On Wed, 27 Aug 2014, Oliver Neukum wrote: > > I don't think we want to add another SCSI flag to say that READ > > CAPACITY(10) is unreliable. > > Why not? It would only be friendly to tell the upper layer > of a malfunction if we know about it.
To what end? What will the upper layer do with this information? > > Given the difficulty of determining the true capacity, I see two > > alternatives. We could set the capacity to a ridiculously large value > > (like 1 billion TB), or we could leave the capacity set to the low > > value and disable the "block within bounds" checks. Neither of these > > is attractive and they both have issues of their own -- although the > > second is close to what Windows does. > > That seems to be the most attractive solution to me. I'm skeptical that you can convince the SCSI and block-layer developers about this. Maybe they'll accept it if it is applied only to USB transports... > > (For example, udev often tries to read the last sectors of a new drive, > > looking for a GPT or RAID signature. That won't work if the capacity > > is set to some random value.) > > Yes, but clipping has its own dangers. Suppose you use the medium > without a partition table. What would Windows do? In the absence of a partition table, it would believe the value from READ CAPACITY, right? Isn't that the same as clipping? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
