On 3/14/25 2:01 AM, Hannes Reinecke wrote:
3. The current EH framework is designed around 'struct scsi_cmnd'. Which means that the command _initiating_ the error handling can only be returned once the _entire_ error handling (with all escalations) is finished. And more often than not, the application is waiting on that command to be completed before the next I/O is sent. And that really limits the effectiveness of any improved error handler; the application ultimatively has to wait for a host reset before it can contine. But anyway. We already have a mechanism for asynchronous command aborts; have you checked if you can adapt if for LUN reset, too? That would be the easiest solution, I guess ...
Hmm ... does this mean submitting a LUN reset while concurrently new SCSI commands can be submitted from another thread? I don't think that's safe. Additionally, how could a LUN reset help if a SCSI abort doesn't help? If a SCSI abort doesn't help, it probably means that the host controller locked up, e.g. due to a firmware bug. How to recover from this without resetting the host controller? Thanks, Bart.
