On Fri, Feb 07, 2020 at 09:46:31AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 07928d9bfc81640bab36f5190e8725894d93b659 Mon Sep 17 00:00:00 2001 From: Herbert Xu herbert@gondor.apana.org.au Date: Tue, 19 Nov 2019 13:17:31 +0800 Subject: [PATCH] padata: Remove broken queue flushing
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@vger.kernel.org Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Reviewed-by: Daniel Jordan daniel.m.jordan@oracle.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au
Conflicts are due to not having 6fc4dbcf0276 ("padata: Replace delayed timer with immediate workqueue in padata_reorder") in older kernels. I've fixed it up and queued for 4.19-4.4.