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Diffstat (limited to 'kernel/cgroup_freezer.c')
-rw-r--r--kernel/cgroup_freezer.c155
1 files changed, 77 insertions, 78 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 75dda1ea5026..f0ff64d0ebaa 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -45,25 +45,19 @@ struct freezer {
spinlock_t lock;
};
-static inline struct freezer *cgroup_freezer(struct cgroup *cgroup)
+static inline struct freezer *css_freezer(struct cgroup_subsys_state *css)
{
- return container_of(cgroup_subsys_state(cgroup, freezer_subsys_id),
- struct freezer, css);
+ return css ? container_of(css, struct freezer, css) : NULL;
}
static inline struct freezer *task_freezer(struct task_struct *task)
{
- return container_of(task_subsys_state(task, freezer_subsys_id),
- struct freezer, css);
+ return css_freezer(task_css(task, freezer_subsys_id));
}
static struct freezer *parent_freezer(struct freezer *freezer)
{
- struct cgroup *pcg = freezer->css.cgroup->parent;
-
- if (pcg)
- return cgroup_freezer(pcg);
- return NULL;
+ return css_freezer(css_parent(&freezer->css));
}
bool cgroup_freezing(struct task_struct *task)
@@ -92,7 +86,8 @@ static const char *freezer_state_strs(unsigned int state)
struct cgroup_subsys freezer_subsys;
-static struct cgroup_subsys_state *freezer_css_alloc(struct cgroup *cgroup)
+static struct cgroup_subsys_state *
+freezer_css_alloc(struct cgroup_subsys_state *parent_css)
{
struct freezer *freezer;
@@ -105,22 +100,22 @@ static struct cgroup_subsys_state *freezer_css_alloc(struct cgroup *cgroup)
}
/**
- * freezer_css_online - commit creation of a freezer cgroup
- * @cgroup: cgroup being created
+ * freezer_css_online - commit creation of a freezer css
+ * @css: css being created
*
- * We're committing to creation of @cgroup. Mark it online and inherit
+ * 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 *cgroup)
+static int freezer_css_online(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
struct freezer *parent = parent_freezer(freezer);
/*
* The following double locking and freezing state inheritance
* guarantee that @cgroup can never escape ancestors' freezing
- * states. See cgroup_for_each_descendant_pre() for details.
+ * states. See css_for_each_descendant_pre() for details.
*/
if (parent)
spin_lock_irq(&parent->lock);
@@ -141,15 +136,15 @@ static int freezer_css_online(struct cgroup *cgroup)
}
/**
- * freezer_css_offline - initiate destruction of @cgroup
- * @cgroup: cgroup being destroyed
+ * freezer_css_offline - initiate destruction of a freezer css
+ * @css: css being destroyed
*
- * @cgroup is going away. Mark it dead and decrement system_freezing_count
- * if it was holding one.
+ * @css is going away. Mark it dead and decrement system_freezing_count if
+ * it was holding one.
*/
-static void freezer_css_offline(struct cgroup *cgroup)
+static void freezer_css_offline(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
spin_lock_irq(&freezer->lock);
@@ -161,9 +156,9 @@ static void freezer_css_offline(struct cgroup *cgroup)
spin_unlock_irq(&freezer->lock);
}
-static void freezer_css_free(struct cgroup *cgroup)
+static void freezer_css_free(struct cgroup_subsys_state *css)
{
- kfree(cgroup_freezer(cgroup));
+ kfree(css_freezer(css));
}
/*
@@ -175,25 +170,26 @@ static void freezer_css_free(struct cgroup *cgroup)
* @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 *new_cgrp, struct cgroup_taskset *tset)
+static void freezer_attach(struct cgroup_subsys_state *new_css,
+ struct cgroup_taskset *tset)
{
- struct freezer *freezer = cgroup_freezer(new_cgrp);
+ struct freezer *freezer = css_freezer(new_css);
struct task_struct *task;
bool clear_frozen = false;
spin_lock_irq(&freezer->lock);
/*
- * Make the new tasks conform to the current state of @new_cgrp.
+ * 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.
*
- * Tasks in @tset are on @new_cgrp but may not conform to its
+ * 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.
*/
- cgroup_taskset_for_each(task, new_cgrp, tset) {
+ cgroup_taskset_for_each(task, new_css, tset) {
if (!(freezer->state & CGROUP_FREEZING)) {
__thaw_task(task);
} else {
@@ -231,7 +227,7 @@ static void freezer_fork(struct task_struct *task)
* The root cgroup is non-freezable, so we can skip the
* following check.
