mempolicy: rework mempolicy Reference Counting [yet again]

[safe/jmp/linux-2.6] / include / linux / mempolicy.h

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 017def8..172b9c6 100644 (file)
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -112,6 +112,31 @@ static inline void mpol_put(struct mempolicy *pol)
                __mpol_put(pol);
 }
 
+/*
+ * Does mempolicy pol need explicit unref after use?
+ * Currently only needed for shared policies.
+ */
+static inline int mpol_needs_cond_ref(struct mempolicy *pol)
+{
+       return (pol && (pol->flags & MPOL_F_SHARED));
+}
+
+static inline void mpol_cond_put(struct mempolicy *pol)
+{
+       if (mpol_needs_cond_ref(pol))
+               __mpol_put(pol);
+}
+
+extern struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
+                                         struct mempolicy *frompol);
+static inline struct mempolicy *mpol_cond_copy(struct mempolicy *tompol,
+                                               struct mempolicy *frompol)
+{
+       if (!frompol)
+               return frompol;
+       return __mpol_cond_copy(tompol, frompol);
+}
+
 extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
 static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
 {
@@ -201,6 +226,16 @@ static inline void mpol_put(struct mempolicy *p)
 {
 }
 
+static inline void mpol_cond_put(struct mempolicy *pol)
+{
+}
+
+static inline struct mempolicy *mpol_cond_copy(struct mempolicy *to,
+                                               struct mempolicy *from)
+{
+       return from;
+}
+
 static inline void mpol_get(struct mempolicy *pol)
 {
 }