blob: 4b4dc6d847f18c2129a09d1dfe1e92e24053dfed [file] [log] [blame]
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -08001/*
2 * linux/ipc/namespace.c
3 * Copyright (C) 2006 Pavel Emelyanov <xemul@openvz.org> OpenVZ, SWsoft Inc.
4 */
5
6#include <linux/ipc.h>
7#include <linux/msg.h>
8#include <linux/ipc_namespace.h>
9#include <linux/rcupdate.h>
10#include <linux/nsproxy.h>
11#include <linux/slab.h>
12
13#include "util.h"
14
15static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns)
16{
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080017 struct ipc_namespace *ns;
18
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080019 ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
20 if (ns == NULL)
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080021 return ERR_PTR(-ENOMEM);
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080022
Nadia Derbey4d89dc62008-04-29 01:00:40 -070023 atomic_inc(&nr_ipc_ns);
24
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080025 sem_init_ns(ns);
26 msg_init_ns(ns);
27 shm_init_ns(ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070028 mq_init_ns(ns);
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080029
Nadia Derbeye2c284d2008-04-29 01:00:44 -070030 /*
31 * msgmni has already been computed for the new ipc ns.
32 * Thus, do the ipcns creation notification before registering that
33 * new ipcns in the chain.
34 */
35 ipcns_notify(IPCNS_CREATED);
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070036 register_ipcns_notifier(ns);
37
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080038 kref_init(&ns->kref);
39 return ns;
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080040}
41
42struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
43{
44 struct ipc_namespace *new_ns;
45
46 BUG_ON(!ns);
47 get_ipc_ns(ns);
48
49 if (!(flags & CLONE_NEWIPC))
50 return ns;
51
52 new_ns = clone_ipc_ns(ns);
53
54 put_ipc_ns(ns);
55 return new_ns;
56}
57
Pierre Peiffer01b8b072008-02-08 04:18:57 -080058/*
59 * free_ipcs - free all ipcs of one type
60 * @ns: the namespace to remove the ipcs from
61 * @ids: the table of ipcs to free
62 * @free: the function called to free each individual ipc
63 *
64 * Called for each kind of ipc when an ipc_namespace exits.
65 */
66void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
67 void (*free)(struct ipc_namespace *, struct kern_ipc_perm *))
68{
69 struct kern_ipc_perm *perm;
70 int next_id;
71 int total, in_use;
72
73 down_write(&ids->rw_mutex);
74
75 in_use = ids->in_use;
76
77 for (total = 0, next_id = 0; total < in_use; next_id++) {
78 perm = idr_find(&ids->ipcs_idr, next_id);
79 if (perm == NULL)
80 continue;
81 ipc_lock_by_ptr(perm);
82 free(ns, perm);
83 total++;
84 }
85 up_write(&ids->rw_mutex);
86}
87
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080088void free_ipc_ns(struct kref *kref)
89{
90 struct ipc_namespace *ns;
91
92 ns = container_of(kref, struct ipc_namespace, kref);
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070093 /*
94 * Unregistering the hotplug notifier at the beginning guarantees
95 * that the ipc namespace won't be freed while we are inside the
96 * callback routine. Since the blocking_notifier_chain_XXX routines
97 * hold a rw lock on the notifier list, unregister_ipcns_notifier()
98 * won't take the rw lock before blocking_notifier_call_chain() has
99 * released the rd lock.
100 */
101 unregister_ipcns_notifier(ns);
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800102 sem_exit_ns(ns);
103 msg_exit_ns(ns);
104 shm_exit_ns(ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700105 mq_exit_ns(ns);
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800106 kfree(ns);
Nadia Derbey4d89dc62008-04-29 01:00:40 -0700107 atomic_dec(&nr_ipc_ns);
Nadia Derbeye2c284d2008-04-29 01:00:44 -0700108
109 /*
110 * Do the ipcns removal notification after decrementing nr_ipc_ns in
111 * order to have a correct value when recomputing msgmni.
112 */
113 ipcns_notify(IPCNS_REMOVED);
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800114}