Re: [RFC][PATCH] PM / Hibernate: Modify signature used to mark swap

[Nigel Cunningham <nigel@tuxonice.net>]

Hi.

On 30/09/10 07:13, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki<rjw@sisk.pl>
> Subject: PM / Hibernate: Modify signature used to mark swap
>
> Since we are adding compression to the kernel's hibernate code,
> change signature used by it to mark swap spaces, so that earlier
> kernels don't attempt to restore compressed images they cannot
> handle.
>
> Signed-off-by: Rafael J. Wysocki<rjw@sisk.pl>
> ---
>   kernel/power/swap.c |    6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> Index: linux-2.6/kernel/power/swap.c
> ===================================================================
> --- linux-2.6.orig/kernel/power/swap.c
> +++ linux-2.6/kernel/power/swap.c
> @@ -29,7 +29,7 @@
>
>   #include "power.h"
>
> -#define SWSUSP_SIG	"S1SUSPEND"
> +#define HIBERNATE_SIG	"LINHIB0001"
>
>   /*
>    *	The swap map is a data structure used for keeping track of each page
> @@ -195,7 +195,7 @@ static int mark_swapfiles(struct swap_ma
>   	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
>   	    !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
>   		memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);

if no compression

> -		memcpy(swsusp_header->sig,SWSUSP_SIG, 10);

else

> +		memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);

??

>   		swsusp_header->image = handle->first_sector;
>   		swsusp_header->flags = flags;
>   		error = hib_bio_write_page(swsusp_resume_block,
> @@ -916,7 +916,7 @@ int swsusp_check(void)
>   		if (error)
>   			goto put;
>
> -		if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
> +		if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {

Reset the signature in either case?

>   			memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
>   			/* Reset swap signature now */
>   			error = hib_bio_write_page(swsusp_resume_block,
>

Regards,

Nigel