gfs2-utils: master - gfs2-utils: Use libuuid for uuid handling

[Andrew Price]

Gitweb:       
http://git.fedorahosted.org/git/?p=gfs2-utils.git;a=commitdiff;h=4d10d11d...
Commit:        4d10d11d3ac7ea0906eb862d3d9ebd1ad0a09040
Parent:        6c36b2f759186e8a796a8aefd1a95fc70085c72e
Author:        Andrew Price <anprice(a)redhat.com&gt;
AuthorDate:    Sun Aug 14 20:46:12 2016 +0100
Committer:     Andrew Price <anprice(a)redhat.com&gt;
CommitterDate: Mon Aug 15 12:34:35 2016 +0100

gfs2-utils: Use libuuid for uuid handling

Use libuuid to generate, parse, to-string and copy uuids when the
sb_uuid field is available. This allows seven custom uuid-related
functions to be removed.

Also add some missing #ifdef GFS2_HAS_UUID guards which fixes building
against a gfs2_ondisk.h without sb_uuid.

Signed-off-by: Andrew Price <anprice(a)redhat.com&gt;
---
 gfs2/convert/Makefile.am  |    1 +
 gfs2/edit/Makefile.am     |    6 ++-
 gfs2/edit/gfs2hex.c       |   10 ++++-
 gfs2/fsck/Makefile.am     |    5 ++-
 gfs2/glocktop/Makefile.am |    3 +-
 gfs2/libgfs2/Makefile.am  |    4 +-
 gfs2/libgfs2/lang.c       |   60 ++++++++++------------------
 gfs2/libgfs2/libgfs2.h    |    2 -
 gfs2/libgfs2/meta.c       |   15 ++++++-
 gfs2/libgfs2/ondisk.c     |   37 ++++-------------
 gfs2/libgfs2/structures.c |   51 ++---------------------
 gfs2/mkfs/Makefile.am     |   13 +++++-
 gfs2/mkfs/main_mkfs.c     |   11 +++++-
 gfs2/tune/Makefile.am     |    5 ++-
 gfs2/tune/super.c         |   98 +++++++++-----------------------------------
 tests/Makefile.am         |    4 ++
 16 files changed, 120 insertions(+), 205 deletions(-)

diff --git a/gfs2/convert/Makefile.am b/gfs2/convert/Makefile.am
index 30924d7..4db643f 100644
--- a/gfs2/convert/Makefile.am
+++ b/gfs2/convert/Makefile.am
@@ -8,3 +8,4 @@ gfs2_convert_CPPFLAGS = \
 	-I$(top_srcdir)/gfs2/libgfs2
 
 gfs2_convert_LDADD = $(top_builddir)/gfs2/libgfs2/libgfs2.la
+gfs2_convert_LDFLAGS = $(uuid_LIBS)
diff --git a/gfs2/edit/Makefile.am b/gfs2/edit/Makefile.am
index 5d2942e..a9b177e 100644
--- a/gfs2/edit/Makefile.am
+++ b/gfs2/edit/Makefile.am
@@ -22,10 +22,12 @@ gfs2_edit_CPPFLAGS = \
 
 gfs2_edit_CFLAGS = \
 	$(ncurses_CFLAGS) \
-	$(zlib_CFLAGS)
+	$(zlib_CFLAGS) \
+	$(uuid_CFLAGS)
 
 gfs2_edit_LDFLAGS = \
 	$(ncurses_LIBS) \
-	$(zlib_LIBS)
+	$(zlib_LIBS) \
+	$(uuid_LIBS)
 
 gfs2_edit_LDADD = $(top_builddir)/gfs2/libgfs2/libgfs2.la
diff --git a/gfs2/edit/gfs2hex.c b/gfs2/edit/gfs2hex.c
index 3d280b5..3d0f10d 100644
--- a/gfs2/edit/gfs2hex.c
+++ b/gfs2/edit/gfs2hex.c
@@ -20,6 +20,9 @@
 #include "extended.h"
 #include "gfs2hex.h"
 #include "libgfs2.h"
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
 
