[PATCH 1/3] dcache: add a new enum type for 'dentry_d_lock_class'

[yu kuai]

'dentry_d_lock_class' can be used for spin_lock_nested in case lockdep
confused about two different dentry take the 'd_lock'.

However, a single 'DENTRY_D_LOCK_NESTED' may not be enough if more than
two dentry are involed. So, and in 'DENTRY_D_LOCK_NESTED_2'

Signed-off-by: yu kuai <yukuai3@xxxxxxxxxx>
---
 include/linux/dcache.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 10090f1..8eb84ef 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -129,7 +129,8 @@ struct dentry {
 enum dentry_d_lock_class
 {
 	DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
-	DENTRY_D_LOCK_NESTED
+	DENTRY_D_LOCK_NESTED,
+	DENTRY_D_LOCK_NESTED_2
 };
 
 struct dentry_operations {
-- 
2.7.4