io_cancel(2)                  System Calls Manual                 io_cancel(2)

NAME
       io_cancel - cancel an outstanding asynchronous I/O operation

LIBRARY
       Standard C library (libc, -lc)

       Alternatively, Asynchronous I/O library (libaio, -laio); see VERSIONS.

SYNOPSIS
       #include <linux/aio_abi.h>    /* Definition of needed types */
       #include <sys/syscall.h>      /* Definition of SYS_* constants */
       #include <unistd.h>

       int syscall(SYS_io_cancel, aio_context_t ctx_id, struct iocb *iocb,
                   struct io_event *result);

DESCRIPTION
       Note: this page describes the raw Linux system call interface.  The
       wrapper function provided by libaio uses a different type for the
       ctx_id argument.  See VERSIONS.

       The io_cancel() system call attempts to cancel an asynchronous I/O
       operation previously submitted with io_submit(2).  The iocb argument
       describes the operation to be canceled and the ctx_id argument is the
       AIO context to which the operation was submitted.  If the operation is
       successfully canceled, the event will be copied into the memory pointed
       to by result without being placed into the completion queue.

RETURN VALUE
       On success, io_cancel() returns 0.  For the failure return, see
       VERSIONS.

ERRORS
       EAGAIN The iocb specified was not canceled.

       EFAULT One of the data structures points to invalid data.

       EINVAL The AIO context specified by ctx_id is invalid.

       ENOSYS io_cancel() is not implemented on this architecture.

VERSIONS
       You probably want to use the io_cancel() wrapper function provided by
       libaio.

       Note that the libaio wrapper function uses a different type
       (io_context_t) for the ctx_id argument.  Note also that the libaio
       wrapper does not follow the usual C library conventions for indicating
       errors: on error it returns a negated error number (the negative of one
       of the values listed in ERRORS).  If the system call is invoked via
       syscall(2), then the return value follows the usual conventions for
       indicating an error: -1, with errno set to a (positive) value that
       indicates the error.

STANDARDS
       Linux.

HISTORY
       Linux 2.5.

SEE ALSO
       io_destroy(2), io_getevents(2), io_setup(2), io_submit(2), aio(7)

Linux man-pages 6.7               2023-10-31                      io_cancel(2)