diff options
| author | Paolo Valente <paolo.valente@linaro.org> | 2020-02-03 11:40:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-12 13:00:32 +0100 |
| commit | 92ed51e65167a6652814db370db22cefb0547257 (patch) | |
| tree | 2ce57fddf4fb9fc9c8a4cc16f2d59caf25624642 | |
| parent | e657b1f6b9f414c7b0ca823ce44c6984b6e309cf (diff) | |
block, bfq: get a ref to a group when adding it to a service tree
commit db37a34c563bf4692b36990ae89005c031385e52 upstream.
BFQ schedules generic entities, which may represent either bfq_queues
or groups of bfq_queues. When an entity is inserted into a service
tree, a reference must be taken, to make sure that the entity does not
disappear while still referred in the tree. Unfortunately, such a
reference is mistakenly taken only if the entity represents a
bfq_queue. This commit takes a reference also in case the entity
represents a group.
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Chris Evich <cevich@redhat.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | block/bfq-cgroup.c | 2 | ||||
| -rw-r--r-- | block/bfq-iosched.h | 1 | ||||
| -rw-r--r-- | block/bfq-wf2q.c | 12 |
3 files changed, 12 insertions, 3 deletions
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index ca5ffe26178e..ead6e4283298 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -332,7 +332,7 @@ static void bfqg_put(struct bfq_group *bfqg) kfree(bfqg); } -static void bfqg_and_blkg_get(struct bfq_group *bfqg) +void bfqg_and_blkg_get(struct bfq_group *bfqg) { /* see comments in bfq_bic_update_cgroup for why refcounting bfqg */ bfqg_get(bfqg); diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 5d1a519640f6..e0e4a413d43a 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -978,6 +978,7 @@ struct bfq_group *bfq_find_set_group(struct bfq_data *bfqd, struct blkcg_gq *bfqg_to_blkg(struct bfq_group *bfqg); struct bfq_group *bfqq_group(struct bfq_queue *bfqq); struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node); +void bfqg_and_blkg_get(struct bfq_group *bfqg); void bfqg_and_blkg_put(struct bfq_group *bfqg); #ifdef CONFIG_BFQ_GROUP_IOSCHED diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index 05f0bf4a1144..44079147e396 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -536,7 +536,9 @@ static void bfq_get_entity(struct bfq_entity *entity) bfqq->ref++; bfq_log_bfqq(bfqq->bfqd, bfqq, "get_entity: %p %d", bfqq, bfqq->ref); - } + } else + bfqg_and_blkg_get(container_of(entity, struct bfq_group, + entity)); } /** @@ -650,8 +652,14 @@ static void bfq_forget_entity(struct bfq_service_tree *st, entity->on_st = false; st->wsum -= entity->weight; - if (bfqq && !is_in_service) + if (is_in_service) + return; + + if (bfqq) bfq_put_queue(bfqq); + else + bfqg_and_blkg_put(container_of(entity, struct bfq_group, + entity)); } /** |