 #define pv(struct, member, fmt, fmt2) do {				\
 		print_it("  "#member, fmt, fmt2, struct->member);	\
@@ -415,7 +418,12 @@ static void gfs2_sb_print2(struct gfs2_sb *sbp2)
 		gfs2_inum_print2("license   ", &gfs1_license_di);
 	}
 #ifdef GFS2_HAS_UUID
-	print_it("  sb_uuid", "%s", NULL, str_uuid(sbp2->sb_uuid));
+	{
+	char readable_uuid[36+1];
+
+	uuid_unparse(sbp2->sb_uuid, readable_uuid);
+	print_it("  sb_uuid", "%s", NULL, readable_uuid);
+	}
 #endif
 }
 
diff --git a/gfs2/fsck/Makefile.am b/gfs2/fsck/Makefile.am
index 4c3498b..97fcd40 100644
--- a/gfs2/fsck/Makefile.am
+++ b/gfs2/fsck/Makefile.am
@@ -35,4 +35,7 @@ fsck_gfs2_CPPFLAGS = \
 	-I$(top_srcdir)/gfs2/include \
 	-I$(top_srcdir)/gfs2/libgfs2
 
-fsck_gfs2_LDADD = $(top_builddir)/gfs2/libgfs2/libgfs2.la
+fsck_gfs2_LDADD = \
+	$(top_builddir)/gfs2/libgfs2/libgfs2.la
+fsck_gfs2_LDFLAGS = \
+	$(uuid_LIBS)
diff --git a/gfs2/glocktop/Makefile.am b/gfs2/glocktop/Makefile.am
index a43c519..1102c8e 100644
--- a/gfs2/glocktop/Makefile.am
+++ b/gfs2/glocktop/Makefile.am
@@ -10,7 +10,8 @@ glocktop_CFLAGS = \
 	$(ncurses_CFLAGS)
 
 glocktop_LDFLAGS = \
-	$(ncurses_LIBS)
+	$(ncurses_LIBS) \
+	$(uuid_LIBS)
 
 glocktop_CPPFLAGS = \
 	-D_FILE_OFFSET_BITS=64 \
diff --git a/gfs2/libgfs2/Makefile.am b/gfs2/libgfs2/Makefile.am
index 2b7aa16..4321a67 100644
--- a/gfs2/libgfs2/Makefile.am
+++ b/gfs2/libgfs2/Makefile.am
@@ -48,10 +48,12 @@ libgfs2_la_CPPFLAGS = \
 	-D_FILE_OFFSET_BITS=64 \
 	-D_LARGEFILE64_SOURCE \
 	-D_GNU_SOURCE \
-	-I$(top_srcdir)/gfs2/include
+	-I$(top_srcdir)/gfs2/include \
+	$(uuid_CFLAGS)
 
 gfs2l_SOURCES = gfs2l.c
 gfs2l_LDADD = libgfs2.la
+gfs2l_LDFLAGS = $(uuid_LIBS)
 gfs2l_CPPFLAGS = \
 	-I$(top_srcdir)/gfs2/include \
 	-D_FILE_OFFSET_BITS=64
diff --git a/gfs2/libgfs2/lang.c b/gfs2/libgfs2/lang.c
index 13333a1..2f93c56 100644
--- a/gfs2/libgfs2/lang.c
+++ b/gfs2/libgfs2/lang.c
@@ -9,6 +9,9 @@
 
