Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / include / linux / res_counter.h

diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index 61363ce..fdeadd9 100644 (file)
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -9,6 +9,8 @@
  *
  * Author: Pavel Emelianov <xemul@openvz.org>
  *
+ * See Documentation/controllers/resource_counter.txt for more
+ * info about what this counter is.
  */
 
 #include <linux/cgroup.h>
@@ -24,6 +26,10 @@ struct res_counter {
         * the current resource consumption level
         */
        unsigned long long usage;
+       /*
+        * the maximal value of the usage from the counter creation
+        */
+       unsigned long long max_usage;
        /*
         * the limit that usage cannot exceed
         */
@@ -39,8 +45,9 @@ struct res_counter {
        spinlock_t lock;
 };
 
-/*
+/**
  * Helpers to interact with userspace
+ * res_counter_read_u64() - returns the value of the specified member.
  * res_counter_read/_write - put/get the specified fields from the
  * res_counter struct to/from the user
  *
@@ -51,12 +58,19 @@ struct res_counter {
  * @pos:     and the offset.
  */
 
+u64 res_counter_read_u64(struct res_counter *counter, int member);
+
 ssize_t res_counter_read(struct res_counter *counter, int member,
                const char __user *buf, size_t nbytes, loff_t *pos,
                int (*read_strategy)(unsigned long long val, char *s));
-ssize_t res_counter_write(struct res_counter *counter, int member,
-               const char __user *buf, size_t nbytes, loff_t *pos,
-               int (*write_strategy)(char *buf, unsigned long long *val));
+
+typedef int (*write_strategy_fn)(const char *buf, unsigned long long *val);
+
+int res_counter_memparse_write_strategy(const char *buf,
+                                       unsigned long long *res);
+
+int res_counter_write(struct res_counter *counter, int member,
+                     const char *buffer, write_strategy_fn write_strategy);
 
 /*
  * the field descriptors. one for each member of res_counter
@@ -64,6 +78,7 @@ ssize_t res_counter_write(struct res_counter *counter, int member,
 
 enum {
        RES_USAGE,
+       RES_MAX_USAGE,
        RES_LIMIT,
        RES_FAILCNT,
 };
@@ -85,8 +100,10 @@ void res_counter_init(struct res_counter *counter);
  * counter->limit _locked call expects the counter->lock to be taken
  */
 
-int res_counter_charge_locked(struct res_counter *counter, unsigned long val);
-int res_counter_charge(struct res_counter *counter, unsigned long val);
+int __must_check res_counter_charge_locked(struct res_counter *counter,
+               unsigned long val);
+int __must_check res_counter_charge(struct res_counter *counter,
+               unsigned long val);
 
 /*
  * uncharge - tell that some portion of the resource is released
@@ -124,4 +141,37 @@ static inline bool res_counter_check_under_limit(struct res_counter *cnt)
        return ret;
 }
 
+static inline void res_counter_reset_max(struct res_counter *cnt)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&cnt->lock, flags);
+       cnt->max_usage = cnt->usage;
+       spin_unlock_irqrestore(&cnt->lock, flags);
+}
+
+static inline void res_counter_reset_failcnt(struct res_counter *cnt)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&cnt->lock, flags);
+       cnt->failcnt = 0;
+       spin_unlock_irqrestore(&cnt->lock, flags);
+}
+
+static inline int res_counter_set_limit(struct res_counter *cnt,
+               unsigned long long limit)
+{
+       unsigned long flags;
+       int ret = -EBUSY;
+
+       spin_lock_irqsave(&cnt->lock, flags);
+       if (cnt->usage < limit) {
+               cnt->limit = limit;
+               ret = 0;
+       }
+       spin_unlock_irqrestore(&cnt->lock, flags);
+       return ret;
+}
+
 #endif