Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/cgroup/freezer.c b/kernel/cgroup/freezer.c
index 0823679..8cf0106 100644
--- a/kernel/cgroup/freezer.c
+++ b/kernel/cgroup/freezer.c
@@ -1,481 +1,314 @@
-/*
- * cgroup_freezer.c - control group freezer subsystem
- *
- * Copyright IBM Corporation, 2007
- *
- * Author : Cedric Le Goater <clg@fr.ibm.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2.1 of the GNU Lesser General Public License
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- */
-
-#include <linux/export.h>
-#include <linux/slab.h>
+//SPDX-License-Identifier: GPL-2.0
#include <linux/cgroup.h>
-#include <linux/fs.h>
-#include <linux/uaccess.h>
-#include <linux/freezer.h>
-#include <linux/seq_file.h>
-#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sched/task.h>
+#include <linux/sched/signal.h>
+
+#include "cgroup-internal.h"
+
+#include <trace/events/cgroup.h>
/*
- * A cgroup is freezing if any FREEZING flags are set. FREEZING_SELF is
- * set if "FROZEN" is written to freezer.state cgroupfs file, and cleared
- * for "THAWED". FREEZING_PARENT is set if the parent freezer is FREEZING
- * for whatever reason. IOW, a cgroup has FREEZING_PARENT set if one of
- * its ancestors has FREEZING_SELF set.
+ * Propagate the cgroup frozen state upwards by the cgroup tree.
*/
-enum freezer_state_flags {
- CGROUP_FREEZER_ONLINE = (1 << 0), /* freezer is fully online */
- CGROUP_FREEZING_SELF = (1 << 1), /* this freezer is freezing */
- CGROUP_FREEZING_PARENT = (1 << 2), /* the parent freezer is freezing */
- CGROUP_FROZEN = (1 << 3), /* this and its descendants frozen */
-
- /* mask for all FREEZING flags */
- CGROUP_FREEZING = CGROUP_FREEZING_SELF | CGROUP_FREEZING_PARENT,
-};
-
-struct freezer {
- struct cgroup_subsys_state css;
- unsigned int state;
-};
-
-static DEFINE_MUTEX(freezer_mutex);
-
-static inline struct freezer *css_freezer(struct cgroup_subsys_state *css)
+static void cgroup_propagate_frozen(struct cgroup *cgrp, bool frozen)
{
- return css ? container_of(css, struct freezer, css) : NULL;
-}
-
-static inline struct freezer *task_freezer(struct task_struct *task)
-{
- return css_freezer(task_css(task, freezer_cgrp_id));
-}
-
-static struct freezer *parent_freezer(struct freezer *freezer)
-{
- return css_freezer(freezer->css.parent);
-}
-
-bool cgroup_freezing(struct task_struct *task)
-{
- bool ret;
-
- rcu_read_lock();
- ret = task_freezer(task)->state & CGROUP_FREEZING;
- rcu_read_unlock();
-
- return ret;
-}
-
-static const char *freezer_state_strs(unsigned int state)
-{
- if (state & CGROUP_FROZEN)
- return "FROZEN";
- if (state & CGROUP_FREEZING)
- return "FREEZING";
- return "THAWED";
-};
-
-static struct cgroup_subsys_state *
-freezer_css_alloc(struct cgroup_subsys_state *parent_css)
-{
- struct freezer *freezer;
-
- freezer = kzalloc(sizeof(struct freezer), GFP_KERNEL);
- if (!freezer)
- return ERR_PTR(-ENOMEM);
-
- return &freezer->css;
-}
-
-/**
- * freezer_css_online - commit creation of a freezer css
- * @css: css being created
- *
- * We're committing to creation of @css. Mark it online and inherit
- * parent's freezing state while holding both parent's and our
- * freezer->lock.
- */
-static int freezer_css_online(struct cgroup_subsys_state *css)
-{
- struct freezer *freezer = css_freezer(css);
- struct freezer *parent = parent_freezer(freezer);
-
- mutex_lock(&freezer_mutex);
-
- freezer->state |= CGROUP_FREEZER_ONLINE;
-
- if (parent && (parent->state & CGROUP_FREEZING)) {
- freezer->state |= CGROUP_FREEZING_PARENT | CGROUP_FROZEN;
- atomic_inc(&system_freezing_cnt);
- }
-
- mutex_unlock(&freezer_mutex);
- return 0;
-}
-
-/**
- * freezer_css_offline - initiate destruction of a freezer css
- * @css: css being destroyed
- *
- * @css is going away. Mark it dead and decrement system_freezing_count if
- * it was holding one.