 #include "lang.h"
 #include "parser.h"
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
 
 const char* ast_type_string[] = {
 	[AST_NONE] = "NONE",
@@ -312,7 +315,14 @@ static int field_print(const struct gfs2_buffer_head *bh, const
struct lgfs2_met
 
 	printf("%s\t%"PRIu64"\t%u\t%u\t%s\t", mtype->name,
bh->b_blocknr, field->offset, field->length, field->name);
 	if (field->flags & LGFS2_MFF_UUID) {
-		printf("'%s'\n", str_uuid((const unsigned char *)fieldp));
+#ifdef GFS2_HAS_UUID
+		char readable_uuid[36+1];
+		uuid_t uuid;
+
+		memcpy(uuid, fieldp, sizeof(uuid_t));
+		uuid_unparse(uuid, readable_uuid);
+		printf("'%s'\n", readable_uuid);
+#endif
 	} else if (field->flags & LGFS2_MFF_STRING) {
 		printf("'%s'\n", fieldp);
 	} else {
@@ -431,40 +441,6 @@ static struct lgfs2_lang_result *ast_interp_get(struct
lgfs2_lang_state *state,
 }
 
 /**
- * Interpret a UUID string by removing hyphens from the string and then
- * interprets 16 pairs of hex digits as octets.
- */
-static int ast_str_to_uuid(const char *str, uint8_t *uuid)
-{
-	char s[33];
-	int head, tail, tmp;
-
-	for (head = tail = 0; head < strlen(str) && tail < 33; head++) {
-		if (str[head] == '-')
-			continue;
-		s[tail] = tolower(str[head]);
-		if (!((s[tail] >= 'a' && s[tail] <= 'f') ||
-		      (s[tail] >= '0' && s[tail] <= '9')))
-			goto invalid;
-		tail++;
-	}
-	if (tail != 32) {
-		goto invalid;
-	}
-	s[tail] = '\0';
-	for (head = 0; head < 16; head++) {
-		if (sscanf(s+(head*2), "%02x", &tmp) != 1) {
-			goto invalid;
-		}
-		*(uuid + head) = tmp;
-	}
-	return AST_INTERP_SUCCESS;
-invalid:
-	fprintf(stderr, "Invalid UUID\n");
-	return AST_INTERP_INVAL;
-}
-
-/**
  * Set a field of a gfs2 block of a given type to a given value.
  * Returns AST_INTERP_* to signal success, an invalid field/value or an error.
  */
@@ -474,12 +450,18 @@ static int ast_field_set(struct gfs2_buffer_head *bh, const struct
lgfs2_metafie
 	int err = 0;
 
 	if (field->flags & LGFS2_MFF_UUID) {
-		uint8_t uuid[16];
-		int ret = ast_str_to_uuid(val->ast_str, uuid);
+#ifdef GFS2_HAS_UUID
+		uuid_t uuid;
 
-		if (ret != AST_INTERP_SUCCESS)
-			return ret;
+		if (uuid_parse(val->ast_str, uuid) != 0) {
+			fprintf(stderr, "Invalid UUID\n");
+			return AST_INTERP_INVAL;
+		}
 		err = lgfs2_field_assign(bh->b_data, field, uuid);
+#else
+		fprintf(stderr, "No UUID support\n");
+		err = 1;
+#endif
 	} else if (field->flags & LGFS2_MFF_STRING) {
 		err = lgfs2_field_assign(bh->b_data, field, val->ast_str);
 	} else {
diff --git a/gfs2/libgfs2/libgfs2.h b/gfs2/libgfs2/libgfs2.h
index 5414a20..ebf6bca 100644
--- a/gfs2/libgfs2/libgfs2.h
+++ b/gfs2/libgfs2/libgfs2.h
@@ -711,8 +711,6 @@ extern int write_sb(struct gfs2_sbd *sdp);
 
 /* ondisk.c */
 extern uint32_t gfs2_disk_hash(const char *data, int len);
-extern const char *str_uuid(const unsigned char *uuid);
-extern void gfs2_print_uuid(const unsigned char *uuid);
 extern void print_it(const char *label, const char *fmt, const char *fmt2, ...)
 	__attribute__((format(printf,2,4)));
 
diff --git a/gfs2/libgfs2/meta.c b/gfs2/libgfs2/meta.c
index 90d5647..500757d 100644
--- a/gfs2/libgfs2/meta.c
+++ b/gfs2/libgfs2/meta.c
@@ -3,6 +3,10 @@
 #include "libgfs2.h"
 #include "clusterautoconfig.h"
 
