[PATCH] page migration cleanup: group functions

Reorder functions in migrate.c.  Group all migration functions for struct
address_space_operations together.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index 1c25040..49e71dd 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -119,15 +119,6 @@ int putback_lru_pages(struct list_head *l)
        return count;
 }
 
-/*
- * Non migratable page
- */
-int fail_migrate_page(struct page *newpage, struct page *page)
-{
-       return -EIO;
-}
-EXPORT_SYMBOL(fail_migrate_page);
-
 /*
  * swapout a single page
  * page is locked upon entry, unlocked on exit
@@ -297,6 +288,17 @@ void migrate_page_copy(struct page *newpage, struct page *page)
 }
 EXPORT_SYMBOL(migrate_page_copy);
 
+/************************************************************
+ *                    Migration functions
+ ***********************************************************/
+
+/* Always fail migration. Used for mappings that are not movable */
+int fail_migrate_page(struct page *newpage, struct page *page)
+{
+       return -EIO;
+}
+EXPORT_SYMBOL(fail_migrate_page);
+
 /*
  * Common logic to directly migrate a single page suitable for
  * pages that do not use PagePrivate.
@@ -329,6 +331,67 @@ int migrate_page(struct page *newpage, struct page *page)
 }
 EXPORT_SYMBOL(migrate_page);
 
+/*
+ * Migration function for pages with buffers. This function can only be used
+ * if the underlying filesystem guarantees that no other references to "page"
+ * exist.
+ */
+int buffer_migrate_page(struct page *newpage, struct page *page)
+{
+       struct address_space *mapping = page->mapping;
+       struct buffer_head *bh, *head;
+       int rc;
+
+       if (!mapping)
+               return -EAGAIN;
+
+       if (!page_has_buffers(page))
+               return migrate_page(newpage, page);
+
+       head = page_buffers(page);
+
+       rc = migrate_page_remove_references(newpage, page, 3);
+
+       if (rc)
+               return rc;
+
+       bh = head;
+       do {
+               get_bh(bh);
+               lock_buffer(bh);
+               bh = bh->b_this_page;
+
+       } while (bh != head);
+
+       ClearPagePrivate(page);
+       set_page_private(newpage, page_private(page));
+       set_page_private(page, 0);
+       put_page(page);
+       get_page(newpage);
+
+       bh = head;
+       do {
+               set_bh_page(bh, newpage, bh_offset(bh));
+               bh = bh->b_this_page;
+
+       } while (bh != head);
+
+       SetPagePrivate(newpage);
+
+       migrate_page_copy(newpage, page);
+
+       bh = head;
+       do {
+               unlock_buffer(bh);
+               put_bh(bh);
+               bh = bh->b_this_page;
+
+       } while (bh != head);
+
+       return 0;
+}
+EXPORT_SYMBOL(buffer_migrate_page);
+
 /*
  * migrate_pages
  *
@@ -528,67 +591,6 @@ next:
        return nr_failed + retry;
 }
 
-/*
- * Migration function for pages with buffers. This function can only be used
- * if the underlying filesystem guarantees that no other references to "page"
- * exist.
- */
-int buffer_migrate_page(struct page *newpage, struct page *page)
-{
-       struct address_space *mapping = page->mapping;
-       struct buffer_head *bh, *head;
-       int rc;
-
-       if (!mapping)
-               return -EAGAIN;
-
-       if (!page_has_buffers(page))
-               return migrate_page(newpage, page);
-
-       head = page_buffers(page);
-
-       rc = migrate_page_remove_references(newpage, page, 3);
-
-       if (rc)
-               return rc;
-
-       bh = head;
-       do {
-               get_bh(bh);
-               lock_buffer(bh);
-               bh = bh->b_this_page;
-
-       } while (bh != head);
-
-       ClearPagePrivate(page);
-       set_page_private(newpage, page_private(page));
-       set_page_private(page, 0);
-       put_page(page);
-       get_page(newpage);
-
-       bh = head;
-       do {
-               set_bh_page(bh, newpage, bh_offset(bh));
-               bh = bh->b_this_page;
-
-       } while (bh != head);
-
-       SetPagePrivate(newpage);
-
-       migrate_page_copy(newpage, page);
-
-       bh = head;
-       do {
-               unlock_buffer(bh);
-               put_bh(bh);
-               bh = bh->b_this_page;
-
-       } while (bh != head);
-
-       return 0;
-}
-EXPORT_SYMBOL(buffer_migrate_page);
-
 /*
  * Migrate the list 'pagelist' of pages to a certain destination.
  *