md/md-bitmap: merge bitmap_write_all() into bitmap_operations

So that the implementation won't be exposed, and it'll be possible
to invent a new bitmap by replacing bitmap_operations.

Also change the parameter from bitmap to mddev, to avoid access
bitmap outside md-bitmap.c as much as possible.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240826074452.1490072-22-yukuai1@huaweicloud.comSigned-off-by: Song Liu <song@kernel.org>

drivers/md/md-bitmap.c

@@ -1224,22 +1224,21 @@ static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
 	return ret;
 }
 
-void md_bitmap_write_all(struct bitmap *bitmap)
+/* just flag bitmap pages as needing to be written. */
+static void bitmap_write_all(struct mddev *mddev)
 {
-	/* We don't actually write all bitmap blocks here,
-	 * just flag them as needing to be written
-	 */
 	int i;
+	struct bitmap *bitmap = mddev->bitmap;
 
 	if (!bitmap || !bitmap->storage.filemap)
 		return;
+
+	/* Only one copy, so nothing needed */
 	if (bitmap->storage.file)
-		/* Only one copy, so nothing needed */
 		return;
 
 	for (i = 0; i < bitmap->storage.file_pages; i++)
-		set_page_attr(bitmap, i,
-			      BITMAP_PAGE_NEEDWRITE);
+		set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
 	bitmap->allclean = 0;
 }
 
@@ -2720,6 +2719,7 @@ static struct bitmap_operations bitmap_ops = {
 	.load			= bitmap_load,
 	.destroy		= bitmap_destroy,
 	.flush			= bitmap_flush,
+	.write_all		= bitmap_write_all,
 
 	.update_sb		= bitmap_update_sb,
 	.get_stats		= bitmap_get_stats,

drivers/md/md-bitmap.h

@@ -251,6 +251,7 @@ struct bitmap_operations {
 	int (*load)(struct mddev *mddev);
 	void (*destroy)(struct mddev *mddev);
 	void (*flush)(struct mddev *mddev);
+	void (*write_all)(struct mddev *mddev);
 
 	void (*update_sb)(struct bitmap *bitmap);
 	int (*get_stats)(struct bitmap *bitmap, struct md_bitmap_stats *stats);
@@ -261,8 +262,6 @@ void mddev_set_bitmap_ops(struct mddev *mddev);
 
 /* these are used only by md/bitmap */
 
-void md_bitmap_write_all(struct bitmap *bitmap);
-
 void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e);
 
 /* these are exported */

drivers/md/md.c

@@ -9544,7 +9544,7 @@ static void md_start_sync(struct work_struct *ws)
 	 * stored on all devices. So make sure all bitmap pages get written.
 	 */
 	if (spares)
-		md_bitmap_write_all(mddev->bitmap);
+		mddev->bitmap_ops->write_all(mddev);
 
 	name = test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ?
 			"reshape" : "resync";