summaryrefslogtreecommitdiffstats
path: root/kernel/cgroup.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 166b514..c53f42e 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2657,9 +2657,15 @@ static int cgroup_create_file(struct dentry *dentry, umode_t mode,
inc_nlink(inode);
inc_nlink(dentry->d_parent->d_inode);
- /* start with the directory inode held, so that we can
- * populate it without racing with another mkdir */
- mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
+ /*
+ * Control reaches here with cgroup_mutex held.
+ * @inode->i_mutex should nest outside cgroup_mutex but we
+ * want to populate it immediately without releasing
+ * cgroup_mutex. As @inode isn't visible to anyone else
+ * yet, trylock will always succeed without affecting
+ * lockdep checks.
+ */
+ WARN_ON_ONCE(!mutex_trylock(&inode->i_mutex));
} else if (S_ISREG(mode)) {
inode->i_size = 0;
inode->i_fop = &cgroup_file_operations;
OpenPOWER on IntegriCloud