If only ext4 is available (as a module or in /proc/filesystems)
blkid wasn't properly testing for it, because the time checks
were backwards and always failed.  This caused old ext4dev
filesystems to fail to mount as ext4.  With this patch it works
fine.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

Index: e2fsprogs/lib/blkid/probe.c
===================================================================
--- e2fsprogs.orig/lib/blkid/probe.c	2008-09-12 10:37:52.000000000 -0500
+++ e2fsprogs/lib/blkid/probe.c	2008-10-08 13:28:42.218001472 -0500
@@ -243,7 +243,7 @@ static int system_supports_ext4(void)
 	static int	ret = -1;
 	time_t		now = time(0);
 
-	if (ret != -1 || (last_check - now) < 5)
+	if (ret != -1 || (now - last_check) < 5)
 		return ret;
 	last_check = now;
 	ret = (fs_proc_check("ext4") || check_for_modules("ext4"));
@@ -256,7 +256,7 @@ static int system_supports_ext4dev(void)
 	static int	ret = -1;
 	time_t		now = time(0);
 
-	if (ret != -1 || (last_check - now) < 5)
+	if (ret != -1 || (now - last_check) < 5)
 		return ret;
 	last_check = now;
 	ret = (fs_proc_check("ext4dev") || check_for_modules("ext4dev"));