On Tue, 28 Feb 2017 09:06:13 -0800 James Bottomley <jejb@xxxxxxxxxxxxxxxxxx> wrote: > On Tue, 2017-02-28 at 08:32 -0700, Jens Axboe wrote: > > On 02/28/2017 07:08 AM, Christoph Hellwig wrote: > > > On Mon, Feb 27, 2017 at 05:19:31PM -0800, Stephen Hemminger wrote: > > > > Fixes: ee5242360424 ("scsi: zero per-cmd driver data before each > > > > I/O") > > > > > > > > but that is already in linux-next. > > > > > > > > Noticed another place where memset(of the data was being done not > > > > the extra bits. > > > > Tried this, but didn't fix it either... > > > > > > Are you using blk-mq or the legacy request code? > > > > Stephen doesn't have MQ set in the config he posted, I'm assuming he > > didn't boot with scsi_mod.use_blk_mq=true. In a previous email, I > > asked if turning on MQ makes a difference. > > OK, since we're not making much progress, Stephen, could you insert > some debugging into the storvsc driver? The trace clearly shows we're > getting zeros back in the buffer when we should have data from the > initial scan. Firstly, does the vmbus think it's transferring any data > for the INQUIRY and READ_CAPACITY commands (looks like > storvsc_command_completion() data_transfer_length)? If it does, > there's probably an issue initialising the sg list. If it doesn't, > we're probably sending bogus commands. > > James I tried booting with scsi_mod.use_blk_mq=true and that did nothing. Rebuilding now with CONFIG_SCSI_MQ_DEFAULT=y Sure, can instrument. after that test.