5c9d535b89
cgroup in general is moving towards using cgroup_subsys_state as the fundamental structural component and css_parent() was introduced to convert from using cgroup->parent to css->parent. It was quite some time ago and we're moving forward with making css more prominent. This patch drops the trivial wrapper css_parent() and let the users dereference css->parent. While at it, explicitly mark fields of css which are public and immutable. v2: New usage from device_cgroup.c converted. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Johannes Weiner <hannes@cmpxchg.org>
111 lines
2.5 KiB
C
111 lines
2.5 KiB
C
/*
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* net/core/netclassid_cgroup.c Classid Cgroupfs Handling
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Thomas Graf <tgraf@suug.ch>
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/cgroup.h>
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#include <linux/fdtable.h>
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#include <net/cls_cgroup.h>
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#include <net/sock.h>
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static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
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{
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return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
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}
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struct cgroup_cls_state *task_cls_state(struct task_struct *p)
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{
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return css_cls_state(task_css(p, net_cls_cgrp_id));
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}
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EXPORT_SYMBOL_GPL(task_cls_state);
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static struct cgroup_subsys_state *
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cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
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{
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struct cgroup_cls_state *cs;
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cs = kzalloc(sizeof(*cs), GFP_KERNEL);
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if (!cs)
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return ERR_PTR(-ENOMEM);
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return &cs->css;
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}
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static int cgrp_css_online(struct cgroup_subsys_state *css)
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{
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struct cgroup_cls_state *cs = css_cls_state(css);
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struct cgroup_cls_state *parent = css_cls_state(css->parent);
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if (parent)
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cs->classid = parent->classid;
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return 0;
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}
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static void cgrp_css_free(struct cgroup_subsys_state *css)
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{
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kfree(css_cls_state(css));
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}
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static int update_classid(const void *v, struct file *file, unsigned n)
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{
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int err;
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struct socket *sock = sock_from_file(file, &err);
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if (sock)
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sock->sk->sk_classid = (u32)(unsigned long)v;
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return 0;
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}
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static void cgrp_attach(struct cgroup_subsys_state *css,
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struct cgroup_taskset *tset)
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{
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struct cgroup_cls_state *cs = css_cls_state(css);
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void *v = (void *)(unsigned long)cs->classid;
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struct task_struct *p;
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cgroup_taskset_for_each(p, tset) {
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task_lock(p);
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iterate_fd(p->files, 0, update_classid, v);
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task_unlock(p);
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}
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}
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static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
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{
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return css_cls_state(css)->classid;
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}
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static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
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u64 value)
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{
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css_cls_state(css)->classid = (u32) value;
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return 0;
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}
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static struct cftype ss_files[] = {
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{
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.name = "classid",
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.read_u64 = read_classid,
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.write_u64 = write_classid,
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},
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{ } /* terminate */
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};
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struct cgroup_subsys net_cls_cgrp_subsys = {
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.css_alloc = cgrp_css_alloc,
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.css_online = cgrp_css_online,
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.css_free = cgrp_css_free,
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.attach = cgrp_attach,
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.base_cftypes = ss_files,
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};
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