Re: man page update (fcntl(2) new set/get write hints)

Jens Axboe
2017-08-28T16:13:50Z

On 08/28/2017 03:07 AM, Florian Weimer wrote:
> On 08/24/2017 12:41 AM, Michael Kerrisk (man-pages) wrote:
>> +.TP
>> +.BR F_GET_RW_HINT " (\fIuint64_t\fP; since Linux 4.13)"
>> +Returns the value of the read/write hint associated with the underlying inode
>> +for the file descriptor.
>> +.TP
>> +.BR F_SET_RW_HINT " (\fIuint64_t\fP; since Linux 4.13)"
>> +Sets the read/write hint value associated with the underlying inode for the
>> +file descriptor.
>
> Surely the arguments are of pointer type for reads *and* writes?
>
> There is no convenient way 32-bit userspace can pass a 64-bit integer
> through are variadic dispatcher interface such as ioctl/fcntl/futex.

Yes, they are pointers to a u64 for both the get/set side. The return type
is 0/Exxxx.

--
Jens Axboe