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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 /include/linux/nsproxy.h
parentb1ba4ddde0cf67991d89f039365eaaeda61aa027 (diff)
[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 'include/linux/nsproxy.h')
-rw-r--r--include/linux/nsproxy.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
new file mode 100644
index 000000000000..7bdebfaab6a5
--- /dev/null
+++ b/include/linux/nsproxy.h
@@ -0,0 +1,45 @@
+#ifndef _LINUX_NSPROXY_H
+#define _LINUX_NSPROXY_H
+
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+
+/*
+ * A structure to contain pointers to all per-process
+ * namespaces - fs (mount), uts, network, sysvipc, etc.
+ *
+ * 'count' is the number of tasks holding a reference.
+ * The count for each namespace, then, will be the number
+ * of nsproxies pointing to it, not the number of tasks.
+ *
+ * The nsproxy is shared by tasks which share all namespaces.
+ * As soon as a single namespace is cloned or unshared, the
+ * nsproxy is copied.
+ */
+struct nsproxy {
+ atomic_t count;
+ spinlock_t nslock;
+};
+extern struct nsproxy init_nsproxy;
+
+struct nsproxy *dup_namespaces(struct nsproxy *orig);
+int copy_namespaces(int flags, struct task_struct *tsk);
+void get_task_namespaces(struct task_struct *tsk);
+void free_nsproxy(struct nsproxy *ns);
+
+static inline void put_nsproxy(struct nsproxy *ns)
+{
+ if (atomic_dec_and_test(&ns->count)) {
+ free_nsproxy(ns);
+ }
+}
+
+static inline void exit_task_namespaces(struct task_struct *p)
+{
+ struct nsproxy *ns = p->nsproxy;
+ if (ns) {
+ put_nsproxy(ns);
+ p->nsproxy = NULL;
+ }
+}
+#endif