Out of openat flag space

David Legault legault.david at gmail.com
Wed Apr 8 05:54:55 EDT 2015


On Tue, Apr 7, 2015 at 7:04 PM, Nicholas Krause <xerofoify at gmail.com> wrote:
>
>
> On April 7, 2015 1:05:42 PM EDT, David Legault <legault.david at gmail.com> wrote:
>>Hello,
>>
>>Now that we have O_TMPFILE and O_BENEATH added to the openat flags,
>>there
>>is no space left to add more flags since the flags variable is a 32 bit
>>int. How does one resolve this issue and extend this? A new syscall
>>with a
>>64bit wide flags support?
>>
>>http://www.spinics.net/lists/fstests/msg01064.html
>>
>>Thanks
>>
>>David
>>
> That would be the easiest way to my knowledge.  However with anything system call related,  test it out in every way you can think of as not to break user space applications using this call already .  I am curious through as to your reasoning for changing this system call as generally this is only done only  with either a very good  reason or when it  is a must.

The reason is that I want to add a new flag and there is no room left
to add it in the current setup since all flag values are used. And
this issue will crop up for the kernel sooner or later for the next
person that wants to add a flag to it. I couldn't find any discussion
online of the "what do we do when we reach that point".

That's what I was thinking but wasn't 100% sure which is why I am
asking. It wouldn't be too difficult since I have full control over
the kernel and libc in this env but I'd prefer doing it the same way
that it would be done so that I could submit my extension to the
kernel as a patch if required.

> Hope this helps,
> Nick
>>
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