[PATCH 1/6] cgroup: Remove prohibited white spaces

[PATCH 1/6] cgroup: Remove prohibited white spaces

[Jakub Kunert]

This patch fixes the checkpatch.pl error:

ERROR: space prohibited before open square bracket

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 470f653..d848888 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -131,14 +131,14 @@ static struct workqueue_struct *cgroup_destroy_wq;
 static struct workqueue_struct *cgroup_pidlist_destroy_wq;
 
 /* generate an array of cgroup subsystem pointers */
-#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys,
+#define SUBSYS(_x)[_x ## _cgrp_id] = &_x ## _cgrp_subsys,
 static struct cgroup_subsys *cgroup_subsys[] = {
 #include <linux/cgroup_subsys.h>
 };
 #undef SUBSYS
 
 /* array of cgroup subsystem names */
-#define SUBSYS(_x) [_x ## _cgrp_id] = #_x,
+#define SUBSYS(_x)[_x ## _cgrp_id] = #_x,
 static const char *cgroup_subsys_name[] = {
 #include <linux/cgroup_subsys.h>
 };
@@ -153,13 +153,13 @@ static const char *cgroup_subsys_name[] = {
 #include <linux/cgroup_subsys.h>
 #undef SUBSYS
 
-#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys_enabled_key,
+#define SUBSYS(_x)[_x ## _cgrp_id] = &_x ## _cgrp_subsys_enabled_key,
 static struct static_key_true *cgroup_subsys_enabled_key[] = {
 #include <linux/cgroup_subsys.h>
 };
 #undef SUBSYS
 
-#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys_on_dfl_key,
+#define SUBSYS(_x)[_x ## _cgrp_id] = &_x ## _cgrp_subsys_on_dfl_key,
 static struct static_key_true *cgroup_subsys_on_dfl_key[] = {
 #include <linux/cgroup_subsys.h>
 };
-- 
2.6.2

[PATCH 2/6] cgroup: Fix line length to 80 characters

[Jakub Kunert]

Fix checkpatch.pl warnings with lines over 80 characters.

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 51 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 19 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d848888..c512ae0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -144,11 +144,13 @@ static const char *cgroup_subsys_name[] = {
 };
 #undef SUBSYS
 
-/* array of static_keys for cgroup_subsys_enabled() and cgroup_subsys_on_dfl() */
-#define SUBSYS(_x)								\
-	DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_enabled_key);			\
-	DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_on_dfl_key);			\
-	EXPORT_SYMBOL_GPL(_x ## _cgrp_subsys_enabled_key);			\
+/*
+ * array of static_keys for cgroup_subsys_enabled() and cgroup_subsys_on_dfl()
+ */
+#define SUBSYS(_x)							\
+	DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_enabled_key);		\
+	DEFINE_STATIC_KEY_TRUE(_x ## _cgrp_subsys_on_dfl_key);		\
+	EXPORT_SYMBOL_GPL(_x ## _cgrp_subsys_enabled_key);		\
 	EXPORT_SYMBOL_GPL(_x ## _cgrp_subsys_on_dfl_key);
 #include <linux/cgroup_subsys.h>
 #undef SUBSYS
@@ -682,7 +684,8 @@ static void css_set_update_populated(struct css_set *cset, bool populated)
  * @from_cset and @to_cset's reference counts.
  */
 static void css_set_move_task(struct task_struct *task,
-			      struct css_set *from_cset, struct css_set *to_cset,
+			      struct css_set *from_cset,
+			      struct css_set *to_cset,
 			      bool use_mg_tasks)
 {
 	lockdep_assert_held(&css_set_lock);
@@ -723,8 +726,8 @@ static void css_set_move_task(struct task_struct *task,
 		if (!css_set_populated(to_cset))
 			css_set_update_populated(to_cset, true);
 		rcu_assign_pointer(task->cgroups, to_cset);
-		list_add_tail(&task->cg_list, use_mg_tasks ? &to_cset->mg_tasks :
-							     &to_cset->tasks);
+		list_add_tail(&task->cg_list,
+			use_mg_tasks ? &to_cset->mg_tasks : &to_cset->tasks);
 	}
 }
 
