[Devel] [PATCH RHEL7 COMMIT] ve/vtty: Register devices in sysfs

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rebase
------>
commit 0644d0fb4d20c8c0af9e8b31ab4034216407afbe
Author: Cyrill Gorcunov <gorcunov at odin.com>
Date:   Wed Dec 2 19:30:41 2015 +0400

    ve/vtty: Register devices in sysfs
    
    In pcs6 we explicitly create /sys/devices/virtual/ttyX
    in init_ve_vtty, but in pcs7 the code has been reworked:
    now all device matching is done via common tty_class
    and dev_match_devt helper.
    
    https://jira.sw.ru/browse/PSBM-41628
    
    Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
    Reviewed-by: Vladimir Davydov <vdavydov at virtuozzo.com>
    
    This fix is going to be a temporary one, later, in the scope of
    https://jira.sw.ru/browse/PSBM-41804
    we'll do the following:
    
     - revert all our tty device-namespace code leaving with native code instead
     - setup proper rules (such as sys/devices/virtual/tty[0-12] rx
       in default CT permissions)
     - drop legacy pty support (in kernel config)
---
 drivers/tty/pty.c    |  1 -
 drivers/tty/tty_io.c | 29 +++++++++++++++++++++++++++--
 include/linux/ve.h   |  1 +
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index b312635..93ab642 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -950,7 +950,6 @@ static DEFINE_IDR(vtty_idr);
 
 static struct file_operations vtty_fops;
 
-#define MAX_NR_VTTY_CONSOLES	(12)
 #define vtty_match_index(idx)	((idx) >= 0 && (idx) < MAX_NR_VTTY_CONSOLES)
 
 typedef struct {
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 8ce0a5f..fc80ccb 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -3653,17 +3653,25 @@ void console_sysfs_notify(void)
 void ve_tty_console_fini(struct ve_struct *ve)
 {
 	struct device *consdev = ve->consdev;
+	int i;
 
 	ve->consdev = NULL;
 	device_remove_file(consdev, &dev_attr_active);
 	device_destroy_namespace(tty_class, MKDEV(TTYAUX_MAJOR, 1), ve);
 	device_destroy_namespace(tty_class, MKDEV(TTYAUX_MAJOR, 0), ve);
+
+	if (!ve_is_super(ve)) {
+		for (i = 0; i <= MAX_NR_VTTY_CONSOLES; i++) {
+			device_destroy_namespace(tty_class,
+						 MKDEV(TTY_MAJOR, i), ve);
+		}
+	}
 }
 
 int ve_tty_console_init(struct ve_struct *ve)
 {
-	struct device *dev;
-	int err;
+	struct device *dev, *d;
+	int err, i;
 
 	dev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), ve, "tty");
 	if (IS_ERR(dev))
@@ -3679,6 +3687,23 @@ int ve_tty_console_init(struct ve_struct *ve)
 	if (err)
 		goto err_consfile;
 
+	if (!ve_is_super(ve)) {
+		for (i = 0; i <= MAX_NR_VTTY_CONSOLES; i++) {
+			d = device_create(tty_class, NULL, MKDEV(TTY_MAJOR, i),
+					  ve, "tty%d", i);
+			if (IS_ERR(d)) {
+				err = PTR_ERR(dev);
+
+				while (i-- > 0)
+					device_destroy_namespace(tty_class,
+								 MKDEV(TTY_MAJOR, i),
+								 ve);
+				device_remove_file(dev, &dev_attr_active);
+				goto err_consfile;
+			}
+		}
+	}
+
 	ve->consdev = dev;
 	return 0;
 
diff --git a/include/linux/ve.h b/include/linux/ve.h
index 2554337..87450c1 100644
--- a/include/linux/ve.h
+++ b/include/linux/ve.h
@@ -220,6 +220,7 @@ extern bool current_user_ns_initial(void);
 struct user_namespace *ve_init_user_ns(void);
 
 #ifdef CONFIG_TTY
+#define MAX_NR_VTTY_CONSOLES	(12)
 extern struct tty_driver *vtty_driver(dev_t dev, int *index);
 extern struct tty_driver *vtty_console_driver(int *index);
 extern int vtty_open_master(envid_t veid, int idx);