- */
-static void freezer_css_offline(struct cgroup_subsys_state *css)
-{
- struct freezer *freezer = css_freezer(css);
-
- mutex_lock(&freezer_mutex);
-
- if (freezer->state & CGROUP_FREEZING)
- atomic_dec(&system_freezing_cnt);
-
- freezer->state = 0;
-
- mutex_unlock(&freezer_mutex);
-}
-
-static void freezer_css_free(struct cgroup_subsys_state *css)
-{
- kfree(css_freezer(css));
-}
-
-/*
- * Tasks can be migrated into a different freezer anytime regardless of its
- * current state. freezer_attach() is responsible for making new tasks
- * conform to the current state.
- *
- * Freezer state changes and task migration are synchronized via
- * @freezer->lock. freezer_attach() makes the new tasks conform to the
- * current state and all following state changes can see the new tasks.
- */
-static void freezer_attach(struct cgroup_taskset *tset)
-{
- struct task_struct *task;
- struct cgroup_subsys_state *new_css;
-
- mutex_lock(&freezer_mutex);
+ int desc = 1;
/*
- * Make the new tasks conform to the current state of @new_css.
- * For simplicity, when migrating any task to a FROZEN cgroup, we
- * revert it to FREEZING and let update_if_frozen() determine the
- * correct state later.
+ * If the new state is frozen, some freezing ancestor cgroups may change
+ * their state too, depending on if all their descendants are frozen.
*
- * Tasks in @tset are on @new_css but may not conform to its
- * current state before executing the following - !frozen tasks may
- * be visible in a FROZEN cgroup and frozen tasks in a THAWED one.
+ * Otherwise, all ancestor cgroups are forced into the non-frozen state.
*/
- cgroup_taskset_for_each(task, new_css, tset) {
- struct freezer *freezer = css_freezer(new_css);
-
- if (!(freezer->state & CGROUP_FREEZING)) {
- __thaw_task(task);
+ while ((cgrp = cgroup_parent(cgrp))) {
+ if (frozen) {
+ cgrp->freezer.nr_frozen_descendants += desc;
+ if (!test_bit(CGRP_FROZEN, &cgrp->flags) &&
+ test_bit(CGRP_FREEZE, &cgrp->flags) &&
+ cgrp->freezer.nr_frozen_descendants ==
+ cgrp->nr_descendants) {
+ set_bit(CGRP_FROZEN, &cgrp->flags);
+ cgroup_file_notify(&cgrp->events_file);
+ TRACE_CGROUP_PATH(notify_frozen, cgrp, 1);
+ desc++;
+ }
} else {
- freeze_task(task);
- /* clear FROZEN and propagate upwards */
- while (freezer && (freezer->state & CGROUP_FROZEN)) {
- freezer->state &= ~CGROUP_FROZEN;
- freezer = parent_freezer(freezer);
+ cgrp->freezer.nr_frozen_descendants -= desc;
+ if (test_bit(CGRP_FROZEN, &cgrp->flags)) {
+ clear_bit(CGRP_FROZEN, &cgrp->flags);
+ cgroup_file_notify(&cgrp->events_file);
+ TRACE_CGROUP_PATH(notify_frozen, cgrp, 0);
+ desc++;
}
}
}
-
- mutex_unlock(&freezer_mutex);
}
-/**
- * freezer_fork - cgroup post fork callback
- * @task: a task which has just been forked
- *
- * @task has just been created and should conform to the current state of
- * the cgroup_freezer it belongs to. This function may race against
- * freezer_attach(). Losing to freezer_attach() means that we don't have
- * to do anything as freezer_attach() will put @task into the appropriate
- * state.
+/*
+ * Revisit the cgroup frozen state.
+ * Checks if the cgroup is really frozen and perform all state transitions.
*/
-static void freezer_fork(struct task_struct *task)
+void cgroup_update_frozen(struct cgroup *cgrp)
{
- struct freezer *freezer;
+ bool frozen;
+
+ lockdep_assert_held(&css_set_lock);
/*
- * The root cgroup is non-freezable, so we can skip locking the
- * freezer. This is safe regardless of race with task migration.
