diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 9d46f60cb943..385c58f2bba1 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4557,9 +4557,15 @@ long btrfs_ioctl(struct file *file, unsigned int
 		return btrfs_ioctl_logical_to_ino(root, argp);
 	case BTRFS_IOC_SPACE_INFO:
 		return btrfs_ioctl_space_info(root, argp);
-	case BTRFS_IOC_SYNC:
-		btrfs_sync_fs(file->f_dentry->d_sb, 1);
-		return 0;
+	case BTRFS_IOC_SYNC: {
+		int ret;
+
+		ret = btrfs_start_all_delalloc_inodes(root->fs_info, 0);
+		if (ret)
+			return ret;
+		ret = btrfs_sync_fs(file->f_dentry->d_sb, 1);
+		return ret;
+	}
 	case BTRFS_IOC_START_SYNC:
 		return btrfs_ioctl_start_sync(root, argp);
 	case BTRFS_IOC_WAIT_SYNC: