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Subject: Re: [block/for-next] writeback: don't access page->mapping directly
 in track_foreign_dirty TP
To:     Tejun Heo <tj@kernel.org>, Jan Kara <jack@suse.cz>
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@fb.com
References: <20190830233954.GC2263813@devbig004.ftw2.facebook.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <ec4d9155-76bc-2586-7a56-d8f495537b80@kernel.dk>
Date:   Fri, 30 Aug 2019 19:54:51 -0600
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On 8/30/19 5:39 PM, Tejun Heo wrote:
> page->mapping may encode different values in it and page_mapping()
> should always be used to access the mapping pointer.
> track_foreign_dirty tracepoint was incorrectly accessing page->mapping
> directly.  Use page_mapping() instead.  Also, add NULL checks while at
> it.

Applied, thanks.

-- 
Jens Axboe