Re: [PATCH] mmc: block: Prevent new req entering queue while freeing up the queue

[Veerabhadrarao Badiganti]

Hi Ulf, Adrian,

Gentle reminder. Can you share your comments on this issue and change?

Thanks

On 10/28/2020 4:49 PM, Veerabhadrarao Badiganti wrote:
> The commit bbdc74dc19e0 ("mmc: block: Prevent new req entering queue
> after its cleanup") has introduced this change but it got moved after
> del_gendisk() with commit 57678e5a3d51 ("mmc: block: Delete gendisk
> before cleaning up the request queue").
>
> It is blocking reboot with below Call stack().
>
> INFO: task reboot:3086 blocked for more than 122 seconds.
>       __schedule
>       schedule
>       schedule_timeout
>       io_schedule_timeout
>       do_wait_for_common
>       wait_for_completion_io
>       submit_bio_wait
>       blkdev_issue_flush
>       ext4_sync_fs
>       __sync_filesystem
>       sync_filesystem
>       fsync_bdev
>       invalidate_partition
>       del_gendisk
>       mmc_blk_remove_req
>       mmc_blk_remove
>       mmc_bus_remove
>       device_release_driver_internal
>       device_release_driver
>       bus_remove_device
>       device_del
>       mmc_remove_card
>       mmc_remove
>       mmc_stop_host
>       mmc_remove_host
>       sdhci_remove_host
>       sdhci_msm_remove
>       sdhci_msm_shutdown
>       platform_drv_shutdown
>       device_shutdown
>       kernel_restart_prepare
>       kernel_restart
>
> So bringing this change back.
>
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
> ---
>
> I'm observing this issue 100% of the time with shutdown callback added to sdhci-msm driver.
> I'm trying on 5.4 kernel with ChromeOS.
>
> Please let me know if this can be fixed in a better way.
> ---
>
>   drivers/mmc/core/block.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index 8d3df0be0355..76dbb2b8a13b 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -2627,6 +2627,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
>   		 * from being accepted.
>   		 */
>   		card = md->queue.card;
> +		blk_set_queue_dying(md->queue.queue);
>   		if (md->disk->flags & GENHD_FL_UP) {
>   			device_remove_file(disk_to_dev(md->disk), &md->force_ro);
>   			if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&