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Commit fa069904 authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: separate out cgroup1_kf_syscall_ops 



Currently, cgroup_kf_syscall_ops is shared by v1 and v2 and the
specific methods test the version and take different actions.  Split
out v1 functions and put them in cgroup1_kf_syscall_ops and remove the
now unnecessary explicit branches in specific methods.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarAcked-by: Zefan Li <lizefan@huawei.com>
parent 633feee3

kernel/cgroup/cgroup-internal.h

+2 −2
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ extern const struct file_operations proc_cgroupstats_operations; 


bool cgroup_ssid_no_v1(int ssid);

void cgroup_pidlist_destroy_all(struct cgroup *cgrp);

int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,

int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,

		   const char *new_name_str);

void cgroup_release_agent(struct work_struct *work);

void check_for_release(struct cgroup *cgrp);

kernel/cgroup/cgroup-v1.c

+2 −9
Original line number Diff line number Diff line
@@ -800,7 +800,7 @@ void cgroup_release_agent(struct work_struct *work) 
/*

 * cgroup_rename - Only allow simple rename of directories in place.

 */

int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,

int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent,

		   const char *new_name_str)

{

	struct cgroup *cgrp = kn->priv;
@@ -811,13 +811,6 @@ int cgroup_rename(struct kernfs_node *kn, struct kernfs_node *new_parent, 
	if (kn->parent != new_parent)

		return -EIO;



	/*

	 * This isn't a proper migration and its usefulness is very

	 * limited.  Disallow on the default hierarchy.

	 */

	if (cgroup_on_dfl(cgrp))

		return -EPERM;



	/*

	 * We're gonna grab cgroup_mutex which nests outside kernfs

	 * active_ref.  kernfs_rename() doesn't require active_ref

kernel/cgroup/cgroup.c

+26 −14
Original line number Diff line number Diff line
@@ -1232,6 +1232,7 @@ struct cgroup *task_cgroup_from_root(struct task_struct *task, 
 * update of a tasks cgroup pointer by cgroup_attach_task()

 */



static struct kernfs_syscall_ops cgroup1_kf_syscall_ops;

static struct kernfs_syscall_ops cgroup_kf_syscall_ops;



static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
@@ -1566,13 +1567,12 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, 
	return len;

}



static int cgroup_show_options(struct seq_file *seq, struct kernfs_root *kf_root)

static int cgroup1_show_options(struct seq_file *seq, struct kernfs_root *kf_root)

{

	struct cgroup_root *root = cgroup_root_from_kf(kf_root);

	struct cgroup_subsys *ss;

	int ssid;



	if (root != &cgrp_dfl_root)

	for_each_subsys(ss, ssid)

		if (root->subsys_mask & (1 << ssid))

			seq_show_option(seq, ss->legacy_name, NULL);
@@ -1736,18 +1736,13 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) 
	return 0;

}



static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)

static int cgroup1_remount(struct kernfs_root *kf_root, int *flags, char *data)

{

	int ret = 0;

	struct cgroup_root *root = cgroup_root_from_kf(kf_root);

	struct cgroup_sb_opts opts;

	u16 added_mask, removed_mask;



	if (root == &cgrp_dfl_root) {

		pr_err("remount is not allowed\n");

		return -EINVAL;

	}



	cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp);



	/* See what subsystems are wanted */
@@ -1798,6 +1793,12 @@ static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data) 
	return ret;

}



static int cgroup_remount(struct kernfs_root *kf_root, int *flags, char *data)

{

	pr_err("remount is not allowed\n");

	return -EINVAL;

}



/*

 * To reduce the fork() overhead for systems that are not actually using

 * their cgroups capability, we don't maintain the lists running through
@@ -1900,6 +1901,7 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) 
{

	LIST_HEAD(tmp_links);

	struct cgroup *root_cgrp = &root->cgrp;

	struct kernfs_syscall_ops *kf_sops;

	struct css_set *cset;

	int i, ret;
@@ -1931,7 +1933,10 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) 
	if (ret)

		goto cancel_ref;



	root->kf_root = kernfs_create_root(&cgroup_kf_syscall_ops,

	kf_sops = root == &cgrp_dfl_root ?

		&cgroup_kf_syscall_ops : &cgroup1_kf_syscall_ops;



	root->kf_root = kernfs_create_root(kf_sops,

					   KERNFS_ROOT_CREATE_DEACTIVATED,

					   root_cgrp);

	if (IS_ERR(root->kf_root)) {
@@ -4813,12 +4818,19 @@ static int cgroup_rmdir(struct kernfs_node *kn) 
	return ret;

}



static struct kernfs_syscall_ops cgroup1_kf_syscall_ops = {

	.remount_fs		= cgroup1_remount,

	.show_options		= cgroup1_show_options,

	.rename			= cgroup1_rename,

	.mkdir			= cgroup_mkdir,

	.rmdir			= cgroup_rmdir,

	.show_path		= cgroup_show_path,

};



static struct kernfs_syscall_ops cgroup_kf_syscall_ops = {

	.remount_fs		= cgroup_remount,

	.show_options		= cgroup_show_options,

	.mkdir			= cgroup_mkdir,

	.rmdir			= cgroup_rmdir,

	.rename			= cgroup_rename,

	.show_path		= cgroup_show_path,

};