From 566f35bc81d992bfec0a41485eea073854f54b0e Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Fri, 25 Sep 2009 16:27:27 +0200
Subject: [PATCH] mkswap: use libblkid to detect PT

Signed-off-by: Karel Zak <kzak@redhat.com>
---
 configure.ac           |  1 +
 disk-utils/Makefile.am |  8 +++++++-
 disk-utils/mkswap.c    | 45 +++++++++++++++++++++++++++++++++---------
 3 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index 52985137..b421d0a1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -353,6 +353,7 @@ else
   # internal library
   AC_DEFINE(HAVE_BLKID_H, 1, [Define to 1 if you have the <blkid.h> header file.])
   AC_DEFINE(HAVE_BLKID_EVALUATE_TAG, 1, [Define to 1 if you have the blkid_evaluate_tag().])
+  AC_DEFINE(HAVE_BLKID_PROBE_ENABLE_PARTITIONS, 1, [Define to 1 if you have the blkid_probe_enable_partitions().])
 fi
 
 if test "x$have_blkid" = xyes; then
diff --git a/disk-utils/Makefile.am b/disk-utils/Makefile.am
index 6bd22bc5..852ae8a0 100644
--- a/disk-utils/Makefile.am
+++ b/disk-utils/Makefile.am
@@ -13,7 +13,7 @@ fsck_minix_SOURCES = fsck.minix.c minix.h
 mkfs_minix_SOURCES = mkfs.minix.c minix.h $(utils_common)
 mkfs_bfs_SOURCES = mkfs.bfs.c $(utils_common)
 
-mkswap_SOURCES = mkswap.c $(utils_common) ../lib/wholedisk.c ../lib/pttype.c
+mkswap_SOURCES = mkswap.c $(utils_common) ../lib/wholedisk.c
 mkswap_LDADD =
 mkswap_CFLAGS =
 
@@ -59,6 +59,12 @@ mkswap_CFLAGS += $(UUID_CFLAGS)
 endif
 endif
 
+if BUILD_LIBBLKID
+# only in-tree libblkid has partitions parsing support
+mkswap_LDADD += $(ul_libblkid_la)
+mkswap_CFLAGS += -I$(ul_libblkid_srcdir)
+endif
+
 if HAVE_SELINUX
 mkswap_LDADD += -lselinux
 endif
diff --git a/disk-utils/mkswap.c b/disk-utils/mkswap.c
index 9feb2111..1205acdb 100644
--- a/disk-utils/mkswap.c
+++ b/disk-utils/mkswap.c
@@ -53,17 +53,20 @@
 #include "nls.h"
 #include "blkdev.h"
 #include "pathnames.h"
-#include "pttype.h"
 #include "wholedisk.h"
 
 #ifdef HAVE_LIBUUID
 # ifdef HAVE_UUID_UUID_H
 #  include <uuid/uuid.h>
-#else
-# include <uuid.h>
+# else
+#  include <uuid.h>
 # endif
 #endif
 
+#ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
+# include <blkid.h>
+#endif
+
 static char * program_name = "mkswap";
 static char * device_name = NULL;
 static int DEV = -1;
@@ -391,21 +394,43 @@ write_all(int fd, const void *buf, size_t count) {
 static void
 zap_bootbits(int fd, const char *devname, int force)
 {
-	const char *type = NULL;
+	char *type = NULL;
+	int whole = 0;
 	int zap = 1;
 
 	if (!force) {
 		if (lseek(fd, 0, SEEK_SET) != 0)
 	                die(_("unable to rewind swap-device"));
 
-		if (is_whole_disk_fd(fd, devname))
+		if (is_whole_disk_fd(fd, devname)) {
 			/* don't zap bootbits on whole disk -- we know nothing
 			 * about bootloaders on the device */
+			whole = 1;
 			zap = 0;
-
-		else if ((type = get_pt_type_fd(fd)))
-			/* don't zap partition table */
+		} else {
+#ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
+			blkid_probe pr = blkid_new_probe();
+			if (!pr)
+				die(_("unable to alloc new libblkid probe"));
+			if (blkid_probe_set_device(pr, fd, 0, 0))
+				die(_("unable to assign device to liblkid probe"));
+
+			blkid_probe_enable_partitions(pr, 1);
+			blkid_probe_enable_superblocks(pr, 0);
+
+			if (blkid_do_fullprobe(pr) == 0)
+				blkid_probe_lookup_value(pr, "PTTYPE",
+						(const char **) &type, NULL);
+			if (type) {
+				type = strdup(type);
+				zap = 0;
+			}
+			blkid_free_probe(pr);
+#else
+			/* don't zap if compiled without libblkid */
 			zap = 0;
+#endif
+		}
 	}
 
 	if (zap) {
@@ -424,8 +449,10 @@ zap_bootbits(int fd, const char *devname, int force)
 		program_name, devname);
 	if (type)
 		fprintf(stderr, _("        (%s partition table detected). "), type);
-	else
+	else if (whole)
 		fprintf(stderr, _("        on whole disk. "));
+	else
+		fprintf(stderr, _("        (compiled without libblkid). "));
 	fprintf(stderr, "Use -f to force.\n");
 }
 
-- 
2.39.5