cgroup: s/for_each_subsys()/for_each_root_subsys()/

for_each_subsys() walks over subsystems attached to a hierarchy and
we're gonna add iterators which walk over all available subsystems.
Rename for_each_subsys() to for_each_root_subsys() so that it's more
appropriately named and for_each_subsys() can be used to iterate all
subsystems.

While at it, remove unnecessary underbar prefix from macro arguments,
put them inside parentheses, and adjust indentation for the two
for_each_*() macros.

This patch is purely cosmetic.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>

1 files changed, 22 insertions, 25 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c8d3175c429c..605cb13a1574 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -259,16 +259,13 @@ static int notify_on_release(const struct cgroup *cgrp)
         return test_bit(CGRP_NOTIFY_ON_RELEASE, &cgrp->flags);
 }
 
-/*
- * for_each_subsys() allows you to iterate on each subsystem attached to
- * an active hierarchy
- */
-#define for_each_subsys(_root, _ss) \
-list_for_each_entry(_ss, &_root->subsys_list, sibling)
+/* iterate each subsystem attached to a hierarchy */
+#define for_each_root_subsys(root, ss)                                  \
+        list_for_each_entry((ss), &(root)->subsys_list, sibling)
 
-/* for_each_active_root() allows you to iterate across the active hierarchies */
-#define for_each_active_root(_root) \
-list_for_each_entry(_root, &cgroup_roots, root_list)
+/* iterate across the active hierarchies */
+#define for_each_active_root(root)                                      \
+        list_for_each_entry((root), &cgroup_roots, root_list)
 
 static inline struct cgroup *__d_cgrp(struct dentry *dentry)
 {
@@ -828,7 +825,7 @@ static void cgroup_free_fn(struct work_struct *work)
         /*
          * Release the subsystem state objects.
          */
-        for_each_subsys(cgrp->root, ss)
+        for_each_root_subsys(cgrp->root, ss)
                 ss->css_free(cgrp);
 
         cgrp->root->number_of_cgroups--;
@@ -944,7 +941,7 @@ static void cgroup_clear_directory(struct dentry *dir, bool base_files,
         struct cgroup *cgrp = __d_cgrp(dir);
         struct cgroup_subsys *ss;
 
-        for_each_subsys(cgrp->root, ss) {
+        for_each_root_subsys(cgrp->root, ss) {
                 struct cftype_set *set;
                 if (!test_bit(ss->subsys_id, &subsys_mask))
                         continue;
@@ -1078,7 +1075,7 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry)
         struct cgroup_subsys *ss;
 
         mutex_lock(&cgroup_root_mutex);
-        for_each_subsys(root, ss)
+        for_each_root_subsys(root, ss)
                 seq_printf(seq, ",%s", ss->name);
         if (root->flags & CGRP_ROOT_SANE_BEHAVIOR)
                 seq_puts(seq, ",sane_behavior");
@@ -2054,7 +2051,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
         /*
          * step 1: check that we can legitimately attach to the cgroup.
          */
-        for_each_subsys(root, ss) {
+        for_each_root_subsys(root, ss) {
                 if (ss->can_attach) {
                         retval = ss->can_attach(cgrp, &tset);
                         if (retval) {
@@ -2091,7 +2088,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
         /*
          * step 4: do subsystem attach callbacks.
          */
-        for_each_subsys(root, ss) {
+        for_each_root_subsys(root, ss) {
                 if (ss->attach)
                         ss->attach(cgrp, &tset);
         }
@@ -2111,7 +2108,7 @@ out_put_css_set_refs:
         }
 out_cancel_attach:
         if (retval) {
-                for_each_subsys(root, ss) {
+                for_each_root_subsys(root, ss) {
                         if (ss == failed_ss)
                                 break;
                         if (ss->cancel_attach)
@@ -4137,7 +4134,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files,
         }
 
         /* process cftsets of each subsystem */
-        for_each_subsys(cgrp->root, ss) {
+        for_each_root_subsys(cgrp->root, ss) {
                 struct cftype_set *set;
                 if (!test_bit(ss->subsys_id, &subsys_mask))
                         continue;
@@ -4147,7 +4144,7 @@ static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files,
         }
 
         /* This cgroup is ready now */
-        for_each_subsys(cgrp->root, ss) {
+        for_each_root_subsys(cgrp->root, ss) {
                 struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
                 /*
                  * Update id->css pointer and make this css visible from
@@ -4294,7 +4291,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
         if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &parent->flags))
                 set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
 
-        for_each_subsys(root, ss) {
+        for_each_root_subsys(root, ss) {
                 struct cgroup_subsys_state *css;
 
                 css = ss->css_alloc(cgrp);
@@ -4333,14 +4330,14 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
         root->number_of_cgroups++;
 
         /* each css holds a ref to the cgroup's dentry */
-        for_each_subsys(root, ss)
+        for_each_root_subsys(root, ss)
                 dget(dentry);
 
         /* hold a ref to the parent's dentry */
         dget(parent->dentry);
 
         /* creation succeeded, notify subsystems */
-        for_each_subsys(root, ss) {
+        for_each_root_subsys(root, ss) {
                 err = online_css(ss, cgrp);
                 if (err)
                         goto err_destroy;
@@ -4365,7 +4362,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
         return 0;
 
 err_free_all:
-        for_each_subsys(root, ss) {
+        for_each_root_subsys(root, ss) {
                 struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
 
                 if (css) {
@@ -4478,7 +4475,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
          * be killed.
          */
         atomic_set(&cgrp->css_kill_cnt, 1);
-        for_each_subsys(cgrp->root, ss) {
+        for_each_root_subsys(cgrp->root, ss) {
                 struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
 
                 /*
@@ -4552,7 +4549,7 @@ static void cgroup_offline_fn(struct work_struct *work)
          * css_tryget() is guaranteed to fail now.  Tell subsystems to
          * initate destruction.
          */
-        for_each_subsys(cgrp->root, ss)
+        for_each_root_subsys(cgrp->root, ss)
                 offline_css(ss, cgrp);
 
         /*
@@ -4562,7 +4559,7 @@ static void cgroup_offline_fn(struct work_struct *work)
          * whenever that may be, the extra dentry ref is put so that dentry
          * destruction happens only after all css's are released.
          */
-        for_each_subsys(cgrp->root, ss)
+        for_each_root_subsys(cgrp->root, ss)
                 css_put(cgrp->subsys[ss->subsys_id]);
 
         /* delete this cgroup from parent->children */
@@ -4967,7 +4964,7 @@ int proc_cgroup_show(struct seq_file *m, void *v)
                 int count = 0;
 
                 seq_printf(m, "%d:", root->hierarchy_id);
-                for_each_subsys(root, ss)
+                for_each_root_subsys(root, ss)
                         seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
                 if (strlen(root->name))
                         seq_printf(m, "%sname=%s", count ? "," : "",