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Date: Fri, 26 Dec 2014 19:30:28 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Leon Ma <xindong.ma@intel.com>
Cc: akpm@linux-foundation.org, oleg@redhat.com, mhocko@suse.cz,
        mingo@kernel.org, peterz@infradead.org, riel@redhat.com,
        ionut.m.alexa@gmail.com, peter@hurleysoftware.com,
        linux-kernel@vger.kernel.org, di.zhang@intel.com,
        zhonghua.sun@intel.com
Subject: Re: [PATCH] move exit_task_work() before exit_fs().
Message-ID: <20141226193028.GE22149@ZenIV.linux.org.uk>
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On Fri, Dec 26, 2014 at 03:45:25PM +0800, Leon Ma wrote:
> We encountered following panic. The scenario is the process is exiting and executing its
> task work. When closing dev node, the driver triggers a firmware reload according to device
> status. Because task->fs is set to NULL in exit_fs(), panic happens.
> Task work is a common interface, we should not limite the resource the user will utilize.

Fix your driver.  Forget ->fs being NULL; what will happen if your process
is chrooted?
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