'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, add in 'DENTRY_D_LOCK_NESTED_TWICE'.
Signed-off-by: yu kuai <yukuai3@xxxxxxxxxx>
---
include/linux/dcache.h | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 10090f11ab95..830405b401ce 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -129,7 +129,16 @@ struct dentry {
enum dentry_d_lock_class
{
DENTRY_D_LOCK_NORMAL, /* implicitly used by plain spin_lock() APIs. */
- DENTRY_D_LOCK_NESTED
+ /*
+ * used by spin_lock_nested when two d_lock need to be taken
+ * at the same time
+ */
+ DENTRY_D_LOCK_NESTED,
+ /*
+ * used by spin_lock_nested when three d_lock need to be taken
+ * at the same time
+ */
+ DENTRY_D_LOCK_NESTED_TWICE
};
struct dentry_operations {
--
2.17.2
