Detect a ZFS filesystem by looking for valid uberblocks.

This support will appear in an upstream version of e2fsprogs.  For the
moment however you will still need to locally patch you e2fsprogs packages.
This patch applies cleanly to fc11's e2fsprogs-*-1.41.4-10 and should
apply easily enough to the e2fsprogs from other distros.

--- e2fsprogs.orig/lib/blkid/probe.c	2009-01-20 09:06:31.000000000 -0800
+++ e2fsprogs/lib/blkid/probe.c	2009-10-06 10:16:37.000000000 -0700
@@ -1359,10 +1361,18 @@
   { "iso9660",	32,	 1,  5, "CD001",		probe_iso9660 },
   { "iso9660",	32,	 9,  5, "CDROM",		probe_iso9660 },
   { "jfs",	32,	 0,  4, "JFS1",			probe_jfs },
-  { "zfs",       8,	 0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
-  { "zfs",       8,	 0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
-  { "zfs",     264,	 0,  8, "\0\0\x02\xf5\xb0\x07\xb1\x0c", probe_zfs },
-  { "zfs",     264,	 0,  8, "\x0c\xb1\x07\xb0\xf5\x02\0\0", probe_zfs },
+  { "zfs",     128,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     132,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     136,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     128,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     132,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     136,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     384,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     388,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     392,	 0,  8, "\0\0\0\0\0\xba\xb1\x0c", probe_zfs },
+  { "zfs",     384,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     388,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
+  { "zfs",     392,	 0,  8, "\x0c\xb1\xba\0\0\0\0\0", probe_zfs },
   { "hfsplus",	 1,	 0,  2, "BD",			probe_hfsplus },
   { "hfsplus",	 1,	 0,  2, "H+",			probe_hfsplus },
   { "hfsplus",	 1,	 0,  2, "HX",			probe_hfsplus },