[PATCH 1/3] block: Fix sysfs queue freeze and limits lock order

[Ming Lei]

On Mon, Jan 06, 2025 at 04:29:31PM +0100, Christoph Hellwig wrote:
> On Mon, Jan 06, 2025 at 07:15:27PM +0800, Ming Lei wrote:
> > On Mon, Jan 06, 2025 at 09:29:02AM +0100, Christoph Hellwig wrote:
> > > On Mon, Jan 06, 2025 at 11:31:43AM +0800, Ming Lei wrote:
> > > > As I mentioned in another thread, freezing queue may not be needed in
> > > > ->store(), so let's discuss and confirm if it is needed here first.
> > > > 
> > > > https://lore.kernel.org/linux-block/Z3tHozKiUqWr7gjO@fedora/
> > > 
> > > We do need the freezing.  What you're proposing is playing fast and loose
> > > which is going to get us in trouble.
> > 
> > It is just soft update from sysfs interface, and both the old and new limits
> > are correct from device viewpoint.
> > 
> > What is the trouble? We have run the .store() code without freezing for
> > more than 10 years, no one report issue in the area.
> 
> No, we had various bug reports due to it, including racing with other
> updates.  Let's stop trying to take shortcuts that will byte us again
> later and sort this out properly.

Can you share the bug reports? I am curious how it happen.


Thanks, 
Ming