Index: xfstests/src/Makefile
===================================================================
--- xfstests.orig/src/Makefile	2008-08-31 19:09:03.000000000 -0300
+++ xfstests/src/Makefile	2008-08-31 19:15:00.000000000 -0300
@@ -15,7 +15,7 @@ TARGETS = dirstress fill fill2 getpagesi
 LINUX_TARGETS = loggen xfsctl bstat t_mtab getdevicesize \
 	preallo_rw_pattern_reader preallo_rw_pattern_writer ftrunc trunc \
 	fs_perms testx looptest locktest unwritten_mmap \
-	bulkstat_unlink_test bulkstat_unlink_test_modified
+	bulkstat_unlink_test bulkstat_unlink_test_modified btree-test
 
 IRIX_TARGETS = open_unlink
 
Index: xfstests/src/btree-test.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ xfstests/src/btree-test.c	2008-08-31 19:15:14.000000000 -0300
@@ -0,0 +1,48 @@
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <xfs/xfs.h>
+
+/*
+ * Until headers are ready.
+ */
+#ifndef XFS_IOC_TEST_BTREE
+struct xfs_ioc_test_btree {
+	__u32		agno;
+	__u32		levels;
+	__u32		flags;
+};
+#define XFS_IOC_TEST_BTREE          _IOW ('X', 126, struct xfs_ioc_test_btree)
+#endif /* XFS_IOC_TEST_BTREE */
+
+int main(int argc, char **argv)
+{
+	struct xfs_ioc_test_btree tb;
+	int fd;
+
+	if (argc != 4) {
+		fprintf(stderr, "usage: %s path agno levels\n", argv[0]);
+		return 1;
+	}
+
+	fd = open(argv[1], O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "can't open %s\n", argv[1]);
+		return 1;
+	}
+
+	tb.agno = atoi(argv[2]);
+	tb.levels = atoi(argv[3]);
+	tb.flags = 0;
+
+	if (ioctl(fd, XFS_IOC_TEST_BTREE, &tb)) {
+		fprintf(stderr, "btree test failed: %s\n",
+			strerror(errno));
+		return 1;
+	}
+
+	return 0;
+}