cgroup: factor out cgroup_create() out of cgroup_mkdir()
We're in the process of refactoring cgroup and css management paths to
separate them out to eventually allow cgroups which aren't visible
through cgroup fs. This patch factors out cgroup_create() out of
cgroup_mkdir(). cgroup_create() contains all internal object creation
and initialization. cgroup_mkdir() uses cgroup_create() to create the
internal cgroup and adds interface directory and file creation.
This patch doesn't cause any behavior differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a6d484a..e1b3d0f 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4888,33 +4888,19 @@
return ERR_PTR(err);
}
-static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
- umode_t mode)
+static struct cgroup *cgroup_create(struct cgroup *parent)
{
- struct cgroup *parent, *cgrp, *tcgrp;
- struct cgroup_root *root;
+ struct cgroup_root *root = parent->root;
struct cgroup_subsys *ss;
- struct kernfs_node *kn;
- int level, ssid, ret;
-
- /* Do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable.
- */
- if (strchr(name, '\n'))
- return -EINVAL;
-
- parent = cgroup_kn_lock_live(parent_kn);
- if (!parent)
- return -ENODEV;
- root = parent->root;
- level = parent->level + 1;
+ struct cgroup *cgrp, *tcgrp;
+ int level = parent->level + 1;
+ int ssid, ret;
/* allocate the cgroup and its ID, 0 is reserved for the root */
cgrp = kzalloc(sizeof(*cgrp) +
sizeof(cgrp->ancestor_ids[0]) * (level + 1), GFP_KERNEL);
- if (!cgrp) {
- ret = -ENOMEM;
- goto out_unlock;
- }
+ if (!cgrp)
+ return ERR_PTR(-ENOMEM);
ret = percpu_ref_init(&cgrp->self.refcnt, css_release, 0, GFP_KERNEL);
if (ret)
@@ -4978,6 +4964,40 @@
cgroup_refresh_subtree_ss_mask(cgrp);
}
+ return cgrp;
+
+out_cancel_ref:
+ percpu_ref_exit(&cgrp->self.refcnt);
+out_free_cgrp:
+ kfree(cgrp);
+ return ERR_PTR(ret);
+out_destroy:
+ cgroup_destroy_locked(cgrp);
+ return ERR_PTR(ret);
+}
+
+static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode)
+{
+ struct cgroup *parent, *cgrp;
+ struct cgroup_subsys *ss;
+ struct kernfs_node *kn;
+ int ssid, ret;
+
+ /* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */
+ if (strchr(name, '\n'))
+ return -EINVAL;
+
+ parent = cgroup_kn_lock_live(parent_kn);
+ if (!parent)
+ return -ENODEV;
+
+ cgrp = cgroup_create(parent);
+ if (IS_ERR(cgrp)) {
+ ret = PTR_ERR(cgrp);
+ goto out_unlock;
+ }
+
/* create the directory */
kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
if (IS_ERR(kn)) {
@@ -5012,17 +5032,11 @@
ret = 0;
goto out_unlock;
-out_cancel_ref:
- percpu_ref_exit(&cgrp->self.refcnt);
-out_free_cgrp:
- kfree(cgrp);
+out_destroy:
+ cgroup_destroy_locked(cgrp);
out_unlock:
cgroup_kn_unlock(parent_kn);
return ret;
-
-out_destroy:
- cgroup_destroy_locked(cgrp);
- goto out_unlock;
}
/*