Re: [PATCH 4.19] mmc: block: Fix in_flight[issue_type] value error

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Aug 23, 2023 at 08:12:32PM +0300, Adrian Hunter wrote:
> From: Yibin Ding <yibin.ding@unisoc.com>
> 
> commit 4b430d4ac99750ee2ae2f893f1055c7af1ec3dc5 upstream.
> 
> For a completed request, after the mmc_blk_mq_complete_rq(mq, req)
> function is executed, the bitmap_tags corresponding to the
> request will be cleared, that is, the request will be regarded as
> idle. If the request is acquired by a different type of process at
> this time, the issue_type of the request may change. It further
> caused the value of mq->in_flight[issue_type] to be abnormal,
> and a large number of requests could not be sent.
> 
> p1:					      p2:
> mmc_blk_mq_complete_rq
>   blk_mq_free_request
> 					      blk_mq_get_request
> 					        blk_mq_rq_ctx_init
> mmc_blk_mq_dec_in_flight
>   mmc_issue_type(mq, req)
> 
> This strategy can ensure the consistency of issue_type
> before and after executing mmc_blk_mq_complete_rq.
> 
> Fixes: 81196976ed94 ("mmc: block: Add blk-mq support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Yibin Ding <yibin.ding@unisoc.com>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> Link: https://lore.kernel.org/r/20230802023023.1318134-1-yunlong.xing@unisoc.com
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> (cherry picked from commit 4b430d4ac99750ee2ae2f893f1055c7af1ec3dc5)
> (backport to 4.19.y)
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>  drivers/mmc/core/block.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)

Now queued up, thanks.

greg k-h