On 2022/12/15 15:06, Christoph Hellwig wrote: > On Wed, Dec 14, 2022 at 03:08:44PM +0800, Wenchao Hao wrote: >> When iSCSI initiator logged in target, the target attached none valid >> lun but lun0. lun0 is not an valid disk, while it would response >> inquiry command with PQ=1 and other general scsi commands like probe lun. >> The others luns of target is added/removed dynamicly. > > I can't find any special casing of LUN0 in RFC7144, can you clarify > where you think that treats LUN0 any differently than other transports? > . This is not described in RFC7144. The sense described above aims to tell that a dummy lun is useful. In my opinion, if the addressed lun still response the inquiry and other commands, we should not skip it, maybe let the scsi drivers like sd/st/sg to determine how to handle this lun accordint to the PQ value. As discussed in following mail, another drivers would be broken too. https://lore.kernel.org/linux-scsi/CA+PODjqrRzyJnOKoabMOV4EPByNnL1LgTi+QAKENP3NwUq5YCw@xxxxxxxxxxxxxx/ The key point of my patch is to add one way to map dummy lun to an sg device.
