On Mon, 19 Jan 2009 20:04:50 +0100 Henrik Stokseth <henrik@xxxxxxx> wrote: > Hi! I'm one of the developers on the CDEmu project. > > We want to get a driver merged into vanilla linux kernel. CDEmu is a > software suite that allows people to take a CD/DVD-image and mount it on > the system in the form of a virtual disc. Major parts of this software > is based on user-space components, but we have a kernel module that's > responsible for acting like a SCSI HBA. Mainly all > this HBA does is to send requests to a userspace daemon for processing > and then fetch the result and send it back to the SCSI subsystem. > > The project's homepage is here: http://cdemu.sourceforge.net > > I went over the code to make sure it follows the coding style that's > used. Is there anything else I need to do? I'm a programmer but > kernel code is something that I seldom touch. >From a quick look at the patch, your driver links requests to a list and then the user-space daemon reads the requests via the special character device file and sends the response back to kernel space. If I correctly understand what you want, there are some possible alternatives, I guess. Note that I'm not sure 2) and 3) is acceptable to the SCSI maintainer. 1) use iSCSI initiator and target on the same machine First, set up iSCSI target software supporting CD/DVD. For example, you can use tgt (http://stgt.berlios.de), user-space program. Then you set up the iSCSI initiator to connect the target. Basically, the iSCSI initiator works like a virtual hba as you like. The iSCSI initiator and target communicate via tcp while your software communicates via the special character device. If you go with this setup, all you need are already in mainline. 2) extend SCSI_TGT CONFIG_SCSI_TGT and CONFIG_SCSI_IBMVSCSIS do the similar thing as you do, creating a virtual hba, sending requests to userspace, and getting the responses. CONFIG_SCSI_IBMVSCSIS is designed for IBM POWER architectures. But you can implement a new driver working with CONFIG_SCSI_TGT. CONFIG_SCSI_TGT also uses tgt so CD/DVD support is ready. 3) extend scsi_debug.c drivers/scsi/scsi_debug.c provides a virtual hba and virtual disk. You could extend it to support CD/DVD. -- 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
