io_uring_register_file_alloc_range - set range for fixed file allocations

       The  io_uring_register_file_alloc_range(3)  function  sets  the  allowable  range  for  fixed  file index
       allocations within the kernel. When requests that  can  instantiate  a  new  fixed  file  are  used  with
       IORING_FILE_INDEX_ALLOC,  the  application is asking the kernel to allocate a new fixed file descriptor
       rather than pass in a specific value for one. By default, the kernel will pick any available  fixed  file
       descriptor  within the range available. Calling this function with off set to the starting offset and len
       set to the number of descriptors, the application can limit the allocated descriptors to that  particular
       range.  This  effectively  allows the application to set aside a range just for dynamic allocations, with
       the remainder being used for specific values.

       The application must have registered a fixed file table upfront, eg through io_uring_register_files(3) or
       io_uring_register_files_sparse(3).

       Available since 6.0.

       io_uring_register_file_alloc_range - set range for fixed file allocations

       On success io_uring_register_file_alloc_range(3) returns 0. On failure it returns -errno.

io_uring_register_files(3)         io_uring_prep_accept_direct(3)          io_uring_prep_openat_direct(3)
       io_uring_prep_socket_direct(3)

liburing-2.3                                      Oct 21, 2022             io_uring_register_file_alloc_range(3)

#include<liburing.h>intio_uring_register_file_alloc_range(structio_uring*ring,unsignedoff,unsignedlen);