From: Joseph Qi <joseph.qi@huawei.com>
Date: Thu, 25 Sep 2014 23:05:16 +0000 (-0700)
Subject: ocfs2/dlm: do not get resource spinlock if lockres is new
X-Git-Tag: v3.2.64~33
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=40d31c4997351e1c80e95eb961366c8842ab3fc1;p=pandora-kernel.git

ocfs2/dlm: do not get resource spinlock if lockres is new

commit 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 upstream.

There is a deadlock case which reported by Guozhonghua:
  https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html

This case is caused by &res->spinlock and &dlm->master_lock
misordering in different threads.

It was introduced by commit 8d400b81cc83 ("ocfs2/dlm: Clean up refmap
helpers").  Since lockres is new, it doesn't not require the
&res->spinlock.  So remove it.

Fixes: 8d400b81cc83 ("ocfs2/dlm: Clean up refmap helpers")
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: joyce.xue <xuejiufei@huawei.com>
Reported-by: Guozhonghua <guozhonghua@h3c.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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