[Cluster-devel] libgfs2: Patch to generate UUIDs for GFS2 volumes

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

This is the support for mkfs to generate UUIDs for GFS2 volumes. Its
bugzilla #242690 and is in support of the recent kernel patch. Its
also backwards comaptible and pretty small.

Steve.

diff --git a/gfs2/libgfs2/ondisk.c b/gfs2/libgfs2/ondisk.c
index 40eb259..d80c9bb 100644
--- a/gfs2/libgfs2/ondisk.c
+++ b/gfs2/libgfs2/ondisk.c
@@ -117,6 +117,9 @@ void gfs2_sb_out(struct gfs2_sb *sb, char *buf)
 
 	CPOUT_08(sb, str, sb_lockproto, GFS2_LOCKNAME_LEN);
 	CPOUT_08(sb, str, sb_locktable, GFS2_LOCKNAME_LEN);
+#ifdef GFS2_HAS_UUID
+	memcpy(str->sb_uuid, sb->sb_uuid, 16);
+#endif
 }
 
 void gfs2_sb_print(struct gfs2_sb *sb)
diff --git a/gfs2/libgfs2/structures.c b/gfs2/libgfs2/structures.c
index eb4c7bd..002edb6 100644
--- a/gfs2/libgfs2/structures.c
+++ b/gfs2/libgfs2/structures.c
@@ -58,7 +58,17 @@ build_sb(struct gfs2_sbd *sdp)
 	sb.sb_root_dir = sdp->md.rooti->i_di.di_num;
 	strcpy(sb.sb_lockproto, sdp->lockproto);
 	strcpy(sb.sb_locktable, sdp->locktable);
-
+#ifdef GFS2_HAS_UUID
+	{
+		int fd = open("/dev/urandom", O_RDONLY);
+		int n;
+		if (fd >= 0)
+			n = read(fd, &sb.sb_uuid, 16);
+		if (fd < 0 || n != 16)
+			memset(&sb.sb_uuid, 0, 16);
+		close(fd);
+	}
+#endif
 	bh = bget(sdp, sdp->sb_addr);
 	gfs2_sb_out(&sb, bh->b_data);
 	brelse(bh, updated);