md/md-bitmap: merge get_bitmap_from_slot() 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.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240826074452.1490072-37-yukuai1@huaweicloud.comSigned-off-by: Song Liu <song@kernel.org>

drivers/md/md-bitmap.c

@@ -2065,7 +2065,7 @@ static int bitmap_load(struct mddev *mddev)
 }
 
 /* caller need to free returned bitmap with md_bitmap_free() */
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
+static struct bitmap *bitmap_get_from_slot(struct mddev *mddev, int slot)
 {
 	int rv = 0;
 	struct bitmap *bitmap;
@@ -2084,7 +2084,6 @@ struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
 
 	return bitmap;
 }
-EXPORT_SYMBOL(get_bitmap_from_slot);
 
 /* Loads the bitmap associated with slot and copies the resync information
  * to our bitmap
@@ -2097,7 +2096,7 @@ int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
 	struct bitmap_counts *counts;
 	struct bitmap *bitmap;
 
-	bitmap = get_bitmap_from_slot(mddev, slot);
+	bitmap = bitmap_get_from_slot(mddev, slot);
 	if (IS_ERR(bitmap)) {
 		pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
 		return -1;
@@ -2782,6 +2781,7 @@ static struct bitmap_operations bitmap_ops = {
 	.get_stats		= bitmap_get_stats,
 
 	.sync_with_cluster	= bitmap_sync_with_cluster,
+	.get_from_slot		= bitmap_get_from_slot,
 };
 
 void mddev_set_bitmap_ops(struct mddev *mddev)

drivers/md/md-bitmap.h

@@ -276,6 +276,7 @@ struct bitmap_operations {
 	void (*sync_with_cluster)(struct mddev *mddev,
 				  sector_t old_lo, sector_t old_hi,
 				  sector_t new_lo, sector_t new_hi);
+	struct bitmap *(*get_from_slot)(struct mddev *mddev, int slot);
 };
 
 /* the bitmap API */
@@ -283,7 +284,6 @@ void mddev_set_bitmap_ops(struct mddev *mddev);
 
 /* these are exported */
 
-struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot);
 int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
 			     sector_t *lo, sector_t *hi, bool clear_bits);
 void md_bitmap_set_pages(struct bitmap *bitmap, unsigned long pages);

drivers/md/md-cluster.c

@@ -1169,7 +1169,7 @@ static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsiz
 		if (i == md_cluster_ops->slot_number(mddev))
 			continue;
 
-		bitmap = get_bitmap_from_slot(mddev, i);
+		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
 		if (IS_ERR(bitmap)) {
 			pr_err("can't get bitmap from slot %d\n", i);
 			bitmap = NULL;
@@ -1236,7 +1236,7 @@ static int cluster_check_sync_size(struct mddev *mddev)
 		if (i == current_slot)
 			continue;
 
-		bitmap = get_bitmap_from_slot(mddev, i);
+		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
 		if (IS_ERR(bitmap)) {
 			pr_err("can't get bitmap from slot %d\n", i);
 			return -1;