diff options
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index b5f4989937f2..e0aeb32415ff 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -830,7 +830,6 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, */ static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode); -static struct dentry *cgroup_lookup(struct inode *, struct dentry *, unsigned int); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask); static const struct inode_operations cgroup_dir_inode_operations; @@ -2650,7 +2649,7 @@ static const struct inode_operations cgroup_file_inode_operations = { }; static const struct inode_operations cgroup_dir_inode_operations = { - .lookup = cgroup_lookup, + .lookup = simple_lookup, .mkdir = cgroup_mkdir, .rmdir = cgroup_rmdir, .rename = cgroup_rename, @@ -2660,14 +2659,6 @@ static const struct inode_operations cgroup_dir_inode_operations = { .removexattr = cgroup_removexattr, }; -static struct dentry *cgroup_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) -{ - if (dentry->d_name.len > NAME_MAX) - return ERR_PTR(-ENAMETOOLONG); - d_add(dentry, NULL); - return NULL; -} - /* * Check if a file is a control file */ @@ -4678,6 +4669,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) struct dentry *d = cgrp->dentry; struct cgroup_event *event, *tmp; struct cgroup_subsys *ss; + struct cgroup *child; bool empty; lockdep_assert_held(&d->d_inode->i_mutex); @@ -4688,12 +4680,28 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) * @cgrp from being removed while __put_css_set() is in progress. */ read_lock(&css_set_lock); - empty = list_empty(&cgrp->cset_links) && list_empty(&cgrp->children); + empty = list_empty(&cgrp->cset_links); read_unlock(&css_set_lock); if (!empty) return -EBUSY; /* + * Make sure there's no live children. We can't test ->children + * emptiness as dead children linger on it while being destroyed; + * otherwise, "rmdir parent/child parent" may fail with -EBUSY. + */ + empty = true; + rcu_read_lock(); + list_for_each_entry_rcu(child, &cgrp->children, sibling) { + empty = cgroup_is_dead(child); + if (!empty) + break; + } + rcu_read_unlock(); + if (!empty) + return -EBUSY; + + /* * Initiate massacre of all css's. cgroup_destroy_css_killed() * will be invoked to perform the rest of destruction once the * percpu refs of all css's are confirmed to be killed. |