linux/net/core
Tejun Heo eb95419b02 cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods
cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup *
in subsystem implementations for the following reasons.

* With unified hierarchy, subsystems will be dynamically bound and
  unbound from cgroups and thus css's (cgroup_subsys_state) may be
  created and destroyed dynamically over the lifetime of a cgroup,
  which is different from the current state where all css's are
  allocated and destroyed together with the associated cgroup.  This
  in turn means that cgroup_css() should be synchronized and may
  return NULL, making it more cumbersome to use.

* Differing levels of per-subsystem granularity in the unified
  hierarchy means that the task and descendant iterators should behave
  differently depending on the specific subsystem the iteration is
  being performed for.

* In majority of the cases, subsystems only care about its part in the
  cgroup hierarchy - ie. the hierarchy of css's.  Subsystem methods
  often obtain the matching css pointer from the cgroup and don't
  bother with the cgroup pointer itself.  Passing around css fits
  much better.

This patch converts all cgroup_subsys methods to take @css instead of
@cgroup.  The conversions are mostly straight-forward.  A few
noteworthy changes are

* ->css_alloc() now takes css of the parent cgroup rather than the
  pointer to the new cgroup as the css for the new cgroup doesn't
  exist yet.  Knowing the parent css is enough for all the existing
  subsystems.

* In kernel/cgroup.c::offline_css(), unnecessary open coded css
  dereference is replaced with local variable access.

This patch shouldn't cause any behavior differences.

v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced
    with local variable @css as suggested by Li Zefan.

    Rebased on top of new for-3.12 which includes for-3.11-fixes so
    that ->css_free() invocation added by da0a12caff ("cgroup: fix a
    leak when percpu_ref_init() fails") is converted too.  Suggested
    by Li Zefan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
2013-08-08 20:11:23 -04:00
..
datagram.c net: rename low latency sockets functions to busy poll 2013-07-08 19:25:45 -07:00
dev.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-07-03 14:55:13 -07:00
dev_addr_lists.c net/core: dev_mc_sync_multiple calls wrong helper 2013-05-31 16:56:56 -07:00
dev_ioctl.c net: fix kernel deadlock with interface rename and netdev name retrieval. 2013-06-26 13:42:54 -07:00
drop_monitor.c net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
dst.c net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
ethtool.c ethtool: make .get_dump_data() harder to misuse by drivers 2013-07-02 00:15:56 -07:00
fib_rules.c net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
filter.c sock_diag: fix filter code sent to userspace 2013-06-10 22:23:32 -07:00
flow.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-04-01 13:36:50 -04:00
flow_dissector.c net: flow_dissector: add __skb_get_poff to get a start offset to payload 2013-03-20 13:15:45 -04:00
gen_estimator.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
gen_stats.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
iovec.c Hoist memcpy_fromiovec/memcpy_toiovec into lib/ 2013-05-20 10:24:22 +09:30
link_watch.c net: make all team port device link events urgent 2013-06-13 02:31:41 -07:00
Makefile net: move procfs code to net/core/net-procfs.c 2013-02-19 00:51:10 -05:00
neighbour.c neighbour: fix a race in neigh_destroy() 2013-07-01 13:35:32 -07:00
net-procfs.c rps: selective flow shedding during softnet overflow 2013-05-20 13:48:04 -07:00
net-sysfs.c rps_dev_flow_table_release(): no need to delay vfree() 2013-05-06 11:06:51 -04:00
net-sysfs.h xps: Add CONFIG_XPS 2010-11-28 18:24:14 -08:00
net-traces.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
net_namespace.c proc: Split the namespace stuff out into linux/proc_ns.h 2013-05-01 17:29:39 -04:00
netevent.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
netpoll.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-07-09 18:24:39 -07:00
netprio_cgroup.c cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods 2013-08-08 20:11:23 -04:00
pktgen.c pktgen: ipv6: numa: consolidate skb allocation to pktgen_alloc_skb 2013-06-12 00:47:25 -07:00
request_sock.c tcp: fix a panic on UP machines in reqsk_fastopen_remove 2013-01-14 18:10:05 -05:00
rtnetlink.c rtnetlink: allow using zero MAC address in rtnl_fdb_{add,del} 2013-06-25 09:31:39 -07:00
scm.c netprio_cgroup: remove task_struct parameter from sock_update_netprio() 2013-04-09 13:19:37 -04:00
secure_seq.c net: defer net_secret[] initialization 2013-04-29 15:14:02 -04:00
skbuff.c core: Copy inner_protocol in copy_skb_header() 2013-07-03 16:52:10 -07:00
sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-07-03 14:55:13 -07:00
sock_diag.c sock_diag: fix filter code sent to userspace 2013-06-10 22:23:32 -07:00
stream.c net: Fix the condition passed to sk_wait_event() 2010-10-03 20:41:32 -07:00
sysctl_net_core.c net: poll/select low latency socket support 2013-06-25 16:35:52 -07:00
timestamping.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
user_dma.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
utils.c net: core: move mac_pton() to lib/net_utils.c 2013-06-05 12:00:27 -07:00