From: Jan Kara <jack@suse.cz>
Date: Tue, 4 Jun 2013 17:21:11 +0000 (-0400)
Subject: ext4: use transaction reservation for extent conversion in ext4_end_io
X-Git-Tag: omap-for-v3.11/fixes-for-merge-window~83^2~43
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b523df4fb5ae281ddbc817f40504b33e6226554;p=pandora-kernel.git

ext4: use transaction reservation for extent conversion in ext4_end_io

Later we would like to clear PageWriteback bit only after extent
conversion from unwritten to written extents is performed.  However it
is not possible to start a transaction after PageWriteback is set
because that violates lock ordering (and is easy to deadlock).  So we
have to reserve a transaction before locking pages and sending them
for IO and later we use the transaction for extent conversion from
ext4_end_io().

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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