@@ -2402,7 +2405,8 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
 	 */
 	spin_lock_bh(&css_set_lock);
 	list_for_each_entry(cset, &tset->src_csets, mg_node) {
-		list_for_each_entry_safe(task, tmp_task, &cset->mg_tasks, cg_list) {
+		list_for_each_entry_safe(task, tmp_task,
+					&cset->mg_tasks, cg_list) {
 			struct css_set *from_cset = task_css_set(task);
 			struct css_set *to_cset = cset->mg_dst_cset;
 
@@ -2464,7 +2468,8 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
 	lockdep_assert_held(&cgroup_mutex);
 
 	spin_lock_bh(&css_set_lock);
-	list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {
+	list_for_each_entry_safe(cset, tmp_cset, preloaded_csets,
+				mg_preload_node) {
 		cset->mg_src_cgrp = NULL;
 		cset->mg_dst_cset = NULL;
 		list_del_init(&cset->mg_preload_node);
@@ -2545,7 +2550,8 @@ static int cgroup_migrate_prepare_dst(struct cgroup *dst_cgrp,
 		return -EBUSY;
 
 	/* look up the dst cset for each src cset and link it to src */
-	list_for_each_entry_safe(src_cset, tmp_cset, preloaded_csets, mg_preload_node) {
+	list_for_each_entry_safe(src_cset, tmp_cset, preloaded_csets,
+				mg_preload_node) {
 		struct css_set *dst_cset;
 
 		dst_cset = find_css_set(src_cset,
@@ -3007,7 +3013,8 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
 			/* unavailable or not enabled on the parent? */
 			if (!(cgrp_dfl_root.subsys_mask & (1 << ssid)) ||
 			    (cgroup_parent(cgrp) &&
-			     !(cgroup_parent(cgrp)->subtree_control & (1 << ssid)))) {
+			     !(cgroup_parent(cgrp)->subtree_control &
+						(1 << ssid)))) {
 				ret = -ENOENT;
 				goto out_unlock;
 			}
@@ -3677,9 +3684,11 @@ struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos,
 	 * races against release and the race window is very small.
 	 */
 	if (!pos) {
-		next = list_entry_rcu(parent->children.next, struct cgroup_subsys_state, sibling);
+		next = list_entry_rcu(parent->children.next,
+				struct cgroup_subsys_state, sibling);
 	} else if (likely(!(pos->flags & CSS_RELEASED))) {
-		next = list_entry_rcu(pos->sibling.next, struct cgroup_subsys_state, sibling);
+		next = list_entry_rcu(pos->sibling.next,
+				struct cgroup_subsys_state, sibling);
 	} else {
 		list_for_each_entry_rcu(next, &parent->children, sibling)
 			if (next->serial_nr > pos->serial_nr)
@@ -4152,7 +4161,8 @@ static void cgroup_pidlist_destroy_all(struct cgroup *cgrp)
 
 	mutex_lock(&cgrp->pidlist_mutex);
 	list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
-		mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
+		mod_delayed_work(cgroup_pidlist_destroy_wq,
+				&l->destroy_dwork, 0);
 	mutex_unlock(&cgrp->pidlist_mutex);
 
 	flush_workqueue(cgroup_pidlist_destroy_wq);
@@ -4968,7 +4978,8 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
 	cgrp->self.serial_nr = css_serial_nr_next++;
 
 	/* allocation complete, commit to creation */
-	list_add_tail_rcu(&cgrp->self.sibling, &cgroup_parent(cgrp)->self.children);
+	list_add_tail_rcu(&cgrp->self.sibling,
+			&cgroup_parent(cgrp)->self.children);
 	atomic_inc(&root->nr_cgrps);
 	cgroup_get(parent);
 
