debugfs.c (do_stat): Check to make sure a filesystem is open
	and abort if with an error if not, to prevent a seg fault
	in that case.

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index ca73c99..e923403 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -595,6 +595,9 @@
 	ext2_ino_t	inode;
 	struct ext2_inode * inode_buf;
 
+	if (check_fs_open(argv[0]))
+		return 1;
+
 	inode_buf = (struct ext2_inode *)
 			malloc(EXT2_INODE_SIZE(current_fs->super));
 	if (!inode_buf) {