2.6.25-rc7

 kernel

diff --git a/kernel/res_counter.c b/kernel/res_counter.c
new file mode 100644
index 0000000..efbfc0f
--- /dev/null
+++ b/kernel/res_counter.c
@@ -0,0 +1,135 @@
+/*
+ * 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>
+
+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;
+   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_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);
+}
+
+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;
+}