FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2025-01-01 14:52:32 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

cgroup: separate out interface file creation from css creation

Browse Source 
Currently, interface files are created when a css is created depending
on whether @visible is set.  This patch separates out the two into
separate steps to help code refactoring and eventually allow cgroups
which aren't visible through cgroup fs.

Move css_populate_dir() out of create_css() and drop @visible.  While
at it, rename the function to css_create() for consistency.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2016-03-03 09:57:58 -05:00
parent 20b454a61f
commit 6cd0f5bbaf
1 changed files with 43 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
kernel/cgroup.c
View File

@ -222,8 +222,8 @@ static struct cftype cgroup_legacy_base_files[];
static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask);
static void css_task_iter_advance(struct css_task_iter *it);
static int cgroup_destroy_locked(struct cgroup *cgrp);
static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
bool visible);
static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
struct cgroup_subsys *ss);
static void css_release(struct percpu_ref *ref);
static void kill_css(struct cgroup_subsys_state *css);
static int cgroup_addrm_files(struct cgroup_subsys_state *css,
@ -3082,14 +3082,26 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
*/
do_each_subsys_mask(ss, ssid, enable) {
cgroup_for_each_live_child(child, cgrp) {
if (css_enable & (1 << ssid))
ret = create_css(child, ss,
cgrp->subtree_control & (1 << ssid));
else
if (css_enable & (1 << ssid)) {
struct cgroup_subsys_state *css;
css = css_create(child, ss);
if (IS_ERR(css)) {
ret = PTR_ERR(css);
goto err_undo_css;
}
if (cgrp->subtree_control & (1 << ssid)) {
ret = css_populate_dir(css, NULL);
if (ret)
goto err_undo_css;
}
} else {
ret = css_populate_dir(cgroup_css(child, ss),
NULL);
if (ret)
goto err_undo_css;
if (ret)
goto err_undo_css;
}
}
} while_each_subsys_mask();
@ -4717,7 +4729,9 @@ static void css_release_work_fn(struct work_struct *work)
* Those are supported by RCU protecting clearing of
* cgrp->kn->priv backpointer.
*/
RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL);
if (cgrp->kn)
RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv,
NULL);
}
mutex_unlock(&cgroup_mutex);
@ -4801,17 +4815,16 @@ static void offline_css(struct cgroup_subsys_state *css)
}
/**
* create_css - create a cgroup_subsys_state
* css_create - create a cgroup_subsys_state
* @cgrp: the cgroup new css will be associated with
* @ss: the subsys of new css
* @visible: whether to create control knobs for the new css or not
*
* Create a new css associated with @cgrp - @ss pair. On success, the new
* css is online and installed in @cgrp with all interface files created if
* @visible. Returns 0 on success, -errno on failure.
* css is online and installed in @cgrp. This function doesn't create the
* interface files. Returns 0 on success, -errno on failure.
*/
static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
bool visible)
static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
struct cgroup_subsys *ss)
{
struct cgroup *parent = cgroup_parent(cgrp);
struct cgroup_subsys_state *parent_css = cgroup_css(parent, ss);
@ -4822,7 +4835,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
css = ss->css_alloc(parent_css);
if (IS_ERR(css))
return PTR_ERR(css);
return css;
init_and_link_css(css, ss, cgrp);
@ -4835,12 +4848,6 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
goto err_free_percpu_ref;
css->id = err;
if (visible) {
err = css_populate_dir(css, NULL);
if (err)
goto err_free_id;
}
/* @css is ready to be brought online now, make it visible */
list_add_tail_rcu(&css->sibling, &parent_css->children);
cgroup_idr_replace(&ss->css_idr, css, css->id);
@ -4858,18 +4865,16 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss,
ss->warned_broken_hierarchy = true;
}
return 0;
return css;
err_list_del:
list_del_rcu(&css->sibling);
css_clear_dir(css, NULL);
err_free_id:
cgroup_idr_remove(&ss->css_idr, css->id);
err_free_percpu_ref:
percpu_ref_exit(&css->refcnt);
err_free_css:
call_rcu(&css->rcu_head, css_free_rcu_fn);
return err;
return ERR_PTR(err);
}
static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
@ -4966,10 +4971,19 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
/* let's create and online css's */
do_each_subsys_mask(ss, ssid, parent->subtree_ss_mask) {
ret = create_css(cgrp, ss,
parent->subtree_control & (1 << ssid));
if (ret)
struct cgroup_subsys_state *css;
css = css_create(cgrp, ss);
if (IS_ERR(css)) {
ret = PTR_ERR(css);
goto out_destroy;
}
if (parent->subtree_control & (1 << ssid)) {
ret = css_populate_dir(css, NULL);
if (ret)
goto out_destroy;
}
} while_each_subsys_mask();
/*