Re: [PATCH scsi] Short the path length of scsi_cmd_to_driver()

From: Li Zhong
Date: Fri Sep 28 2012 - 03:13:44 EST


On Thu, 2012-09-27 at 13:43 -0400, Martin K. Petersen wrote:
> >>>>> "Li" == Li Zhong <zhong@xxxxxxxxxxxxxxxxxx> writes:
>
> > @@ -845,8 +844,11 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
> >
> > scsi_eh_restore_cmnd(scmd, &ses);
> >
> >- if (sdrv && sdrv->eh_action)
> >- rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn);
> >+ if (scmd->request->cmd_type == REQ_TYPE_FS) {
> >+ struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
> >+ if (sdrv->eh_action)
> >+ rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn);
> >+ }
> >
> > return rtn;
> > }
>
> My only concern is whether our device lifetime rules guarantee that the
> ULD is always attached when we service an error handling command?

Thank you, Martin, for the review.

I don't know much about scsi, it might take me some more time to have an
answer to the above question.

For now, if I understand correctly, maybe we could only do the
not-consistent behaviours bug fix? Or could we provide two versions of
scsi_cmd_to_driver(), one with NULL checking for scsi_send_eh_cmnd(),
one without the checking for scsi_finish_command()?

Thanks, Zhong

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