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
+
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 #define SYM(x) { x, #x },
 
@@ -150,7 +154,9 @@ F(sb_lockproto, .flags = LGFS2_MFF_STRING)
 F(sb_locktable, .flags = LGFS2_MFF_STRING)
 INR(__pad3, .points_to = (1 << LGFS2_MT_GFS2_DINODE))
 INR(__pad4, .points_to = (1 << LGFS2_MT_GFS2_DINODE))
+#ifdef GFS2_HAS_UUID
 F(sb_uuid, .flags = LGFS2_MFF_UUID)
+#endif
 };
 
 #undef STRUCT
@@ -878,7 +884,14 @@ int lgfs2_field_str(char *str, const size_t size, const char *blk,
const struct
 		return 1;
 
 	if (field->flags & LGFS2_MFF_UUID) {
-		snprintf(str, size, "%s", str_uuid((unsigned char *)fieldp));
+#ifdef GFS2_HAS_UUID
+		char readable_uuid[36+1];
+		uuid_t uuid;
+
+		memcpy(uuid, fieldp, sizeof(uuid_t));
+		uuid_unparse(uuid, readable_uuid);
+		snprintf(str, size, "%s", readable_uuid);
+#endif
 	} else if (field->flags & LGFS2_MFF_STRING) {
 		snprintf(str, size, "%s", fieldp);
 	} else {
diff --git a/gfs2/libgfs2/ondisk.c b/gfs2/libgfs2/ondisk.c
index d49455e..66de223 100644
--- a/gfs2/libgfs2/ondisk.c
+++ b/gfs2/libgfs2/ondisk.c
@@ -6,9 +6,11 @@
 #include <stdint.h>
 #include <inttypes.h>
 #include <ctype.h>
-
 #include <linux/types.h>
 #include "libgfs2.h"
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
 
 #define pv(struct, member, fmt, fmt2) do {				\
 		print_it("  "#member, fmt, fmt2, struct->member);	\
@@ -151,32 +153,6 @@ void gfs2_sb_out(const struct gfs2_sb *sb, char *buf)
 #endif
 }
 
-const char *str_uuid(const unsigned char *uuid)
-{
-	static char str[64];
-	char *ch;
-	int i;
-
-	memset(str, 0, sizeof(str));
-	ch = str;
-	for (i = 0; i < 16; i++) {
-		sprintf(ch, "%02x", uuid[i]);
-		ch += 2;
-		if ((i == 3) || (i == 5) || (i == 7) || (i == 9)) {
-			*ch = '-';
-			ch++;
-		}
-	}
-	return str;
-}
-
-#ifdef GFS2_HAS_UUID
-void gfs2_print_uuid(const unsigned char *uuid)
-{
-	print_it("  uuid", "%s", NULL, str_uuid(uuid));
-}
-#endif
-
 void gfs2_sb_print(const struct gfs2_sb *sb)
 {
 	gfs2_meta_header_print(&sb->sb_header);
@@ -194,7 +170,12 @@ void gfs2_sb_print(const struct gfs2_sb *sb)
 	pv(sb, sb_locktable, "%s", NULL);
 
 #ifdef GFS2_HAS_UUID
-	gfs2_print_uuid(sb->sb_uuid);
+	{
+	char readable_uuid[36+1];
+
+	uuid_unparse(sb->sb_uuid, readable_uuid);
+	print_it("  uuid", "%36s", NULL, readable_uuid);
+	}
 #endif
 }
 
diff --git a/gfs2/libgfs2/structures.c b/gfs2/libgfs2/structures.c
index 87ffde7..1cc88b5 100644
--- a/gfs2/libgfs2/structures.c
+++ b/gfs2/libgfs2/structures.c
@@ -16,6 +16,10 @@
 #include "libgfs2.h"
 #include "config.h"
 
