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

From: Veerabhadrarao Badiganti
Date: Tue Nov 03 2020 - 08:28:42 EST


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) &&