res_counter: fix off-by-one bug in setting limit
I found we can no longer set limit to 0 with 2.6.27-rcX:
# mount -t cgroup -omemory xxx /mnt
# mkdir /mnt/0
# echo 0 > /mnt/0/memory.limit_in_bytes
bash: echo: write error: Device or resource busy
It turned out 'limit' can't be set to 'usage', which is wrong IMO.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
index fdeadd9..271c1c2 100644
--- a/include/linux/res_counter.h
+++ b/include/linux/res_counter.h
@@ -166,7 +166,7 @@
int ret = -EBUSY;
spin_lock_irqsave(&cnt->lock, flags);
- if (cnt->usage < limit) {
+ if (cnt->usage <= limit) {
cnt->limit = limit;
ret = 0;
}