blk-iocost: don't allow to configure bio based device

iocost is based on rq_qos, which can only work for request based device,
thus it doesn't make sense to configure iocost for bio based device.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230117070806.3857142-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 3b99c6a..42a4920 100644 (file)
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3187,6 +3187,11 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
                return PTR_ERR(bdev);
 
        disk = bdev->bd_disk;
+       if (!queue_is_mq(disk->queue)) {
+               ret = -EOPNOTSUPP;
+               goto err;
+       }
+
        ioc = q_to_ioc(disk->queue);
        if (!ioc) {
                ret = blk_iocost_init(disk);
@@ -3367,6 +3372,11 @@ static ssize_t ioc_cost_model_write(struct kernfs_open_file *of, char *input,
                return PTR_ERR(bdev);
 
        q = bdev_get_queue(bdev);
+       if (!queue_is_mq(q)) {
+               ret = -EOPNOTSUPP;
+               goto err;
+       }
+
        ioc = q_to_ioc(q);
        if (!ioc) {
                ret = blk_iocost_init(bdev->bd_disk);