diff options
| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2018-08-02 15:36:01 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-05 09:20:04 +0200 |
| commit | f108e46efaac72dedc96204c9f235d6aa31c80fd (patch) | |
| tree | ecb32171e59832b8865170d55fa50a36dc6776c3 /mm/memcontrol.c | |
| parent | a6c6516eee1591bc09cf3dd839f71e023dae5ddf (diff) | |
memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure
[ Upstream commit 7e97de0b033bcac4fa9a35cef72e0c06e6a22c67 ]
In case of memcg_online_kmem() failure, memcg_cgroup::id remains hashed
in mem_cgroup_idr even after memcg memory is freed. This leads to leak
of ID in mem_cgroup_idr.
This patch adds removal into mem_cgroup_css_alloc(), which fixes the
problem. For better readability, it adds a generic helper which is used
in mem_cgroup_alloc() and mem_cgroup_id_put_many() as well.
Link: http://lkml.kernel.org/r/152354470916.22460.14397070748001974638.stgit@localhost.localdomain
Fixes 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 349f4a8e3c4f..86a6b331b964 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4072,6 +4072,14 @@ static struct cftype mem_cgroup_legacy_files[] = { static DEFINE_IDR(mem_cgroup_idr); +static void mem_cgroup_id_remove(struct mem_cgroup *memcg) +{ + if (memcg->id.id > 0) { + idr_remove(&mem_cgroup_idr, memcg->id.id); + memcg->id.id = 0; + } +} + static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) { VM_BUG_ON(atomic_read(&memcg->id.ref) <= 0); @@ -4082,8 +4090,7 @@ static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n) { VM_BUG_ON(atomic_read(&memcg->id.ref) < n); if (atomic_sub_and_test(n, &memcg->id.ref)) { - idr_remove(&mem_cgroup_idr, memcg->id.id); - memcg->id.id = 0; + mem_cgroup_id_remove(memcg); /* Memcg ID pins CSS */ css_put(&memcg->css); @@ -4208,8 +4215,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void) idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); return memcg; fail: - if (memcg->id.id > 0) - idr_remove(&mem_cgroup_idr, memcg->id.id); + mem_cgroup_id_remove(memcg); __mem_cgroup_free(memcg); return NULL; } @@ -4268,6 +4274,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) return &memcg->css; fail: + mem_cgroup_id_remove(memcg); mem_cgroup_free(memcg); return ERR_PTR(-ENOMEM); } |