bfq-iosched: fix NULL ioc check in bfq_get_rq_private

icq_to_bic is a container_of operation, so we need to check for NULL
before it.  Also move the check outside the spinlock while we're at
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 5 insertions, 10 deletions

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 4f69e39c2f89..f037b005faa1 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4398,16 +4398,17 @@ static int bfq_get_rq_private(struct request_queue *q, struct request *rq,
                               struct bio *bio)
 {
         struct bfq_data *bfqd = q->elevator->elevator_data;
-        struct bfq_io_cq *bic = icq_to_bic(rq->elv.icq);
+        struct bfq_io_cq *bic;
         const int is_sync = rq_is_sync(rq);
         struct bfq_queue *bfqq;
         bool new_queue = false;
         bool split = false;
 
-        spin_lock_irq(&bfqd->lock);
+        if (!rq->elv.icq)
+                return 1;
+        bic = icq_to_bic(rq->elv.icq);
 
-        if (!bic)
-                goto queue_fail;
+        spin_lock_irq(&bfqd->lock);
 
         bfq_check_ioprio_change(bic, bio);
 
@@ -4465,13 +4466,7 @@ static int bfq_get_rq_private(struct request_queue *q, struct request *rq,
                 bfq_handle_burst(bfqd, bfqq);
 
         spin_unlock_irq(&bfqd->lock);
-
         return 0;
-
-queue_fail:
-        spin_unlock_irq(&bfqd->lock);
-
-        return 1;
 }
 
 static void bfq_idle_slice_timer_body(struct bfq_queue *bfqq)