Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 34683efa2cceee37f0a76db7531b8f5fc265a325 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * resource cgroups
 *
 * Copyright 2007 OpenVZ SWsoft Inc
 *
 * Author: Pavel Emelianov <xemul@openvz.org>
 *
 */

#include <linux/types.h>
#include <linux/parser.h>
#include <linux/fs.h>
#include <linux/res_counter.h>
#include <linux/uaccess.h>
#include <linux/mm.h>

void res_counter_init(struct res_counter *counter, struct res_counter *parent)
{
	spin_lock_init(&counter->lock);
	counter->limit = RESOURCE_MAX;
	counter->soft_limit = RESOURCE_MAX;
	counter->parent = parent;
}

int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
{
	if (counter->usage + val > counter->limit) {
		counter->failcnt++;
		return -ENOMEM;
	}

	counter->usage += val;
	if (counter->usage > counter->max_usage)
		counter->max_usage = counter->usage;
	return 0;
}

int res_counter_charge(struct res_counter *counter, unsigned long val,
			struct res_counter **limit_fail_at)
{
	int ret;
	unsigned long flags;
	struct res_counter *c, *u;

	*limit_fail_at = NULL;
	local_irq_save(flags);
	for (c = counter; c != NULL; c = c->parent) {
		spin_lock(&c->lock);
		ret = res_counter_charge_locked(c, val);
		spin_unlock(&c->lock);
		if (ret < 0) {
			*limit_fail_at = c;
			goto undo;
		}
	}
	ret = 0;
	goto done;
undo:
	for (u = counter; u != c; u = u->parent) {
		spin_lock(&u->lock);
		res_counter_uncharge_locked(u, val);
		spin_unlock(&u->lock);
	}
done:
	local_irq_restore(flags);
	return ret;
}

void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
{
	if (WARN_ON(counter->usage < val))
		val = counter->usage;

	counter->usage -= val;
}

void res_counter_uncharge(struct res_counter *counter, unsigned long val)
{
	unsigned long flags;
	struct res_counter *c;

	local_irq_save(flags);
	for (c = counter; c != NULL; c = c->parent) {
		spin_lock(&c->lock);
		res_counter_uncharge_locked(c, val);
		spin_unlock(&c->lock);
	}
	local_irq_restore(flags);
}


static inline unsigned long long *
res_counter_member(struct res_counter *counter, int member)
{
	switch (member) {
	case RES_USAGE:
		return &counter->usage;
	case RES_MAX_USAGE:
		return &counter->max_usage;
	case RES_LIMIT:
		return &counter->limit;
	case RES_FAILCNT:
		return &counter->failcnt;
	case RES_SOFT_LIMIT:
		return &counter->soft_limit;
	};

	BUG();
	return NULL;
}

ssize_t res_counter_read(struct res_counter *counter, int member,
		const char __user *userbuf, size_t nbytes, loff_t *pos,
		int (*read_strategy)(unsigned long long val, char *st_buf))
{
	unsigned long long *val;
	char buf[64], *s;

	s = buf;
	val = res_counter_member(counter, member);
	if (read_strategy)
		s += read_strategy(*val, s);
	else
		s += sprintf(s, "%llu\n", *val);
	return simple_read_from_buffer((void __user *)userbuf, nbytes,
			pos, buf, s - buf);
}

#if BITS_PER_LONG == 32
u64 res_counter_read_u64(struct res_counter *counter, int member)
{
	unsigned long flags;
	u64 ret;

	spin_lock_irqsave(&counter->lock, flags);
	ret = *res_counter_member(counter, member);
	spin_unlock_irqrestore(&counter->lock, flags);

	return ret;
}
#else
u64 res_counter_read_u64(struct res_counter *counter, int member)
{
	return *res_counter_member(counter, member);
}
#endif

int res_counter_memparse_write_strategy(const char *buf,
					unsigned long long *res)
{
	char *end;

	/* return RESOURCE_MAX(unlimited) if "-1" is specified */
	if (*buf == '-') {
		*res = simple_strtoull(buf + 1, &end, 10);
		if (*res != 1 || *end != '\0')
			return -EINVAL;
		*res = RESOURCE_MAX;
		return 0;
	}

	/* FIXME - make memparse() take const char* args */
	*res = memparse((char *)buf, &end);
	if (*end != '\0')
		return -EINVAL;

	*res = PAGE_ALIGN(*res);
	return 0;
}

int res_counter_write(struct res_counter *counter, int member,
		      const char *buf, write_strategy_fn write_strategy)
{
	char *end;
	unsigned long flags;
	unsigned long long tmp, *val;

	if (write_strategy) {
		if (write_strategy(buf, &tmp))
			return -EINVAL;
	} else {
		tmp = simple_strtoull(buf, &end, 10);
		if (*end != '\0')
			return -EINVAL;
	}
	spin_lock_irqsave(&counter->lock, flags);
	val = res_counter_member(counter, member);
	*val = tmp;
	spin_unlock_irqrestore(&counter->lock, flags);
	return 0;
}