@@ -5337,7 +5348,8 @@ int __init cgroup_init(void)
 			WARN_ON(cgroup_add_cftypes(ss, ss->dfl_cftypes));
 		} else {
 			WARN_ON(cgroup_add_dfl_cftypes(ss, ss->dfl_cftypes));
-			WARN_ON(cgroup_add_legacy_cftypes(ss, ss->legacy_cftypes));
+			WARN_ON(cgroup_add_legacy_cftypes(ss,
+							ss->legacy_cftypes));
 		}
 
 		if (ss->bind)
@@ -5408,8 +5420,9 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
 		if (root != &cgrp_dfl_root)
 			for_each_subsys(ss, ssid)
 				if (root->subsys_mask & (1 << ssid))
-					seq_printf(m, "%s%s", count++ ? "," : "",
-						   ss->legacy_name);
+					seq_printf(m, "%s%s",
+						count++ ? "," : "",
+						ss->legacy_name);
 		if (strlen(root->name))
 			seq_printf(m, "%sname=%s", count ? "," : "",
 				   root->name);
-- 
2.6.2

Re: [PATCH 2/6] cgroup: Fix line length to 80 characters

[Tejun Heo]

On Tue, Dec 15, 2015 at 01:20:41PM +0100, Jakub Kunert wrote:
> Fix checkpatch.pl warnings with lines over 80 characters.

Again, checkpatch.pl isn't ten commandments.  I'm gonna skip the rest
of the patchset.  If you think there are salvegeable changes in this
series, please actually think about them and resend separately.

-- 
tejun

[PATCH 3/6] cgroup: Fix trailing */ in block comments.

[Jakub Kunert]

Fix checkpatch.pl warning:

WARNING: Block comments use a trailing */ on a separate line

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index c512ae0..3e1e112 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1015,8 +1015,10 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 
 	lockdep_assert_held(&cgroup_mutex);
 
-	/* First see if we already have a cgroup group that matches
-	 * the desired set */
+	/*
+	 * First see if we already have a cgroup group that matches
+	 * the desired set
+	 */
 	spin_lock_bh(&css_set_lock);
 	cset = find_existing_css_set(old_cset, cgrp, template);
 	if (cset)
@@ -1045,8 +1047,10 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 	INIT_LIST_HEAD(&cset->task_iters);
 	INIT_HLIST_NODE(&cset->hlist);
 
-	/* Copy the set of subsystem state objects generated in
-	 * find_existing_css_set() */
+	/*
+	 * Copy the set of subsystem state objects generated in
+	 * find_existing_css_set()
+	 */
 	memcpy(cset->subsys, template, sizeof(cset->subsys));
 
 	spin_lock_bh(&css_set_lock);
@@ -5227,10 +5231,12 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
 		BUG_ON(css->id < 0);
 	}
 
-	/* Update the init_css_set to contain a subsys
+	/*
+	 * Update the init_css_set to contain a subsys
 	 * pointer to this state - since the subsystem is
 	 * newly registered, all tasks and hence the
-	 * init_css_set is in the subsystem's root cgroup. */
+	 * init_css_set is in the subsystem's root cgroup.
+	 */
 	init_css_set.subsys[ss->id] = css;
 
 	have_fork_callback |= (bool)ss->fork << ss->id;
@@ -5238,9 +5244,11 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
 	have_free_callback |= (bool)ss->free << ss->id;
 	have_canfork_callback |= (bool)ss->can_fork << ss->id;
 
-	/* At system boot, before all subsystems have been
+	/*
+	 * At system boot, before all subsystems have been
 	 * registered, no tasks have been forked, so we don't
-	 * need to invoke fork callbacks here. */
+	 * need to invoke fork callbacks here.
+	 */
 	BUG_ON(!list_empty(&init_task.tasks));
 
 	BUG_ON(online_css(css));
-- 
2.6.2

[PATCH 4/6] cgroup: Add blank lines after declarations.

