On 01/25/2017 11:23 AM, Christoph Hellwig wrote: > On Wed, Jan 25, 2017 at 08:26:05AM +0100, Hannes Reinecke wrote: >> For any device with an older SCSI revision we might not >> be scanning VPD pages, which results in a wrongly configured >> discard mode if thin provisioned is enabled. >> According to sbc3 any thin provisioned device (ie devices which >> have the LBPME bit set in the output of READ CAPACITY(16)) need >> to support VPD pages. So this patch always enables VPD pages >> even for older SCSI revisions if thin provisioning is enabled. > > Can you explain what you need this for? A device with a per-SBC3 > revision that wants us to use UNMAP? > Some storage arrays essentially lie about the SCSI revision (most notably Hitachi :-), and some claim to support SPC-2 (or even SPC) but support newer features, too. Most notably VPD pages support. In this case it was an HP EVA claiming to support SPC-2 only, but providing thin provisioning. >> + /* >> + * sbc3r36 states: >> + * The device server in a logical unit the supports >> + * logical block provisioning management shall support >> + * the Logical Block Provisioning VPD page. >> + * So VPD pages should be supported if lbpme is set. >> + */ > > It's a bit odd to quote SBC3 when the device clearly is pre-SBC3 > to need this workaround.. > _Actually_ it's pre-SPC-3. But that was the earliest draft I had :-( I'd be happy to modify this if I had access to sbc-2 drafts. >> + if (!scsi_device_supports_vpd(sdp)) >> + sdp->try_vpd_pages = 1; > > Do the assignment unconditionally? > Yeah, can do. 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) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
