Re: [PATCH 00/14] scsi: scsi_error: Introduce new error handle mechanism

[Hannes Reinecke]

On 8/16/25 13:24, JiangJianJun wrote:
> It's unbearable for systems with large scale scsi devices share HBAs to
> block all devices' IOs when handle error commands, we need a new error
> handle mechanism to address this issue.
>
> I consulted about this issue a year ago, the discuss link can be found in
> refenence. Hannes replied about why we have to block the SCSI host
> then perform error recovery kindly. I think it's unnecessary to block
> SCSI host for all drivers and can try a small level recovery(LUN based for
> example) first to avoid block the SCSI host.
>
> The new error handle mechanism introduced in this patchset has been
> developed and tested with out self developed hardware since one year
> ago, now we want this mechanism can be used by more drivers.
>
> Drivers can decide if using the new error handle mechanism and how to
> handle error commands when scsi_device are scanned,the new mechanism
> makes SCSI error handle more flexible.
Hmm. Yes, and no.

I fully agree that SCSI EH is in need of reworking. But adding
another layer of complexity on top of the existing one ... not sure.

Additionally: TARGET RESET TMF is dead, and has been removed from SAM
since several years. It really is not worthwhile implementing.

Can't we take a simple step, and just try to have a non-blocking version
of device reset?
I think that should cover quite some issues already.

Cheers,

Hannes
--
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@xxxxxxx                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich