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

From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
To: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	akuster@mvista.com, linux-kernel@vger.kernel.org,
	Pavel Machek <pavel@ucw.cz>, "Rafael J. Wysocki" <rjw@sisk.pl>
Subject: Re: [patch 1/1] PM: Adds remount fs ro at suspend
Date: Tue, 6 Feb 2007 12:32:31 -0200	[thread overview]
Message-ID: <20070206143231.GD18392@khazad-dum.debian.net> (raw)
In-Reply-To: <1170710913.6105.39.camel@nigel.suspend2.net>

On Tue, 06 Feb 2007, Nigel Cunningham wrote:
> Why do you think remounting filesystems is necessary? Are you getting
> problems with some particular filesystem?

No.  But anything in a removable device neets to be either remounted
read-only or unmounted if that is at all possible, because the user could
unplug it.  It is of course, sync'd anyway, so if the remount/umount fails,
no corruption should happen...  but the fs will be dirty, etc.

It can get very ugly when you factor in docks and removable bays. It's not
just USB/firewire mass-storage devices and memory cards.  And there is the
patological cases where the user suspends with the device in one port, and
resumes with the device in another port.

I feel userspace *can* do all that needs to be done, but we are (currently)
very bad at it.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh