| /* |
| * 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/slab.h> |
| #include <linux/res_counter.h> |
| #include <linux/uaccess.h> |
| |
| void res_counter_init(struct res_counter *counter) |
| { |
| spin_lock_init(&counter->lock); |
| counter->limit = (unsigned long long)LLONG_MAX; |
| } |
| |
| 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) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&counter->lock, flags); |
| ret = res_counter_charge_locked(counter, val); |
| spin_unlock_irqrestore(&counter->lock, 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; |
| |
| spin_lock_irqsave(&counter->lock, flags); |
| res_counter_uncharge_locked(counter, val); |
| spin_unlock_irqrestore(&counter->lock, 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; |
| }; |
| |
| 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); |
| } |
| |
| u64 res_counter_read_u64(struct res_counter *counter, int member) |
| { |
| return *res_counter_member(counter, member); |
| } |
| |
| ssize_t res_counter_write(struct res_counter *counter, int member, |
| const char __user *userbuf, size_t nbytes, loff_t *pos, |
| int (*write_strategy)(char *st_buf, unsigned long long *val)) |
| { |
| int ret; |
| char *buf, *end; |
| unsigned long flags; |
| unsigned long long tmp, *val; |
| |
| buf = kmalloc(nbytes + 1, GFP_KERNEL); |
| ret = -ENOMEM; |
| if (buf == NULL) |
| goto out; |
| |
| buf[nbytes] = '\0'; |
| ret = -EFAULT; |
| if (copy_from_user(buf, userbuf, nbytes)) |
| goto out_free; |
| |
| ret = -EINVAL; |
| |
| strstrip(buf); |
| if (write_strategy) { |
| if (write_strategy(buf, &tmp)) { |
| goto out_free; |
| } |
| } else { |
| tmp = simple_strtoull(buf, &end, 10); |
| if (*end != '\0') |
| goto out_free; |
| } |
| spin_lock_irqsave(&counter->lock, flags); |
| val = res_counter_member(counter, member); |
| *val = tmp; |
| spin_unlock_irqrestore(&counter->lock, flags); |
| ret = nbytes; |
| out_free: |
| kfree(buf); |
| out: |
| return ret; |
| } |