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Date: Fri, 24 Aug 2018 13:46:22 +0200
From: David Sterba <dsterba@suse.cz>
To: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Cc: David Howells <dhowells@redhat.com>, Qu Wenruo <wqu@suse.com>,
        David Sterba <dsterba@suse.com>, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] btrfs: ctree.h: Fix suspicious rcu usage warning in
 btrfs_debug_in_rcu()
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On Fri, Aug 24, 2018 at 11:35:28AM +0900, Misono Tomohiro wrote:
> commit 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove
> duplicate code") replaces some open coded rcu string handling with macro.
> 
> It turns out that btrfs_debug_in_rcu() is used for the first time and
> the macro lacks lock/unlock of rcu string for non debug case
> (i.e. when message is not printed), leading suspicious RCU usage warning
> when CONFIG_PROVE_RCU is on.
> 
> Fix this by adding a wrapper to call lock/unlock for non debug case too.
> 
> Fixes: 672d599041c8 ("btrfs: Use wrapper macro for rcu string to remove
> duplicate code")
> Reported-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>

Reviewed-by: David Sterba <dsterba@suse.com>

Thanks, I'll add it to the 4.19 queue, expected to appear in rc2.