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-rw-r--r--mm/migrate.c142
1 files changed, 72 insertions, 70 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 1c25040693d..49e71ddb679 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -120,15 +120,6 @@ int putback_lru_pages(struct list_head *l)
}
/*
- * 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.
@@ -330,6 +332,67 @@ 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
*
* Two lists are passed to this function. The first list
@@ -529,67 +592,6 @@ next:
}
/*
- * 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.
*
* Specify destination with either non-NULL vma or dest_node >= 0