Re: md regression caused by commit 9e59d609763f70a992a8f3808dabcce60f14eb5c

[Mikulas Patocka <mpatocka@redhat.com>]

On Thu, 7 Aug 2025, Luca Boccassi wrote:

> On Thu, 7 Aug 2025 at 01:04, Xiao Ni <xni@redhat.com> wrote:
> >
> > Hi all
> >
> > It needs to use the latest upstream mdadm
> > https://github.com/md-raid-utilities/mdadm/ which has fixed this
> > problem. And for fedora, it hasn't updated to the latest upstream. So
> > it has this problem. I'll update fedora mdadm to latest upstream.
> >
> > Best Regards
> > Xiao
> 
> Thank you for looking into it and providing a solution - however,
> isn't it against the rules to break existing released userspace
> components and requiring new versions to be released in order to use a
> new kernel version? Is there any way this kernel patch could be
> amended to avoid breaking the existing userspace as it is?
> 
> Thanks

I also think that the misbehavior should be fixed in the kernel.

We shouldn't use arbitrary timeouts to clean up the sysfs entries, because 
it would introduce race conditions.

What about destroying the sysfs entries when the file descriptor is 
closed? (instead of on the STOP_ARRAY ioctl) That wouldn't interfere with 
other code trying to stop the array and it would make it work with the 
buggy mdadm that calls STOP_ARRAY and then tries to find the sysfs entries 
and then calls SET_ARRAY_INFO.

Mikulas