- * If we didn't race or won, skipping is obviously the right thing
- * to do. If we lost and root is the new cgroup, noop is still the
- * right thing to do.
+ * If the cgroup has to be frozen (CGRP_FREEZE bit set),
+ * and all tasks are frozen and/or stopped, let's consider
+ * the cgroup frozen. Otherwise it's not frozen.
*/
- if (task_css_is_root(task, freezer_cgrp_id))
- return;
+ frozen = test_bit(CGRP_FREEZE, &cgrp->flags) &&
+ cgrp->freezer.nr_frozen_tasks == __cgroup_task_count(cgrp);
- mutex_lock(&freezer_mutex);
- rcu_read_lock();
-
- freezer = task_freezer(task);
- if (freezer->state & CGROUP_FREEZING)
- freeze_task(task);
-
- rcu_read_unlock();
- mutex_unlock(&freezer_mutex);
-}
-
-/**
- * update_if_frozen - update whether a cgroup finished freezing
- * @css: css of interest
- *
- * Once FREEZING is initiated, transition to FROZEN is lazily updated by
- * calling this function. If the current state is FREEZING but not FROZEN,
- * this function checks whether all tasks of this cgroup and the descendant
- * cgroups finished freezing and, if so, sets FROZEN.
- *
- * The caller is responsible for grabbing RCU read lock and calling
- * update_if_frozen() on all descendants prior to invoking this function.
- *
- * Task states and freezer state might disagree while tasks are being
- * migrated into or out of @css, so we can't verify task states against
- * @freezer state here. See freezer_attach() for details.
- */
-static void update_if_frozen(struct cgroup_subsys_state *css)
-{
- struct freezer *freezer = css_freezer(css);
- struct cgroup_subsys_state *pos;
- struct css_task_iter it;
- struct task_struct *task;
-
- lockdep_assert_held(&freezer_mutex);
-
- if (!(freezer->state & CGROUP_FREEZING) ||
- (freezer->state & CGROUP_FROZEN))
- return;
-
- /* are all (live) children frozen? */
- rcu_read_lock();
- css_for_each_child(pos, css) {
- struct freezer *child = css_freezer(pos);
-
- if ((child->state & CGROUP_FREEZER_ONLINE) &&
- !(child->state & CGROUP_FROZEN)) {
- rcu_read_unlock();
+ if (frozen) {
+ /* Already there? */
+ if (test_bit(CGRP_FROZEN, &cgrp->flags))
return;
- }
+
+ set_bit(CGRP_FROZEN, &cgrp->flags);
+ } else {
+ /* Already there? */
+ if (!test_bit(CGRP_FROZEN, &cgrp->flags))
+ return;
+
+ clear_bit(CGRP_FROZEN, &cgrp->flags);
}
- rcu_read_unlock();
+ cgroup_file_notify(&cgrp->events_file);
+ TRACE_CGROUP_PATH(notify_frozen, cgrp, frozen);
- /* are all tasks frozen? */
- css_task_iter_start(css, 0, &it);
-
- while ((task = css_task_iter_next(&it))) {
- if (freezing(task)) {
- /*
- * freezer_should_skip() indicates that the task
- * should be skipped when determining freezing
- * completion. Consider it frozen in addition to
- * the usual frozen condition.
