io_uring_register_sync_cancel(3) liburing Manual io_uring_register_sync_cancel(3)

io_uring_register_sync_cancel - issue a synchronous cancelation request

#include <liburing.h>
int io_uring_register_sync_cancel(struct io_uring *ring,
                                  struct io_uring_sync_cancel_reg *reg);

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;
    __u64 pad[4];

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.

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.


September 21, 2022 liburing-2.3