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-rw-r--r--include/linux/res_counter.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index c9d625ca659..da81af086ea 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -109,12 +109,18 @@ void res_counter_init(struct res_counter *counter, struct res_counter *parent);
*
* returns 0 on success and <0 if the counter->usage will exceed the
* counter->limit _locked call expects the counter->lock to be taken
+ *
+ * charge_nofail works the same, except that it charges the resource
+ * counter unconditionally, and returns < 0 if the after the current
+ * charge we are over limit.
*/
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, struct res_counter **limit_fail_at);
+int __must_check res_counter_charge_nofail(struct res_counter *counter,
+ unsigned long val, struct res_counter **limit_fail_at);
/*
* uncharge - tell that some portion of the resource is released
@@ -142,7 +148,10 @@ static inline unsigned long long res_counter_margin(struct res_counter *cnt)
unsigned long flags;
spin_lock_irqsave(&cnt->lock, flags);
- margin = cnt->limit - cnt->usage;
+ if (cnt->limit > cnt->usage)
+ margin = cnt->limit - cnt->usage;
+ else
+ margin = 0;
spin_unlock_irqrestore(&cnt->lock, flags);
return margin;
}