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Commit b0ca5a84 authored by Tejun Heo's avatar Tejun Heo
Browse files

cgroup: build list of all cgroups under a given cgroupfs_root 



Build a list of all cgroups anchored at cgroupfs_root->allcg_list and
going through cgroup->allcg_node.  The list is protected by
cgroup_mutex and will be used to improve cgroup file handling.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent ff4c8d50

include/linux/cgroup.h

+2 −0
Original line number Diff line number Diff line
@@ -191,6 +191,8 @@ struct cgroup { 
	 */

	struct list_head css_sets;



	struct list_head allcg_node;	/* cgroupfs_root->allcg_list */



	/*

	 * Linked list running through all cgroups that can

	 * potentially be reaped by the release agent. Protected by

kernel/cgroup.c

+10 −0
Original line number Diff line number Diff line
@@ -127,6 +127,9 @@ struct cgroupfs_root { 
	/* A list running through the active hierarchies */

	struct list_head root_list;



	/* All cgroups on this root, cgroup_mutex protected */

	struct list_head allcg_list;



	/* Hierarchy-specific flags */

	unsigned long flags;
@@ -1350,11 +1353,14 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) 
static void init_cgroup_root(struct cgroupfs_root *root)

{

	struct cgroup *cgrp = &root->top_cgroup;



	INIT_LIST_HEAD(&root->subsys_list);

	INIT_LIST_HEAD(&root->root_list);

	INIT_LIST_HEAD(&root->allcg_list);

	root->number_of_cgroups = 1;

	cgrp->root = root;

	cgrp->top_cgroup = cgrp;

	list_add_tail(&cgrp->allcg_node, &root->allcg_list);

	init_cgroup_housekeeping(cgrp);

}
@@ -3790,6 +3796,8 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, 
	/* The cgroup directory was pre-locked for us */

	BUG_ON(!mutex_is_locked(&cgrp->dentry->d_inode->i_mutex));



	list_add_tail(&cgrp->allcg_node, &root->allcg_list);



	err = cgroup_populate_dir(cgrp);

	/* If err < 0, we have a half-filled directory - oh well ;) */
@@ -3998,6 +4006,8 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry) 
	list_del_init(&cgrp->sibling);

	cgroup_unlock_hierarchy(cgrp->root);



	list_del_init(&cgrp->allcg_node);



	d = dget(cgrp->dentry);



	cgroup_d_remove_dir(d);