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/kernel/cgroup.c b/kernel/cgroup.c
index c389f42..d35463b 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -876,7 +876,7 @@
* Release the subsystem state objects.
*/
for_each_subsys(cgrp->root, ss)
- ss->destroy(cgrp);
+ ss->css_free(cgrp);
cgrp->root->number_of_cgroups--;
mutex_unlock(&cgroup_mutex);
@@ -4048,8 +4048,8 @@
lockdep_assert_held(&cgroup_mutex);
- if (ss->post_create)
- ret = ss->post_create(cgrp);
+ if (ss->css_online)
+ ret = ss->css_online(cgrp);
if (!ret)
cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
return ret;
@@ -4067,14 +4067,14 @@
return;
/*
- * pre_destroy() should be called with cgroup_mutex unlocked. See
+ * css_offline() should be called with cgroup_mutex unlocked. See
* 3fa59dfbc3 ("cgroup: fix potential deadlock in pre_destroy") for
* details. This temporary unlocking should go away once
* cgroup_mutex is unexported from controllers.
*/
- if (ss->pre_destroy) {
+ if (ss->css_offline) {
mutex_unlock(&cgroup_mutex);
- ss->pre_destroy(cgrp);
+ ss->css_offline(cgrp);
mutex_lock(&cgroup_mutex);
}
@@ -4136,7 +4136,7 @@
for_each_subsys(root, ss) {
struct cgroup_subsys_state *css;
- css = ss->create(cgrp);
+ css = ss->css_alloc(cgrp);
if (IS_ERR(css)) {
err = PTR_ERR(css);
goto err_free_all;
@@ -4147,7 +4147,7 @@
if (err)
goto err_free_all;
}
- /* At error, ->destroy() callback has to free assigned ID. */
+ /* At error, ->css_free() callback has to free assigned ID. */
if (clone_children(parent) && ss->post_clone)
ss->post_clone(cgrp);
@@ -4201,7 +4201,7 @@
err_free_all:
for_each_subsys(root, ss) {
if (cgrp->subsys[ss->subsys_id])
- ss->destroy(cgrp);
+ ss->css_free(cgrp);
}
mutex_unlock(&cgroup_mutex);
/* Release the reference count that we took on the superblock */
@@ -4381,7 +4381,7 @@
/* Create the top cgroup state for this subsystem */
list_add(&ss->sibling, &rootnode.subsys_list);
ss->root = &rootnode;
- css = ss->create(dummytop);
+ css = ss->css_alloc(dummytop);
/* We don't handle early failures gracefully */
BUG_ON(IS_ERR(css));
init_cgroup_css(css, ss, dummytop);
@@ -4425,7 +4425,7 @@
/* check name and function validity */
if (ss->name == NULL || strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN ||
- ss->create == NULL || ss->destroy == NULL)
+ ss->css_alloc == NULL || ss->css_free == NULL)
return -EINVAL;
/*
@@ -4454,10 +4454,11 @@
subsys[ss->subsys_id] = ss;
/*
- * no ss->create seems to need anything important in the ss struct, so
- * this can happen first (i.e. before the rootnode attachment).
+ * no ss->css_alloc seems to need anything important in the ss
+ * struct, so this can happen first (i.e. before the rootnode
+ * attachment).
*/
- css = ss->create(dummytop);
+ css = ss->css_alloc(dummytop);
if (IS_ERR(css)) {
/* failure case - need to deassign the subsys[] slot. */
subsys[ss->subsys_id] = NULL;
@@ -4577,12 +4578,12 @@
write_unlock(&css_set_lock);
/*
- * remove subsystem's css from the dummytop and free it - need to free
- * before marking as null because ss->destroy needs the cgrp->subsys
- * pointer to find their state. note that this also takes care of
- * freeing the css_id.
+ * remove subsystem's css from the dummytop and free it - need to
+ * free before marking as null because ss->css_free needs the
+ * cgrp->subsys pointer to find their state. note that this also
+ * takes care of freeing the css_id.
*/
- ss->destroy(dummytop);
+ ss->css_free(dummytop);
dummytop->subsys[ss->subsys_id] = NULL;
mutex_unlock(&cgroup_mutex);
@@ -4626,8 +4627,8 @@
BUG_ON(!ss->name);
BUG_ON(strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN);
- BUG_ON(!ss->create);
- BUG_ON(!ss->destroy);
+ BUG_ON(!ss->css_alloc);
+ BUG_ON(!ss->css_free);
if (ss->subsys_id != i) {
printk(KERN_ERR "cgroup: Subsys %s id == %d\n",
ss->name, ss->subsys_id);
@@ -5439,7 +5440,7 @@
}
#ifdef CONFIG_CGROUP_DEBUG
-static struct cgroup_subsys_state *debug_create(struct cgroup *cont)
+static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cont)
{
struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
@@ -5449,7 +5450,7 @@
return css;
}
-static void debug_destroy(struct cgroup *cont)
+static void debug_css_free(struct cgroup *cont)
{
kfree(cont->subsys[debug_subsys_id]);
}
@@ -5578,8 +5579,8 @@
struct cgroup_subsys debug_subsys = {
.name = "debug",
- .create = debug_create,
- .destroy = debug_destroy,
+ .css_alloc = debug_css_alloc,
+ .css_free = debug_css_free,
.subsys_id = debug_subsys_id,
.base_cftypes = debug_files,
};