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authorSerge E. Hallyn <serue@us.ibm.com>2006-10-02 02:18:06 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-02 07:57:20 -0700
commitab516013ad9ca47f1d3a936fa81303bfbf734d52 (patch)
tree643ea9c4c3d28958cb42dd87b1856f74edd22b11 /kernel/nsproxy.c
parentb1ba4ddde0cf67991d89f039365eaaeda61aa027 (diff)
downloadlwn-ab516013ad9ca47f1d3a936fa81303bfbf734d52.tar.gz
lwn-ab516013ad9ca47f1d3a936fa81303bfbf734d52.zip
[PATCH] namespaces: add nsproxy
This patch adds a nsproxy structure to the task struct. Later patches will move the fs namespace pointer into this structure, and introduce a new utsname namespace into the nsproxy. The vserver and openvz functionality, then, would be implemented in large part by virtualizing/isolating more and more resources into namespaces, each contained in the nsproxy. [akpm@osdl.org: build fix] Signed-off-by: Serge Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/nsproxy.c')
-rw-r--r--kernel/nsproxy.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
new file mode 100644
index 000000000000..ad9508865473
--- /dev/null
+++ b/kernel/nsproxy.c
@@ -0,0 +1,77 @@
+/*
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/nsproxy.h>
+
+static inline void get_nsproxy(struct nsproxy *ns)
+{
+ atomic_inc(&ns->count);
+}
+
+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 = kmalloc(sizeof(struct nsproxy), GFP_KERNEL);
+ if (ns) {
+ memcpy(ns, orig, sizeof(struct nsproxy));
+ atomic_set(&ns->count, 1);
+ }
+ 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);
+
+ 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;
+
+ if (!old_ns)
+ return 0;
+
+ get_nsproxy(old_ns);
+
+ return 0;
+}
+
+void free_nsproxy(struct nsproxy *ns)
+{
+ kfree(ns);
+}