Re: [PATCH 5.15] kernfs: switch global kernfs_rwsem lock to per-fs lock

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Nov 29, 2024 at 10:20:48PM +0100, Jeremi Piotrowski wrote:
> > And why not just switch them to 6.1.y kernels or newer?
> 
> I wish we could just do that. Right now all our users are on 5.15 and a lot of their
> workloads are sensitive to changes to any part of the container stack including kernel
> version. So they will gradually migrate to kernel 6.1.y and newer as part of upgrading
> their clusters to a new kubernetes release after they validate their workloads on it.
> This is a slow process and in the meantime they are hitting the issue that the patch
> addresses. I'm sure there are other similar users of 5.15 out there.

If they are "hitting this issue" then that is the perfect reason for
them to migrate off of that kernel version.  Don't think that modifying
a core kernel functionality like this is somehow any more "safe" than
moving to a newer kernel (especially given all of the unfixed issues in
the 5.15.y branch compared to 6.1.y).

Saying "your workload is causing problems on this kernel version, please
move to a newer one to resolve the issue." is a valid thing to tell
customers.

Try that first please.

thanks,

greg k-h