- */
- if (!frozen(task) && !freezer_should_skip(task))
- goto out_iter_end;
- }
- }
-
- freezer->state |= CGROUP_FROZEN;
-out_iter_end:
- css_task_iter_end(&it);
+ /* Update the state of ancestor cgroups. */
+ cgroup_propagate_frozen(cgrp, frozen);
}
-static int freezer_read(struct seq_file *m, void *v)
-{
- struct cgroup_subsys_state *css = seq_css(m), *pos;
-
- mutex_lock(&freezer_mutex);
- rcu_read_lock();
-
- /* update states bottom-up */
- css_for_each_descendant_post(pos, css) {
- if (!css_tryget_online(pos))
- continue;
- rcu_read_unlock();
-
- update_if_frozen(pos);
-
- rcu_read_lock();
- css_put(pos);
- }
-
- rcu_read_unlock();
- mutex_unlock(&freezer_mutex);
-
- seq_puts(m, freezer_state_strs(css_freezer(css)->state));
- seq_putc(m, '\n');
- return 0;
-}
-
-static void freeze_cgroup(struct freezer *freezer)
-{
- struct css_task_iter it;
- struct task_struct *task;
-
- css_task_iter_start(&freezer->css, 0, &it);
- while ((task = css_task_iter_next(&it)))
- freeze_task(task);
- css_task_iter_end(&it);
-}
-
-static void unfreeze_cgroup(struct freezer *freezer)
-{
- struct css_task_iter it;
- struct task_struct *task;
-
- css_task_iter_start(&freezer->css, 0, &it);
- while ((task = css_task_iter_next(&it)))
- __thaw_task(task);
- css_task_iter_end(&it);
-}
-
-/**
- * freezer_apply_state - apply state change to a single cgroup_freezer
- * @freezer: freezer to apply state change to
- * @freeze: whether to freeze or unfreeze
- * @state: CGROUP_FREEZING_* flag to set or clear
- *
- * Set or clear @state on @cgroup according to @freeze, and perform
- * freezing or thawing as necessary.
+/*
+ * Increment cgroup's nr_frozen_tasks.
*/
-static void freezer_apply_state(struct freezer *freezer, bool freeze,
- unsigned int state)
+static void cgroup_inc_frozen_cnt(struct cgroup *cgrp)
{
- /* also synchronizes against task migration, see freezer_attach() */
- lockdep_assert_held(&freezer_mutex);
+ cgrp->freezer.nr_frozen_tasks++;
+}
- if (!(freezer->state & CGROUP_FREEZER_ONLINE))
+/*
+ * Decrement cgroup's nr_frozen_tasks.
+ */
+static void cgroup_dec_frozen_cnt(struct cgroup *cgrp)
+{
+ cgrp->freezer.nr_frozen_tasks--;
+ WARN_ON_ONCE(cgrp->freezer.nr_frozen_tasks < 0);
+}
+
+/*
+ * Enter frozen/stopped state, if not yet there. Update cgroup's counters,
+ * and revisit the state of the cgroup, if necessary.
+ */
+void cgroup_enter_frozen(void)
+{
+ struct cgroup *cgrp;
+
+ if (current->frozen)
+ return;
+
+ spin_lock_irq(&css_set_lock);
+ current->frozen = true;
+ cgrp = task_dfl_cgroup(current);
+ cgroup_inc_frozen_cnt(cgrp);
+ cgroup_update_frozen(cgrp);
+ spin_unlock_irq(&css_set_lock);
+}
+
+/*
+ * Conditionally leave frozen/stopped state. Update cgroup's counters,
+ * and revisit the state of the cgroup, if necessary.
+ *
+ * If always_leave is not set, and the cgroup is freezing,
+ * we're racing with the cgroup freezing. In this case, we don't
+ * drop the frozen counter to avoid a transient switch to
+ * the unfrozen state.
+ */
+void cgroup_leave_frozen(bool always_leave)
+{
+ struct cgroup *cgrp;
+
+ spin_lock_irq(&css_set_lock);
+ cgrp = task_dfl_cgroup(current);
+ if (always_leave || !test_bit(CGRP_FREEZE, &cgrp->flags)) {
+ cgroup_dec_frozen_cnt(cgrp);
+ cgroup_update_frozen(cgrp);
+ WARN_ON_ONCE(!current->frozen);
+ current->frozen = false;
+ } else if (!(current->jobctl & JOBCTL_TRAP_FREEZE)) {
+ spin_lock(¤t->sighand->siglock);
+ current->jobctl |= JOBCTL_TRAP_FREEZE;
+ set_thread_flag(TIF_SIGPENDING);
+ spin_unlock(¤t->sighand->siglock);
+ }
+ spin_unlock_irq(&css_set_lock);
+}
+
+/*
+ * Freeze or unfreeze the task by setting or clearing the JOBCTL_TRAP_FREEZE
+ * jobctl bit.
