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: Li 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Li Zefan 2009-01-07 18:07:42 -08:00 committed by Linus Torvalds
parent 33a68ac1c1
commit c12f65d439

View file

@ -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);
}