Messages in this thread | | | Date | Mon, 14 Jul 2014 08:15:17 +0200 | From | Hannes Reinecke <> | Subject | Re: [PATCH V3 1/7] Drivers: scsi: storvsc: Change the limits to reflect the values on the host |
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On 07/12/2014 06:48 PM, K. Y. Srinivasan wrote: > Hyper-V hosts can support multiple targets and multiple channels and larger number of > LUNs per target. Update the code to reflect this. With this patch we can correctly > enumerate all the paths in a multi-path storage environment. > > In this version of the patch I have addressed comments from > Christoph Hellwig <hch@infradead.org> > > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> > Cc: <stable@vger.kernel.org> > --- > drivers/scsi/storvsc_drv.c | 47 +++++++++++++++++++++++++++++--------------- > 1 files changed, 31 insertions(+), 16 deletions(-) > > diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c > index 9969fa1..8938b13 100644 > --- a/drivers/scsi/storvsc_drv.c > +++ b/drivers/scsi/storvsc_drv.c > @@ -330,17 +330,17 @@ static int storvsc_timeout = 180; > > static void storvsc_on_channel_callback(void *context); > > -/* > - * In Hyper-V, each port/path/target maps to 1 scsi host adapter. In > - * reality, the path/target is not used (ie always set to 0) so our > - * scsi host adapter essentially has 1 bus with 1 target that contains > - * up to 256 luns. > - */ > -#define STORVSC_MAX_LUNS_PER_TARGET 64 > -#define STORVSC_MAX_TARGETS 1 > -#define STORVSC_MAX_CHANNELS 1 > +#define STORVSC_MAX_LUNS_PER_TARGET 255 > +#define STORVSC_MAX_TARGETS 2 > +#define STORVSC_MAX_CHANNELS 8 > > +#define STORVSC_FC_MAX_LUNS_PER_TARGET 255 > +#define STORVSC_FC_MAX_TARGETS 128 > +#define STORVSC_FC_MAX_CHANNELS 8 > > +#define STORVSC_IDE_MAX_LUNS_PER_TARGET 64 > +#define STORVSC_IDE_MAX_TARGETS 1 > +#define STORVSC_IDE_MAX_CHANNELS 1 > > struct storvsc_cmd_request { > struct list_head entry; Limiting max_lun to 255 will make the driver to _not_ respond to LUNs higher than that; ie Well-known LUN won't work here. Also the SCSI stack will be using REPORT LUNS anyway since you're advertising SPC-2 compliance. So your driver runs into issues if Hyper-V would ever return more than 256 LUNs with the REPORT LUN command or if any of the LUNs has an addressing scheme other than '0x00'. I would suggest to raise this to the technical limit (ie the largest LUN which the _protocol_ supports) and let REPORT LUNS deal with the actual LUNs.
Cheers,
Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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