Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
[platform/adaptation/renesas_rcar/renesas_kernel.git] / kernel / res_counter.c
1 /*
2  * resource cgroups
3  *
4  * Copyright 2007 OpenVZ SWsoft Inc
5  *
6  * Author: Pavel Emelianov <xemul@openvz.org>
7  *
8  */
9
10 #include <linux/types.h>
11 #include <linux/parser.h>
12 #include <linux/fs.h>
13 #include <linux/res_counter.h>
14 #include <linux/uaccess.h>
15 #include <linux/mm.h>
16
17 void res_counter_init(struct res_counter *counter, struct res_counter *parent)
18 {
19         spin_lock_init(&counter->lock);
20         counter->limit = RES_COUNTER_MAX;
21         counter->soft_limit = RES_COUNTER_MAX;
22         counter->parent = parent;
23 }
24
25 int res_counter_charge_locked(struct res_counter *counter, unsigned long val,
26                               bool force)
27 {
28         int ret = 0;
29
30         if (counter->usage + val > counter->limit) {
31                 counter->failcnt++;
32                 ret = -ENOMEM;
33                 if (!force)
34                         return ret;
35         }
36
37         counter->usage += val;
38         if (counter->usage > counter->max_usage)
39                 counter->max_usage = counter->usage;
40         return ret;
41 }
42
43 static int __res_counter_charge(struct res_counter *counter, unsigned long val,
44                                 struct res_counter **limit_fail_at, bool force)
45 {
46         int ret, r;
47         unsigned long flags;
48         struct res_counter *c, *u;
49
50         r = ret = 0;
51         *limit_fail_at = NULL;
52         local_irq_save(flags);
53         for (c = counter; c != NULL; c = c->parent) {
54                 spin_lock(&c->lock);
55                 r = res_counter_charge_locked(c, val, force);
56                 spin_unlock(&c->lock);
57                 if (r < 0 && !ret) {
58                         ret = r;
59                         *limit_fail_at = c;
60                         if (!force)
61                                 break;
62                 }
63         }
64
65         if (ret < 0 && !force) {
66                 for (u = counter; u != c; u = u->parent) {
67                         spin_lock(&u->lock);
68                         res_counter_uncharge_locked(u, val);
69                         spin_unlock(&u->lock);
70                 }
71         }
72         local_irq_restore(flags);
73
74         return ret;
75 }
76
77 int res_counter_charge(struct res_counter *counter, unsigned long val,
78                         struct res_counter **limit_fail_at)
79 {
80         return __res_counter_charge(counter, val, limit_fail_at, false);
81 }
82
83 int res_counter_charge_nofail(struct res_counter *counter, unsigned long val,
84                               struct res_counter **limit_fail_at)
85 {
86         return __res_counter_charge(counter, val, limit_fail_at, true);
87 }
88
89 u64 res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
90 {
91         if (WARN_ON(counter->usage < val))
92                 val = counter->usage;
93
94         counter->usage -= val;
95         return counter->usage;
96 }
97
98 u64 res_counter_uncharge_until(struct res_counter *counter,
99                                struct res_counter *top,
100                                unsigned long val)
101 {
102         unsigned long flags;
103         struct res_counter *c;
104         u64 ret = 0;
105
106         local_irq_save(flags);
107         for (c = counter; c != top; c = c->parent) {
108                 u64 r;
109                 spin_lock(&c->lock);
110                 r = res_counter_uncharge_locked(c, val);
111                 if (c == counter)
112                         ret = r;
113                 spin_unlock(&c->lock);
114         }
115         local_irq_restore(flags);
116         return ret;
117 }
118
119 u64 res_counter_uncharge(struct res_counter *counter, unsigned long val)
120 {
121         return res_counter_uncharge_until(counter, NULL, val);
122 }
123
124 static inline unsigned long long *
125 res_counter_member(struct res_counter *counter, int member)
126 {
127         switch (member) {
128         case RES_USAGE:
129                 return &counter->usage;
130         case RES_MAX_USAGE:
131                 return &counter->max_usage;
132         case RES_LIMIT:
133                 return &counter->limit;
134         case RES_FAILCNT:
135                 return &counter->failcnt;
136         case RES_SOFT_LIMIT:
137                 return &counter->soft_limit;
138         };
139
140         BUG();
141         return NULL;
142 }
143
144 ssize_t res_counter_read(struct res_counter *counter, int member,
145                 const char __user *userbuf, size_t nbytes, loff_t *pos,
146                 int (*read_strategy)(unsigned long long val, char *st_buf))
147 {
148         unsigned long long *val;
149         char buf[64], *s;
150
151         s = buf;
152         val = res_counter_member(counter, member);
153         if (read_strategy)
154                 s += read_strategy(*val, s);
155         else
156                 s += sprintf(s, "%llu\n", *val);
157         return simple_read_from_buffer((void __user *)userbuf, nbytes,
158                         pos, buf, s - buf);
159 }
160
161 #if BITS_PER_LONG == 32
162 u64 res_counter_read_u64(struct res_counter *counter, int member)
163 {
164         unsigned long flags;
165         u64 ret;
166
167         spin_lock_irqsave(&counter->lock, flags);
168         ret = *res_counter_member(counter, member);
169         spin_unlock_irqrestore(&counter->lock, flags);
170
171         return ret;
172 }
173 #else
174 u64 res_counter_read_u64(struct res_counter *counter, int member)
175 {
176         return *res_counter_member(counter, member);
177 }
178 #endif
179
180 int res_counter_memparse_write_strategy(const char *buf,
181                                         unsigned long long *resp)
182 {
183         char *end;
184         unsigned long long res;
185
186         /* return RES_COUNTER_MAX(unlimited) if "-1" is specified */
187         if (*buf == '-') {
188                 res = simple_strtoull(buf + 1, &end, 10);
189                 if (res != 1 || *end != '\0')
190                         return -EINVAL;
191                 *resp = RES_COUNTER_MAX;
192                 return 0;
193         }
194
195         res = memparse(buf, &end);
196         if (*end != '\0')
197                 return -EINVAL;
198
199         if (PAGE_ALIGN(res) >= res)
200                 res = PAGE_ALIGN(res);
201         else
202                 res = RES_COUNTER_MAX;
203
204         *resp = res;
205
206         return 0;
207 }