9p: Creating files with names too long should fail with ENAMETOOLONG.

Signed-off-by: NSripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

fs/9p/vfs_inode.c

@@ -660,6 +660,9 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 	P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 		dir, dentry->d_name.name, dentry, nameidata);
 
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
 	sb = dir->i_sb;
 	v9ses = v9fs_inode2v9ses(dir);
 	dfid = v9fs_fid_lookup(dentry->d_parent);