+ */
+static void cgroup_freeze_task(struct task_struct *task, bool freeze)
+{
+ unsigned long flags;
+
+ /* If the task is about to die, don't bother with freezing it. */
+ if (!lock_task_sighand(task, &flags))
return;
if (freeze) {
- if (!(freezer->state & CGROUP_FREEZING))
- atomic_inc(&system_freezing_cnt);
- freezer->state |= state;
- freeze_cgroup(freezer);
+ task->jobctl |= JOBCTL_TRAP_FREEZE;
+ signal_wake_up(task, false);
} else {
- bool was_freezing = freezer->state & CGROUP_FREEZING;
-
- freezer->state &= ~state;
-
- if (!(freezer->state & CGROUP_FREEZING)) {
- if (was_freezing)
- atomic_dec(&system_freezing_cnt);
- freezer->state &= ~CGROUP_FROZEN;
- unfreeze_cgroup(freezer);
- }
+ task->jobctl &= ~JOBCTL_TRAP_FREEZE;
+ wake_up_process(task);
}
+
+ unlock_task_sighand(task, &flags);
}
-/**
- * freezer_change_state - change the freezing state of a cgroup_freezer
- * @freezer: freezer of interest
- * @freeze: whether to freeze or thaw
- *
- * Freeze or thaw @freezer according to @freeze. The operations are
- * recursive - all descendants of @freezer will be affected.
+/*
+ * Freeze or unfreeze all tasks in the given cgroup.
*/
-static void freezer_change_state(struct freezer *freezer, bool freeze)
+static void cgroup_do_freeze(struct cgroup *cgrp, bool freeze)
{
- struct cgroup_subsys_state *pos;
+ struct css_task_iter it;
+ struct task_struct *task;
+
+ lockdep_assert_held(&cgroup_mutex);
+
+ spin_lock_irq(&css_set_lock);
+ if (freeze)
+ set_bit(CGRP_FREEZE, &cgrp->flags);
+ else
+ clear_bit(CGRP_FREEZE, &cgrp->flags);
+ spin_unlock_irq(&css_set_lock);
+
+ if (freeze)
+ TRACE_CGROUP_PATH(freeze, cgrp);
+ else
+ TRACE_CGROUP_PATH(unfreeze, cgrp);
+
+ css_task_iter_start(&cgrp->self, 0, &it);
+ while ((task = css_task_iter_next(&it))) {
+ /*
+ * Ignore kernel threads here. Freezing cgroups containing
+ * kthreads isn't supported.
+ */
+ if (task->flags & PF_KTHREAD)
+ continue;
+ cgroup_freeze_task(task, freeze);
+ }
+ css_task_iter_end(&it);
/*
- * Update all its descendants in pre-order traversal. Each
- * descendant will try to inherit its parent's FREEZING state as
- * CGROUP_FREEZING_PARENT.
+ * Cgroup state should be revisited here to cover empty leaf cgroups
+ * and cgroups which descendants are already in the desired state.
*/
- mutex_lock(&freezer_mutex);
- rcu_read_lock();
- css_for_each_descendant_pre(pos, &freezer->css) {
- struct freezer *pos_f = css_freezer(pos);
- struct freezer *parent = parent_freezer(pos_f);
+ spin_lock_irq(&css_set_lock);
+ if (cgrp->nr_descendants == cgrp->freezer.nr_frozen_descendants)
+ cgroup_update_frozen(cgrp);
+ spin_unlock_irq(&css_set_lock);
+}
- if (!css_tryget_online(pos))
- continue;
- rcu_read_unlock();
+/*
+ * Adjust the task state (freeze or unfreeze) and revisit the state of
+ * source and destination cgroups.
+ */
+void cgroup_freezer_migrate_task(struct task_struct *task,
+ struct cgroup *src, struct cgroup *dst)
+{
+ lockdep_assert_held(&css_set_lock);
- if (pos_f == freezer)
- freezer_apply_state(pos_f, freeze,
- CGROUP_FREEZING_SELF);
- else
- freezer_apply_state(pos_f,
- parent->state & CGROUP_FREEZING,
- CGROUP_FREEZING_PARENT);
+ /*
+ * Kernel threads are not supposed to be frozen at all.
+ */
+ if (task->flags & PF_KTHREAD)
+ return;
- rcu_read_lock();
- css_put(pos);
+ /*
+ * Adjust counters of freezing and frozen tasks.
+ * Note, that if the task is frozen, but the destination cgroup is not
+ * frozen, we bump both counters to keep them balanced.
