btrfs: open code btrfs_dev_replace_cancel()

btrfs_dev_replace_cancel() calls __btrfs_dev_replace_cancel() for the
actual cancel so just open code it.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/dev-replace.c

@@ -44,7 +44,6 @@ static void btrfs_dev_replace_update_device_in_mapping_tree(
 						struct btrfs_fs_info *fs_info,
 						struct btrfs_device *srcdev,
 						struct btrfs_device *tgtdev);
-static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 static int btrfs_dev_replace_kthread(void *data);
 static int btrfs_dev_replace_continue_on_mount(struct btrfs_fs_info *fs_info);
 
@@ -694,14 +693,7 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 	btrfs_dev_replace_unlock(dev_replace, 0);
 }
 
-int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
-			     struct btrfs_ioctl_dev_replace_args *args)
-{
-	args->result = __btrfs_dev_replace_cancel(fs_info);
-	return 0;
-}
-
-static u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
+u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
 {
 	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
 	struct btrfs_device *tgt_device = NULL;

fs/btrfs/dev-replace.h

@@ -32,8 +32,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info,
 		int read_src);
 void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info,
 			      struct btrfs_ioctl_dev_replace_args *args);
-int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info,
-			     struct btrfs_ioctl_dev_replace_args *args);
+u64 __btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info);
 void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);
 int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);
 int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);

fs/btrfs/ioctl.c

@@ -4429,7 +4429,8 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
 		ret = 0;
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
-		ret = btrfs_dev_replace_cancel(fs_info, p);
+		p->result = __btrfs_dev_replace_cancel(fs_info);
+		ret = 0;
 		break;
 	default:
 		ret = -EINVAL;