From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [git pull] fix for nasty races in br_write_lock() Date: Thu, 22 Dec 2011 07:09:12 +0000 Message-ID: <20111222070912.GL23916@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Linus Torvalds Return-path: Received: from zeniv.linux.org.uk ([195.92.253.2]:54027 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176Ab1LVHJN (ORCPT ); Thu, 22 Dec 2011 02:09:13 -0500 Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-ID: There's a nasty race between CPU hotplug and br_write_lock(); the latter pretty much assumes that the set of online CPUs can't change between br_write_lock() and br_write_unlock(). Caught by Cong Meng, solution hashed out during the last few days between me and Srivatsa S. Bhat on l-k/fsdevel thread, appears to fix the problem in a reasonably sane way. It'll need to go into -stable as well; all branches since 2.6.36. Please, pull from the usual place; git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git for-linus Shortlog: Srivatsa S. Bhat (1): VFS: Fix race between CPU hotplug and lglocks Diffstat: include/linux/lglock.h | 36 ++++++++++++++++++++++++++++++++---- 1 files changed, 32 insertions(+), 4 deletions(-)