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10#include <linux/types.h>
11#include <linux/parser.h>
12#include <linux/fs.h>
13#include <linux/slab.h>
14#include <linux/res_counter.h>
15#include <linux/uaccess.h>
16#include <linux/mm.h>
17
18void res_counter_init(struct res_counter *counter, struct res_counter *parent)
19{
20 spin_lock_init(&counter->lock);
21 counter->limit = RESOURCE_MAX;
22 counter->soft_limit = RESOURCE_MAX;
23 counter->parent = parent;
24}
25
26int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
27{
28 if (counter->usage + val > counter->limit) {
29 counter->failcnt++;
30 return -ENOMEM;
31 }
32
33 counter->usage += val;
34 if (counter->usage > counter->max_usage)
35 counter->max_usage = counter->usage;
36 return 0;
37}
38
39int res_counter_charge(struct res_counter *counter, unsigned long val,
40 struct res_counter **limit_fail_at)
41{
42 int ret;
43 unsigned long flags;
44 struct res_counter *c, *u;
45
46 *limit_fail_at = NULL;
47 local_irq_save(flags);
48 for (c = counter; c != NULL; c = c->parent) {
49 spin_lock(&c->lock);
50 ret = res_counter_charge_locked(c, val);
51 spin_unlock(&c->lock);
52 if (ret < 0) {
53 *limit_fail_at = c;
54 goto undo;
55 }
56 }
57 ret = 0;
58 goto done;
59undo:
60 for (u = counter; u != c; u = u->parent) {
61 spin_lock(&u->lock);
62 res_counter_uncharge_locked(u, val);
63 spin_unlock(&u->lock);
64 }
65done:
66 local_irq_restore(flags);
67 return ret;
68}
69
70void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
71{
72 if (WARN_ON(counter->usage < val))
73 val = counter->usage;
74
75 counter->usage -= val;
76}
77
78void res_counter_uncharge(struct res_counter *counter, unsigned long val)
79{
80 unsigned long flags;
81 struct res_counter *c;
82
83 local_irq_save(flags);
84 for (c = counter; c != NULL; c = c->parent) {
85 spin_lock(&c->lock);
86 res_counter_uncharge_locked(c, val);
87 spin_unlock(&c->lock);
88 }
89 local_irq_restore(flags);
90}
91
92
93static inline unsigned long long *
94res_counter_member(struct res_counter *counter, int member)
95{
96 switch (member) {
97 case RES_USAGE:
98 return &counter->usage;
99 case RES_MAX_USAGE:
100 return &counter->max_usage;
101 case RES_LIMIT:
102 return &counter->limit;
103 case RES_FAILCNT:
104 return &counter->failcnt;
105 case RES_SOFT_LIMIT:
106 return &counter->soft_limit;
107 };
108
109 BUG();
110 return NULL;
111}
112
113ssize_t res_counter_read(struct res_counter *counter, int member,
114 const char __user *userbuf, size_t nbytes, loff_t *pos,
115 int (*read_strategy)(unsigned long long val, char *st_buf))
116{
117 unsigned long long *val;
118 char buf[64], *s;
119
120 s = buf;
121 val = res_counter_member(counter, member);
122 if (read_strategy)
123 s += read_strategy(*val, s);
124 else
125 s += sprintf(s, "%llu\n", *val);
126 return simple_read_from_buffer((void __user *)userbuf, nbytes,
127 pos, buf, s - buf);
128}
129
130u64 res_counter_read_u64(struct res_counter *counter, int member)
131{
132 return *res_counter_member(counter, member);
133}
134
135int res_counter_memparse_write_strategy(const char *buf,
136 unsigned long long *res)
137{
138 char *end;
139
140
141 if (*buf == '-') {
142 *res = simple_strtoull(buf + 1, &end, 10);
143 if (*res != 1 || *end != '\0')
144 return -EINVAL;
145 *res = RESOURCE_MAX;
146 return 0;
147 }
148
149
150 *res = memparse((char *)buf, &end);
151 if (*end != '\0')
152 return -EINVAL;
153
154 *res = PAGE_ALIGN(*res);
155 return 0;
156}
157
158int res_counter_write(struct res_counter *counter, int member,
159 const char *buf, write_strategy_fn write_strategy)
160{
161 char *end;
162 unsigned long flags;
163 unsigned long long tmp, *val;
164
165 if (write_strategy) {
166 if (write_strategy(buf, &tmp))
167 return -EINVAL;
168 } else {
169 tmp = simple_strtoull(buf, &end, 10);
170 if (*end != '\0')
171 return -EINVAL;
172 }
173 spin_lock_irqsave(&counter->lock, flags);
174 val = res_counter_member(counter, member);
175 *val = tmp;
176 spin_unlock_irqrestore(&counter->lock, flags);
177 return 0;
178}
179
