NAME

       io_uring_register_sync_cancel - issue a synchronous cancelation request

SYNOPSIS

       #include <liburing.h>

       int io_uring_register_sync_cancel(struct io_uring *ring,
                                         struct io_uring_sync_cancel_reg *reg);

DESCRIPTION

       The  io_uring_register_sync_cancel(3)  function  performs  a synchronous cancelation request based on the
       parameters specified in reg .

       The reg argument must be filled in with the appropriate information for the cancelation request. It looks
       as follows:

           struct io_uring_sync_cancel_reg {
               __u64 addr;
               __s32 fd;
               __u32 flags;
               struct __kernel_timespec timeout;
               __u8 opcode;
               __u8 pad[7];
               __u64 pad2[3];
           };

       The arguments largely mirror what the async  prep  functions  support,  see  io_uring_prep_cancel(3)  for
       details.  Similarly,  the  return  value is the same. The exception is the timeout argument, which can be
       used to limit the time that the kernel will wait for cancelations to be successful.  If  the  tv_sec  and
       tv_nsec  values  are  set  to  anything  but  -1UL  ,  then  they  indicate a relative timeout upon which
       cancelations should be completed by.

       The pad values must be zero filled.

RETURN VALUE

       See io_uring_prep_cancel(3) for details on the return value. If timeout is set  to  indicate  a  timeout,
       then -ETIME will be returned if exceeded. If an unknown value is set in the request, or if the pad values
       are not cleared to zero, then -EINVAL is returned.

SEE ALSO

       io_uring_prep_cancel(3)

liburing-2.3                                   September 21, 2022               io_uring_register_sync_cancel(3)