[Jakub Kunert]

Fix checkpatch.pl warnings:

WARNING: Missing a blank line after declarations

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 3e1e112..9e248bc 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1688,6 +1688,7 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
 			/* Must match [\w.-]+ */
 			for (i = 0; i < strlen(name); i++) {
 				char c = name[i];
+
 				if (isalnum(c))
 					continue;
 				if ((c == '.') || (c == '-') || (c == '_'))
@@ -3228,11 +3229,13 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
 
 	if (cft->write_u64) {
 		unsigned long long v;
+
 		ret = kstrtoull(buf, 0, &v);
 		if (!ret)
 			ret = cft->write_u64(css, cft, v);
 	} else if (cft->write_s64) {
 		long long v;
+
 		ret = kstrtoll(buf, 0, &v);
 		if (!ret)
 			ret = cft->write_s64(css, cft, v);
@@ -4493,6 +4496,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
 
 		while (index < end) {
 			int mid = (index + end) / 2;
+
 			if (cgroup_pid_fry(cgrp, l->list[mid]) == pid) {
 				index = mid;
 				break;
@@ -5520,6 +5524,7 @@ static void **subsys_canfork_priv_p(void *ss_priv[CGROUP_CANFORK_COUNT], int i)
 static void *subsys_canfork_priv(void *ss_priv[CGROUP_CANFORK_COUNT], int i)
 {
 	void **private = subsys_canfork_priv_p(ss_priv, i);
+
 	return private ? *private : NULL;
 }
 
-- 
2.6.2

[PATCH 5/6] cgroup: Replace printk(KERN_INFO) with pr_info().

[Jakub Kunert]

Fix checkpatch.pl warning.

Replace printk(KERN_INFO...) with pr_info().

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 9e248bc..a6ceb61 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -5207,7 +5207,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
 {
 	struct cgroup_subsys_state *css;
 
-	printk(KERN_INFO "Initializing cgroup subsys %s\n", ss->name);
+	pr_info("Initializing cgroup subsys %s\n", ss->name);
 
 	mutex_lock(&cgroup_mutex);
 
@@ -5346,7 +5346,7 @@ int __init cgroup_init(void)
 		 */
 		if (cgroup_disable_mask & (1 << ssid)) {
 			static_branch_disable(cgroup_subsys_enabled_key[ssid]);
-			printk(KERN_INFO "Disabling %s control group subsystem\n",
+			pr_info("Disabling %s control group subsystem\n",
 			       ss->name);
 			continue;
 		}
-- 
2.6.2

[PATCH 6/6] cgroup: Move constant to the right site of comparison.

[Jakub Kunert]

Fix checkpatch.pl warning.

Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 kernel/cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a6ceb61..1ceb3fe 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -5516,7 +5516,7 @@ static const struct file_operations proc_cgroupstats_operations = {
 
 static void **subsys_canfork_priv_p(void *ss_priv[CGROUP_CANFORK_COUNT], int i)
 {
-	if (CGROUP_CANFORK_START <= i && i < CGROUP_CANFORK_END)
+	if (i >= CGROUP_CANFORK_START && i < CGROUP_CANFORK_END)
 		return &ss_priv[i - CGROUP_CANFORK_START];
 	return NULL;
 }
-- 
2.6.2

Re: [PATCH 1/6] cgroup: Remove prohibited white spaces

[Tejun Heo]

Hello, Jakub.

On Tue, Dec 15, 2015 at 01:20:40PM +0100, Jakub Kunert wrote:
> This patch fixes the checkpatch.pl error:
> 
> ERROR: space prohibited before open square bracket
> 
> Signed-off-by: Jakub Kunert <kuba.kunert-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
...
>  /* generate an array of cgroup subsystem pointers */
> -#define SUBSYS(_x) [_x ## _cgrp_id] = &_x ## _cgrp_subsys,
> +#define SUBSYS(_x)[_x ## _cgrp_id] = &_x ## _cgrp_subsys,

Don't follow the checkpatch.pl output without thinking.  No space
before opening brackets rule clearly isn't for cases like above.

-- 
tejun

Re: [PATCH 1/6] cgroup: Remove prohibited white spaces

[Zefan Li]

Hi Jakub,

On 2015/12/15 20:20, Jakub Kunert wrote:
> This patch fixes the checkpatch.pl error:
>
> ERROR: space prohibited before open square bracket
>

checkpatch.pl should be used to check patches that are going to be
sent to the mailing list, and normally should not be used to check
againt existing code.