NAME

       io_uring_prep_fsync - prepare an fsync request

SYNOPSIS

       #include <liburing.h>

       void io_uring_prep_fsync(struct io_uring_sqe *sqe,
                                int fd,
                                unsigned flags);

DESCRIPTION

       The  io_uring_prep_fsync(3) function prepares an fsync request. The submission queue entry
       sqe is setup to use the file descriptor fd that should get synced, with the modifier flags
       indicated by the flags argument.

       This  function  prepares  an  fsync request. It can act either like an fsync(2) operation,
       which is the default behavior. If IORING_FSYNC_DATASYNC is set in the flags argument, then
       it  behaves  like fdatasync(2).  If no range is specified, the fd will be synced from 0 to
       end-of-file.

       It's possible to specify a range to sync, if one is desired. If the off field of  the  SQE
       is  set  to non-zero, then that indicates the offset to start syncing at. If len is set in
       the SQE, then that indicates the size in bytes to sync from the offset.  Note  that  these
       fields  are  not accepted by this helper, so they have to be set manually in the SQE after
       calling this prep helper.

RETURN VALUE

       None

ERRORS

       The CQE res field will contain the result of the operation. See the related man  page  for
       details  on  possible  values.  Note that where synchronous system calls will return -1 on
       failure and set errno to the actual error value, io_uring never uses  errno.   Instead  it
       returns the negated errno directly in the CQE res field.

SEE ALSO

       io_uring_get_sqe(3), io_uring_submit(3), fsync(2), fdatasync(2)