The patch titled
Subject: memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure
has been removed from the -mm tree. Its filename was
memcg-remove-memcg_cgroup-id-from-idr-on-mem_cgroup_css_alloc-failure.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
Subject: memcg: remove memcg_cgroup::id from IDR on mem_cgroup_css_alloc() failure
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@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
--- a/mm/memcontrol.c~memcg-remove-memcg_cgroup-id-from-idr-on-mem_cgroup_css_alloc-failure
+++ a/mm/memcontrol.c
@@ -4037,6 +4037,14 @@ static struct cftype mem_cgroup_legacy_f
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);
@@ -4047,8 +4055,7 @@ static void mem_cgroup_id_put_many(struc
{
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);
@@ -4185,8 +4192,7 @@ static struct mem_cgroup *mem_cgroup_all
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;
}
@@ -4245,6 +4251,7 @@ mem_cgroup_css_alloc(struct cgroup_subsy
return &memcg->css;
fail:
+ mem_cgroup_id_remove(memcg);
mem_cgroup_free(memcg);
return ERR_PTR(-ENOMEM);
}
_
Patches currently in -mm which might be from ktkhai@xxxxxxxxxxxxx are
list_lru-combine-code-under-the-same-define.patch
mm-introduce-config_memcg_kmem-as-combination-of-config_memcg-config_slob.patch
mm-assign-id-to-every-memcg-aware-shrinker.patch
mm-assign-id-to-every-memcg-aware-shrinker-v9.patch
memcg-move-up-for_each_mem_cgroup-_tree-defines.patch
mm-assign-memcg-aware-shrinkers-bitmap-to-memcg.patch
mm-assign-memcg-aware-shrinkers-bitmap-to-memcg-v9.patch
mm-assign-memcg-aware-shrinkers-bitmap-to-memcg-fix.patch
mm-refactoring-in-workingset_init.patch
mm-refactoring-in-workingset_init-v9.patch
fs-refactoring-in-alloc_super.patch
fs-propagate-shrinker-id-to-list_lru.patch
list_lru-add-memcg-argument-to-list_lru_from_kmem.patch
list_lru-pass-dst_memcg-argument-to-memcg_drain_list_lru_node.patch
list_lru-pass-lru-argument-to-memcg_drain_list_lru_node.patch
mm-export-mem_cgroup_is_root.patch
mm-set-bit-in-memcg-shrinker-bitmap-on-first-list_lru-item-apearance.patch
mm-set-bit-in-memcg-shrinker-bitmap-on-first-list_lru-item-apearance-v9.patch
mm-iterate-only-over-charged-shrinkers-during-memcg-shrink_slab.patch
mm-iterate-only-over-charged-shrinkers-during-memcg-shrink_slab-v9.patch
mm-add-shrink_empty-shrinker-methods-return-value.patch
mm-clear-shrinker-bit-if-there-are-no-objects-related-to-memcg.patch
mm-clear-shrinker-bit-if-there-are-no-objects-related-to-memcg-v9.patch
mm-move-check-for-shrinker_numa_aware-to-do_shrink_slab.patch
mm-keep-int-fields-in-struct-shrink_control-together.patch
mm-make-flags-of-unsigned-type-in-struct-shrinker.patch
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