area.

We 'upgrade' skb->head as a fragment in itself

This avoids the frag_list fallback, and permits to build true GRO skb
(one sk_buff and up to 16 fragments), using less memory.

This reduces number of cache misses when user makes its copy, since a
single sk_buff is fetched.

This is a followup of patch "net: allow skb->head to be a page fragment"
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Matt Carlson <mcarlson@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

skb->head is currently allocated from kmalloc(). This is convenient but
has the drawback the data cannot be converted to a page fragment if
needed.

We have three spots were it hurts :

1) GRO aggregation

 When a linear skb must be appended to another skb, GRO uses the
frag_list fallback, very inefficient since we keep all struct sk_buff
around. So drivers enabling GRO but delivering linear skbs to network
stack aren't enabling full GRO power.

2) splice(socket -> pipe).

 We must copy the linear part to a page fragment.
 This kind of defeats splice() purpose (zero copy claim)

3) TCP coalescing.

 Recently introduced, this permits to group several contiguous segments
into a single skb. This shortens queue lengths and save kernel memory,
and greatly reduce probabilities of TCP collapses. This coalescing
doesnt work on linear skbs (or we would need to copy data, this would be
too slow)

Given all these issues, the following patch introduces the possibility
of having skb->head be a fragment in itself. We use a new skb flag,
skb->head_frag to carry this information.

build_skb() is changed to accept a frag_size argument. Drivers willing
to provide a page fragment instead of kmalloc() data will set a non zero
value, set to the fragment size.

Then, on situations we need to convert the skb head to a frag in itself,
we can check if skb->head_frag is set and avoid the copies or various
fallbacks we have.

This means drivers currently using frags could be updated to avoid the
current skb->head allocation and reduce their memory footprint (aka skb
truesize). (thats 512 or 1024 bytes saved per skb). This also makes
bpf/netfilter faster since the 'first frag' will be part of skb linear
part, no need to copy data.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Matt Carlson <mcarlson@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

More recent versions of the UEFI spec have added new attributes for
variables. Add them.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Denys Fedoryshchenko reported frequent crashes on a proxy server and kindly
provided a lockdep report that explains it all :

