md: fix bitmap-on-external-file bug.

commit a2ed9615e3222645007fc19991aedf30eed3ecfd
fixed a bug with 'internal' bitmaps, but in the process broke
'in a file' bitmaps.  So they are broken in 2.6.28

This fixes it, and needs to go in 2.6.28-stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index ab7c8e4..666b7ba 100644 (file)
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -964,9 +964,11 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
                                 */
                                page = bitmap->sb_page;
                                offset = sizeof(bitmap_super_t);
-                               read_sb_page(bitmap->mddev, bitmap->offset,
-                                            page,
-                                            index, count);
+                               if (!file)
+                                       read_sb_page(bitmap->mddev,
+                                                    bitmap->offset,
+                                                    page,
+                                                    index, count);
                        } else if (file) {
                                page = read_page(file, index, bitmap, count);
                                offset = 0;