Re: [PATCH v2 4.14] padata: Remove broken queue flushing

[Greg Kroah-Hartman]

On Fri, Feb 14, 2020 at 02:46:51PM -0500, Daniel Jordan wrote:
> From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> 
> [ Upstream commit 07928d9bfc81640bab36f5190e8725894d93b659 ]
> 
> The function padata_flush_queues is fundamentally broken because
> it cannot force padata users to complete the request that is
> underway.  IOW padata has to passively wait for the completion
> of any outstanding work.
> 
> As it stands flushing is used in two places.  Its use in padata_stop
> is simply unnecessary because nothing depends on the queues to
> be flushed afterwards.
> 
> The other use in padata_replace is more substantial as we depend
> on it to free the old pd structure.  This patch instead uses the
> pd->refcnt to dynamically free the pd structure once all requests
> are complete.
> 
> Fixes: 2b73b07ab8a4 ("padata: Flush the padata queues actively")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> [dj: leave "pd->pinst = pinst" assignment in padata_alloc_pd()]
> Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>

Thanks, all 3 backports now queued up.

greg k-h