Additionally, don't assign directly to disk->queue, otherwise blk_put_queue (called via put_disk) will choke (panic) on the errno stored there. Bug found by code inspection after Omar found a similar issue in virtio_blk. Compile-tested only. Signed-off-by: Jeff Moyer <jmoyer@xxxxxxxxxx> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 38c576f..50a2020 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1042,6 +1042,7 @@ static int __init nbd_init(void) return -ENOMEM; for (i = 0; i < nbds_max; i++) { + struct request_queue *q; struct gendisk *disk = alloc_disk(1 << part_shift); if (!disk) goto out; @@ -1067,12 +1068,13 @@ static int __init nbd_init(void) * every gendisk to have its very own request_queue struct. * These structs are big so we dynamically allocate them. */ - disk->queue = blk_mq_init_queue(&nbd_dev[i].tag_set); - if (!disk->queue) { + q = blk_mq_init_queue(&nbd_dev[i].tag_set); + if (IS_ERR(q)) { blk_mq_free_tag_set(&nbd_dev[i].tag_set); put_disk(disk); goto out; } + disk->queue = q; /* * Tell the block layer that we are not a rotational device -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html