Christian Franke wrote:
> Jon Turney wrote:
>> On 14/01/2024 16:07, Christian Franke wrote:
>>> Recently I learned about the existence and usefulness of close_range():
>>> https://github.com/smartmontools/smartmontools/issues/235
>>>
>>> https://man.freebsd.org/cgi/man.cgi?query=close_range&sektion=2
>>> https://man7.org/linux/man-pages/man2/close_range.2.html
>>>
>>> Note that the above Linux man page is not fully correct. The include 
>>> file "linux/close_range.h" exists, but provides only the defines. It 
>>> is sufficient to include "unistd.h" as on FreeBSD.
>>>
>>> The attached patch adds this to Cygwin. It does not implement the 
>>> Linux-specific CLOSE_RANGE_UNSHARE as I have no idea how to do this :-)
>>
>> This API should also be mentioned in the
>> "System interfaces compatible with GNU or Linux extensions" section 
>> of doc/posix.xml
>>
>>
>
> Thanks for the info. I used the recent "Cygwin: introduce 
> fallocate(2)" patch as a blueprint for which other files should be 
> changed (fallocate is also missing in the posix.xml file).
>
> I will provide a new patch soon which also fixes an unlikely but 
> possible corner case: Pass a value larger than MAX_INT as lower limit.
>

Attached. I also decided to simply ignore CLOSE_RANGE_UNSHARE for now.