On Tue, Mar 03 2020 at  3:45am -0500,
Hou Tao <[email protected]> wrote:

> We neither assign congested_fn for requested-based blk-mq device
> nor implement it correctly. So fix both.
> 
> Fixes: 4aa9c692e052 ("bdi: separate out congested state into a separate 
> struct")
> Signed-off-by: Hou Tao <[email protected]>
> ---
>  drivers/md/dm.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/dm.c b/drivers/md/dm.c
> index b89f07ee2eff..80b95e21db43 100644
> --- a/drivers/md/dm.c
> +++ b/drivers/md/dm.c
> @@ -1784,11 +1784,13 @@ static int dm_any_congested(void *congested_data, int 
> bdi_bits)
>  
>       if (!test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) {
>               if (dm_request_based(md)) {
> +                     struct backing_dev_info *bdi =
> +                             md->queue->backing_dev_info;
>                       /*
>                        * With request-based DM we only need to check the
>                        * top-level queue for congestion.
>                        */
> -                     r = md->queue->backing_dev_info->wb.state & bdi_bits;
> +                     r = bdi->wb.congested->state & bdi_bits;
>               } else {
>                       map = dm_get_live_table_fast(md);
>                       if (map)

The above change does indeed fix missing conversion that should've
occurred in commit 4aa9c692e052.

> @@ -2265,6 +2267,7 @@ int dm_setup_md_queue(struct mapped_device *md, struct 
> dm_table *t)
>                       DMERR("Cannot initialize queue for request-based dm-mq 
> mapped device");
>                       return r;
>               }
> +             dm_init_normal_md_queue(md);
>               break;
>       case DM_TYPE_BIO_BASED:
>       case DM_TYPE_DAX_BIO_BASED:

I've renamed dm_init_normal_md_queue to dm_init_congested_fn and removed
it's incorrect comment.

Here is the final fix I just staged:
https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.6&id=974f51e8633f0f3f33e8f86bbb5ae66758aa63c7

Thanks,
Mike

--
dm-devel mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/dm-devel

Reply via email to