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8#include <linux/module.h>
9#include <net/net_namespace.h>
10#include <net/netns/generic.h>
11#include <linux/fs.h>
12
13static unsigned int grace_net_id;
14static DEFINE_SPINLOCK(grace_lock);
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28void
29locks_start_grace(struct net *net, struct lock_manager *lm)
30{
31 struct list_head *grace_list = net_generic(net, grace_net_id);
32
33 spin_lock(&grace_lock);
34 if (list_empty(&lm->list))
35 list_add(&lm->list, grace_list);
36 else
37 WARN(1, "double list_add attempt detected in net %x %s\n",
38 net->ns.inum, (net == &init_net) ? "(init_net)" : "");
39 spin_unlock(&grace_lock);
40}
41EXPORT_SYMBOL_GPL(locks_start_grace);
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52
53
54void
55locks_end_grace(struct lock_manager *lm)
56{
57 spin_lock(&grace_lock);
58 list_del_init(&lm->list);
59 spin_unlock(&grace_lock);
60}
61EXPORT_SYMBOL_GPL(locks_end_grace);
62
63static bool
64__state_in_grace(struct net *net, bool open)
65{
66 struct list_head *grace_list = net_generic(net, grace_net_id);
67 struct lock_manager *lm;
68
69 if (!open)
70 return !list_empty(grace_list);
71
72 spin_lock(&grace_lock);
73 list_for_each_entry(lm, grace_list, list) {
74 if (lm->block_opens) {
75 spin_unlock(&grace_lock);
76 return true;
77 }
78 }
79 spin_unlock(&grace_lock);
80 return false;
81}
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91bool locks_in_grace(struct net *net)
92{
93 return __state_in_grace(net, false);
94}
95EXPORT_SYMBOL_GPL(locks_in_grace);
96
97bool opens_in_grace(struct net *net)
98{
99 return __state_in_grace(net, true);
100}
101EXPORT_SYMBOL_GPL(opens_in_grace);
102
103static int __net_init
104grace_init_net(struct net *net)
105{
106 struct list_head *grace_list = net_generic(net, grace_net_id);
107
108 INIT_LIST_HEAD(grace_list);
109 return 0;
110}
111
112static void __net_exit
113grace_exit_net(struct net *net)
114{
115 struct list_head *grace_list = net_generic(net, grace_net_id);
116
117 WARN_ONCE(!list_empty(grace_list),
118 "net %x %s: grace_list is not empty\n",
119 net->ns.inum, __func__);
120}
121
122static struct pernet_operations grace_net_ops = {
123 .init = grace_init_net,
124 .exit = grace_exit_net,
125 .id = &grace_net_id,
126 .size = sizeof(struct list_head),
127};
128
129static int __init
130init_grace(void)
131{
132 return register_pernet_subsys(&grace_net_ops);
133}
134
135static void __exit
136exit_grace(void)
137{
138 unregister_pernet_subsys(&grace_net_ops);
139}
140
141MODULE_AUTHOR("Jeff Layton <jlayton@primarydata.com>");
142MODULE_LICENSE("GPL");
143module_init(init_grace)
144module_exit(exit_grace)
145