[PATCH 15/17] zsmalloc: Add zs_pin_lock

[Matthew Wilcox (Oracle)]

Allow lockdep to track zsmalloc's pin bit spin lock.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 mm/zsmalloc.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 9a7c91c14b84..9d89a1857901 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -874,6 +874,8 @@ static unsigned long obj_to_head(struct page *page, void *obj)
 		return *(unsigned long *)obj;
 }
 
+static DEFINE_SPLIT_LOCK(zs_pin_lock);
+
 static inline int testpin_tag(unsigned long handle)
 {
 	return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle);
@@ -881,17 +883,20 @@ static inline int testpin_tag(unsigned long handle)
 
 static inline int trypin_tag(unsigned long handle)
 {
-	return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
+	return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle,
+				&zs_pin_lock);
 }
 
 static void pin_tag(unsigned long handle) __acquires(bitlock)
 {
-	bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
+	bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle,
+			&zs_pin_lock);
 }
 
 static void unpin_tag(unsigned long handle) __releases(bitlock)
 {
-	bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
+	bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle,
+			&zs_pin_lock);
 }
 
 static void reset_page(struct page *page)
-- 
2.30.2