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

From: Greg Kroah-Hartman
Date: Mon Feb 17 2020 - 23:48:14 EST

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