diff options
| -rw-r--r-- | block/blk-mq.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 24dc8fe0a9d2..16c524e37123 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4604,9 +4604,6 @@ static bool blk_mq_elv_switch_none(struct list_head *head, { struct blk_mq_qe_pair *qe; - if (!q->elevator) - return true; - qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); if (!qe) return false; @@ -4614,6 +4611,12 @@ static bool blk_mq_elv_switch_none(struct list_head *head, /* q->elevator needs protection from ->sysfs_lock */ mutex_lock(&q->sysfs_lock); + /* the check has to be done with holding sysfs_lock */ + if (!q->elevator) { + kfree(qe); + goto unlock; + } + INIT_LIST_HEAD(&qe->node); qe->q = q; qe->type = q->elevator->type; @@ -4621,6 +4624,7 @@ static bool blk_mq_elv_switch_none(struct list_head *head, __elevator_get(qe->type); list_add(&qe->node, head); elevator_disable(q); +unlock: mutex_unlock(&q->sysfs_lock); return true; |