# Re: \[PATCH v2 3/6\] block: add iopoll method to support bio-based IO polling

- From: Mike Snitzer \<hidden\>
- Date: 2021-01-27 17:18:06 
- List: io-uring
- Page: https://ratatoskr.run/io-uring/2021/01/6400567
- Thread: https://ratatoskr.run/linux-block/2021/01/6400532/t.md

```text
On Mon, Jan 25 2021 at  7:13am -0500,
Jeffle Xu [ref] wrote:

> ->poll_fn was introduced in commit ea435e1b9392 ("block: add a poll_fn
> callback to struct request_queue") to support bio-based queues such as
> nvme multipath, but was later removed in commit 529262d56dbe ("block:
> remove ->poll_fn").
> 
> Given commit c62b37d96b6e ("block: move ->make_request_fn to struct
> block_device_operations") restore the possibility of bio-based IO
> polling support by adding an ->iopoll method to gendisk->fops.
> Elevate bulk of blk_mq_poll() implementation to blk_poll() and reduce
> blk_mq_poll() to blk-mq specific code that is called from blk_poll().
> 
> Signed-off-by: Jeffle Xu <redacted>
> Suggested-by: Mike Snitzer <redacted>

Reviewed-by: Mike Snitzer <redacted>

```