On 03/07/2017 06:15 PM, Stephen Hemminger wrote: > Hyper-V host emulation of SCSI for virtual DVD device reports SCSI > version 0 (UNKNOWN) but is still capable of supporting REPORTLUN. > > Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11 > successfully with virtual DVD ROM device. What happens is that the > SCSI scan process falls back to doing sequential probing by INQUIRY. > But the storvsc driver has a previous workaround that masks/blocks all > errors reports from INQUIRY (or MODE_SENSE) commands. This workaround > causes the scan to then populate a full set of bogus LUN's on the > target and then sends kernel spinning off into a death spiral doing > block reads on the non-existent LUNs. > > By setting the correct blacklist flags, the target with the > DVD device is scanned with REPORTLUN and that works correctly. > > Patch needs to go in current 4.11, it is safe but not necessary > in older kernels. > > Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> > --- > drivers/scsi/storvsc_drv.c | 27 +++++++++++++++++---------- > 1 file changed, 17 insertions(+), 10 deletions(-) > > PS: The error handling does need to be fixed (have patches pending) > but that is interrelated with hotplug and can wait. > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)
