>>>>> "Christoph" == hch@infradead org <hch@xxxxxxxxxxxxx> writes: Christoph> Oh, we actually have devices that support WRITE SAME with Christoph> unmap, but not without? That's defintively a little strange. Yep :( There were several SSDs that did not want to support wearing out flash by writing gobs of zeroes and only support the UNMAP case. Christoph> Yes, and it did this intentionally. I really wouldn't expect Christoph> devices to support WRITE SAME with UNMAP but blow up on a Christoph> WRITE SAME without it (and not just simple fail it in an Christoph> orderly way). *sigh* Christoph> It definitively seems odd to default to trying WRITE SAME for Christoph> unmap for a device that explicitly tells us that it doesn't Christoph> support WRITE SAME. Maybe it's just a naming thing. I was really trying to convey no_req_write_same support, not no_write_same_10_or_16. Christoph> Note that I'm not against your patch - I suspect forcing us Christoph> to read EVPD pages even for devices that claim to be SPC-2 Christoph> will come in useful in various scenarios. I don't have a problem with a BLIST_PREFER_UNMAP flag or something like that. But BLIST_TRY_VPD_PAGES seems more generally useful and it does fix the problem at hand. That's why I went that route. -- Martin K. Petersen Oracle Linux Engineering -- 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
