io_uring_register_file_alloc_range(3) — Linux manual page


io_uring_re...alloc_range(3) liburing Manualio_uring_re...alloc_range(3)

NAME         top

       io_uring_register_file_alloc_range - set range for fixed file

SYNOPSIS         top

       #include <liburing.h>

       int io_uring_register_file_alloc_range(struct io_uring *ring,
                                              unsigned off,
                                              unsigned len);

DESCRIPTION         top

       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

       Available since 6.0.

RETURN VALUE         top

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

SEE ALSO         top

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

COLOPHON         top

       This page is part of the liburing (A library for io_uring)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for
       this manual page, send it to  This page
       was obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2023-12-19.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

liburing-2.3                  Oct 21, 2022  io_uring_re...alloc_range(3)

Pages that refer to this page: io_uring_prep_accept(3)io_uring_prep_accept_direct(3)io_uring_prep_multishot_accept(3)io_uring_prep_multishot_accept_direct(3)io_uring_register_file_alloc_range(3)