This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / kernel / nsproxy.c

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
new file mode 100644 (file)
index 0000000..bec0e22
--- /dev/null
+++ b/kernel/nsproxy.c
@@ -0,0 +1,147 @@
+/*
+ *  Copyright (C) 2006 IBM Corporation
+ *
+ *  Author: Serge Hallyn <serue@us.ibm.com>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License as
+ *  published by the Free Software Foundation, version 2 of the
+ *  License.
+ *
+ *  Jun 2006 - namespaces support
+ *             OpenVZ, SWsoft Inc.
+ *             Pavel Emelianov <xemul@openvz.org>
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/nsproxy.h>
+#include <linux/init_task.h>
+#include <linux/mnt_namespace.h>
+#include <linux/utsname.h>
+#include <linux/pid_namespace.h>
+#include <linux/vserver/global.h>
+
+struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
+
+void get_task_namespaces(struct task_struct *tsk)
+{
+       struct nsproxy *ns = tsk->nsproxy;
+       if (ns) {
+               get_nsproxy(ns);
+       }
+}
+
+/*
+ * creates a copy of "orig" with refcount 1.
+ * This does not grab references to the contained namespaces,
+ * so that needs to be done by dup_namespaces.
+ */
+static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
+{
+       struct nsproxy *ns;
+
+       ns = kmemdup(orig, sizeof(struct nsproxy), GFP_KERNEL);
+       if (ns)
+               atomic_set(&ns->count, 1);
+       atomic_inc(&vs_global_nsproxy);
+       return ns;
+}
+
+/*
+ * copies the nsproxy, setting refcount to 1, and grabbing a
+ * reference to all contained namespaces.  Called from
+ * sys_unshare()
+ */
+struct nsproxy *dup_namespaces(struct nsproxy *orig)
+{
+       struct nsproxy *ns = clone_namespaces(orig);
+
+       if (ns) {
+               if (ns->mnt_ns)
+                       get_mnt_ns(ns->mnt_ns);
+               if (ns->uts_ns)
+                       get_uts_ns(ns->uts_ns);
+               if (ns->ipc_ns)
+                       get_ipc_ns(ns->ipc_ns);
+               if (ns->pid_ns)
+                       get_pid_ns(ns->pid_ns);
+       }
+
+       return ns;
+}
+
+/*
+ * called from clone.  This now handles copy for nsproxy and all
+ * namespaces therein.
+ */
+int copy_namespaces(int flags, struct task_struct *tsk)
+{
+       struct nsproxy *old_ns = tsk->nsproxy;
+       struct nsproxy *new_ns;
+       int err = 0;
+
+       if (!old_ns)
+               return 0;
+
+       get_nsproxy(old_ns);
+
+       if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
+               return 0;
+
+       new_ns = clone_namespaces(old_ns);
+       if (!new_ns) {
+               err = -ENOMEM;
+               goto out;
+       }
+
+       tsk->nsproxy = new_ns;
+
+       err = copy_mnt_ns(flags, tsk);
+       if (err)
+               goto out_ns;
+
+       err = copy_utsname(flags, tsk);
+       if (err)
+               goto out_uts;
+
+       err = copy_ipcs(flags, tsk);
+       if (err)
+               goto out_ipc;
+
+       err = copy_pid_ns(flags, tsk);
+       if (err)
+               goto out_pid;
+
+out:
+       put_nsproxy(old_ns);
+       return err;
+
+out_pid:
+       if (new_ns->ipc_ns)
+               put_ipc_ns(new_ns->ipc_ns);
+out_ipc:
+       if (new_ns->uts_ns)
+               put_uts_ns(new_ns->uts_ns);
+out_uts:
+       if (new_ns->mnt_ns)
+               put_mnt_ns(new_ns->mnt_ns);
+out_ns:
+       tsk->nsproxy = old_ns;
+       kfree(new_ns);
+       goto out;
+}
+
+void free_nsproxy(struct nsproxy *ns)
+{
+       if (ns->mnt_ns)
+               put_mnt_ns(ns->mnt_ns);
+       if (ns->uts_ns)
+               put_uts_ns(ns->uts_ns);
+       if (ns->ipc_ns)
+               put_ipc_ns(ns->ipc_ns);
+       if (ns->pid_ns)
+               put_pid_ns(ns->pid_ns);
+       atomic_dec(&vs_global_nsproxy);
+       kfree(ns);
+}