Re: [PATCH] dm mpath: fix missing blk_account_io_done() in error path

From: Christoph Hellwig
Date: Tue Jan 25 2022 - 15:41:22 EST


On Tue, Jan 25, 2022 at 08:26:54PM +0800, Yu Kuai wrote:
> If blk_mq_request_issue_directly() failed from
> blk_insert_cloned_request(), the request will be accounted start.
> Currently, blk_insert_cloned_request() is only called by dm, and such
> request won't be accounted done by dm.
>
> In normal path, io will be accounted start from blk_mq_bio_to_request(),
> when the request is allocated, and such io will be accounted done from
> __blk_mq_end_request_acct() whether it succeeded or failed. Thus add
> blk_account_io_done() to fix the problem.

The patch looks good, but the subject is incorrect, this is not in
dm-mpath but in the block layer.