Hi Christoph On 06/21/2018 04:19 PM, Christoph Hellwig wrote: > On Thu, Jun 21, 2018 at 09:43:26AM +0800, jianchao.wang wrote: >> So we have to preserve the ability of block layer that it could prevent >> IO completion path from entering a timeout request. >> >> With scsi-debug module, I tried to simulate a scenario where timeout and IO >> completion path could occur concurrently, the system ran into crash easily. > > Trace, please. With the latest kernel. I'm not saying that there > is nothing to fix, but the mode of never completing once timeout > requests as currently done is SCSI is clearly broken. > Sorry, I don't quite get your point. Do you mean we should do the modification in the scsi layer ? Actually, I used to look at the code to try to stop io completion on timeout request in scsi-mid layer, but it looks like difficult, especially, scsi eh would try to borrow the command to issue admin command such as get sense, test unit,etc. Thanks Jianchao
