memcg: fix account leak at failure of memsw acconting

commit 01c88e2d6b7330c0cc5867fe2297e7d826e1337d upstream.

Commit 4b53433468 ("memcg: clean up try_charge main loop") removes a
cancel of charge at case: memory charge-> success.  mem+swap charge->
failure.

This leaks usage of memory.  Fix it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 00bb8a6..1654bd4 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1842,6 +1842,7 @@ static int __mem_cgroup_do_charge(struct mem_cgroup *mem, gfp_t gfp_mask,
                if (likely(!ret))
                        return CHARGE_OK;
 
+               res_counter_uncharge(&mem->res, csize);
                mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
                flags |= MEM_CGROUP_RECLAIM_NOSWAP;
        } else