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
+
 int build_master(struct gfs2_sbd *sdp)
 {
 	struct gfs2_inum inum;
@@ -45,51 +49,6 @@ int build_master(struct gfs2_sbd *sdp)
 	return 0;
 }
 
-#ifdef GFS2_HAS_UUID
-/**
- * Generate a series of random bytes using /dev/urandom.
- * Modified from original code in gen_uuid.c in e2fsprogs/lib
- */
-static void get_random_bytes(void *buf, int nbytes)
-{
-	int i, n = nbytes, fd;
-	int lose_counter = 0;
-	unsigned char *cp = (unsigned char *) buf;
-	struct timeval	tv;
-
-	gettimeofday(&tv, 0);
-	fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC);
-	srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec);
-	/* Crank the random number generator a few times */
-	gettimeofday(&tv, 0);
-	for (i = (tv.tv_sec ^ tv.tv_usec) & 0x1F; i > 0; i--)
-		rand();
-	if (fd >= 0) {
-		while (n > 0) {
-			i = read(fd, cp, n);
-			if (i <= 0) {
-				if (lose_counter++ > 16)
-					break;
-				continue;
-			}
-			n -= i;
-			cp += i;
-			lose_counter = 0;
-		}
-		close(fd);
-	}
-
-	/*
-	 * We do this all the time, but this is the only source of
-	 * randomness if /dev/random/urandom is out to lunch.
-	 */
-	for (cp = buf, i = 0; i < nbytes; i++)
-		*cp++ ^= (rand() >> 7) & 0xFF;
-
-	return;
-}
-#endif
-
 /**
  * Initialise a gfs2_sb structure with sensible defaults.
  */
@@ -104,7 +63,7 @@ void lgfs2_sb_init(struct gfs2_sb *sb, unsigned bsize)
 	sb->sb_bsize = bsize;
 	sb->sb_bsize_shift = ffs(bsize) - 1;
 #ifdef GFS2_HAS_UUID
-	get_random_bytes(&sb->sb_uuid, sizeof(sb->sb_uuid));
+	uuid_generate(sb->sb_uuid);
 #endif
 }
 
diff --git a/gfs2/mkfs/Makefile.am b/gfs2/mkfs/Makefile.am
index 074c4c1..f0dd961 100644
--- a/gfs2/mkfs/Makefile.am
+++ b/gfs2/mkfs/Makefile.am
@@ -22,8 +22,12 @@ mkfs_gfs2_SOURCES = \
 	progress.h
 
 mkfs_gfs2_CPPFLAGS = $(COMMON_CPPFLAGS)
-mkfs_gfs2_CFLAGS = $(blkid_CFLAGS)
-mkfs_gfs2_LDFLAGS = $(blkid_LIBS)
+mkfs_gfs2_CFLAGS = \
+	$(blkid_CFLAGS) \
+	$(uuid_CFLAGS)
+mkfs_gfs2_LDFLAGS = \
+	$(blkid_LIBS) \
+	$(uuid_LIBS)
 mkfs_gfs2_LDADD	= $(top_builddir)/gfs2/libgfs2/libgfs2.la
 
 gfs2_grow_SOURCES = \
@@ -32,7 +36,9 @@ gfs2_grow_SOURCES = \
 
 gfs2_grow_CPPFLAGS = $(COMMON_CPPFLAGS)
 gfs2_grow_CFLAGS = $(blkid_CFLAGS)
-gfs2_grow_LDFLAGS = $(blkid_LIBS)
+gfs2_grow_LDFLAGS = \
+	$(blkid_LIBS) \
+	$(uuid_LIBS)
 gfs2_grow_LDADD = $(top_builddir)/gfs2/libgfs2/libgfs2.la
 
