Re: [PATCH v2 08/12] scsi: sd: Fix scsi_mode_sense caller's sshdr use

[Mike Christie <michael.christie@oracle.com>]

On 10/5/23 8:12 PM, Damien Le Moal wrote:
>> As far as future safety goes, this patch is not great. Right now
>> we assume scsi_execute_cmd and the functions it calls does not
>> return -EIO. To make it safer we could change scsi_mode_sense to
>> return 1 for the case there is sense or add another arg which
>> gets set when there is sense.
> Indeed, that would be better because scsi does not prevent a device from
> returning sense data for successfull commands as well (see device statistics or
> CDL as examples). So that would be a better solution than relying on -EIO for
> sense data validi

For the sd_read_app_tag_own case and similar ones are you wanting to
log the sense for cases like the CDL where scsi_execute_cmd returns 0?

The thing is that this patches uses -EIO to indicate if the sshdr is
setup (not exactly that sense is valid). If it is then we check if the sense
is valid and if is then sd_read_app_tag_own will log it.

In other places we do something similar and check if
scsi_execute_cmd returns > 0. If it does then we know the sshdr is setup
and will do something with it like print it. Those cases will not work
for your CDL example because scsi_execute_cmd returns 0.