Merge master.kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6

[pandora-kernel.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index 7cdf48a..62cfd17 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1022,12 +1022,13 @@ try_again:
 
                bh->b_state = 0;
                atomic_set(&bh->b_count, 0);
+               bh->b_private = NULL;
                bh->b_size = size;
 
                /* Link the buffer to its page */
                set_bh_page(bh, page, offset);
 
-               bh->b_end_io = NULL;
+               init_buffer(bh, NULL, NULL);
        }
        return head;
 /*
@@ -2866,22 +2867,22 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[])
                else if (test_set_buffer_locked(bh))
                        continue;
 
-               get_bh(bh);
                if (rw == WRITE || rw == SWRITE) {
                        if (test_clear_buffer_dirty(bh)) {
                                bh->b_end_io = end_buffer_write_sync;
+                               get_bh(bh);
                                submit_bh(WRITE, bh);
                                continue;
                        }
                } else {
                        if (!buffer_uptodate(bh)) {
                                bh->b_end_io = end_buffer_read_sync;
+                               get_bh(bh);
                                submit_bh(rw, bh);
                                continue;
                        }
                }
                unlock_buffer(bh);
-               put_bh(bh);
        }
 }
 
@@ -3049,6 +3050,66 @@ asmlinkage long sys_bdflush(int func, long data)
        return 0;
 }
 
+/*
+ * Migration function for pages with buffers. This function can only be used
+ * if the underlying filesystem guarantees that no other references to "page"
+ * exist.
+ */
+#ifdef CONFIG_MIGRATION
+int buffer_migrate_page(struct page *newpage, struct page *page)
+{
+       struct address_space *mapping = page->mapping;
+       struct buffer_head *bh, *head;
+
+       if (!mapping)
+               return -EAGAIN;
+
+       if (!page_has_buffers(page))
+               return migrate_page(newpage, page);
+
+       head = page_buffers(page);
+
+       if (migrate_page_remove_references(newpage, page, 3))
+               return -EAGAIN;
+
+       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);
+#endif
+
 /*
  * Buffer-head allocation
  */