mm: page-writeback.c: local functions should not be exposed globally

The function global_dirtyable_memory is only referenced in this file and
should be marked static to prevent it from being exposed globally.

This quiets the sparse warning:

warning: symbol 'global_dirtyable_memory' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds

Reorder structure writeback_control to remove 8 bytes of padding on 64
bit builds, this shrinks its size from 48 to 40 bytes.

This structure is always on the stack and uses C99 named initialisation,
so should be safe and have a small impact on stack usage.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
net: ipv6: ping: Use socket mark in routing lookup

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
net: ipv6: autoconf routes into per-device tables

Currently, IPv6 router discovery always puts routes into
RT6_TABLE_MAIN. This causes problems for connection managers
that want to support multiple simultaneous network connections
and want control over which one is used by default (e.g., wifi
and wired).

To work around this connection managers typically take the routes
they prefer and copy them to static routes with low metrics in
the main table. This puts the burden on the connection manager
to watch netlink to see if the routes have changed, delete the
routes when their lifetime expires, etc.

Instead, this patch adds a per-interface sysctl to have the
kernel put autoconf routes into different tables. This allows
each interface to have its own autoconf table, and choosing the
default interface (or using different interfaces at the same
time for different types of traffic) can be done using
appropriate ip rules.

The sysctl behaves as follows:

- = 0: default. Put routes into RT6_TABLE_MAIN as before.
- > 0: manual. Put routes into the specified table.
- < 0: automatic. Add the absolute value of the sysctl to the
       device's ifindex, and use that table.

The automatic mode is most useful in conjunction with
net.ipv6.conf.default.accept_ra_rt_table. A connection manager
or distribution could set it to, say, -100 on boot, and
thereafter just use IP rules.

Change-Id: I093d39fb06ec413905dc0d0d5792c1bc5d5c73a9
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
net: add a sysctl to reflect the fwmark on replies

Kernel-originated IP packets that have no user socket associated
with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.)
are emitted with a mark of zero. Add a sysctl to make them have
the same mark as the packet they are replying to.

This allows an administrator that wishes to do so to use
mark-based routing, firewalling, etc. for these replies by
marking the original packets inbound.

Tested using user-mode linux:
 - ICMP/ICMPv6 echo replies and errors.
 - TCP RST packets (IPv4 and IPv6).

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
net: support marking accepting TCP sockets

When using mark-based routing, sockets returned from accept()
may need to be marked differently depending on the incoming
connection request.

This is the case, for example, if different socket marks identify
different networks: a listening socket may want to accept
connections from all networks, but each connection should be
marked with the network that the request came in on, so that
subsequent packets are sent on the correct network.

This patch adds a sysctl to mark TCP sockets based on the fwmark
of the incoming SYN packet. If enabled, and an unmarked socket
receives a SYN, then the SYN packet's fwmark is written to the
connection's inet_request_sock, and later written back to the
accepted socket when the connection is established.  If the
socket already has a nonzero mark, then the behaviour is the same
as it is today, i.e., the listening socket's fwmark is used.

Black-box tested using user-mode linux:

- IPv4/IPv6 SYN+ACK, FIN, etc. packets are routed based on the
  mark of the incoming SYN packet.
- The socket returned by accept() is marked with the mark of the
  incoming SYN packet.
- Tested with syncookies=1 and syncookies=2.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
kernel/power/powersuspend: LCD screen on/off hooks (Yank555.lu)

- add an alternative hook for screen on / off detection in the display
  pannel driver
- sleeps  ~0.1s sooner, wakes up ~1s later then autosleep
- clean up source formatting a bit (Paul Reioux)

Signed-off-by: Paul Reioux <reioux@gmail.com>

+lots of cleanups of white space.
Kernel 3.9