Re: [patch] suspend: update documentation

[Nigel Cunningham <ncunningham@cyclades.com>]

Hi.

On Wed, 2005-07-13 at 03:24, randy_dunlap wrote:
> On Tue, 12 Jul 2005 11:05:10 +0200 Pavel Machek wrote:
> 
> | Update suspend documentation.
> | 
> | Signed-off-by: Pavel Machek <pavel@suse.cz>
> | 
> | ---
> | 
> | diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
> | --- a/Documentation/power/swsusp.txt
> | +++ b/Documentation/power/swsusp.txt
> | @@ -318,3 +318,10 @@ As a rule of thumb use encrypted swap to
> |  system is shut down or suspended. Additionally use the encrypted
> |  suspend image to prevent sensitive data from being stolen after
> |  resume.
> | +
> | +Q: Why we cannot suspend to a swap file?
> 
> Q: Why can't we suspend to a swap file?
> or
> Q: Why can we not suspend to a swap file?
> 
> | +
> | +A: Because accessing swap file needs the filesystem mounted, and
> | +filesystem might do something wrong (like replaying the journal)
> | +during mount. [Probably could be solved by modifying every filesystem
> | +to support some kind of "really read-only!" option. Patches welcome.]

This is wrong. Suspend2 has supported writing to a swap file for a long
time (since 1.0), without requiring the filesystem to be mounted when
resuming. We just need to store the bdev and block numbers in the image
header.

Regards,

Nigel
-- 
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