Make page->private usable in compound pages

[powerpc.git] / include / linux / page-flags.h

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 9d7921d..a1e1436 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -76,7 +76,7 @@
 #define PG_active               6
 #define PG_slab                         7      /* slab debug (Suparna wants this) */
 
-#define PG_checked              8      /* kill me in 2.5.<early>. */
+#define PG_owner_priv_1                 8      /* Owner use. If pagecache, fs may use*/
 #define PG_arch_1               9
 #define PG_reserved            10
 #define PG_private             11      /* If pagecache, has fs-private data */
@@ -91,6 +91,14 @@
 #define PG_nosave_free         18      /* Used for system suspend/resume */
 #define PG_buddy               19      /* Page is free, on buddy lists */
 
+/* PG_owner_priv_1 users should have descriptive aliases */
+#define PG_checked             PG_owner_priv_1 /* Used by some filesystems */
+
+/*
+ * Marks tail portion of a compound page. We currently do not reclaim
+ * compound pages so we can reuse a flag only used for reclaim here.
+ */
+#define PG_tail                        PG_reclaim
 
 #if (BITS_PER_LONG > 32)
 /*
@@ -128,12 +136,11 @@
 
 #define PageUptodate(page)     test_bit(PG_uptodate, &(page)->flags)
 #ifdef CONFIG_S390
-#define SetPageUptodate(_page) \
-       do {                                                                  \
-               struct page *__page = (_page);                                \
-               if (!test_and_set_bit(PG_uptodate, &__page->flags))           \
-                       page_test_and_clear_dirty(_page);                     \
-       } while (0)
+static inline void SetPageUptodate(struct page *page)
+{
+       if (!test_and_set_bit(PG_uptodate, &page->flags))
+               page_clear_dirty(page);
+}
 #else
 #define SetPageUptodate(page)  set_bit(PG_uptodate, &(page)->flags)
 #endif
@@ -240,6 +247,14 @@
 #define __SetPageCompound(page)        __set_bit(PG_compound, &(page)->flags)
 #define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
 
+/*
+ * Note: PG_tail is an alias of another page flag. The result of PageTail()
+ * is only valid if PageCompound(page) is true.
+ */
+#define PageTail(page) test_bit(PG_tail, &(page)->flags)
+#define __SetPageTail(page)    __set_bit(PG_tail, &(page)->flags)
+#define __ClearPageTail(page)  __clear_bit(PG_tail, &(page)->flags)
+
 #ifdef CONFIG_SWAP
 #define PageSwapCache(page)    test_bit(PG_swapcache, &(page)->flags)
 #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
@@ -254,15 +269,11 @@
 
 struct page;   /* forward declaration */
 
-int test_clear_page_dirty(struct page *page);
+extern void cancel_dirty_page(struct page *page, unsigned int account_size);
+
 int test_clear_page_writeback(struct page *page);
 int test_set_page_writeback(struct page *page);
 
-static inline void clear_page_dirty(struct page *page)
-{
-       test_clear_page_dirty(page);
-}
-
 static inline void set_page_writeback(struct page *page)
 {
        test_set_page_writeback(page);