Commit a14c6874 authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[] 



Currently cgroup_base_files[] contains the cgroup core interface files
for both legacy and default hierarchies with each file tagged with
CFTYPE_INSANE and CFTYPE_ONLY_ON_DFL.  This is difficult to read.

Let's separate it out to two separate tables, cgroup_dfl_base_files[]
and cgroup_legacy_base_files[], and use the appropriate one in
cgroup_mkdir() depending on the hierarchy type.  This makes tagging
each file unnecessary.

This patch doesn't introduce any behavior changes.

v2: cgroup_dfl_base_files[] was missing the termination entry
    triggering WARN in cgroup_init_cftypes() for 0day kernel testing
    robot.  Fixed.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
Cc: Jet Chen <jet.chen@intel.com>
parent afd1a8b3

kernel/cgroup.c

+48 −28
Original line number Diff line number Diff line
@@ -180,7 +180,8 @@ static u64 css_serial_nr_next = 1; 
 */

static int need_forkexit_callback __read_mostly;



static struct cftype cgroup_base_files[];

static struct cftype cgroup_dfl_base_files[];

static struct cftype cgroup_legacy_base_files[];



static void cgroup_put(struct cgroup *cgrp);

static int rebind_subsystems(struct cgroup_root *dst_root,
@@ -1614,6 +1615,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask) 
{

	LIST_HEAD(tmp_links);

	struct cgroup *root_cgrp = &root->cgrp;

	struct cftype *base_files;

	struct css_set *cset;

	int i, ret;
@@ -1651,7 +1653,12 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask) 
	}

	root_cgrp->kn = root->kf_root->kn;



	ret = cgroup_addrm_files(root_cgrp, cgroup_base_files, true);

	if (root == &cgrp_dfl_root)

		base_files = cgroup_dfl_base_files;

	else

		base_files = cgroup_legacy_base_files;



	ret = cgroup_addrm_files(root_cgrp, base_files, true);

	if (ret)

		goto destroy_root;
@@ -4095,7 +4102,8 @@ static int cgroup_clone_children_write(struct cgroup_subsys_state *css, 
	return 0;

}



static struct cftype cgroup_base_files[] = {

/* cgroup core interface files for the default hierarchy */

static struct cftype cgroup_dfl_base_files[] = {

	{

		.name = "cgroup.procs",

		.seq_start = cgroup_pidlist_start,
@@ -4106,47 +4114,53 @@ static struct cftype cgroup_base_files[] = { 
		.write = cgroup_procs_write,

		.mode = S_IRUGO | S_IWUSR,

	},

	{

		.name = "cgroup.clone_children",

		.flags = CFTYPE_INSANE,

		.read_u64 = cgroup_clone_children_read,

		.write_u64 = cgroup_clone_children_write,

	},

	{

		.name = "cgroup.sane_behavior",

		.flags = CFTYPE_INSANE | CFTYPE_ONLY_ON_ROOT,

		.seq_show = cgroup_sane_behavior_show,

	},

	{

		.name = "cgroup.controllers",

		.flags = CFTYPE_ONLY_ON_DFL | CFTYPE_ONLY_ON_ROOT,

		.flags = CFTYPE_ONLY_ON_ROOT,

		.seq_show = cgroup_root_controllers_show,

	},

	{

		.name = "cgroup.controllers",

		.flags = CFTYPE_ONLY_ON_DFL | CFTYPE_NOT_ON_ROOT,

		.flags = CFTYPE_NOT_ON_ROOT,

		.seq_show = cgroup_controllers_show,

	},

	{

		.name = "cgroup.subtree_control",

		.flags = CFTYPE_ONLY_ON_DFL,

		.seq_show = cgroup_subtree_control_show,

		.write = cgroup_subtree_control_write,

	},

	{

		.name = "cgroup.populated",

		.flags = CFTYPE_ONLY_ON_DFL | CFTYPE_NOT_ON_ROOT,

		.flags = CFTYPE_NOT_ON_ROOT,

		.seq_show = cgroup_populated_show,

	},

	{ }	/* terminate */

};



	/*

	 * Historical crazy stuff.  These don't have "cgroup."  prefix and

	 * don't exist if sane_behavior.  If you're depending on these, be

	 * prepared to be burned.

	 */

/* cgroup core interface files for the legacy hierarchies */

static struct cftype cgroup_legacy_base_files[] = {

	{

		.name = "cgroup.procs",

		.seq_start = cgroup_pidlist_start,

		.seq_next = cgroup_pidlist_next,

		.seq_stop = cgroup_pidlist_stop,

		.seq_show = cgroup_pidlist_show,

		.private = CGROUP_FILE_PROCS,

		.write = cgroup_procs_write,

		.mode = S_IRUGO | S_IWUSR,

	},

	{

		.name = "cgroup.clone_children",

		.read_u64 = cgroup_clone_children_read,

		.write_u64 = cgroup_clone_children_write,

	},

	{

		.name = "cgroup.sane_behavior",

		.flags = CFTYPE_ONLY_ON_ROOT,

		.seq_show = cgroup_sane_behavior_show,

	},

	{

		.name = "tasks",

		.flags = CFTYPE_INSANE,		/* use "procs" instead */

		.seq_start = cgroup_pidlist_start,

		.seq_next = cgroup_pidlist_next,

		.seq_stop = cgroup_pidlist_stop,
@@ -4157,13 +4171,12 @@ static struct cftype cgroup_base_files[] = { 
	},

	{

		.name = "notify_on_release",

		.flags = CFTYPE_INSANE,

		.read_u64 = cgroup_read_notify_on_release,

		.write_u64 = cgroup_write_notify_on_release,

	},

	{

		.name = "release_agent",

		.flags = CFTYPE_INSANE | CFTYPE_ONLY_ON_ROOT,

		.flags = CFTYPE_ONLY_ON_ROOT,

		.seq_show = cgroup_release_agent_show,

		.write = cgroup_release_agent_write,

		.max_write_len = PATH_MAX - 1,
@@ -4444,6 +4457,7 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, 
	struct cgroup_root *root;

	struct cgroup_subsys *ss;

	struct kernfs_node *kn;

	struct cftype *base_files;

	int ssid, ret;



	parent = cgroup_kn_lock_live(parent_kn);
@@ -4514,7 +4528,12 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, 
	if (ret)

		goto out_destroy;



	ret = cgroup_addrm_files(cgrp, cgroup_base_files, true);

	if (cgroup_on_dfl(cgrp))

		base_files = cgroup_dfl_base_files;

	else

		base_files = cgroup_legacy_base_files;



	ret = cgroup_addrm_files(cgrp, base_files, true);

	if (ret)

		goto out_destroy;
@@ -4836,7 +4855,8 @@ int __init cgroup_init(void) 
	unsigned long key;

	int ssid, err;



	BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files));

	BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));

	BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));



	mutex_lock(&cgroup_mutex);

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