diff options
| -rw-r--r-- | kernel/cgroup.c | 30 |
1 files changed, 12 insertions, 18 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index b042673171e9..d62a529db2f7 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4112,15 +4112,22 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, } } - list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children); - root->number_of_cgroups++; - + /* + * Create directory. cgroup_create_file() returns with the new + * directory locked on success so that it can be populated without + * dropping cgroup_mutex. + */ err = cgroup_create_file(dentry, S_IFDIR | mode, sb); if (err < 0) - goto err_remove; + goto err_destroy; + lockdep_assert_held(&dentry->d_inode->i_mutex); + /* allocation complete, commit to creation */ dentry->d_fsdata = cgrp; rcu_assign_pointer(cgrp->dentry, dentry); + list_add_tail(&cgrp->allcg_node, &root->allcg_list); + list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children); + root->number_of_cgroups++; for_each_subsys(root, ss) { /* each css holds a ref to the cgroup's dentry */ @@ -4131,11 +4138,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, ss->post_create(cgrp); } - /* 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, true, root->subsys_mask); /* If err < 0, we have a half-filled directory - oh well ;) */ @@ -4144,20 +4146,12 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, return 0; - err_remove: - - list_del_rcu(&cgrp->sibling); - root->number_of_cgroups--; - - err_destroy: - +err_destroy: for_each_subsys(root, ss) { if (cgrp->subsys[ss->subsys_id]) ss->destroy(cgrp); } - mutex_unlock(&cgroup_mutex); - /* Release the reference count that we took on the superblock */ deactivate_super(sb); err_free: |