Re: [patch 1/1] PM: Adds remount fs ro at suspend

From: Pavel Machek <pavel@ucw.cz>
To: akuster <akuster@mvista.com>
Cc: Christoph Hellwig <hch@infradead.org>,
	linux-kernel@vger.kernel.org, akpm@osdl.org
Subject: Re: [patch 1/1] PM: Adds remount fs ro at suspend
Date: Wed, 14 Feb 2007 12:07:30 +0100	[thread overview]
Message-ID: <20070214110730.GA21620@elf.ucw.cz> (raw)
In-Reply-To: <45C53841.5000505@mvista.com>

Hi!

> >>This adds the ability for the file system to remounted as read only 
> >>during a
> >>system suspend.  Log the mount points so when the resume occurs, they can 
> >>be remounted back to their original states. This is so in an advent of a 
> >>power
> >>failure, we try our best to keep data from being corrupted or lost.
> >
> >Can you please explain why this can't be done in userspace?  
> 
> I am sure it can.  The idea came from customer inputs, speed is my 
> guess. echo mem > /sys/../state seems a whole lot simpler and cleaner 
> than having userspace figure out what it mounted and then doing echo
>mem.

Well, customers have little knowledge of linux kernel, sorry.

Do it in userspace, then find out if it is too slow, and if it is,
develop extensions to kernel to do it properly.

But no, you can't simply do it in kernel.
									Pavel
-- 
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