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)

liburing-2.4                                   September 25, 2022                      io_uring_close_ring_fd(3)