  [  762.903868]
  [  762.903880] =================================
  [  762.903890] [ INFO: inconsistent lock state ]
  [  762.903903] 3.3.4-build-0061 #8 Not tainted
  [  762.904133] ---------------------------------
  [  762.904344] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
  [  762.904542] squid/1603 [HC0[0]:SC0[0]:HE1:SE1] takes:
  [  762.904542]  (key#3){+.?...}, at: [<c0232cc4>]
__percpu_counter_sum+0xd/0x58
  [  762.904542] {IN-SOFTIRQ-W} state was registered at:
  [  762.904542]   [<c0158b84>] __lock_acquire+0x284/0xc26
  [  762.904542]   [<c01598e8>] lock_acquire+0x71/0x85
  [  762.904542]   [<c0349765>] _raw_spin_lock+0x33/0x40
  [  762.904542]   [<c0232c93>] __percpu_counter_add+0x58/0x7c
  [  762.904542]   [<c02cfde1>] sk_clone_lock+0x1e5/0x200
  [  762.904542]   [<c0303ee4>] inet_csk_clone_lock+0xe/0x78
  [  762.904542]   [<c0315778>] tcp_create_openreq_child+0x1b/0x404
  [  762.904542]   [<c031339c>] tcp_v4_syn_recv_sock+0x32/0x1c1
  [  762.904542]   [<c031615a>] tcp_check_req+0x1fd/0x2d7
  [  762.904542]   [<c0313f77>] tcp_v4_do_rcv+0xab/0x194
  [  762.904542]   [<c03153bb>] tcp_v4_rcv+0x3b3/0x5cc
  [  762.904542]   [<c02fc0c4>] ip_local_deliver_finish+0x13a/0x1e9
  [  762.904542]   [<c02fc539>] NF_HOOK.clone.11+0x46/0x4d
  [  762.904542]   [<c02fc652>] ip_local_deliver+0x41/0x45
  [  762.904542]   [<c02fc4d1>] ip_rcv_finish+0x31a/0x33c
  [  762.904542]   [<c02fc539>] NF_HOOK.clone.11+0x46/0x4d
  [  762.904542]   [<c02fc857>] ip_rcv+0x201/0x23e
  [  762.904542]   [<c02daa3a>] __netif_receive_skb+0x319/0x368
  [  762.904542]   [<c02dac07>] netif_receive_skb+0x4e/0x7d
  [  762.904542]   [<c02dacf6>] napi_skb_finish+0x1e/0x34
  [  762.904542]   [<c02db122>] napi_gro_receive+0x20/0x24
  [  762.904542]   [<f85d1743>] e1000_receive_skb+0x3f/0x45 [e1000e]
  [  762.904542]   [<f85d3464>] e1000_clean_rx_irq+0x1f9/0x284 [e1000e]
  [  762.904542]   [<f85d3926>] e1000_clean+0x62/0x1f4 [e1000e]
  [  762.904542]   [<c02db228>] net_rx_action+0x90/0x160
  [  762.904542]   [<c012a445>] __do_softirq+0x7b/0x118
  [  762.904542] irq event stamp: 156915469
  [  762.904542] hardirqs last  enabled at (156915469): [<c019b4f4>]
__slab_alloc.clone.58.clone.63+0xc4/0x2de
  [  762.904542] hardirqs last disabled at (156915468): [<c019b452>]
__slab_alloc.clone.58.clone.63+0x22/0x2de
  [  762.904542] softirqs last  enabled at (156915466): [<c02ce677>]
lock_sock_nested+0x64/0x6c
  [  762.904542] softirqs last disabled at (156915464): [<c0349914>]
_raw_spin_lock_bh+0xe/0x45
  [  762.904542]
  [  762.904542] other info that might help us debug this:
  [  762.904542]  Possible unsafe locking scenario:
  [  762.904542]
  [  762.904542]        CPU0
  [  762.904542]        ----
  [  762.904542]   lock(key#3);
  [  762.904542]   <Interrupt>
  [  762.904542]     lock(key#3);
  [  762.904542]
  [  762.904542]  *** DEADLOCK ***
  [  762.904542]
  [  762.904542] 1 lock held by squid/1603:
  [  762.904542]  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<c03055c0>]
lock_sock+0xa/0xc
  [  762.904542]
  [  762.904542] stack backtrace:
  [  762.904542] Pid: 1603, comm: squid Not tainted 3.3.4-build-0061 #8
  [  762.904542] Call Trace:
  [  762.904542]  [<c0347b73>] ? printk+0x18/0x1d
  [  762.904542]  [<c015873a>] valid_state+0x1f6/0x201
  [  762.904542]  [<c0158816>] mark_lock+0xd1/0x1bb
  [  762.904542]  [<c015876b>] ? mark_lock+0x26/0x1bb
  [  762.904542]  [<c015805d>] ? check_usage_forwards+0x77/0x77
  [  762.904542]  [<c0158bf8>] __lock_acquire+0x2f8/0xc26
  [  762.904542]  [<c0159b8e>] ? mark_held_locks+0x5d/0x7b
  [  762.904542]  [<c0159cf6>] ? trace_hardirqs_on+0xb/0xd
  [  762.904542]  [<c0158dd4>] ? __lock_acquire+0x4d4/0xc26
  [  762.904542]  [<c01598e8>] lock_acquire+0x71/0x85
  [  762.904542]  [<c0232cc4>] ? __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c0349765>] _raw_spin_lock+0x33/0x40
  [  762.904542]  [<c0232cc4>] ? __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c0232cc4>] __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c02cebc4>] __sk_mem_schedule+0xdd/0x1c7
  [  762.904542]  [<c02d178d>] ? __alloc_skb+0x76/0x100
  [  762.904542]  [<c0305e8e>] sk_wmem_schedule+0x21/0x2d
  [  762.904542]  [<c0306370>] sk_stream_alloc_skb+0x42/0xaa
  [  762.904542]  [<c0306567>] tcp_sendmsg+0x18f/0x68b
  [  762.904542]  [<c031f3dc>] ? ip_fast_csum+0x30/0x30
  [  762.904542]  [<c0320193>] inet_sendmsg+0x53/0x5a
  [  762.904542]  [<c02cb633>] sock_aio_write+0xd2/0xda
  [  762.904542]  [<c015876b>] ? mark_lock+0x26/0x1bb
  [  762.904542]  [<c01a1017>] do_sync_write+0x9f/0xd9
  [  762.904542]  [<c01a2111>] ? file_free_rcu+0x2f/0x2f
  [  762.904542]  [<c01a17a1>] vfs_write+0x8f/0xab
  [  762.904542]  [<c01a284d>] ? fget_light+0x75/0x7c
  [  762.904542]  [<c01a1900>] sys_write+0x3d/0x5e
  [  762.904542]  [<c0349ec9>] syscall_call+0x7/0xb
  [  762.904542]  [<c0340000>] ? rp_sidt+0x41/0x83

Bug is that sk_sockets_allocated_read_positive() calls
percpu_counter_sum_positive() without BH being disabled.

This bug was added in commit 180d8cd9
(foundations of per-cgroup memory pressure controlling.), since previous
code was using percpu_counter_read_positive() which is IRQ safe.

In __sk_mem_schedule() we dont need the precise count of allocated
sockets and can revert to previous behavior.
Reported-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Sined-off-by: NEric Dumazet <edumazet@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Change order of init so netns init is ready
when register ioctl and netlink.

Ver2
	Whitespace fixes and __init added.
Reported-by: N"Ryan O'Hara" <rohara@redhat.com>
Signed-off-by: NHans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>