diff options
| -rw-r--r-- | include/linux/cgroup.h | 2 | ||||
| -rw-r--r-- | kernel/cgroup.c | 26 |
2 files changed, 15 insertions, 13 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 39c1d9469677..10d59f3a5ebd 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -169,6 +169,8 @@ struct cgroup { * * The ID of the root cgroup is always 0, and a new cgroup * will be assigned with a smallest available ID. + * + * Allocating/Removing ID must be protected by cgroup_mutex. */ int id; diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 271acd834913..b44dd4989bc1 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4363,16 +4363,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, rcu_assign_pointer(cgrp->name, name); /* - * Temporarily set the pointer to NULL, so idr_find() won't return - * a half-baked cgroup. - */ - cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL); - if (cgrp->id < 0) { - err = -ENOMEM; - goto err_free_name; - } - - /* * Only live parents can have children. Note that the liveliness * check isn't strictly necessary because cgroup_mkdir() and * cgroup_rmdir() are fully synchronized by i_mutex; however, do it @@ -4381,7 +4371,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, */ if (!cgroup_lock_live_group(parent)) { err = -ENODEV; - goto err_free_id; + goto err_free_name; } /* Grab a reference on the superblock so the hierarchy doesn't @@ -4391,6 +4381,16 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, * fs */ atomic_inc(&sb->s_active); + /* + * Temporarily set the pointer to NULL, so idr_find() won't return + * a half-baked cgroup. + */ + cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL); + if (cgrp->id < 0) { + err = -ENOMEM; + goto err_unlock; + } + init_cgroup_housekeeping(cgrp); dentry->d_fsdata = cgrp; @@ -4491,11 +4491,11 @@ err_free_all: ss->css_free(css); } } + idr_remove(&root->cgroup_idr, cgrp->id); +err_unlock: mutex_unlock(&cgroup_mutex); /* Release the reference count that we took on the superblock */ deactivate_super(sb); -err_free_id: - idr_remove(&root->cgroup_idr, cgrp->id); err_free_name: kfree(rcu_dereference_raw(cgrp->name)); err_free_cgrp: |