1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 0dd1610a94a9..471781ffeab1 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -114,6 +114,18 @@ struct dentry {
         unsigned char d_iname[DNAME_INLINE_LEN_MIN];    /* small names */
 };
 
+/*
+ * dentry->d_lock spinlock nesting subclasses:
+ *
+ * 0: normal
+ * 1: nested
+ */
+enum dentry_d_lock_class
+{
+        DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
+        DENTRY_D_LOCK_NESTED
+};
+
 struct dentry_operations {
         int (*d_revalidate)(struct dentry *, struct nameidata *);
         int (*d_hash) (struct dentry *, struct qstr *);