blk-cgroup, netprio_cgroup, cls_cgroup and tcp_memcontrol
unnecessarily define cftype array and cgroup_subsys structures at the
top of the file, which is unconventional and necessiates forward
declaration of methods.

This patch relocates those below the definitions of the methods and
removes the forward declarations.  Note that forward declaration of
tcp_files[] is added in tcp_memcontrol.c for tcp_init_cgroup().  This
will be removed soon by another patch.

This patch doesn't introduce any functional change.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizf@cn.fujitsu.com>

So we delay the allocation till the priority is set through cgroup,
and this makes skb_update_priority() faster when it's not set.

This also eliminates an off-by-one bug similar with the one fixed
in the previous patch.
Origionally-authored-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

# mount -t cgroup xxx /mnt
  # mkdir /mnt/tmp
  # cat /mnt/tmp/net_prio.ifpriomap
  lo 0
  eth0 0
  virbr0 0
  # echo 'lo 999' > /mnt/tmp/net_prio.ifpriomap
  # cat /mnt/tmp/net_prio.ifpriomap
  lo 999
  eth0 0
  virbr0 4101267344

We got weired output, because we exceeded the boundary of the array.
We may even crash the kernel..
Origionally-authored-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It was recently pointed out to me that the get_prioidx function sets a bit in
the prioidx map prior to checking to see if the index being set is out of
bounds.  This patch corrects that, avoiding the possiblity of us writing beyond
the end of the array
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reported-by: NStanislaw Gruszka <sgruszka@redhat.com>
CC: Stanislaw Gruszka <sgruszka@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.

Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().

So we reduce a few lines of code, though the shrinking of object size
is minimal.

 16 files changed, 113 insertions(+), 162 deletions(-)

   text    data     bss     dec     hex filename
5486240  656987 7039960 13183187         c928d3 vmlinux.o.orig
5486170  656987 7039960 13183117         c9288d vmlinux.o
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

This reverts commit 865d9f9f.

This commit breaks the build with CONFIG_NETPRIO_CGROUP=y so
revert it. It does build as a module though. The SUBSYS macro
in the cgroup core code automatically defines a subsys structure
as extern. Long term we should fix the macro. And I need to
fully build test things.

Tested with CONFIG_NETPRIO_CGROUP={y|m|n} with and without
CONFIG_CGROUPS defined.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Reported-By: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net_prio_subsys can be made static this removes the sparse
warning it was throwing.
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rcu_assign_pointer(ptr, NULL) can be safely replaced by
RCU_INIT_POINTER(ptr, NULL)

(old rcu_assign_pointer() macro was testing the NULL value and could
omit the smp_wmb(), but this had to be removed because of compiler
warnings)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds in the infrastructure code to create the network priority
cgroup.  The cgroup, in addition to the standard processes file creates two
control files:

1) prioidx - This is a read-only file that exports the index of this cgroup.
This is a value that is both arbitrary and unique to a cgroup in this subsystem,
and is used to index the per-device priority map

2) priomap - This is a writeable file.  On read it reports a table of 2-tuples
<name:priority> where name is the name of a network interface and priority is
indicates the priority assigned to frames egresessing on the named interface and
originating from a pid in this cgroup

This cgroup allows for skb priority to be set prior to a root qdisc getting
selected. This is benenficial for DCB enabled systems, in that it allows for any
application to use dcb configured priorities so without application modification
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NJohn Fastabend <john.r.fastabend@intel.com>
CC: Robert Love <robert.w.love@intel.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>