From: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Date: Fri, 16 Oct 2009 22:18:15 +0000 (+0100)
Subject: dm: dec_pending needs locking to save error value
X-Git-Tag: v2.6.32-rc6~118^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f88fb981183e71daf40bbd84bc8251bbf7b59e19;p=pandora-kernel.git

dm: dec_pending needs locking to save error value

Multiple instances of dec_pending() can run concurrently so a lock is
needed when it saves the first error code.

I have never experienced actual problem without locking and just found
this during code inspection while implementing the barrier support
patch for request-based dm.

This patch adds the locking.
I've done compile, boot and basic I/O testings.

Cc: stable@kernel.org
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---

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