cgroup: cosmetic updates to rebind_subsystems()
* Use local variables @scgrp and @dcgrp for @src_root->cgrp and
@dst_root->cgrp respectively.
* Use initializers to set @src_root and @css in the inner bind loop.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f09bab1..a4ff496 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1366,6 +1366,7 @@
static int rebind_subsystems(struct cgroup_root *dst_root,
unsigned long ss_mask)
{
+ struct cgroup *dcgrp = &dst_root->cgrp;
struct cgroup_subsys *ss;
unsigned long tmp_ss_mask;
int ssid, i, ret;
@@ -1387,7 +1388,7 @@
if (dst_root == &cgrp_dfl_root)
tmp_ss_mask &= ~cgrp_dfl_root_inhibit_ss_mask;
- ret = cgroup_populate_dir(&dst_root->cgrp, tmp_ss_mask);
+ ret = cgroup_populate_dir(dcgrp, tmp_ss_mask);
if (ret) {
if (dst_root != &cgrp_dfl_root)
return ret;
@@ -1413,37 +1414,35 @@
cgroup_clear_dir(&ss->root->cgrp, 1 << ssid);
for_each_subsys_which(ss, ssid, &ss_mask) {
- struct cgroup_root *src_root;
- struct cgroup_subsys_state *css;
+ struct cgroup_root *src_root = ss->root;
+ struct cgroup *scgrp = &src_root->cgrp;
+ struct cgroup_subsys_state *css = cgroup_css(scgrp, ss);
struct css_set *cset;
- src_root = ss->root;
- css = cgroup_css(&src_root->cgrp, ss);
+ WARN_ON(!css || cgroup_css(dcgrp, ss));
- WARN_ON(!css || cgroup_css(&dst_root->cgrp, ss));
-
- RCU_INIT_POINTER(src_root->cgrp.subsys[ssid], NULL);
- rcu_assign_pointer(dst_root->cgrp.subsys[ssid], css);
+ RCU_INIT_POINTER(scgrp->subsys[ssid], NULL);
+ rcu_assign_pointer(dcgrp->subsys[ssid], css);
ss->root = dst_root;
- css->cgroup = &dst_root->cgrp;
+ css->cgroup = dcgrp;
down_write(&css_set_rwsem);
hash_for_each(css_set_table, i, cset, hlist)
list_move_tail(&cset->e_cset_node[ss->id],
- &dst_root->cgrp.e_csets[ss->id]);
+ &dcgrp->e_csets[ss->id]);
up_write(&css_set_rwsem);
src_root->subsys_mask &= ~(1 << ssid);
- src_root->cgrp.subtree_control &= ~(1 << ssid);
- cgroup_refresh_child_subsys_mask(&src_root->cgrp);
+ scgrp->subtree_control &= ~(1 << ssid);
+ cgroup_refresh_child_subsys_mask(scgrp);
/* default hierarchy doesn't enable controllers by default */
dst_root->subsys_mask |= 1 << ssid;
if (dst_root == &cgrp_dfl_root) {
static_branch_enable(cgroup_subsys_on_dfl_key[ssid]);
} else {
- dst_root->cgrp.subtree_control |= 1 << ssid;
- cgroup_refresh_child_subsys_mask(&dst_root->cgrp);
+ dcgrp->subtree_control |= 1 << ssid;
+ cgroup_refresh_child_subsys_mask(dcgrp);
static_branch_disable(cgroup_subsys_on_dfl_key[ssid]);
}
@@ -1451,7 +1450,7 @@
ss->bind(css);
}
- kernfs_activate(dst_root->cgrp.kn);
+ kernfs_activate(dcgrp->kn);
return 0;
}