NAME

       io_uring_close_ring_fd - close a ring file descriptor and use it only via registered index

SYNOPSIS

       #include <liburing.h>

       int io_uring_close_ring_fd(struct io_uring *ring);

DESCRIPTION

       io_uring_close_ring_fd(3) closes the ring file descriptor, which must have been previously
       registered.  The file will remain open, but accessible only via the registered index,  not
       via  any  file  descriptor.  Subsequent  liburing  calls  will continue to work, using the
       registered ring fd.

       The kernel must support IORING_FEAT_REG_REG_RING.

       Libraries that must avoid disrupting their users'  uses  of  file  descriptors,  and  must
       continue   working   even   in   the   face   of   close_range(2)  and  similar,  can  use
       io_uring_close_ring_fd(3) to work with liburing without having any open file descriptor.

NOTES

       Each thread that wants to make use of io_uring must register the fd. A  library  that  may
       get  called  from  arbitrary theads may need to detect when it gets called on a previously
       unseen thread and create and register a ring for that thread.

RETURN VALUE

       Returns 1 on success, or -errno on error.

SEE ALSO

       io_uring_register_ring_fd(3)