[Devel] [PATCH RH7 08/32] Revert "ms/pidns: expose task pid_ns_for_children to userspace"

[Pavel Tikhomirov]

This reverts commit edaecdb8adac2871e9d5afa0dd127d4a92a34162.

We switch from procfs ns-files to nsfs ones, so we will apply nsfs
version of the patch instead.

https://jira.sw.ru/browse/PSBM-102357

Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 fs/proc/namespaces.c    |  1 -
 include/linux/proc_ns.h |  1 -
 kernel/pid_namespace.c  | 33 ---------------------------------
 3 files changed, 35 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 280e90ecf105..6976ef6cb193 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -27,7 +27,6 @@ static const struct proc_ns_operations *ns_entries[] = {
 #endif
 #ifdef CONFIG_PID_NS
 	&pidns_operations,
-	&pidns_for_children_operations,
 #endif
 #ifdef CONFIG_USER_NS
 	&userns_operations,
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index 8deba57cbb45..b8dc2bca2575 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -27,7 +27,6 @@ extern const struct proc_ns_operations netns_operations;
 extern const struct proc_ns_operations utsns_operations;
 extern const struct proc_ns_operations ipcns_operations;
 extern const struct proc_ns_operations pidns_operations;
-extern const struct proc_ns_operations pidns_for_children_operations;
 extern const struct proc_ns_operations userns_operations;
 extern const struct proc_ns_operations mntns_operations;
 
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 3728139e7e54..482b6c3e0143 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -355,29 +355,6 @@ static void *pidns_get(struct task_struct *task)
 	return ns;
 }
 
-static void *pidns_for_children_get(struct task_struct *task)
-{
-	struct pid_namespace *ns = NULL;
-
-	task_lock(task);
-	if (task->nsproxy) {
-		ns = task->nsproxy->pid_ns;
-		get_pid_ns(ns);
-	}
-	task_unlock(task);
-
-	if (ns) {
-		qread_lock(&tasklist_lock);
-		if (!ns->child_reaper) {
-			put_pid_ns(ns);
-			ns = NULL;
-		}
-		qread_unlock(&tasklist_lock);
-	}
-
-	return ns;
-}
-
 static void pidns_put(void *ns)
 {
 	put_pid_ns(ns);
@@ -429,16 +406,6 @@ const struct proc_ns_operations pidns_operations = {
 	.inum		= pidns_inum,
 };
 
-const struct proc_ns_operations pidns_for_children_operations = {
-	.name		= "pid_for_children",
-	.real_ns_name	= "pid",
-	.type		= CLONE_NEWPID,
-	.get		= pidns_for_children_get,
-	.put		= pidns_put,
-	.install	= pidns_install,
-	.inum		= pidns_inum,
-};
-
 static __init int pid_namespaces_init(void)
 {
 	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
-- 
2.24.1