[PATCH 5/7] smartpqi: fix rare system hang during LUN reset

Don Brace
2024-08-27T18:55:32Z

From: Murthy Bhat <Murthy.Bhat@microchip.com>

Correct a rare case where in a LUN reset occurs on a device
and I/O requests for other devices persist in the driver's internal
request queue.

Part of a LUN reset involves waiting for our internal request queue
to empty before proceeding. The internal request queue contains requests
not yet sent down to the controller.

We were clearing the requests queued for the LUN undergoing a reset, but
not all of the queued requests. Causing a hang.

For all requests in our internal request queue:
Complete requests with DID_RESET for queued requests for the device
undergoing a reset.

Complete requests with DID_REQUEUE for all other queued requests.

Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Scott Teel <scott.teel@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Signed-off-by: Murthy Bhat <Murthy.Bhat@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
---
drivers/scsi/smartpqi/smartpqi_init.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index 46bef2cf95c4..d1d117d5d08d 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -6200,14 +6200,12 @@ static void pqi_fail_io_queued_for_device(struct pqi_ctrl_info *ctrl_info,
continue;

scsi_device = scmd->device->hostdata;
- if (scsi_device != device)
- continue;
-
- if ((u8)scmd->device->lun != lun)
- continue;

list_del(&io_request->request_list_entry);
- set_host_byte(scmd, DID_RESET);
+ if (scsi_device == device && (u8)scmd->device->lun == lun)
+ set_host_byte(scmd, DID_RESET);
+ else
+ set_host_byte(scmd, DID_REQUEUE);
pqi_free_io_request(io_request);
scsi_dma_unmap(scmd);
pqi_scsi_done(scmd);
--
2.46.0.421.g159f2d50e7