URING_BLOCK_SZ
int blocks = (int)(fi->file_sz + URING_BLOCK_SZ - 1) / URING_BLOCK_SZ;
int blocks = (int)(remain + URING_BLOCK_SZ - 1) / URING_BLOCK_SZ;
if (bytes > URING_BLOCK_SZ)
bytes = URING_BLOCK_SZ;
if (posix_memalign(&buf, URING_BLOCK_SZ, URING_BLOCK_SZ))
int blocks = (int)(file_sz + URING_BLOCK_SZ - 1) / URING_BLOCK_SZ;