Commit ec9780e4 authored by Wenchao Hao's avatar Wenchao Hao Committed by Martin K. Petersen
Browse files

scsi: core: Increase scsi_device's iodone_cnt in scsi_timeout() 



If a SCSI command times out and is going to be aborted, we should increase
the iodone_cnt of the related scsi_device. Otherwise the iodone_cnt would
be smaller than iorequest_cnt.

Increasing iodone_cnt in scsi_timeout() would not cause a double accounting
issue. Brief analysis follows:

 - We add the iodone_cnt when BLK_EH_DONE is returned in
   scsi_timeout(). The related command's timeout event would not happen.

 - If the abort succeeds and the command is not retried, the command would
   be completed with scsi_finish_command() which would not increase
   iodone_cnt.

 - If the abort succeeds and the command is retried, it would be requeue. A
   scsi_dispatch_cmd() would be called and iorequest_cnt would be increased
   again.

 - If the abort fails, the error handler successfully recovers the device,
   and the command is not retried, the command would be completed with
   scsi_finish_command() which would not increase iodone_cnt.

 - If the abort fails, the error handler successfully recovers the device,
   and the command is retried, the iorequest_cnt would be increased again.

Signed-off-by: default avatarWenchao Hao <haowenchao@huawei.com>
Link: https://lore.kernel.org/r/20221123122137.150776-2-haowenchao@huawei.com


Reviewed-by: default avatarMike Christie <michael.christie@oracle.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 0c26a2d7

drivers/scsi/scsi_error.c

+1 −0
Original line number Diff line number Diff line
@@ -354,6 +354,7 @@ enum blk_eh_timer_return scsi_timeout(struct request *req) 
	 */

	if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))

		return BLK_EH_DONE;

	atomic_inc(&scmd->device->iodone_cnt);

	if (scsi_abort_command(scmd) != SUCCESS) {

		set_host_byte(scmd, DID_TIME_OUT);

		scsi_eh_scmd_add(scmd);