On Thu, 2007-08-02 at 12:51 -0600, Matthew Wilcox wrote: > On Thu, Aug 02, 2007 at 12:47:25PM -0500, James Bottomley wrote: > > This looks small and innocuous, but it's actually the beginning of > > moving the upper layer drivers into block and adding a filtering layer. > > The idea is that the queue contains a queue_protocol parameter which > > details what the device actually speaks. The requests are likewise > > filled in with a cmd_protocol parameter by the ULDs (or bsg if it's a > > user initiated command, using the existing sgv4 protocol fields). > > > > Now we have the capability of adding say native ATA pass through to BSG, > > but also we can add things like an ATAPI filter: sr creates SCSI > > requests, but these could be sent through a PACKET_COMMAND wrapper and > > emerge as BLK_PROTOCOL_ATAPI before being sent to the device. Likewise, > > sd requests going to BLK_PROTOCOL_ATA devices would have to go through > > SATL filters. > > Will it also add the ability to add device-specific filters? For > example, the CD burners that have manufacturer specific opcodes to turn > on various features that are safe for users to use ... but have to be > limited to root-only currently as we can't know what kind of device the > command is going to. I wasn't planning on doing this ... the idea is basically a protocol conversion filter. Device quirks don't quite fit into this model. James - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
