From ab516013ad9ca47f1d3a936fa81303bfbf734d52 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Mon, 2 Oct 2006 02:18:06 -0700 Subject: [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 Cc: Kirill Korotaev Cc: "Eric W. Biederman" Cc: Herbert Poetzl Cc: Andrey Savochkin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/nsproxy.h | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 include/linux/nsproxy.h (limited to 'include/linux/nsproxy.h') diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h new file mode 100644 index 0000000000000..7bdebfaab6a5b --- /dev/null +++ b/include/linux/nsproxy.h @@ -0,0 +1,45 @@ +#ifndef _LINUX_NSPROXY_H +#define _LINUX_NSPROXY_H + +#include +#include + +/* + * 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 -- cgit 1.2.3-korg