+ */
+ if (task->frozen) {
+ cgroup_inc_frozen_cnt(dst);
+ cgroup_dec_frozen_cnt(src);
}
- rcu_read_unlock();
- mutex_unlock(&freezer_mutex);
+ cgroup_update_frozen(dst);
+ cgroup_update_frozen(src);
+
+ /*
+ * Force the task to the desired state.
+ */
+ cgroup_freeze_task(task, test_bit(CGRP_FREEZE, &dst->flags));
}
-static ssize_t freezer_write(struct kernfs_open_file *of,
- char *buf, size_t nbytes, loff_t off)
+void cgroup_freeze(struct cgroup *cgrp, bool freeze)
{
- bool freeze;
+ struct cgroup_subsys_state *css;
+ struct cgroup *dsct;
+ bool applied = false;
- buf = strstrip(buf);
+ lockdep_assert_held(&cgroup_mutex);
- if (strcmp(buf, freezer_state_strs(0)) == 0)
- freeze = false;
- else if (strcmp(buf, freezer_state_strs(CGROUP_FROZEN)) == 0)
- freeze = true;
- else
- return -EINVAL;
+ /*
+ * Nothing changed? Just exit.
+ */
+ if (cgrp->freezer.freeze == freeze)
+ return;
- freezer_change_state(css_freezer(of_css(of)), freeze);
- return nbytes;
+ cgrp->freezer.freeze = freeze;
+
+ /*
+ * Propagate changes downwards the cgroup tree.
+ */
+ css_for_each_descendant_pre(css, &cgrp->self) {
+ dsct = css->cgroup;
+
+ if (cgroup_is_dead(dsct))
+ continue;
+
+ if (freeze) {
+ dsct->freezer.e_freeze++;
+ /*
+ * Already frozen because of ancestor's settings?
+ */
+ if (dsct->freezer.e_freeze > 1)
+ continue;
+ } else {
+ dsct->freezer.e_freeze--;
+ /*
+ * Still frozen because of ancestor's settings?
+ */
+ if (dsct->freezer.e_freeze > 0)
+ continue;
+
+ WARN_ON_ONCE(dsct->freezer.e_freeze < 0);
+ }
+
+ /*
+ * Do change actual state: freeze or unfreeze.
+ */
+ cgroup_do_freeze(dsct, freeze);
+ applied = true;
+ }
+
+ /*
+ * Even if the actual state hasn't changed, let's notify a user.
+ * The state can be enforced by an ancestor cgroup: the cgroup
+ * can already be in the desired state or it can be locked in the
+ * opposite state, so that the transition will never happen.
+ * In both cases it's better to notify a user, that there is
+ * nothing to wait for.
+ */
+ if (!applied) {
+ TRACE_CGROUP_PATH(notify_frozen, cgrp,
+ test_bit(CGRP_FROZEN, &cgrp->flags));
+ cgroup_file_notify(&cgrp->events_file);
+ }
}
-
-static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- struct freezer *freezer = css_freezer(css);
-
- return (bool)(freezer->state & CGROUP_FREEZING_SELF);
-}
-
-static u64 freezer_parent_freezing_read(struct cgroup_subsys_state *css,
- struct cftype *cft)
-{
- struct freezer *freezer = css_freezer(css);
-
- return (bool)(freezer->state & CGROUP_FREEZING_PARENT);
-}
-
-static struct cftype files[] = {
- {
- .name = "state",
- .flags = CFTYPE_NOT_ON_ROOT,
- .seq_show = freezer_read,
- .write = freezer_write,
- },
- {
- .name = "self_freezing",
- .flags = CFTYPE_NOT_ON_ROOT,
- .read_u64 = freezer_self_freezing_read,
- },
- {
- .name = "parent_freezing",
- .flags = CFTYPE_NOT_ON_ROOT,
- .read_u64 = freezer_parent_freezing_read,
- },
- { } /* terminate */
-};
-
-struct cgroup_subsys freezer_cgrp_subsys = {
- .css_alloc = freezer_css_alloc,
- .css_online = freezer_css_online,
- .css_offline = freezer_css_offline,
- .css_free = freezer_css_free,
- .attach = freezer_attach,
- .fork = freezer_fork,
- .legacy_cftypes = files,
-};