struct io_uring_cmd {
        struct file     *file;
        const struct io_uring_sqe *sqe;
-       union {
-               /* callback to defer completions to task context */
-               void (*task_work_cb)(struct io_uring_cmd *cmd, unsigned);
-               /* used for polled completion */
-               void *cookie;
-       };
+       /* callback to defer completions to task context */
+       void (*task_work_cb)(struct io_uring_cmd *cmd, unsigned);
        u32             cmd_op;
        u32             flags;
        u8              pdu[32]; /* available inline for free use */
 
                        return -EOPNOTSUPP;
                issue_flags |= IO_URING_F_IOPOLL;
                req->iopoll_completed = 0;
-               WRITE_ONCE(ioucmd->cookie, NULL);
        }
 
        ret = file->f_op->uring_cmd(ioucmd, issue_flags);