md/md-bitmap: introduce CONFIG_MD_BITMAP

Now that all implementations are internal, it's sensible to add a config
option for md-bitmap, and it's a good way for isolation.

Link: https://lore.kernel.org/linux-raid/20250707012711.376844-16-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>

1 files changed, 21 insertions, 2 deletions

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 29de99e0de3e..5f62f2fd8f3f 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -224,6 +224,8 @@ struct bitmap {
 	int cluster_slot;
 };
 
+static struct workqueue_struct *md_bitmap_wq;
+
 static int __bitmap_resize(struct bitmap *bitmap, sector_t blocks,
 			   int chunksize, bool init);
 
@@ -2979,6 +2981,12 @@ static struct attribute_group md_bitmap_group = {
 };
 
 static struct bitmap_operations bitmap_ops = {
+	.head = {
+		.type	= MD_BITMAP,
+		.id	= ID_BITMAP,
+		.name	= "bitmap",
+	},
+
 	.enabled		= bitmap_enabled,
 	.create			= bitmap_create,
 	.resize			= bitmap_resize,
@@ -3013,7 +3021,18 @@ static struct bitmap_operations bitmap_ops = {
 	.group			= &md_bitmap_group,
 };
 
-void mddev_set_bitmap_ops(struct mddev *mddev)
+int md_bitmap_init(void)
+{
+	md_bitmap_wq = alloc_workqueue("md_bitmap", WQ_MEM_RECLAIM | WQ_UNBOUND,
+				       0);
+	if (!md_bitmap_wq)
+		return -ENOMEM;
+
+	return register_md_submodule(&bitmap_ops.head);
+}
+
+void md_bitmap_exit(void)
 {
-	mddev->bitmap_ops = &bitmap_ops;
+	destroy_workqueue(md_bitmap_wq);
+	unregister_md_submodule(&bitmap_ops.head);
 }