From ad48fd754676bfae4139be1a897b1ea58f9aaf21 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zheng.yan@oracle.com>
Date: Thu, 12 Nov 2009 09:33:58 +0000
Subject: [PATCH] Btrfs: Add btrfs_duplicate_item

btrfs_duplicate_item duplicates item with new key, guaranteeing
the source item and the new items are in the same tree leaf and
contiguous. It allows us to split file extent in place, without
using lock_extent to prevent bookend extent race.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
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Reading git-format-patch failed