2022-11-30 13:22:17

by Li Nan

Subject: [PATCH -next v2 3/9] blk-iocost: don't allow to configure bio based device

From: Yu Kuai <[email protected]>

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 <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Li Nan <[email protected]>
---
block/blk-iocost.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index c532129a1456..bc6522bb314d 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3181,6 +3181,11 @@ 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 out;
+ }
+
ioc = q_to_ioc(disk->queue);
if (!ioc) {
ret = blk_iocost_init(disk);
@@ -3364,6 +3369,11 @@ 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 out;
+ }
+
ioc = q_to_ioc(q);
if (!ioc) {
ret = blk_iocost_init(bdev->bd_disk);
--
2.31.1

2022-11-30 21:07:59

by Tejun Heo

Subject: Re: [PATCH -next v2 3/9] blk-iocost: don't allow to configure bio based device

On Wed, Nov 30, 2022 at 09:21:50PM +0800, Li Nan wrote:
> From: Yu Kuai <[email protected]>
>
> 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 <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>
> Signed-off-by: Li Nan <[email protected]>

Acked-by: Tejun Heo <[email protected]>

Thanks.

--
tejun