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Commit | Line | Data |
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ae5e1b22 PE |
1 | /* |
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 | ||
15 | static struct ipc_namespace *clone_ipc_ns(struct ipc_namespace *old_ns) | |
16 | { | |
ae5e1b22 PE |
17 | struct ipc_namespace *ns; |
18 | ||
ae5e1b22 PE |
19 | ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL); |
20 | if (ns == NULL) | |
ed2ddbf8 | 21 | return ERR_PTR(-ENOMEM); |
ae5e1b22 | 22 | |
4d89dc6a ND |
23 | atomic_inc(&nr_ipc_ns); |
24 | ||
ed2ddbf8 PP |
25 | sem_init_ns(ns); |
26 | msg_init_ns(ns); | |
27 | shm_init_ns(ns); | |
ae5e1b22 | 28 | |
b6b337ad ND |
29 | register_ipcns_notifier(ns); |
30 | ||
ae5e1b22 PE |
31 | kref_init(&ns->kref); |
32 | return ns; | |
ae5e1b22 PE |
33 | } |
34 | ||
35 | struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) | |
36 | { | |
37 | struct ipc_namespace *new_ns; | |
38 | ||
39 | BUG_ON(!ns); | |
40 | get_ipc_ns(ns); | |
41 | ||
42 | if (!(flags & CLONE_NEWIPC)) | |
43 | return ns; | |
44 | ||
45 | new_ns = clone_ipc_ns(ns); | |
46 | ||
47 | put_ipc_ns(ns); | |
48 | return new_ns; | |
49 | } | |
50 | ||
01b8b07a PP |
51 | /* |
52 | * free_ipcs - free all ipcs of one type | |
53 | * @ns: the namespace to remove the ipcs from | |
54 | * @ids: the table of ipcs to free | |
55 | * @free: the function called to free each individual ipc | |
56 | * | |
57 | * Called for each kind of ipc when an ipc_namespace exits. | |
58 | */ | |
59 | void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids, | |
60 | void (*free)(struct ipc_namespace *, struct kern_ipc_perm *)) | |
61 | { | |
62 | struct kern_ipc_perm *perm; | |
63 | int next_id; | |
64 | int total, in_use; | |
65 | ||
66 | down_write(&ids->rw_mutex); | |
67 | ||
68 | in_use = ids->in_use; | |
69 | ||
70 | for (total = 0, next_id = 0; total < in_use; next_id++) { | |
71 | perm = idr_find(&ids->ipcs_idr, next_id); | |
72 | if (perm == NULL) | |
73 | continue; | |
74 | ipc_lock_by_ptr(perm); | |
75 | free(ns, perm); | |
76 | total++; | |
77 | } | |
78 | up_write(&ids->rw_mutex); | |
79 | } | |
80 | ||
ae5e1b22 PE |
81 | void free_ipc_ns(struct kref *kref) |
82 | { | |
83 | struct ipc_namespace *ns; | |
84 | ||
85 | ns = container_of(kref, struct ipc_namespace, kref); | |
b6b337ad ND |
86 | /* |
87 | * Unregistering the hotplug notifier at the beginning guarantees | |
88 | * that the ipc namespace won't be freed while we are inside the | |
89 | * callback routine. Since the blocking_notifier_chain_XXX routines | |
90 | * hold a rw lock on the notifier list, unregister_ipcns_notifier() | |
91 | * won't take the rw lock before blocking_notifier_call_chain() has | |
92 | * released the rd lock. | |
93 | */ | |
94 | unregister_ipcns_notifier(ns); | |
ae5e1b22 PE |
95 | sem_exit_ns(ns); |
96 | msg_exit_ns(ns); | |
97 | shm_exit_ns(ns); | |
98 | kfree(ns); | |
4d89dc6a | 99 | atomic_dec(&nr_ipc_ns); |
ae5e1b22 | 100 | } |