[Devel] [PATCH VZ10 v4 1/3] ve_namespace: Allow entering non-running VE namespace

[Konstantin Khorenko]

From: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>

The restriction doesn't bring a lot of value and makes tests more
complex: to enter a VE namespace, the VE has to be actually started.

In vzctl we have locking to prevent parallel creations.
If someone decides to skip locks and start one CT
in parallel - big mistake, but not ours.

Still, entering a non-running CT is a strange thing to do. Our
selftests do it on purpose, but if some of our userspace does the
same on a production node, that is a bug we want to know about and
fix, so leave a warning in place of the check.

https://virtuozzo.atlassian.net/browse/VSTOR-144504

Feature: ve selftests
Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
Reviewed-by: Vasileios Almpanis <vasileios.almpanis at virtuozzo.com>
Reviewed-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 kernel/ve/ve_namespace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/ve/ve_namespace.c b/kernel/ve/ve_namespace.c
index 3dbe0dde2645d..6b12bcd605ea4 100644
--- a/kernel/ve/ve_namespace.c
+++ b/kernel/ve/ve_namespace.c
@@ -227,7 +227,9 @@ static int ve_ns_install(struct nsset *nsset, struct ns_common *new)
 		return -EPERM;
 
 	if (!VE_IS_RUNNING(ve_ns->ve))
-		return -EINVAL;
+		pr_warn_once("CT: %s: setns to the VE namespace of a non-running CT (state %d) by %s (%d)\n",
+			     ve_name(ve_ns->ve), ve_ns->ve->state,
+			     current->comm, task_pid_nr(current));
 
 	/*
 	 * Don't need to put_ve_ns(nsset->ve_ns) here,

-- 
2.43.0