Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 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 | |
| 16 | void res_counter_init(struct res_counter *counter) |
| 17 | { |
| 18 | spin_lock_init(&counter->lock); |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 19 | counter->limit = (unsigned long long)LLONG_MAX; |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 20 | } |
| 21 | |
| 22 | int res_counter_charge_locked(struct res_counter *counter, unsigned long val) |
| 23 | { |
| 24 | if (counter->usage + val > counter->limit) { |
| 25 | counter->failcnt++; |
| 26 | return -ENOMEM; |
| 27 | } |
| 28 | |
| 29 | counter->usage += val; |
| 30 | return 0; |
| 31 | } |
| 32 | |
| 33 | int res_counter_charge(struct res_counter *counter, unsigned long val) |
| 34 | { |
| 35 | int ret; |
| 36 | unsigned long flags; |
| 37 | |
| 38 | spin_lock_irqsave(&counter->lock, flags); |
| 39 | ret = res_counter_charge_locked(counter, val); |
| 40 | spin_unlock_irqrestore(&counter->lock, flags); |
| 41 | return ret; |
| 42 | } |
| 43 | |
| 44 | void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val) |
| 45 | { |
| 46 | if (WARN_ON(counter->usage < val)) |
| 47 | val = counter->usage; |
| 48 | |
| 49 | counter->usage -= val; |
| 50 | } |
| 51 | |
| 52 | void res_counter_uncharge(struct res_counter *counter, unsigned long val) |
| 53 | { |
| 54 | unsigned long flags; |
| 55 | |
| 56 | spin_lock_irqsave(&counter->lock, flags); |
| 57 | res_counter_uncharge_locked(counter, val); |
| 58 | spin_unlock_irqrestore(&counter->lock, flags); |
| 59 | } |
| 60 | |
| 61 | |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 62 | static inline unsigned long long * |
| 63 | res_counter_member(struct res_counter *counter, int member) |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 64 | { |
| 65 | switch (member) { |
| 66 | case RES_USAGE: |
| 67 | return &counter->usage; |
| 68 | case RES_LIMIT: |
| 69 | return &counter->limit; |
| 70 | case RES_FAILCNT: |
| 71 | return &counter->failcnt; |
| 72 | }; |
| 73 | |
| 74 | BUG(); |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | ssize_t res_counter_read(struct res_counter *counter, int member, |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 79 | const char __user *userbuf, size_t nbytes, loff_t *pos, |
| 80 | int (*read_strategy)(unsigned long long val, char *st_buf)) |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 81 | { |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 82 | unsigned long long *val; |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 83 | char buf[64], *s; |
| 84 | |
| 85 | s = buf; |
| 86 | val = res_counter_member(counter, member); |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 87 | if (read_strategy) |
| 88 | s += read_strategy(*val, s); |
| 89 | else |
| 90 | s += sprintf(s, "%llu\n", *val); |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 91 | return simple_read_from_buffer((void __user *)userbuf, nbytes, |
| 92 | pos, buf, s - buf); |
| 93 | } |
| 94 | |
| 95 | ssize_t res_counter_write(struct res_counter *counter, int member, |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 96 | const char __user *userbuf, size_t nbytes, loff_t *pos, |
| 97 | int (*write_strategy)(char *st_buf, unsigned long long *val)) |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 98 | { |
| 99 | int ret; |
| 100 | char *buf, *end; |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 101 | unsigned long flags; |
| 102 | unsigned long long tmp, *val; |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 103 | |
| 104 | buf = kmalloc(nbytes + 1, GFP_KERNEL); |
| 105 | ret = -ENOMEM; |
| 106 | if (buf == NULL) |
| 107 | goto out; |
| 108 | |
| 109 | buf[nbytes] = '\0'; |
| 110 | ret = -EFAULT; |
| 111 | if (copy_from_user(buf, userbuf, nbytes)) |
| 112 | goto out_free; |
| 113 | |
| 114 | ret = -EINVAL; |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 115 | |
Balbir Singh | fb78922 | 2008-03-04 14:28:24 -0800 | [diff] [blame] | 116 | strstrip(buf); |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 117 | if (write_strategy) { |
| 118 | if (write_strategy(buf, &tmp)) { |
| 119 | goto out_free; |
| 120 | } |
| 121 | } else { |
| 122 | tmp = simple_strtoull(buf, &end, 10); |
| 123 | if (*end != '\0') |
| 124 | goto out_free; |
| 125 | } |
| 126 | spin_lock_irqsave(&counter->lock, flags); |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 127 | val = res_counter_member(counter, member); |
| 128 | *val = tmp; |
Balbir Singh | 0eea103 | 2008-02-07 00:13:57 -0800 | [diff] [blame] | 129 | spin_unlock_irqrestore(&counter->lock, flags); |
Pavel Emelianov | e552b66 | 2008-02-07 00:13:49 -0800 | [diff] [blame] | 130 | ret = nbytes; |
| 131 | out_free: |
| 132 | kfree(buf); |
| 133 | out: |
| 134 | return ret; |
| 135 | } |