Re: [PATCH v12 2/5] xenbus/backend: Protect xenbus callback with lock

[JÃrgen GroÃ]

On 18.12.19 11:42, SeongJae Park wrote:
> From: SeongJae Park <sjpark@xxxxxxxxx>
>
> 'reclaim_memory' callback can race with a driver code as this callback
> will be called from any memory pressure detected context.  To deal with
> the case, this commit adds a spinlock in the 'xenbus_device'.  Whenever
> 'reclaim_memory' callback is called, the lock of the device which passed
> to the callback as its argument is locked.  Thus, drivers registering
> their 'reclaim_memory' callback should protect the data that might race
> with the callback with the lock by themselves.

Any reason you don't take the lock around the .probe() and .remove()
calls of the backend (xenbus_dev_probe() and xenbus_dev_remove())? This
would eliminate the need to do that in each backend instead.


Juergen