On Thu, Apr 22, 2021 at 05:35:42PM +0100, John Garry wrote: > On 22/04/2021 02:38, Ming Lei wrote: > > > I would rather not change the values which are provided from the driver. I > > > would rather take the original values and try to use them in a sane way. > > > > > > I have not seen other places where driver shost config values are modified > > > by the core code. > > Hi Ming, > > > Wrt. .cmd_per_lun, I think it is safe to modify it into one correct > > depth because almost all drivers are just producer of .cmd_per_lun. And > > except for debug purpose, there are only three consumers of .cmd_per_lun > > in scsi, and all are for scsi_change_queue_depth(): > > > > process_message() > > scsi_alloc_sdev() > > virtscsi_change_queue_depth() > > sg_ioctl_common() also looks to read it, but I can't imagine we could break > that interface with either suggested change. Then one bad .cmd_per_lun can be passed to userspace, as your patch doesn't cover this case. > > So I still prefer not to modify shost.cmd_per_lun, but if you feel strongly > enough then I can look to make that change. I still suggest to make .cmd_per_lun correct since the beginning, otherwise you may have to cover anywhere .cmd_per_lun is used. Thanks, Ming
