cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()
Rename cgroup_subsys css lifetime related callbacks to better describe
what their roles are. Also, update documentation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 03d8a92..7a2189c 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -82,7 +82,7 @@
/* bits in struct cgroup_subsys_state flags field */
enum {
CSS_ROOT = (1 << 0), /* this CSS is the root of the subsystem */
- CSS_ONLINE = (1 << 1), /* between ->post_create() and ->pre_destroy() */
+ CSS_ONLINE = (1 << 1), /* between ->css_online() and ->css_offline() */
};
/* Caller must verify that the css is not for root cgroup */
@@ -439,10 +439,11 @@
*/
struct cgroup_subsys {
- struct cgroup_subsys_state *(*create)(struct cgroup *cgrp);
- int (*post_create)(struct cgroup *cgrp);
- void (*pre_destroy)(struct cgroup *cgrp);
- void (*destroy)(struct cgroup *cgrp);
+ struct cgroup_subsys_state *(*css_alloc)(struct cgroup *cgrp);
+ int (*css_online)(struct cgroup *cgrp);
+ void (*css_offline)(struct cgroup *cgrp);
+ void (*css_free)(struct cgroup *cgrp);
+
int (*can_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
void (*cancel_attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
void (*attach)(struct cgroup *cgrp, struct cgroup_taskset *tset);
@@ -541,13 +542,13 @@
* @cgroup: cgroup whose children to walk
*
* Walk @cgroup's children. Must be called under rcu_read_lock(). A child
- * cgroup which hasn't finished ->post_create() or already has finished
- * ->pre_destroy() may show up during traversal and it's each subsystem's
+ * cgroup which hasn't finished ->css_online() or already has finished
+ * ->css_offline() may show up during traversal and it's each subsystem's
* responsibility to verify that each @pos is alive.
*
- * If a subsystem synchronizes against the parent in its ->post_create()
- * and before starting iterating, a cgroup which finished ->post_create()
- * is guaranteed to be visible in the future iterations.
+ * If a subsystem synchronizes against the parent in its ->css_online() and
+ * before starting iterating, a cgroup which finished ->css_online() is
+ * guaranteed to be visible in the future iterations.
*/
#define cgroup_for_each_child(pos, cgroup) \
list_for_each_entry_rcu(pos, &(cgroup)->children, sibling)
@@ -561,19 +562,19 @@
* @cgroup: cgroup whose descendants to walk
*
* Walk @cgroup's descendants. Must be called under rcu_read_lock(). A
- * descendant cgroup which hasn't finished ->post_create() or already has
- * finished ->pre_destroy() may show up during traversal and it's each
+ * descendant cgroup which hasn't finished ->css_online() or already has
+ * finished ->css_offline() may show up during traversal and it's each
* subsystem's responsibility to verify that each @pos is alive.
*
- * If a subsystem synchronizes against the parent in its ->post_create()
- * and before starting iterating, and synchronizes against @pos on each
- * iteration, any descendant cgroup which finished ->post_create() is
+ * If a subsystem synchronizes against the parent in its ->css_online() and
+ * before starting iterating, and synchronizes against @pos on each
+ * iteration, any descendant cgroup which finished ->css_offline() is
* guaranteed to be visible in the future iterations.
*
* In other words, the following guarantees that a descendant can't escape
* state updates of its ancestors.
*
- * my_post_create(@cgrp)
+ * my_online(@cgrp)
* {
* Lock @cgrp->parent and @cgrp;
* Inherit state from @cgrp->parent;
@@ -606,7 +607,7 @@
* iteration should lock and unlock both @pos->parent and @pos.
*
* Alternatively, a subsystem may choose to use a single global lock to
- * synchronize ->post_create() and ->pre_destroy() against tree-walking
+ * synchronize ->css_online() and ->css_offline() against tree-walking
* operations.
*/
#define cgroup_for_each_descendant_pre(pos, cgroup) \