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To: Marc Ballarin <Ballarin.Marc@gmx.de>
Cc: akpm@osdl.org, torvalds@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/23] Don't export machine_restart, machine_halt, or
 machine_power_off.
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From: ebiederm@xmission.com (Eric W. Biederman)
Date: Tue, 26 Jul 2005 18:20:57 -0600
In-Reply-To: <20050727015519.614dbf2f.Ballarin.Marc@gmx.de> (Marc Ballarin's
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Marc Ballarin <Ballarin.Marc@gmx.de> writes:

> On Tue, 26 Jul 2005 11:36:01 -0600
> ebiederm@xmission.com (Eric W. Biederman) wrote:
>
>> 
>> machine_restart, machine_halt and machine_power_off are machine
>> specific hooks deep into the reboot logic, that modules
>> have no business messing with. Usually code should be calling
>> kernel_restart, kernel_halt, kernel_power_off, or
>> emergency_restart. So don't export machine_restart,
>> machine_halt, and machine_power_off so we can catch buggy users.
>
> The first is reiser4 in fs/reiser4/vfs_ops.c, line 1338.
> (Are filesystems supposed to restart the machine at all?!)

I suspect a call to panic would be more appropriate there.

I actually missed this one as I generated the patches against
Linus's latest tree.

Are we in process context where we can afford to do a clean shutdown
of the machine?  I would have expected an error handling path to
not be able to do better than emergency_restart. 

Regardless a panic sounds much more appropriate and will let the action
taken depend on the users policy.

Eric