From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Wed, 26 Sep 2012 16:54:52 +0000 (-0400)
Subject: ext4: reimplement uninit extent optimization for move_extent_per_page()
X-Git-Tag: v3.7-rc1~91^2~24
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8c85447391735469f407add6fdb0630ce59d7f6d;p=pandora-kernel.git

ext4: reimplement uninit extent optimization for move_extent_per_page()

Uninitialized extent may became initialized(parallel writeback task)
at any moment after we drop i_data_sem, so we have to recheck extent's
state after we hold page's lock and i_data_sem.

If we about to change page's mapping we must hold page's lock in order to
serialize other users.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

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