/* * 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> #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->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; }; 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); } 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; }