On 11/29/17 4:56 PM, Ming Lei wrote:
> Now we track legacy requests with .q_usage_counter in commit 055f6e18e08f
> ("block: Make q_usage_counter also track legacy requests"), but that
> commit never runs and drains legacy queue before waiting for this counter
> becoming zero, then IO hang is caused in the test of pulling disk during IO.
>
> This patch fixes the issue by draining requests before waiting for
> q_usage_counter becoming zero, both Mauricio and chenxiang reported this
> issue, and observed that it can be fixed by this patch.
Better late than never, added for 4.15, thanks Ming.
--
Jens Axboe
