[Devel] [PATCH rh7] ve/pty: create ptmx device per ve namespace

[Vladimir Davydov]

After Unix98 PTY driver "virtualization" was reverted, we have to
manually set sysfs permissions for ptmx. This, however, is currently
impossible, because tty_class is still virtualized, which makes
ve.sysfs_permissions ignore it (see sysfs_perms_set).

This patch is a quick-fix which simply creates/destroys ptmx device in
ve namespace on container start/stop. It must be dropped when commit
6022450d12653 ("ve/tty: make tty_class VE-namespace aware") is reverted.

Signed-off-by: Vladimir Davydov <vdavydov at parallels.com>
---
 drivers/tty/pty.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index bd17a459af67..529046b79b0d 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -818,6 +818,32 @@ err_file:
 	return retval;
 }
 
+static int ve_unix98_pty_init(void *data)
+{
+	struct ve_struct *ve = data;
+	struct device *dev;
+
+	dev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), ve, "ptmx");
+	if (IS_ERR(dev)) {
+		pr_warn("Failed to create ptmx device for ve %s: %ld\n",
+			ve->ve_name, PTR_ERR(dev));
+		return PTR_ERR(dev);
+	}
+	return 0;
+}
+
+static void ve_unix98_pty_fini(void *data)
+{
+	device_destroy_namespace(tty_class, MKDEV(TTYAUX_MAJOR, 2), data);
+}
+
+static struct ve_hook ve_unix98_pty_hook = {
+	.init		= ve_unix98_pty_init,
+	.fini		= ve_unix98_pty_fini,
+	.priority	= HOOK_PRIO_DEFAULT,
+	.owner		= THIS_MODULE,
+};
+
 static struct file_operations ptmx_fops;
 
 static void __init unix98_pty_init(void)
@@ -882,6 +908,7 @@ static void __init unix98_pty_init(void)
 	    register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
 		panic("Couldn't register /dev/ptmx driver");
 	device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
+	ve_hook_register(VE_SS_CHAIN, &ve_unix98_pty_hook);
 }
 
 #else
-- 
2.1.4