Index: zap.c
===================================================================
RCS file: /usr/store/mlaier/fcvs/src/sys/contrib/opensolaris/uts/common/fs/zfs/zap.c,v
retrieving revision 1.1
diff -u -r1.1 zap.c
--- zap.c	6 Apr 2007 01:09:02 -0000	1.1
+++ zap.c	8 Apr 2007 17:48:07 -0000
@@ -84,6 +84,9 @@
 	(void) dmu_buf_update_user(zap->zap_dbuf, zap, zap,
 	    &zap->zap_f.zap_phys, zap_evict);
 
+#ifdef _KERNEL
+	memset(&zap->zap_f.zap_num_entries_mtx, 0, sizeof(struct mtx));
+#endif
 	mutex_init(&zap->zap_f.zap_num_entries_mtx, NULL, MUTEX_DEFAULT, 0);
 	zap->zap_f.zap_block_shift = highbit(zap->zap_dbuf->db_size) - 1;