 gfs2_jadd_SOURCES = \
@@ -41,4 +47,5 @@ gfs2_jadd_SOURCES = \
 
 gfs2_jadd_CPPFLAGS = $(COMMON_CPPFLAGS)
 gfs2_jadd_LDADD = $(top_builddir)/gfs2/libgfs2/libgfs2.la
+gfs2_jadd_LDFLAGS = $(uuid_LIBS)
 
diff --git a/gfs2/mkfs/main_mkfs.c b/gfs2/mkfs/main_mkfs.c
index 7ede5ad..363878c 100644
--- a/gfs2/mkfs/main_mkfs.c
+++ b/gfs2/mkfs/main_mkfs.c
@@ -30,6 +30,10 @@
 #include "gfs2_mkfs.h"
 #include "progress.h"
 
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
+
 static void print_usage(const char *prog_name)
 {
 	int i;
@@ -537,8 +541,13 @@ static void print_results(struct gfs2_sb *sb, struct mkfs_opts *opts,
uint64_t r
 	printf("%-27s\"%s\"\n", _("Locking protocol:"),
opts->lockproto);
 	printf("%-27s\"%s\"\n", _("Lock table:"),
opts->locktable);
 #ifdef GFS2_HAS_UUID
+	{
+	char readable_uuid[36+1];
+
+	uuid_unparse(sb->sb_uuid, readable_uuid);
 	/* Translators: "UUID" = universally unique identifier. */
-	printf("%-27s%s\n", _("UUID:"), str_uuid(sb->sb_uuid));
+	printf("%-27s%s\n", _("UUID:"), readable_uuid);
+	}
 #endif
 }
 
diff --git a/gfs2/tune/Makefile.am b/gfs2/tune/Makefile.am
index c060183..7628f42 100644
--- a/gfs2/tune/Makefile.am
+++ b/gfs2/tune/Makefile.am
@@ -7,8 +7,11 @@ noinst_HEADERS = tunegfs2.h
 tunegfs2_SOURCES = \
 	main.c \
 	super.c
-
 tunegfs2_CPPFLAGS = \
 	-D_FILE_OFFSET_BITS=64 \
 	-I$(top_srcdir)/gfs2/include \
 	-I$(top_srcdir)/group/include
+tunegfs2_CFLAGS = \
+	$(uuid_CFLAGS)
+tunegfs2_LDFLAGS = \
+	$(uuid_LIBS)
diff --git a/gfs2/tune/super.c b/gfs2/tune/super.c
index 560ce68..c4ffd7e 100644
--- a/gfs2/tune/super.c
+++ b/gfs2/tune/super.c
@@ -14,78 +14,9 @@
 #include <linux/gfs2_ondisk.h>
 #include "tunegfs2.h"
 
-static int str_to_hexchar(const char *estring)
-{
-	int ch = 0;
-
-	if (isdigit(*estring))
-		ch = (*estring - '0') * 0x10;
-	else if (*estring >= 'a' && *estring <= 'f')
-		ch = (*estring - 'a' + 0x0a) * 0x10;
-	else if (*estring >= 'A' && *estring <= 'F')
-		ch = (*estring - 'A' + 0x0a) * 0x10;
-
-	estring++;
-	if (isdigit(*estring))
-		ch += (*estring - '0');
-	else if (*estring >= 'a' && *estring <= 'f')
-		ch += (*estring - 'a' + 0x0a);
-	else if (*estring >= 'A' && *estring <= 'F')
-		ch += (*estring - 'A' + 0x0a);
-	return ch;
-}
-
-
-
-static const char *uuid2str(const unsigned char *uuid)
-{
-	static char str[64];
-	char *ch;
-	int i;
-
-	memset(str, 0, 64);
-	ch = str;
-	for (i = 0; i < 16; i++) {
-		sprintf(ch, "%02x", uuid[i]);
-		ch += 2;
-		if ((i == 3) || (i == 5) || (i == 7) || (i == 9)) {
-			*ch = '-';
-			ch++;
-		}
-	}
-	return str;
-}
-
-static int str2uuid(const char *newval, char *uuid)
-{
-	char *cp;
-	int i;
-
-	if (strlen(newval) != 36) {
-		fprintf(stderr, _("Invalid UUID: %s\n"), newval);
-		return EX_DATAERR;
-	}
-
-	cp = uuid;
-	for (i = 0; i < 36; i++) {
-		if ((i == 8) || (i == 13) ||
-				(i == 18) || (i == 23)) {
-			if (newval[i] == '-')
-				continue;
-			fprintf(stderr, _("Invalid UUID: %s\n"), newval);
-			return EX_DATAERR;
-		}
-		if (!isxdigit(newval[i])) {
-			fprintf(stderr, _("Invalid UUID: %s\n"), newval);
-			fprintf(stderr, _("Bad digit '%c' at position %d\n"),
-			                newval[i], i + 1);
-			return EX_DATAERR;
-		}
-		*cp = str_to_hexchar(&newval[i++]);
-		cp++;
-	}
-	return 0;
-}
+#ifdef GFS2_HAS_UUID
+#include <uuid.h>
+#endif
 
