a9786b6f04
fd_insert() is currently called just after setting the owner and iocb, but proceeding like this prevents the operation from being atomic and requires a lock to protect the maxfd computation in another thread from meeting an incompletely initialized FD and computing a wrong maxfd. Fortunately for now all fdtab[].owner are set before calling fd_insert(), and the first lock in fd_insert() enforces a memory barrier so the code is safe. This patch moves the initialization of the owner and iocb to fd_insert() so that the function will be able to properly arrange its operations and remain safe even when modified to become lockless. There's no other change beyond the internal API.