Re: [PATCH v2 01/11] scsi: Convert struct Scsi_Host->cmd_serial_number to atomic_t

[Mike Christie <michaelc@cs.wisc.edu>]

On 09/24/2010 01:33 PM, Mike Anderson wrote:
> In reviewing the current code paths wasn't the serial_number also used to
> avoid calling __scsi_try_to_abort_cmd for START_UNIT case also.

You mean from scsi_eh_try_stu....->__scsi_try_to_abort_cmd? How does it 
work for that case or what is the code path? Is it when it is called 
from the sas code through scsi_eh_ready_devs?


>
> If we skip __scsi_try_to_abort_cmd when REQ_ATOM_COMPLETE is set it would
> be correct for the scsi_decide_disposition cases but it would appear this
> would stop __scsi_try_to_abort_cmd from being called in the time out
> case as REQ_ATOM_COMPLETE is set prior to calling blk_rq_timed_out.
>
> 1.) Request timed out path to scsi_eh_scmd_add.
>
> blk_rq_timed_out_timer
> 	...
> 	if (blk_mark_rq_complete(rq))
> 		continue;
> 	blk_rq_timed_out
> 		q->rq_timed_out_fn "scsi_times_out"
> 			scsi_times_out
> 				scsi_eh_scmd_add
>

You are right.