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Date: Mon, 17 Apr 2017 09:27:27 +0800
From: robbieko <robbieko@synology.com>
To: linux-btrfs@vger.kernel.org
Subject: Extent map generation question
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Hi,

I have a question in the function "clone_update_extent_map".

If em->generation is set -1, stands for we can't ignore it in
incremental fsync.

Why em->generation is set -1 when there is a path exists, and the 
generation is always -1.
It can not set to trans-> transid ?

Thanks.
Robbie Ko