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 --- kernel/Makefile | 2 +- kernel/exit.c | 7 ++++++ kernel/fork.c | 18 ++++++++++++- kernel/nsproxy.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 102 insertions(+), 2 deletions(-) create mode 100644 kernel/nsproxy.c (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index aacaafb28b9..6ec53009b86 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -8,7 +8,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ signal.o sys.o kmod.o workqueue.o pid.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ - hrtimer.o rwsem.o latency.o + hrtimer.o rwsem.o latency.o nsproxy.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ diff --git a/kernel/exit.c b/kernel/exit.c index 3b47f26985f..1d0e9ea1fa0 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include @@ -397,9 +398,14 @@ void daemonize(const char *name, ...) fs = init_task.fs; current->fs = fs; atomic_inc(&fs->count); + exit_namespace(current); + exit_task_namespaces(current); current->namespace = init_task.namespace; + current->nsproxy = init_task.nsproxy; get_namespace(current->namespace); + get_task_namespaces(current); + exit_files(current); current->files = init_task.files; atomic_inc(¤t->files->count); @@ -918,6 +924,7 @@ fastcall NORET_TYPE void do_exit(long code) __exit_files(tsk); __exit_fs(tsk); exit_namespace(tsk); + exit_task_namespaces(tsk); exit_thread(); cpuset_exit(tsk); exit_keys(tsk); diff --git a/kernel/fork.c b/kernel/fork.c index 89f666491d1..c9e660ae47a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -1116,8 +1117,10 @@ static struct task_struct *copy_process(unsigned long clone_flags, goto bad_fork_cleanup_signal; if ((retval = copy_keys(clone_flags, p))) goto bad_fork_cleanup_mm; - if ((retval = copy_namespace(clone_flags, p))) + if ((retval = copy_namespaces(clone_flags, p))) goto bad_fork_cleanup_keys; + if ((retval = copy_namespace(clone_flags, p))) + goto bad_fork_cleanup_namespaces; retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs); if (retval) goto bad_fork_cleanup_namespace; @@ -1262,6 +1265,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, bad_fork_cleanup_namespace: exit_namespace(p); +bad_fork_cleanup_namespaces: + exit_task_namespaces(p); bad_fork_cleanup_keys: exit_keys(p); bad_fork_cleanup_mm: @@ -1606,6 +1611,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; struct files_struct *fd, *new_fd = NULL; struct sem_undo_list *new_ulist = NULL; + struct nsproxy *new_nsproxy, *old_nsproxy; check_unshare_flags(&unshare_flags); @@ -1632,7 +1638,15 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist) { + old_nsproxy = current->nsproxy; + new_nsproxy = dup_namespaces(old_nsproxy); + if (!new_nsproxy) { + err = -ENOMEM; + goto bad_unshare_cleanup_semundo; + } + task_lock(current); + current->nsproxy = new_nsproxy; if (new_fs) { fs = current->fs; @@ -1668,8 +1682,10 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) } task_unlock(current); + put_nsproxy(old_nsproxy); } +bad_unshare_cleanup_semundo: bad_unshare_cleanup_fd: if (new_fd) put_files_struct(new_fd); diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c new file mode 100644 index 00000000000..ad950886547 --- /dev/null +++ b/kernel/nsproxy.c @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2006 IBM Corporation + * + * Author: Serge Hallyn + * + * 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 +#include +#include + +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); +} -- cgit v1.2.3-70-g09d2