From: Pavel Emelyanov <xemul@openvz.org>

Ignoring their return values may result in counter underflow in the future -
when the value charged will be uncharged (or in "leaks" - when the value is
not uncharged).

This also prevents from using charging routines to decrement the
counter value (i.e. uncharge it) ;)

(Current code works OK with res_counter, however :) )

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/res_counter.h |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff -puN include/linux/res_counter.h~mark-res_counter_charge_locked-with-__must_check include/linux/res_counter.h
--- a/include/linux/res_counter.h~mark-res_counter_charge_locked-with-__must_check
+++ a/include/linux/res_counter.h
@@ -95,8 +95,10 @@ void res_counter_init(struct res_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
_