The commit is pushed to "branch-rh10-6.12.0-55.13.1.2.x.vz10-ovz" and will
appear at [email protected]:openvz/vzkernel.git
after rh10-6.12.0-55.13.1.2.21.vz10
------>
commit 27f71c7761228d3f467522eaff9821d0657207f3
Author: Pavel Tikhomirov <[email protected]>
Date: Mon Nov 24 19:20:43 2025 +0800
ve: Switch from get_curr_ve() to get_exec_env()
Previously a task could've being moved by the outside event to another
ve cgroup and its link to ve_struct might change (task->task_ve). Now
when the link to ve_struct goes through ve namespace, the link is
persistent unless the task itself does clone3/unshare/setns.
So now we are safe to use ve_struct returned from get_exec_env(),
without worrying that it will be freed under us. And don't need any
special helper to get reference to the current ve.
Also remove get_curr_ve() as we no longer need it.
https://virtuozzo.atlassian.net/browse/VSTOR-118289
Signed-off-by: Pavel Tikhomirov <[email protected]>
Feature: ve: ve generic structures
======
Patchset description:
ve: Add VE namespace
Main ideas behind VE namespace explained in "ve: Introduce VE
namespace".
---
include/linux/cgroup.h | 1 -
kernel/cgroup/cgroup.c | 42 ------------------------------------------
net/core/netprio_cgroup.c | 6 ++----
3 files changed, 2 insertions(+), 47 deletions(-)
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 2e01e484cbac7..6fe5422e27b93 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -867,7 +867,6 @@ static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
#ifdef CONFIG_VE
int ve_hide_cgroups(struct cgroup_root *root);
-struct ve_struct *get_curr_ve(void);
struct cgroup_subsys_state *cgroup_get_e_ve_css(struct cgroup *cgrp,
struct cgroup_subsys *ss);
#endif
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 5893d8f4d010a..26ad3faf2e218 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2102,48 +2102,6 @@ static int cgroup_reconfigure(struct fs_context *fc)
}
#ifdef CONFIG_VE
-/*
- * This helper is a safe alternative to get_exec_env(), this helper actually
- * gets reference on current ve so if in other thread we would be moved from
- * this ve, at least this ve would not be freed under us.
- */
-struct ve_struct *get_curr_ve(void)
-{
- struct ve_struct *ve;
-
- /*
- * If first thread loads current->task_ve pointer, and if just after
- * that current is moved by other thread from this ve cgroup to some
- * other and this ve cgroup gets destroyed, ve pointer gets freed, so
- * first thread can't use such ve pointer safely.
- */
-
- /*
- * Fast path: Let's make it safe with rcu lock, though current can be
- * moved to other ve cgroup and our ve cgroup can start destroying, ve
- * pointer would be still valid. As it is freed in ve_destroy. And
- * ve_destroy is called from rcu callback after task_ve had changed.
- */
- rcu_read_lock();
- ve = rcu_dereference(current->task_ve);
- if (css_tryget(&ve->css)) {
- rcu_read_unlock();
- return ve;
- }
- rcu_read_unlock();
-
- /*
- * Slow path: Under cgroup_mutex both current tasks ve cgroup and
- * task_ve pointer can't change. Corresponding cgroup_mutex around
- * cgroup_attach_task() protects us from it.
- */
- mutex_lock(&cgroup_mutex);
- ve = get_ve(current->task_ve);
- mutex_unlock(&cgroup_mutex);
-
- return ve;
-}
-
/*
* Let's skip optional cgroups in Virtuozzo containers. Admin on host can
* do "mount -t cgroup cgroup -onone,name=namedcgroup /mnt", and this should
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 30c2599e3cc1c..bfe0ff69b0b67 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -220,7 +220,7 @@ static int read_priomap(struct seq_file *sf, void *v)
struct net *net, *_net = NULL;
struct net_device *dev;
- ve = get_curr_ve();
+ ve = get_exec_env();
if (!ve_is_super(ve)) {
struct nsproxy *ve_nsproxy;
@@ -230,7 +230,6 @@ static int read_priomap(struct seq_file *sf, void *v)
_net = get_net(ve_nsproxy->net_ns);
rcu_read_unlock();
}
- put_ve(ve);
net = _net ? : &init_net;
rcu_read_lock();
@@ -256,7 +255,7 @@ static ssize_t write_priomap(struct kernfs_open_file *of,
if (sscanf(buf, "%"__stringify(IFNAMSIZ)"s %u", devname, &prio) != 2)
return -EINVAL;
- ve = get_curr_ve();
+ ve = get_exec_env();
if (!ve_is_super(ve)) {
struct nsproxy *ve_nsproxy;
@@ -266,7 +265,6 @@ static ssize_t write_priomap(struct kernfs_open_file *of,
_net = get_net(ve_nsproxy->net_ns);
rcu_read_unlock();
}
- put_ve(ve);
net = _net ? : &init_net;
dev = dev_get_by_name(net, devname);
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