 int read_super(struct tunegfs2 *tfs)
 {
@@ -125,7 +56,12 @@ int print_super(const struct tunegfs2 *tfs)
 {
 	printf(_("File system volume name: %s\n"), tfs->sb->sb_locktable);
 #ifdef GFS2_HAS_UUID
-	printf(_("File system UUID: %s\n"), uuid2str(tfs->sb->sb_uuid));
+	{
+	char readable_uuid[36+1];
+
+	uuid_unparse(tfs->sb->sb_uuid, readable_uuid);
+	printf(_("File system UUID: %s\n"), readable_uuid);
+	}
 #endif
 	printf( _("File system magic number: 0x%X\n"),
be32_to_cpu(tfs->sb->sb_header.mh_magic));
 	printf(_("Block size: %d\n"), be32_to_cpu(tfs->sb->sb_bsize));
@@ -152,12 +88,18 @@ int write_super(const struct tunegfs2 *tfs)
 
 int change_uuid(struct tunegfs2 *tfs, const char *str)
 {
-	char uuid[16];
-	int status = 0;
-	status = str2uuid(str, uuid);
-	if (!status)
-		memcpy(tfs->sb->sb_uuid, uuid, 16);
+#ifdef GFS2_HAS_UUID
+	uuid_t uuid;
+	int status;
+
+	status = uuid_parse(str, uuid);
+	if (status == 0)
+		uuid_copy(tfs->sb->sb_uuid, uuid);
 	return status;
+#else
+	fprintf(stderr, _("UUID support unavailable in this build\n"));
+	return 1;
+#endif
 }
 
 int change_lockproto(struct tunegfs2 *tfs, const char *lockproto)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 273be71..1dedc2b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -23,6 +23,8 @@ nukerg_CFLAGS = \
 	-I$(top_srcdir)/gfs2/include
 nukerg_LDADD = \
 	$(top_builddir)/gfs2/libgfs2/libgfs2.la
+nukerg_LDFLAGS = \
+	$(uuid_LIBS)
 
 if HAVE_CHECK
 UNIT_TESTS = \
@@ -49,6 +51,7 @@ check_meta_SOURCES = \
 	check_meta.c
 check_meta_CFLAGS = $(UNIT_CFLAGS)
 check_meta_LDADD = $(UNIT_LDADD)
+check_meta_LDFLAGS = $(uuid_LIBS)
 check_meta_CPPFLAGS = $(UNIT_CPPFLAGS)
 
 check_rgrp_SOURCES = \
@@ -56,6 +59,7 @@ check_rgrp_SOURCES = \
 	check_rgrp.c
 check_rgrp_CFLAGS = $(UNIT_CFLAGS)
 check_rgrp_LDADD = $(UNIT_LDADD)
+check_rgrp_LDFLAGS = $(uuid_LIBS)
 check_rgrp_CPPFLAGS = $(UNIT_CPPFLAGS)
 endif