[PATCH] reserve space for swap label

[PATCH] reserve space for swap label

[Andreas Dilger]

The following patch reserves space in the swap disk header for a LABEL and
UUID to be specified.  This has been possible with util-linux-2.12b (via
e2fsprogs 1.36 libblkid), and is used by at least FC3 and later.  The kernel
doesn't really care about this, but the space shouldn't accidentally be used
by something else either.

It also makes the on-disk structures be fixed-size types, instead of "int",
though I don't know of any architecture in use where an "int" isn't the
same size as a "__u32" (all current kernel arches have it as "unsigned int").

Signed-off-by: Andreas Dilger <adilger@shaw.ca>

--- ./include/linux/swap.h.orig	2005-06-17 13:48:29.000000000 -0600
+++ ./include/linux/swap.h	2006-04-23 01:01:47.000000000 -0600
@@ -48,12 +48,14 @@
 		char magic[10];			/* SWAP-SPACE or SWAPSPACE2 */
 	} magic;
 	struct {
-		char	     bootbits[1024];	/* Space for disklabel etc. */
-		unsigned int version;
-		unsigned int last_page;
-		unsigned int nr_badpages;
-		unsigned int padding[125];
-		unsigned int badpages[1];
+		char		bootbits[1024];	/* Space for disklabel etc. */
+		__u32		version;
+		__u32		last_page;
+		__u32		nr_badpages;
+		unsigned char	sws_uuid[16];
+		unsigned char	sws_volume[16];
+		__u32		padding[117];
+		__u32		badpages[1];
 	} info;
 };
 
Cheers, Andreas
--
Andreas Dilger