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Commit c12f65d4 authored by Li Zefan's avatar Li Zefan Committed by Linus Torvalds
Browse files

cgroups: introduce link_css_set() to remove duplicate code 



Add a common function link_css_set() to link a css_set to a cgroup.

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 33a68ac1

kernel/cgroup.c

+30 −38
Original line number Diff line number Diff line
@@ -384,6 +384,25 @@ static int allocate_cg_links(int count, struct list_head *tmp) 
	return 0;

}



/**

 * link_css_set - a helper function to link a css_set to a cgroup

 * @tmp_cg_links: cg_cgroup_link objects allocated by allocate_cg_links()

 * @cg: the css_set to be linked

 * @cgrp: the destination cgroup

 */

static void link_css_set(struct list_head *tmp_cg_links,

			 struct css_set *cg, struct cgroup *cgrp)

{

	struct cg_cgroup_link *link;



	BUG_ON(list_empty(tmp_cg_links));

	link = list_first_entry(tmp_cg_links, struct cg_cgroup_link,

				cgrp_link_list);

	link->cg = cg;

	list_move(&link->cgrp_link_list, &cgrp->css_sets);

	list_add(&link->cg_link_list, &cg->cg_links);

}



/*

 * find_css_set() takes an existing cgroup group and a

 * cgroup object, and returns a css_set object that's
@@ -399,7 +418,6 @@ static struct css_set *find_css_set( 
	int i;



	struct list_head tmp_cg_links;

	struct cg_cgroup_link *link;



	struct hlist_head *hhead;
@@ -444,26 +462,11 @@ static struct css_set *find_css_set( 
		 * only do it for the first subsystem in each

		 * hierarchy

		 */

		if (ss->root->subsys_list.next == &ss->sibling) {

			BUG_ON(list_empty(&tmp_cg_links));

			link = list_entry(tmp_cg_links.next,

					  struct cg_cgroup_link,

					  cgrp_link_list);

			list_del(&link->cgrp_link_list);

			list_add(&link->cgrp_link_list, &cgrp->css_sets);

			link->cg = res;

			list_add(&link->cg_link_list, &res->cg_links);

		}

	}

	if (list_empty(&rootnode.subsys_list)) {

		link = list_entry(tmp_cg_links.next,

				  struct cg_cgroup_link,

				  cgrp_link_list);

		list_del(&link->cgrp_link_list);

		list_add(&link->cgrp_link_list, &dummytop->css_sets);

		link->cg = res;

		list_add(&link->cg_link_list, &res->cg_links);

		if (ss->root->subsys_list.next == &ss->sibling)

			link_css_set(&tmp_cg_links, res, cgrp);

	}

	if (list_empty(&rootnode.subsys_list))

		link_css_set(&tmp_cg_links, res, dummytop);



	BUG_ON(!list_empty(&tmp_cg_links));
@@ -988,7 +991,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, 
		root = NULL;

	} else {

		/* New superblock */

		struct cgroup *cgrp = &root->top_cgroup;

		struct cgroup *root_cgrp = &root->top_cgroup;

		struct inode *inode;

		int i;
@@ -1029,7 +1032,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, 
		list_add(&root->root_list, &roots);

		root_count++;



		sb->s_root->d_fsdata = &root->top_cgroup;

		sb->s_root->d_fsdata = root_cgrp;

		root->top_cgroup.dentry = sb->s_root;



		/* Link the top cgroup in this hierarchy into all
@@ -1040,29 +1043,18 @@ static int cgroup_get_sb(struct file_system_type *fs_type, 
			struct hlist_node *node;

			struct css_set *cg;



			hlist_for_each_entry(cg, node, hhead, hlist) {

				struct cg_cgroup_link *link;



				BUG_ON(list_empty(&tmp_cg_links));

				link = list_entry(tmp_cg_links.next,

						  struct cg_cgroup_link,

						  cgrp_link_list);

				list_del(&link->cgrp_link_list);

				link->cg = cg;

				list_add(&link->cgrp_link_list,

					 &root->top_cgroup.css_sets);

				list_add(&link->cg_link_list, &cg->cg_links);

			}

			hlist_for_each_entry(cg, node, hhead, hlist)

				link_css_set(&tmp_cg_links, cg, root_cgrp);

		}

		write_unlock(&css_set_lock);



		free_cg_links(&tmp_cg_links);



		BUG_ON(!list_empty(&cgrp->sibling));

		BUG_ON(!list_empty(&cgrp->children));

		BUG_ON(!list_empty(&root_cgrp->sibling));

		BUG_ON(!list_empty(&root_cgrp->children));

		BUG_ON(root->number_of_cgroups != 1);



		cgroup_populate_dir(cgrp);

		cgroup_populate_dir(root_cgrp);

		mutex_unlock(&inode->i_mutex);

		mutex_unlock(&cgroup_mutex);

	}