*/
- if (!freezer->css.cgroup->parent)
+ if (!parent_freezer(freezer))
goto out;
spin_lock_irq(&freezer->lock);
@@ -244,7 +240,7 @@ out:
/**
* update_if_frozen - update whether a cgroup finished freezing
- * @cgroup: cgroup of interest
+ * @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,
@@ -255,14 +251,14 @@ out:
* 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 @cgroup, so we can't verify task states against
+ * 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 *cgroup)
+static void update_if_frozen(struct cgroup_subsys_state *css)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
- struct cgroup *pos;
- struct cgroup_iter it;
+ struct freezer *freezer = css_freezer(css);
+ struct cgroup_subsys_state *pos;
+ struct css_task_iter it;
struct task_struct *task;
WARN_ON_ONCE(!rcu_read_lock_held());
@@ -274,8 +270,8 @@ static void update_if_frozen(struct cgroup *cgroup)
goto out_unlock;
/* are all (live) children frozen? */
- cgroup_for_each_child(pos, cgroup) {
- struct freezer *child = cgroup_freezer(pos);
+ css_for_each_child(pos, css) {
+ struct freezer *child = css_freezer(pos);
if ((child->state & CGROUP_FREEZER_ONLINE) &&
!(child->state & CGROUP_FROZEN))
@@ -283,9 +279,9 @@ static void update_if_frozen(struct cgroup *cgroup)
}
/* are all tasks frozen? */
- cgroup_iter_start(cgroup, &it);
+ css_task_iter_start(css, &it);
- while ((task = cgroup_iter_next(cgroup, &it))) {
+ while ((task = css_task_iter_next(&it))) {
if (freezing(task)) {
/*
* freezer_should_skip() indicates that the task
@@ -300,52 +296,49 @@ static void update_if_frozen(struct cgroup *cgroup)
freezer->state |= CGROUP_FROZEN;
out_iter_end:
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
out_unlock:
spin_unlock_irq(&freezer->lock);
}
-static int freezer_read(struct cgroup *cgroup, struct cftype *cft,
+static int freezer_read(struct cgroup_subsys_state *css, struct cftype *cft,
struct seq_file *m)
{
- struct cgroup *pos;
+ struct cgroup_subsys_state *pos;
rcu_read_lock();
/* update states bottom-up */
- cgroup_for_each_descendant_post(pos, cgroup)
+ css_for_each_descendant_post(pos, css)
update_if_frozen(pos);
- update_if_frozen(cgroup);
rcu_read_unlock();
- seq_puts(m, freezer_state_strs(cgroup_freezer(cgroup)->state));
+ seq_puts(m, freezer_state_strs(css_freezer(css)->state));
seq_putc(m, '\n');
return 0;
}
static void freeze_cgroup(struct freezer *freezer)
{
- struct cgroup *cgroup = freezer->css.cgroup;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *task;
- cgroup_iter_start(cgroup, &it);
- while ((task = cgroup_iter_next(cgroup, &it)))
+ css_task_iter_start(&freezer->css, &it);
+ while ((task = css_task_iter_next(&it)))
freeze_task(task);
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
}
static void unfreeze_cgroup(struct freezer *freezer)
{
- struct cgroup *cgroup = freezer->css.cgroup;
- struct cgroup_iter it;
+ struct css_task_iter it;
struct task_struct *task;
- cgroup_iter_start(cgroup, &it);
- while ((task = cgroup_iter_next(cgroup, &it)))
+ css_task_iter_start(&freezer->css, &it);
+ while ((task = css_task_iter_next(&it)))
__thaw_task(task);
- cgroup_iter_end(cgroup, &it);
+ css_task_iter_end(&it);
}
/**
@@ -395,12 +388,7 @@ static void freezer_apply_state(struct freezer *freezer, bool freeze,
*/
static void freezer_change_state(struct freezer *freezer, bool freeze)
{
- struct cgroup *pos;
-
- /* update @freezer */
- spin_lock_irq(&freezer->lock);
- freezer_apply_state(freezer, freeze, CGROUP_FREEZING_SELF);
- spin_unlock_irq(&freezer->lock);
+ struct cgroup_subsys_state *pos;
/*
* Update all its descendants in pre-order traversal. Each
@@ -408,24 +396,33 @@ static void freezer_change_state(struct freezer *freezer, bool freeze)
* CGROUP_FREEZING_PARENT.
*/
rcu_read_lock();
- cgroup_for_each_descendant_pre(pos, freezer->css.cgroup) {
- struct freezer *pos_f = cgroup_freezer(pos);
+ css_for_each_descendant_pre(pos, &freezer->css) {
+ struct freezer *pos_f = css_freezer(pos);
struct freezer *parent = parent_freezer(pos_f);
- /*
- * Our update to @parent->state is already visible which is
- * all we need. No need to lock @parent. For more info on
- * synchronization, see freezer_post_create().
- */
spin_lock_irq(&pos_f->lock);
- freezer_apply_state(pos_f, parent->state & CGROUP_FREEZING,
- CGROUP_FREEZING_PARENT);
+
+ if (pos_f == freezer) {
+ freezer_apply_state(pos_f, freeze,
+ CGROUP_FREEZING_SELF);
+ } else {
+ /*
+ * Our update to @parent->state is already visible
+ * which is all we need. No need to lock @parent.
+ * For more info on synchronization, see
+ * freezer_post_create().
+ */
+ freezer_apply_state(pos_f,
+ parent->state & CGROUP_FREEZING,
+ CGROUP_FREEZING_PARENT);
+ }
+
spin_unlock_irq(&pos_f->lock);
}
rcu_read_unlock();
}
-static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
+static int freezer_write(struct cgroup_subsys_state *css, struct cftype *cft,
const char *buffer)
{
bool freeze;
@@ -437,20 +434,22 @@ static int freezer_write(struct cgroup *cgroup, struct cftype *cft,
else
return -EINVAL;
- freezer_change_state(cgroup_freezer(cgroup), freeze);
+ freezer_change_state(css_freezer(css), freeze);
return 0;
}
-static u64 freezer_self_freezing_read(struct cgroup *cgroup, struct cftype *cft)
+static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
return (bool)(freezer->state & CGROUP_FREEZING_SELF);
}
-static u64 freezer_parent_freezing_read(struct cgroup *cgroup, struct cftype *cft)
+static u64 freezer_parent_freezing_read(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- struct freezer *freezer = cgroup_freezer(cgroup);
+ struct freezer *freezer = css_freezer(css);
return (bool)(freezer->state & CGROUP_FREEZING_PARENT);
}